Flame Thrower - Apogee
Beautiful two-motors model rocket for 24 mm motors type C11, D, E and F
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The Flame Thrower is a two-motors cluster rocket with two different body sizes that are connected by a blow-molded plastic transition. Its distinctive shape will not get unnoticed on the launch field, and the two motors make it a faster lift-off rocket.
The upper body can be used as payload section by simply taking the nosecone off. A couple of small screws are recommended to keep the nosecone in place during the flight and recovery. You can carry a small video camera aloft with some simple modification or an electronic altimeter without any modification.
The Flame Thrower is a larger size rocket, a typical mid-power rocket, because it takes 24mm diameter motors from a C-size up to a G-size. You don't need an high power certification to fly it unless you plan on using two G-size motors in the same flight. But we don't recommend it for high-power because it is built using thin-wall body tubes.
The Flame Thrower is an easy-to-build rocket. It features pre-cut tubes with laser-cut fin slots that save you time and increase the durability of the model. The blow-molded nose cone and transition section accept paint easily without chipping off. The centering rings are laser-cut plywood while the fins are made of basswood. The quality of all the parts is excellent, as it is usual for every Apogee product. The kit include a set of colorful, self-adhesive vinyl decals and a 80 cm plastic parachute. The instruction booklet is very clear and filled with pictures: it is impossible to make mistakes!
For motor retention, the FlameThrower kit uses a unique threaded rod system, similar to the Klima cluster motor mounts that we sell.
NOTE ON MULTI-ENGINES:
In a two-engine model like this one, the engines need to have identical characteristics. Two engines with different thrust and/or duration, in fact, would only make the model deviate from the vertical trajectory, exposing it to the risk of crashing to the ground or causing damage. The only difference that can exist between the two motors is the length of the delay. If one of the two motors has a longer delay (eg a D12-5 and a D12-7) it can serve as an emergency parachute ejection in case it has not been correctly ejected by the motor with a shorter delay.
The simultaneous ignition of several motors is always critical. If you use Estes type C11 or D12 engines in this model, we recommend that you use the system consisting of Klima's Tapematch and Stage Igniters for a safe and reliable ignition of all engines.
If you use two Aerotech composite engines you will need to use two Magnelite or Clusterfire type igniters and a 12 volt battery capable of supplying a strong current (no less than 7 A continuous). A lead-acid car battery is ideal.
- Laser-cut tubes, including slots for stabilizers.
- Sturdy plastic nosecone
- Plastic conical transition between the two body parts
- Laser-cut basswood fins
- Kevlar shock cord
- Cardboard display stand
- Detailed instructions, with lots of pictures
To fly this rocket you need (not included):
- Launchpad with 6 mm launch rod (Klima, Estes Porta Pad II, Estes Pro Series Launch Pad)
- Launch Controller (Klima, Estes Electron Beam, Estes PS II)
- Engines (see recommended engines)
- Protective wadding for the parachute
- 62 cm
- 66 mm
- 124 g
- Diamètre du moteur
- 24 mm
- Rampe de lancement
- Avec tige de lancement de 6 mm
- Type de fusée
- Avec charge utile


text:
|The first excerpt represents the element of Air. It speaks of mental influences and the process of thought, and is drawn from Tono Bungay by H. G. Wells:
Style. Smart business, smart men. She tries to pass it off as
humorous"--my aunt pulled a grimace-- "it isn't humorous! See!
We're on the up-grade now, fair and square. We're going to be
big. We aren't going to be laughed at as Poovenoos, see!"
"Nobody laughed at you," said my aunt. "Old Bladder!"
"Nobody isn't going to laugh at me," said my uncle, glancing at
his contours and suddenly sitting up.
My aunt raised her eyebrows slightly, swung her foot, and said
"We aren't keeping pace with our own progress, George. We got
to. We're bumping against new people, and they set up to be
|The second excerpt represents the element of Fire. It speaks of emotional influences and base passions, and is drawn from Dead Souls by Nikolai Vasilievich Gogol:
first place, make a pasty in four divisions. Into one of the divisions
put the sturgeon's cheeks and some viaziga, and into another
division some buckwheat porridge, young mushrooms and onions, sweet
milk, calves' brains, and anything else that you may find
suitable--anything else that you may have got handy. Also, bake the
pastry to a nice brown on one side, and but lightly on the other. Yes,
and, as to the under side, bake it so that it will be all juicy and
flaky, so that it shall not crumble into bits, but melt in the mouth
like the softest snow that ever you heard of." And as he said this
Pietukh fairly smacked his lips.
 Dried spinal marrow of the sturgeon.
|The third excerpt represents the element of Water. It speaks of pure spiritual influences and feelings of love, and is drawn from The Underground City by Jules Verne:
why should not the supernatural personages come there to
play their parts?
So reasoned Jack Ryan and his comrades in the Aberfoyle mines.
We have said that the different pits communicated with
each other by means of long subterranean galleries.
Thus there existed beneath the county of Stirling
a vast tract, full of burrows, tunnels, bored with caves,
and perforated with shafts, a subterranean labyrinth,
which might be compared to an enormous ant-hill.
Miners, though belonging to different pits, often met, when going
to or returning from their work. Consequently there was a constant
|The fourth excerpt represents the element of Earth. It speaks of physical influences and the impact of the unseen on the visible world, and is drawn from The Mountains by Stewart Edward White:
The finish of the second route is directly over the
summit of a mountain. You climb two thousand
feet and then drop down five. The ascent is heart-
breaking but safe. The descent is hair-raising and
unsafe: no profanity can do justice to it. Out of a
pack-train of thirty mules, nine were lost in the
course of that five thousand feet. Legend has it that
once many years ago certain prospectors took in a
Chinese cook. At first the Mongolian bewailed his
fate loudly and fluently, but later settled to a single
terrified moan that sounded like "tu-ne-mah! tu-ne-

domain: artistic


text:
The caspase-8/RIPK3 signaling axis in antigen presenting cells controls the inflammatory arthritic response
Arthritis Research & Therapy volume 19, Article number: 224 (2017)
Caspase-8 is a well-established initiator of apoptosis and suppressor of necroptosis, but maintains functions beyond cell death that involve suppression of receptor-interacting serine-threonine kinases (RIPKs). A genome-wide association study meta-analysis revealed an SNP associated with risk of rheumatoid arthritis (RA) development within the locus containing the gene encoding for caspase-8. Innate immune cells, like macrophages and dendritic cells, are gaining momentum as facilitators of autoimmune disease pathogenesis, and, in particular, RA. Therefore, we examined the involvement of caspase-8 within these antigen-presenting cell populations in the pathogenesis of an arthritis model that resembles the RA effector phase.
Cre LysM Casp8 flox/flox and Cre CD11c Casp8 flox/flox mice were bred via a cross between Casp8 flox/flox and Cre LysM or Cre CD11c mice. RIPK3 –/– Cre LysM Casp8 flox/flox and RIPK3 –/– Cre CD11c Casp8 flox/flox mice were generated to assess RIPK3 contribution. Mice were subjected to K/BxN serum-transfer-induced arthritis. Luminex-based assays were used to measure cytokines/chemokines. Histological analyses were utilized to examine joint damage. Mixed bone marrow chimeras were generated to assess synovial cell survival. Flow cytometric analysis was employed to characterize cellular distribution. For arthritis, differences between the groups were assessed using two-way analysis of variance (ANOVA) for repeated measurements. All other data were compared by the Mann-Whitney test.
We show that intact caspase-8 signaling maintains opposing roles in lysozyme-M- and CD11c-expressing cells in the joint; namely, caspase-8 is crucial in CD11c-expressing cells to delay arthritis induction, while caspase-8 in lysozyme M-expressing cells hinders arthritis resolution. Caspase-8 is also implicated in the maintenance of synovial tissue-resident macrophages that can limit arthritis. Global loss of RIPK3 in both caspase-8 deletion constructs causes the response to arthritis to revert back to control levels via a mechanism potentially independent of cell death. Mixed bone marrow chimeric mice demonstrate that caspase-8 deficiency does not confer preferential expansion of synovial macrophage and dendritic cell populations, nor do caspase-8-deficient synovial populations succumb to RIPK3-mediated necroptotic death.
These data demonstrate that caspase-8 functions in synovial antigen-presenting cells to regulate the response to inflammatory stimuli by controlling RIPK3 action, and this delicate balance maintains homeostasis within the joint.
Rheumatoid arthritis (RA) is a prevalent chronic inflammatory autoimmune disease that begins with dysregulation of the immune system and culminates in progressive joint destruction leading to increased morbidity and mortality. While lymphocytes are crucial for the initiation of this disease , professional phagocytes of the innate immune system, including macrophages and dendritic cells (DCs), are also emerging as critical cell populations in the pathogenesis of RA. There are increased numbers of circulating monocytes in the peripheral blood of patients with RA , which in the joint differentiate into pro-inflammatory macrophages, leading to the elevation in macrophage numbers that is associated with articular destruction. Synovial macrophages are highly activated in RA, express elevated levels of toll-like receptors (TLR) 2, 3, 4 and 7 [3, 4] and contribute to inflammation and cartilage and bone destruction through the production of degradative enzymes and cytokines/chemokines. Approved therapeutic agents decrease inflammation, bone destruction and macrophage numbers in the synovial sublining [5,6,7]. Further, reduced macrophage number correlates with better outcomes in RA and is a potential biomarker for efficacious therapies [8, 9]. While synovial macrophages are critical for the pathogenesis of RA, the impact of DCs in the arthritic joint is less defined. DCs contribute to the marked increase in leukocyte infiltration into the synovial tissue in patients with RA , where they may contribute to the initiation of disease by producing cytokines and presenting arthritogenic antigens, which in combination activate autoreactive T cells [11, 12]. Evidence from human synovial tissue in RA and murine models of RA indicates that DCs drive the formation of ectopic lymphoid organs commonly found in synovial biopsies in RA . A substantial portion of patients with RA present with a clear type I interferon signature, thereby potentially implicating plasmacytoid DCs in disease pathogenesis, as this population is a major producer of type I interferon [14, 15]. Irregular expression of Fc-γ-RII and hyperactive responses to stimulation of TLR2 and TLR4 are observed in dendritic cells from patients with RA with increased disease activity [16, 17]. Lower levels of circulating DCs in patients with RA suggest that plasmacytoid and myeloid DCs may selectively home to the inflamed joint [18,19,20,21,22]. Moreover, this decrease correlates with the presence of a population of DCs enriched for a high T cell stimulatory capacity in the inflamed synovium [18,19,20,21,22]. Although macrophages and DCs are clearly implicated in the pathogenesis of RA, relatively little is known about the mechanisms behind their involvement.
Caspase-8 is a cysteine-aspartic acid protease critically involved in two essential death pathways, apoptosis and necroptosis, responsible for the fate of a cell. Stimulation of a death receptor (Fas or tumor necrosis factor receptor 1 (TNFR1)) by its ligand recruits Fas-associated death domain protein (FADD) . This protein aggregation then recruits pro-caspase-8, which upon dimerization becomes active. Active caspase-8 initiates the degradative phase of apoptosis through caspase-3/7 activation or blocks necroptosis via receptor-interacting serine-threonine kinase (RIPK) 1-RIPK3 suppression, depending upon the availability of cellular FADD-like interleukin (IL)-1β-converting enzyme (FLICE)-inhibitory protein (cFLIP) [23, 24]. Should levels of cFLIP be low, caspase-8 homodimers form and apoptosis ensues . Conversely, high levels of cFLIP enable formation of caspase-8-cFLIP heterodimers, which limit RIPK signaling for necroptosis and prevent apoptosis . In the absence of caspase-8, apoptosis cannot occur but RIPK signaling proceeds unchecked, leading to necroptosis . While RIPK1 -/- mice die perinatally  and RIPK3 -/- mice show no gross defect in development , global deletion of either RIPK rescues the embryonic lethality associated with global knockout of caspase-8 [24, 27].
Aside from its prescribed role in necroptosis, RIPK signaling has also been implicated in cell-death-independent activities in innate immune cells. Examination of a kinase-dead mutant of RIPK1 (D138N) in macrophages suggests that RIPK1 kinase activity promotes acute inflammatory responses to lipopolysaccharide (LPS) . Evaluation of an alternate kinase-dead mutant of RIPK1 (K45A) in macrophages shows that RIPK1 kinase activity plays a critical role in promoting host responses to inflammatory stimuli and cytokine signaling . It has also been shown that RIPK3 -/- DCs are highly defective in LPS-induced expression of inflammatory cytokines and contribute to a reduced response to injury-induced tissue repair in a colitis model . Similar to RIPK, mounting evidence implicates caspase-8 in death-independent activities [31,32,33,34,35,36] that may also require RIPK. Our own studies supplement death-independent functions for caspase-8. Studies of Cre LysM Casp8 flox/flox mice, where caspase-8 is deleted in lysozyme M-expressing cells, reveal that caspase-8 associates with RIPK1 and RIPK3 to limit its signaling following TLR activation by gut microflora and prevents the continued activation of these populations to keep systemic inflammation in check . Further, Cre CD11c Casp8 flox/flox mice, where caspase-8 is deleted in CD11c-expressing cells, develop systemic autoimmunity independent of DC lifespan, indicating that caspase-8 signaling in CD11c-expressing populations maintains tolerance . Although RIPK3 is dispensable for this process in CD11c-expressing cells, uncontrolled TLR activation in an RIPK1-dependent manner is responsible for the enhanced functionality of caspase-8-deficient DCs . Collectively, these data connect caspase-8 and RIPK not only to death, but also to death-independent inflammatory processes.
A genome-wide association study meta-analysis in more than 100,000 subjects of European and Asian ancestry (29,880 were diagnosed with RA), evaluated nearly 10 million single-nucleotide polymorphisms (SNPs) and identified a SNP associated with risk of RA development within the locus containing the gene encoding for both caspase-8 and cFLIP . Despite this newly discovered link between caspase-8 and RA, the cellular mechanisms by which caspase-8 mediates this predisposition to RA are unknown. Here, we investigated how caspase-8 signaling impacts development and progression of the acute K/BxN serum-transfer-induced arthritis model of inflammatory arthritis that resembles the effector stage of RA. The K/BxN serum-transfer-induced arthritis model entails initiation, developmental/propagation and resolution phases and is advantageous because it is not T and B cell dependent but rather depends on innate immune cells, including macrophages and DCs, to mediate disease [40,41,42,43,44]. We showed that Cre LysM Casp8 flox/flox mice resolve K/BxN serum-transfer-induced arthritis more rapidly than control mice, which suggests that caspase-8 in this context prolongs the inflammatory response. In stark contrast to Cre LysM Casp8 flox/flox mice, Cre CD11c Casp8 flox/flox mice exhibited a more rapid and severe onset of arthritis, indicating that in this caspase-8-deletion construct, caspase-8 controls the magnitude of the initial inflammatory response. Further, in Cre CD11c Casp8 flox/flox mice, caspase-8 is implicated in the maintenance of synovial tissue-resident macrophages that can limit arthritis development. We observed that global deletion of RIPK3 in both of our caspase-8 deletion constructs (Cre LysM Casp8 flox/flox and Cre CD11c Casp8 flox/flox) caused the response to K/BxN serum-transfer-induced arthritis to revert back to that of control Casp8 flox/flox mice, potentially independent of controlling necroptosis. These data suggest that deletion of caspase-8 leads to unchecked action of RIPK3, and this delicate balance maintains homeostasis within the joint.
Male KRN mice were kindly provided by Dr. Diane Mathis and were crossed with female NOD mice (Taconic) for the generation of K/BxN serum. All subsequently described strains are on a C57BL/6 (B6) background. Mice homozygous for the loxP flanked Caspase-8 allele (Casp8 flox/flox; generated on a 129 background and backcrossed to B6 for at least 12 generations [45, 46]) were crossed with mice expressing Cre under control of either the murine lysozyme M gene promoter (Cre LysM; generated on a 129 background, backcrossed to B6 for at least six generations and homozygous for Cre, Jackson Laboratory 004781) or CD11c promoter (Cre CD11c; generated on a B6 background and transgene positive for Cre, Jackson Laboratory 007567, Alexander Chervonsky) to generate Cre LysM Casp8 flox/flox (homozygous for Cre, homozygous for floxed caspase-8) and Cre CD11c Casp8 flox/flox (transgene positive for Cre, homozygous for floxed caspase-8) mice, as previously described [38, 47]. Cre LysM Casp8 flox/flox and Cre CD11c Casp8 flox/flox mice were crossed with RIPK3 –/– (homozygous RIPK3 –/–, generated on a 129 background and backcrossed to B6 for at least four generations, Genentech ) to generate RIPK3 –/– Cre LysM Casp8 flox/flox (homozygous RIPK3 –/–, homozygous for Cre, homozygous for floxed caspase-8) and RIPK3 –/– Cre CD11c Casp8 flox/flox (homozygous RIPK3 –/–, transgene positive for Cre, homozygous for floxed caspase-8) mice as previously described [38, 47]. RIPK3 –/– Casp8 flox/flox (homozygous RIPK3 –/–, homozygous for floxed caspase-8) mice were also generated as a control. B6.CD45.1/2 mice were generated from a cross of B6 (Jackson Laboratory) and B6.CD45.1 mice. Mice were housed at a barrier-free and specific pathogen-free facility at the Center for Comparative Medicine at Northwestern University (Chicago, IL, USA). All lines were bred homozygously. Weanlings homozygous for RIPK3 –/–, Casp8 flox/flox, and/or Cre LysM constructs or transgene positive for the Cre CD11c construct where applicable were kept for experiments. Male mice were used in all studies and housed according to strain. Transnetyx (Memphis, TN, USA) performed all genotyping of mice and analysis of caspase-8 gene deletion in sorted cell populations. All procedures were approved by the Institutional Animal Care and Use committee at Northwestern University.
K/BxN serum-transfer-induced arthritis
K/BxN serum-transfer-induced arthritis was induced by intravenous injection of 75 μL of arthritogenic serum from 8-week-old progeny of KRN and NOD mice (K/BxN) mice . K/BxN mice (transgene positive offspring of KRN and NOD mice) develop severe, spontaneous, symmetric, erosive and chronic arthritis that mimics RA , and disease may be passively transferred via a single intravenous injection of serum obtained from these mice. Change in ankle width was monitored using a caliper (Fowler Tools of Canada). In addition, a clinical score was determined from the sum of clinical scores for each paw (0 – no arthritis, 1 – mild arthritis, foot maintains a V-shape, 2 – moderate arthritis, foot no longer maintains a V-shape, 3 – severe arthritis). Each experiment was performed two to three times to confirm reproducibility. Whenever possible, scoring was performed in a blinded manner. At days 3, 7, 11 or 14 days post injection, mice were killed, serum was collected via cardiac puncture and ankles were harvested for fixation in 10% formalin or flow cytometric analysis.
Mixed bone marrow chimeras
Bone marrow was aseptically harvested from tibias, femurs and humeri from 9-week-old mice, erythrocytes lysed (BD Pharm Lyse buffer) and cells incubated with Fc-block followed by incubation with fluorochrome-conjugated antibodies against B220, CD4, CD8, CD11b, Ly6G, NK1.1, Siglec F, Ter119, c-Kit and Sca-1 (BD Biosciences, eBioscience, Biolegend), as previously described . Cell suspensions were sorted by fluorescence-activated cell sorting (FACS) to obtain the Lin-Sca-1+c-kit + (LSK) population. Two-month-old B6.CD45.1 mice received a single 1000-cGy γ-irradiation dose using a Cs-137-based Gammacell-40 irradiator (Nordion). After 12 hours, 5 × 104 LSK cells were intravenously injected from: Casp8 flox/flox, Cre CD11c Casp8 flox/flox, RIPK3 –/– Cre CD11c Casp8 flox/flox, a mixture of Casp8 flox/flox plus B6.CD45.1/2, Cre CD11c Casp8 flox/flox plus B6.CD45.1/2 or RIPK3 –/– Cre CD11c Casp8 flox/flox plus B6.CD45.1/2 (1:1 ratio). Chimeric mice were maintained on Trimetoprim/Sulfamethoxazole (40 mg/5 mg, respectively; Hi-Tech Pharmacal) diluted in autoclaved water (2 mL antibiotics/500 mL water) and phenotyped 2 months post transfer.
Blood was collected into EDTA-containing tubes via cardiac puncture from euthanized animals. Whole blood was stained with fluorochrome-conjugated antibodies and erythrocytes were then lysed using BD FACS lysing solution (BD Biosciences). Flow cytometric analysis of the ankles was performed as previously described . Briefly, ankles were cut 3 mm above the heel and skin was removed from the feet. To avoid contamination with bone marrow cells, the bone marrow cavity in the tibia was thoroughly flushed with Hanks balanced salt solution (HBSS), the finger joints were disarticulated by pulling with blunt forceps and the tibiotalar joint was opened via the posterior access route to expose the synovial lining. The feet were incubated in digestion buffer (2.4 mg/mL dispase II, 2 mg/mL collagenase D and 0.2 mg/mL of DNase I in HBSS) for 60 min at 37 °C. Cells released during the digestion were filtered through a 40-μm nylon mesh, erythrocytes were lysed using BD Pharm Lyse (BD Biosciences) and cells were counted using the Countess automated cell counter (Invitrogen); dead cells were discriminated using trypan blue. Cells were stained with the eFluor 506 viability dye (eBioscience), incubated with FcBlock (BD Bioscience) and stained with fluorochrome-conjugated antibodies (see Additional file 1: Table S1 for the list of antibodies, clones, fluorochromes and manufacturers). Data from blood and ankles were acquired on BD LSR II flow cytometer (BD Biosciences, San Jose, CA, USA), and at least 200,000 events were acquired. Compensation and analysis of the flow cytometric data were performed using FlowJo software (TreeStar, Ashland, OR, USA). “Fluorescence minus one” controls were used when necessary to set up gates. Expression of the activation markers was presented as median fluorescence intensity (MFI). To assess deletion of caspase-8 in synovial antigen-presenting cell populations, CD11b+ DCs, major histocompatibility complex (MHC) II+ macrophages and MHC II– macrophages were sorted (average purity of 97%) at the Northwestern University RLHCCC Flow Cytometry Core Facility on a BD FACSAria III instrument (BD Biosciences, San Jose, CA, USA) and analyzed for the presence of the Casp8 floxed allele by Transnetyx.
Cytokine measurements and histologic analysis
Serum was screened for cytokines/chemokines using a mouse Procarta Cytokine Assay Kit (Affymetrix) according to the manufacturer’s instructions. The fixed ankles were decalcified in ethylenediaminetetraacetic acid (Sigma-Aldrich, St. Louis, MO, USA). The ankles were embedded in paraffin, sectioned and 5-μm sections were stained with hematoxylin and eosin (H&E) at the Northwestern University Mouse Histology and Phenotyping Laboratory. Histopathologic scoring was performed as described  by a pathologist (GKH) blinded to the study, using an Olympus BS40 microscope (Olympus, Tokyo, Japan). Images were taken on an Olympus BX41 microscope equipped with a DP20 Digital Camera (Olympus) at magnification × 40 or × 100.
Statistical analyses were performed using the GraphPad Prism 7.0 Software. Data are represented as mean ± SEM. For arthritis experiments, differences in ankle width and clinical score between the groups were compared using two-way analysis of variance (ANOVA) for repeated measurements with the Bonferroni post-hoc test. For all other analyses, differences between groups were assessed using the Mann-Whitney test.
Cre LysM Casp8 flox/flox mice display accelerated resolution, while Cre CD11c Casp8 flox/flox mice exhibit accelerated initiation, of K/BxN serum-transfer-induced arthritis
Since we have previously published that caspase-8 signaling in myeloid cells and DCs is critical to suppress systemic inflammation and caspase-8 has been linked to RA susceptibility, the role that cell-specific caspase-8 plays in the development of acute inflammation in young mice prior to overt development of autoimmune disease was evaluated using the K/BxN serum-transfer-induced arthritis model. Cre LysM Casp8 flox/flox mice presented with an accelerated resolution and reduced severity of K/BxN serum-transfer-induced arthritis compared to Casp8 flox/flox mice beginning at day 7 following injection (Fig. 1a). In contrast, Cre CD11c Casp8 flox/flox mice had enhanced initiation and exacerbated severity of K/BxN serum-transfer-induced arthritis compared to Casp8 flox/flox mice (Fig. 1a), which was most pronounced at days 2 and 4 following injection. Circulating cytokine levels were assessed because elevated cytokine production may contribute to the inflammation and destruction within the joint (Fig. 1b and Additional file 1: Figure S1). Heightened IL-12/IL-23p40 and serum RANKL (sRANKL) levels were found in Cre LysM Casp8 flox/flox and Cre CD11c Casp8 flox/flox serum compared to control serum, which only persists in Cre CD11c Casp8 flox/flox mice till day 7 (Fig. 1b). Evidence of increased bone erosion was detected in Cre CD11c Casp8 flox/flox ankles harvested at 7 and 14 days following injection of K/BxN serum (Fig. 1c-d). Further, higher levels of polymorphonuclear (PMN) cells were observed in the joints of Cre CD11c Casp8 flox/flox mice at day 7 (Fig. 1e). Examination of structural damage during the resolution phase of arthritis at day 14 showed that while Cre CD11c Casp8 flox/flox ankles mirror Casp8 flox/flox ankles, pannus formation subsided more quickly in Cre LysM Casp8 flox/flox joints, which was consistent with accelerated disease resolution (Fig. 1c, f). Further, fewer PMN cells were identified in Cre CD11c Casp8 flox/flox and Cre LysM Casp8 flox/flox joints compared to Casp8 flox/flox joints by day 14 (Fig. 1g). Taken together, these data suggest that caspase-8 deficiency can either accelerate the resolution of, or enhance the initial magnitude of, acute inflammatory arthritis depending on the deletion construct.
Caspase-8 deficiency alters circulating and synovial populations of Cre LysM Casp8 flox/flox and Cre CD11c Casp8 flox/flox mice at steady state
We have previously shown that the pathogenesis of the K/BxN serum-transfer-induced model of arthritis depends upon the Ly6Clo monocyte population, which patrol the luminal side of the endothelium and extravasate into the joint during the initiation phase of arthritis preceding the massive neutrophil influx . These recruited cells not only differentiate into classically activated macrophages to drive joint destruction, but also possess the capacity to switch after differentiation to an alternatively activated phenotype to assist in the resolution of inflammation . Further, there are long-lived radio-resistant tissue-resident MHC II– macrophages in the naïve joint, which do not require input from the bone marrow to maintain their population . During K/BxN serum-transfer-induced arthritis, these tissue-resident MHC II– macrophages can limit the initial severity of arthritis and play a role in maintaining joint integrity . Our data suggest that a differential response to inflammatory arthritis occurs depending on the caspase-8 deletion construct. We therefore examined whether a preexisting disruption of the cellular composition of the circulation and/or the synovium may potentially account for this variable outcome following induction of K/BxN serum-transfer-induced arthritis. B cell, neutrophil and natural killer (NK) cell population levels were consistent between all strains, but circulating eosinophils were decreased in the circulation of naïve Cre LysM Casp8 flox/flox and Cre CD11c Casp8 flox/flox mice compared to Casp8 flox/flox mice using 10-color flow cytometric analysis (Fig. 2a, b). Since circulating monocytes extravasate into tissues following an inflammatory insult and differentiate into tissue macrophages, we also examined levels of the monocyte subsets in control and experimental strains. While Ly6Chi and Ly6Cint monocyte levels of naïve Cre LysM Casp8 flox/flox and Cre CD11c Casp8 flox/flox mice resembled those of control Casp8 flox/flox mice, Cre CD11c Casp8 flox/flox mice had increased levels of Ly6Clo monocytes (Fig. 2b). These data suggest that deletion of caspase-8 in CD11c-expressing cells leads to increased levels of Ly6Clo monocytes that are crucial to instigating the initial inflammation observed following induction of K/BxN serum-transfer-induced arthritis.
We then determined the cellular composition of naïve synovium of Casp8 flox/flox, Cre LysM Casp8 flox/flox and Cre CD11c Casp8 flox/flox mice using 10-color flow cytometric analysis (Fig. 2c-e). While the cellular distribution of the naïve synovium of Cre LysM Casp8 flox/flox mice mimicked that of control Casp8 flox/flox mice, Cre CD11c Casp8 flox/flox mice had increased CD45+ hematopoietic cells in the joint at steady state (Fig. 2d). Examination of this increased hematopoietic population revealed that the synovium of Cre CD11c Casp8 flox/flox mice contained elevated numbers of MHC II+ macrophages and CD11b+ DCs. Further, increased numbers of Ly6ChiCD64lo and Ly6CloCD64- cells were also observed in Cre CD11c Casp8 flox/flox joints compared to control Casp8 flox/flox joints (Fig. 2d). While the macrophage distribution from Cre LysM Casp8 flox/flox and Casp8 flox/flox joints were indistinguishable, Cre CD11c Casp8 flox/flox joints exhibited an increased proportion of MHC II+ macrophages and a correspondingly reduced proportion of MHC II– tissue-resident macrophages potentially capable of limiting arthritis progression. Taken together, these data implicate caspase-8 in CD11c-expressing cells in the maintenance of pathogenic Ly6Clo monocytes and anti-inflammatory synovial tissue-resident macrophages.
RIPK3 signaling contributes to the dysregulated responses to K/BxN serum-transfer-induced arthritis in Cre LysM Casp8 flox/flox and Cre CD11c Casp8 flox/flox mice
Caspase-8 is an endogenous suppressor of RIPK signaling; therefore, we examined whether unchecked RIPK3 signaling may contribute to the aberrant responses to K/BxN serum-transfer-induced arthritis observed in our Cre LysM Casp8 flox/flox and Cre CD11c Casp8 flox/flox caspase-8-deficient mice. We utilized our previously published RIPK3 –/– Cre LysM Casp8 flox/flox and RIPK3 –/– Cre CD11c Casp8 flox/flox strains [37, 38]. Further, we included analysis of K/BxN serum-transfer-induced arthritis in B6, RIPK3 –/– and RIPK3 –/– Casp8 flox/flox control mice (Additional file 1: Figure S2). We observed no difference between control Casp8 flox/flox mice and B6, RIPK3 –/– or RIPK3 –/– Casp8 flox/flox strains, though we detected slower induction of arthritis in RIPK3 –/– Casp8 flox/flox mice compared to RIPK3 –/– mice. Global deletion of RIPK3 in Cre LysM Casp8 flox/flox mice was sufficient to restore the inflammatory response to K/BxN serum-transfer-induced arthritis to that of the control Casp8 flox/flox mice (Fig. 3a). The reduction in overall histologically identified inflammation, bone erosion and influx of PMN cells in Cre LysM Casp8 flox/flox mice was reversed, though not to the level of significance (Fig. 3b-d). Deletion of RIPK3 in Cre CD11c Casp8 flox/flox mice reversed the response to K/BxN serum-transfer-induced arthritis to levels below that of Casp8 flox/flox mice (Fig. 3e). Further, joint inflammation and influx of PMN cells were prevented by deletion of RIPK3 in Cre CD11c Casp8 flox/flox mice (Fig. 3f-h). These data indicate that the dysregulated response to K/BxN serum-transfer-induced arthritis observed in Cre LysM Casp8 flox/flox and Cre CD11c Casp8 flox/flox mice requires RIPK3 signaling.
The caspase-8-RIPK3 signaling axis functions in the naive joint independent of cell death
Our previous publications show that in Cre LysM Casp8 flox/flox splenocytes, caspase-8 deletion is restricted to CD11b+Ly6G+ neutrophils, the CD11b+F4/80+ Ly6Chi and Ly6Clo monocyte/macrophage populations and a portion of tissue-resident CD11b-F4/80+ red pulp macrophages, but not conventional DC subsets. In contrast, deletion of caspase-8 in Cre CD11c Casp8 flox/flox splenocytes is restricted to conventional DC subsets and a portion of tissue-resident CD11b-F4/80+ red pulp macrophages, but not neutrophils or CD11b+F4/80+ Ly6Chi and Ly6Clo monocyte/macrophage populations [37, 38]. Previous reports suggest that cre recombinase constructs that utilize the lysozyme M and CD11c promoters are not entirely cell-specific . Therefore, we examined deletion of caspase-8 in tissue-resident antigen-presenting cell populations within the joint of control and experimental strains. Caspase-8 was at least 75% deleted in the MHC II+ and MHC II– macrophage populations and the CD11b+ DC population of both naïve Cre LysM Casp8 flox/flox and Cre CD11c Casp8 flox/flox joints (Additional file 1: Figure S3). These data suggest that lysozyme M and CD11c are turned on in both tissue-resident synovial macrophages and DCs. To eliminate the potential confounder of caspase-8-deficient neutrophils and monocytes entering the joint of Cre LysM Casp8 flox/flox mice, we focused our attention on the Cre CD11c Casp8 flox/flox strain.
Previous studies in lymphocytes show that loss of caspase-8 results in RIPK3-mediated necroptosis . Although caspase-8 is known to regulate death, evidence implicates caspase-8 in cell-specific death-independent processes that rely on RIPK suppression. Therefore, we generated mixed bone marrow chimeric mice to determine how the caspase-8-RIPK3 signaling axis affects synovial cell distribution (Fig. 4a). Cre CD11c Casp8 flox/flox-derived subsets of synovial Ly6ChiCD64lo, Ly6CintCD64- and Ly6CloCD64- cells, CD11b+ DCs, neutrophils and eosinophils were found at similar proportions compared to wild-type (WT)-derived subsets in mixed chimeric mice (Additional file 1: Figure S4 and Fig. 4b-g). However, Cre CD11c Casp8 flox/flox-derived MHC II+ and MHC II– macrophage subsets were observed at decreased proportions compared to WT-derived subsets in mixed chimeric mice (Additional file 1: Figure S4 and Fig. 4h-i). Deletion of RIPK3 did not reverse this abnormality, as the proportion of RIPK3 –/– Cre CD11c Casp8 flox/flox-derived MHC II+ and MHC II– macrophage subsets in mixed chimeric mice were not restored to WT proportions. Taken together, these data suggest that caspase-8 in synovial macrophage and DC populations plays only a minor role in the survival of these cells.
Deletion of RIPK3 reverses the cellular dysregulation in the joint under steady state and arthritic conditions in Cre CD11c Casp8 flox/flox mice
Since caspase-8 may mediate its suppressive effect during K/BxN serum-transfer-induced arthritis independent of preventing RIPK3-mediated necroptosis, we sought to determine alternate modalities by which this RIPK3-mediated suppression potentially occurs. We therefore interrogated naïve and arthritic joints from Casp8 flox/flox, Cre CD11c Casp8 flox/floxl and RIPK3 –/– Cre CD11c Casp8 flox/flox mice by flow cytometric analysis. We detected increased numbers of CD45+ hematopoeitic cells in the joint of Cre CD11c Casp8 flox/flox mice at steady state compared to control Casp8 flox/flox joints owing to elevated numbers of MHC II+ macrophages, CD11b+ DCs, Ly6ChiCD64lo cells and Ly6CloCD64- cells (Fig. 5a). Further, Cre CD11c Casp8 flox/flox joints exhibited an increased proportion of MHC II+ macrophages and a correspondingly reduced proportion of MHC II– tissue-resident macrophages (Fig. 5b). We then examined expression levels of CD36, a scavenger receptor that participates in the internalization of apoptotic cells and modified low-density lipoproteins, and CD206 (C-type mannose receptor 1), a protein active in endocytosis/phagocytosis, within the macrophage and DC populations of the naïve joint. Cre CD11c Casp8 flox/flox MHC II+ and MHC II– macrophage populations and DCs expressed elevated levels of CD36, compared to control Casp8 flox/flox populations (Fig. 5c). Further, Cre CD11c Casp8 flox/flox MHC II+ and MHC II– macrophage populations presented with reduced levels of CD206, compared to control Casp8 flox/flox populations, while Cre CD11c Casp8 flox/flox CD11b+ DCs displayed elevated expression CD206 compared to Casp8 flox/flox CD11b+ DCs (Fig. 5d). Strikingly, deletion of RIPK3 prevented these cellular alterations in caspase-8 deficient naïve joints (Fig. 5a-d).
Next we assessed the arthritic joint at day 3, in which the initiation of inflammation was greater in Cre CD11c Casp8 flox/flox mice than control Casp8 flox/flox mice as determined from Fig. 3e. Cre CD11c Casp8 flox/flox mice continued to show increased CD45+ hematopoeitic cells in the joint at day 3 due to elevated numbers of MHC II+ and MHC II– macrophages, neutrophils and Ly6CloCD64- cells (Fig. 5e). However, the disparity in proportion of MHC II+ and MHC II– macrophages in Cre CD11c Casp8 flox/flox joints at steady state was no longer apparent at day 3 following K/BxN serum-transfer-induced arthritis induction (Fig. 5f). Further, MHC II+ and MHC II– macrophage populations showed a reduction in both CD36 and CD206 expression compared to control Casp8 flox/flox populations, while no difference was observed in the expression of these markers between experimental and control CD11b+ DC populations (Fig. 5g, h). Similar to naïve joints, deletion of RIPK3 in Cre CD11c Casp8 flox/flox mice prevented the aberrant presence of increased hematopoietic cells observed in Cre CD11c Casp8 flox/flox joints (Fig. 5e, f), and restored expression of CD36 and CD206 to levels similar to control Casp8 flox/flox populations (Fig. 5g, h). Taken together, these data provide evidence that implicates the caspase-8-RIPK3 signaling axis in the maintenance of synovial populations under both steady state and inflammatory conditions that are capable of either driving or preventing K/BxN serum-transfer-induced arthritis.
Rheumatoid arthritis (RA) affects nearly 1% of the world’s population, making it one of the most prevalent autoimmune diseases. While aberrant monocyte/macrophage and DC function have been detected in the RA synovium, the underlying mechanisms remain largely a mystery. We show here that caspase-8 in lysozyme M-expressing cells promotes a prolonged inflammatory response, as Cre CD11c Casp8 flox/flox mice exhibit reduced severity and accelerated resolution of K/BxN serum-transfer-induced arthritis. In contrast, loss of caspase-8 in CD11c-expressing cells controls the magnitude of the initial inflammatory response, as Cre CD11c Casp8 flox/flox mice have accelerated induction and exacerbated severity of the effector phase of disease. These data suggest that intact caspase-8 signaling maintains opposing roles in lysozyme M-expressing and CD11c-expressing cells in the pathogenesis of RA. Interestingly, in both cre recombinase constructs, caspase-8 is deleted in both of the synovial macrophage subpopulations and the CD11b+ DCs in the naïve joint. However, in the spleen, a secondary lymphoid organ, caspase-8 is restricted to the neutrophil and monocyte/macrophage populations in Cre LysM Casp8 flox/flox mice and the conventional DC populations in Cre CD11c Casp8 flox/flox mice. We postulate that caspase-8 deletion in the neutrophils and monocytes of Cre LysM Casp8 flox/flox mice that enter the joint under inflammatory conditions may contribute to the differing responses to K/BxN serum-transfer-induced arthritis in Cre LysM Casp8 flox/flox and Cre CD11c Casp8 flox/flox mice. These data suggest that the specificity of the Cre LysM and Cre CD11c deletion constructs are not so clear within tissue-resident populations.
We previously demonstrated that circulating Ly6Clo monocytes are critical for the induction of K/BxN serum-transfer-induced arthritis. Further, we showed that naïve murine joints contain both MHC II+ and MHC II– macrophages, with the majority being MHC II– tissue-resident macrophages that are capable of limiting the initiation of K/BxN serum-transfer-induced arthritis . Here we show that Cre CD11c Casp8 flox/flox mice possess an increased population of Ly6Clo monocytes, which potentially facilitate the observed accelerated initiation of K/BxN serum-transfer-induced arthritis. Cre CD11c Casp8 flox/flox mice are also predisposed to a reduced proportion of MHC II– macrophages in the naïve joint, suggesting that the lack of a sufficient population of these cells at the onset of disease may contribute to the accelerated initiation of arthritis. Further, we show that caspase-8 potentially controls the endocytic capacity of macrophages, as caspase-8-deficient synovial macrophages in Cre CD11c Casp8 flox/flox mice express reduced CD206. Although the M1/M2 macrophage classification system may not be entirely relevant beyond in vitro settings, elevated CD206 expression has been associated with M2 alternatively activated macrophages that participate in wound healing and remission and/or prevention of disease . It is possible that the observed reduction in CD206 may render caspase-8-deficient macrophages less capable of endocytosing cellular debris arising from the damage induced by the arthritic inflammatory assault, and are therefore unable to control the ensuing inflammation. Further, based on in vitro studies, M2 macrophages exhibit poor antigen-presentation capabilities unlike classically activated macrophages . This reduction of CD206 may be indicative of a smaller proportion of M2-like macrophages in the joints of Cre CD11c Casp8 flox/flox mice. Therefore, caspase-8-deficient synovial macrophages may show increased antigen-presenting capabilities. Thus, further analysis is required to determine how reduced CD206 affects synovial macrophage function. Taken together, these data suggest that within the joint, the caspase-8/RIPK3 signaling axis controls macrophage function, potentially not through death-related mechanisms.
The function of caspase-8 extends to inhibition of signaling through RIPK, a family of enzymes that turn on programmed necrotic cell death, or necroptosis. However, RIPK inhibition by caspase-8 not only leads to suppression of necroptosis but also potentially death-independent, cell-specific processes including inflammation. We have previously shown that caspase-8 controls the response to TLR activation in monocytes/macrophages, while caspase-8 limits DC activation and prevents a break in tolerance, and both of these functions are RIPK-dependent. In vitro studies implicate RIPK1 in the hyper-activation of bone marrow-derived macrophages and bone marrow-derived DCs from Cre LysM Casp8 flox/flox and Cre CD11c Casp8 flox/flox mice following TLR activation [37, 38]. These data suggest that uncontrolled RIPK1 activity might contribute to the systemic lupus erythematosus (SLE)-like symptoms of caspase-8-deficient mice. Further, symptoms of systemic inflammation in myeloid cell-specific caspase-8-deficient mice are ameliorated by deletion of RIPK3 . However, we find that RIPK3 is not involved in the aggressive SLE-like disease in Cre CD11c Casp8 flox/flox mice [38, 55]. While a recent report shows that RIPK3 –/– mice display more rapid resolution of K/BxN serum-transfer-induced arthritis compared to control mice , we did not observe this pattern in our study, which may be the result of K/BxN serum differences, colony environment and/or diet. We did find that RIPK3 –/– Casp8 flox/flox mice have slower induction of arthritis than RIPK3 –/– mice, potentially owing to interactions from the remaining 129 background present in both Casp8 flox/flox and RIPK3 –/– strains despite being backcrossed to B6 for over 12 and 4 generations, respectively [26, 37, 38, 46]. However, we observed that global deletion of RIPK3 in Cre LysM Casp8 flox/flox and Cre CD11c Casp8 flox/flox mice causes the response to K/BxN serum-transfer-induced arthritis to revert to that of Casp8 flox/flox control mice, indicating that the aberrant responses observed require RIPK3 action. Further, global deletion of RIPK3 in Cre CD11c Casp8 flox/flox mice reversed the response to levels below that of Casp8 flox/flox mice, potentially indicating a caspase-8-independent effect of RIPK3 in Cre CD11c Casp8 flox/flox mice; future studies are required to understand this phenomenon. Caspase-8 initiates the degradative phase of the apoptotic cascade. However, in our mixed bone marrow chimera mice, Cre CD11c Casp8 flox/flox-derived synovial macrophage subsets were detected at decreased proportions compared to WT-derived subsets, indicating that caspase-8-deficient synovial macrophage subsets do not accumulate and/or persist in the joint due to a lack of apoptosis. One interpretation of these data is that synovial macrophage subsets are succumbing to RIPK3-mediated necroptosis, since caspase-8 is not present to inhibit RIPK3. However, the proportion of RIPK3 –/– Cre CD11c Casp8 flox/flox-derived macrophage subsets were not restored to WT proportions, indicating that caspase-8-deficient macrophages are not undergoing necroptosis in the naïve joint. These data point to a death-independent function for the caspase-8/RIPK3 signaling axis within the joint; however, further investigation will be required to determine potential mechanisms.
IL-1β is a key inflammatory cytokine in the pathogenesis of RA, as highlighted by its role in driving cartilage destruction and the efficacy of its blockade in both mice and humans . IL-1β is predominantly produced by innate immune cells through activation of the NLRP3 inflammasome . Humanized mice expressing disease-associated mutations in NLRP3 develop normally but acquire progressive and debilitating arthritis with age . Numerous studies have implicated caspase-8 in controlling activation of the NLRP3 inflammasome. Loss of caspase-8 in DCs and macrophages facilitates LPS-induced and Pam3Cys-induced NLRP3 activation through RIPK3 [55, 56, 60]. Further, in the absence of both inhibitors of apoptosis (IAPs) and caspase-8, RIPK3-mediated NLRP3 inflammasome activation can occur . However, in contrast, under certain circumstances, caspase-8 can directly cleave pro-IL-1β into its mature form [61,62,63], suggesting that caspase-8 is necessary for IL-1β production. Indeed, a recent study suggests that whole blood cells from patients with RA show increased expression of NLRP3 and secretion of NLRP3-mediated IL-1β via TLR3 and TLR4, but not TLR2, activation that is driven by caspase-1 and caspase-8 . While we do not see differences in serum IL-1β between our strains, we have not yet examined IL-1β within the joint. Taken together, depending on the stimulus, the delicate balance of caspase-8/RIPK3 signaling axis may be controlling NLRP3 inflammasome activation within the arthritic joint and warrants further investigation.
A recent study examined an SNP within Caspase-8 in the context of a large Chinese-based cohort (615 patients with RA and 839 controls) and found no association between this particular SNP and susceptibility to RA development . However, a prior genome-wide association study identified an SNP associated with risk of RA development within the locus containing the gene encoding for both caspase-8 and the catalytically inactive homolog of caspase-8, cFLIP . It has been shown that mice with targeted deletion of cFLIP in CD11c-expressing populations develop spontaneous erosive inflammatory arthritis that resembles RA and is accompanied by the production of autoantibodies to joint antigens . However, a report by a different research group shows that mice lacking cFLIP in CD11c-expressing cells were found to develop neutrophilia (caused by excessive production of granulocyte colony-stimulating factor receptor, (G-CSF)) and splenomegaly, but do not spontaneously develop arthritis, potentially owing to either differences in the efficiency of cFLIP deletion or variability in colony environment [67,68,69,70]. In contrast to both models of CD11c-specific deletion of cFLIP, caspase-8 deletion in CD11c-expressing populations does not result in the spontaneous development of arthritis or neutrophilia. This suggests that although cFLIP is a catalytically inactive form of caspase-8, these molecules possess differing functions within CD11c-expressing populations, and further examination is warranted to determine if the RA-risk SNP affects cFLIP or caspase-8.
Caspase-8 is a downstream signaling mediator of the death receptor Fas, which has been implicated in inducible murine models of RA-like disease [71, 72]. The onset of K/BxN serum-transfer-induced arthritis in lysozyme-M-specific Fas-knockout (Cre LysM Fas flox/flox) mice is comparable to that of control Fas flox/flox mice. However, arthritis resolution is accelerated in the chronic phase in Cre LysM Fas flox/flox mice, as evidenced by the reduction of inflammation and neutrophil infiltration . Consistent with this rapid resolution of disease, higher levels of IL-10 and reduced CXCL5 (a neutrophil chemotactic chemokine) and TLR2 ligand, endoplasmin (also known as GRP94) , are expressed in the joints of Cre LysM Fas flox/flox mice. Here we show that Cre LysM Casp8 flox/flox, similar to Cre LysM Fas flox/flox mice, exhibit accelerated resolution of K/BxN serum-transfer-induced arthritis. This finding suggests that in lysozyme-expressing cells, Fas and caspase-8 function may be involved in the same pathway to control IL-10 expression to enable sufficient response to an inflammatory insult.
We believe that future studies will elucidate new cell autonomous mechanisms by which caspase-8 regulates arthritis pathogenesis. Here, we provide a potential mechanism between the link between caspase-8 and RA susceptibility and the cellular mechanisms by which this predisposition takes effect that includes suppression of inflammation induced by RIPK3. Therefore, these studies substantiate critical and opposing cell-specific roles for the caspase-8/RIPK3 signaling axis in arthritis pathogenesis and highlight the need for further mechanistic insight.
Since patients with RA often fail to achieve remission using current immunosuppressive and biologic therapies and side effects from treatment are substantial, the ultimate objective is to utilize these research discoveries that link established susceptibility to RA development with caspase-8/RIPK3 signaling in macrophages and DCs to assist in the development of safer and more effective therapies.
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We thank the members of the Perlman Lab for their thoughtful critiques and helpful suggestions.
This body of work was supported by a grant from the National Institutes of Health to Carla Cuda (AR060169).
Availability of data and material
All data generated or analyzed during this study are included in this published article and Additional file 1.
All experiments were approved by the Northwestern University IACUC (IS00000532).
Consent for publication
The authors declare that they have no competing interests.
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
List of antibodies utilized for circulating and synovial cell flow cytometric analysis. Figure S1. Serum cytokine levels in Casp8 flox/flox, Cre LysM Casp8 flox/flox and Cre CD11c Casp8 flox/flox mice before and during K/BxN serum-transfer-induced arthritis. Figure S2. K/BxN serum transfer-induced arthritis in control strains. Figure S3. Caspase-8 deletion in synovial macrophages and dendritic cells of the naïve joint. Figure S4. Gating strategy for synovial population distribution in mixed bone marrow chimeric joints. (DOCX 463 kb)
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Cite this article
Dominguez, S., Montgomery, A.B., Haines, G.K. et al. The caspase-8/RIPK3 signaling axis in antigen presenting cells controls the inflammatory arthritic response. Arthritis Res Ther 19, 224 (2017). https://doi.org/10.1186/s13075-017-1436-4
- Rheumatoid arthritis
- Dendritic cells

domain: biology


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In Luanda, Angolas capital, the government has forcibly and violently evicted thousands of people living in informal housing areas with little or no notice. In violation of Angolas own laws and its international human rights obligations, the government has destroyed houses, crops and residents personal possessions without due process and has rarely provided compensation.
The evictions have taken place in a city where the majority of the population lives in informal housing areas with lack of clarity over land possession and ownership, and consequent insecurity of land tenure. The victims are poor and vulnerable Angolans. They include women supporting families on their own, elderly persons and children. Many fled to Luanda during the countrys long civil war, seeking shelter and protection from conflict zones or from agricultural areas destroyed by fighting and insecurity. The governments large scale evictions have resulted in further displacement and left many individuals homeless and destitute with no access to legal remedy.
This report focuses on 18 mass evictions carried out by the government between 2002 and 2006 documented by Human Rights Watch and the Angolan organization SOS Habitat. Other small-scale evictions that took place in the same areas and over the same period are also included in this research. In total, more than 3,000 houses were destroyed and many small-scale cultivated land plots were seized, affecting some 20,000 people.
By documenting forced evictions that occurred between 2002 and 2006, this report provides evidence that such evictions were neither sporadic nor isolated events in Luanda. The forced evictions represent a pattern of abusive conduct on the part of the Angolan government that has not significantly changed over the past several years or been fully addressed. Despite calls from national and international organizations and victims, the government has neither taken the steps necessary to ensure forced evictions end nor provided accountability for abuses associated with these evictions. The Angolan government has also not adequately compensated the vast majority of evictees as it is required to do under Angolan and international law.
Human Rights Watch has not received information that large-scale forced evictions have occurred in Luanda since the field research was completed for this report. However, the residents of the large informal areas of the city remain extremely vulnerable to both new and repeated forced evictions due to the governments failure to date to effectively address the question of insecurity of tenure.
Evictees from the evictions researched for this report and SOS staff members who witnessed such evictions told Human Rights Watch that uniformed police officers and local government officials used intimidation, violence, and excessive force when carrying out evictions. Police and government officials often forcibly tried to prevent residents from rescuing their personal belongings from demolition. Evictees described how police officers, sometimes accompanied by members of private security companies, used firearms to intimidate residents, shooting into the air or to the ground. Four residents, including a five-year-old child, were shot at or hit by stray bullets. Many others were beaten with batons and gun butts.
Several residents of neighborhoods where evictions occurred were arbitrarily detained by police, generally for short periods. They were held during and after evictions, sometimes for days, without being informed of the reason for their arrest or the formal charges being brought against them. Many of those arrested told Human Rights Watch that they were physically abused while in police custody. SOS Habitat staff members present during the evictions documented in this report were harassed and sometimes arbitrarily arrested while trying to obtain information about the eviction or simply attempting to explain the evictees rights to government officials.
In most of the evictions researched by Human Rights Watch and SOS Habitat, the Angolan government provided evictees with little or no information about the purpose of their eviction and the use planned for the land they occupied. The government also failed to discuss with the affected communities possible alternative solutions to their forcible removal. The majority of evictees interviewed by Human Rights Watch did not receive formal notification of their eviction. They described how they were caught unaware by the sudden arrival of police, bulldozers, and trucks to evict them from their land and homes.
In the few situations where the government provided notice of evictions, it failed to allow residents sufficient time before their removal and did not include accurate information about the authority that issued the eviction order, its legal grounds, and the appropriate body for appealing such decisions. In most of the evictions, the Angolan government failed to ascertain whether residents held a formal title or other legal claim to the land they occupied before evicting them.
In addition, the Angolan authorities carried out these forced evictions without a proper and consistent procedure in place to determine the form or amount of compensation to individual evictees. Often compensation was offered to residents after their property and belongings had been destroyed, without the possibility to negotiate the amount in question. The Angolan Government has provided general information on relocation and resettlement sites that it has established for low income families in Luanda. But the governments information has not included precise details on the total number of evictees that received land plots or housing as compensation after evictions from the areas researched by Human Rights Watch and SOS Habitat.
Many evictees who were relocated by the government were not consulted about their removal to a particular site and were often resettled in these new sites unwillingly. The relocation areas were too distant from the evictees original places of residence and employment. The sites were also not adequately supplied with services, such as transportation, health care, and schools when the evictees arrived. Women and children were particularly affected by the loss of income generating activities in local markets and the disruption to access to education.
To date, the Angolan government has not fully addressed the violations of Angolans rights documented in this report. The number of evictees today in need of urgent humanitarian assistance is not alarmingly high; however, this is not a result of the Angolan government acting in accordance with the law and providing evictees with necessary assistance. Rather, failing to receive such government assistance, evictees were forced to find their own often inadequate solutions to continue their lives and rebuild shelter elsewhere.
Moreover, the governments conduct in carrying out the evictions documented in this report was in clear violation of its obligations under both international and Angolan law. Angola is a party to the International Covenant on Economic, Social and Cultural Rights (ICESCR). Article 11 of the Covenant establishes the obligation to protect the right to adequate housing, which includes protection against forced evictions. International law recognizes the right for governments to expropriate land from private citizens even without their consent or to forcibly evict residents. However, such measures can only be taken in the most exceptional circumstances, with a clearly identified public interest and with appropriate processes in place.
For a compulsory eviction to comply with international standards, governments must ensure that feasible alternatives are explored and that individuals have a right to compensation for both real estate and personal property. They must also apply minimum procedural protections that include genuine consultation with those affected; adequate and reasonable notice of the date of eviction; timely information on the proposed evictions, including, where possible, the alternative purpose for which the land is to be used; proper identification of the staff carrying out the evictions; and the availability of legal remedies for those affected.
The forced evictions documented in this report and, in many instances, the conduct of police officers and government officials implementing the evictions also involve violations of rights enshrined in the International Covenant on Civil and Political Rights (ICCPR), to which Angola is a party. Rights violated include the right not to be subjected to arbitrary or unlawful interference with ones privacy and home (Article 17), and the right to liberty and security of the person (Article 9).
The Angolan Constitution and various pieces of legislation also provide a protective framework. Article 12 of the Angolan Constitutional Law protects the possession of land. Angolan laws and regulations on land and urban management, as well as general public administration rules, contain provisions that largely reflect the information, notification and compensation requirements provided for under international law. The government has not generally complied with these laws.
In the evictions researched by Human Rights Watch and SOS Habitat, insecure land tenure stemming from the overwhelming informality of housing and land possession, have made many poor Angolans particularly vulnerable to forced evictions. Secure land tenure gives residents clear legal rights against the government or private entities who make competing claims to the land. The UN Committee on Economic, Social and Cultural Rights has stated that irrespective of the type of tenure, all persons should possess a degree of security of tenure that guarantees legal protection against forced evictions, harassment, and other threats.
Insecure tenure in the evictions documented in this report resulted, in particular, from inadequate land and urban management legislation in Angola, as well as ineffective real estate registration procedures. The legal framework for land rights in Angola that has been in place since independence is complex and confusing. Urban land was largely unregulated until 2004. The real estate registration system was also essentially paralyzed over the 27 years of war. Past attempts by the Angolan government to address this problem were unsuccessful due to the conflict, as well as to limited human, financial, and material resources.
Angolas current minister for urban management and environment has acknowledged that informality of land tenure is extensive in Luanda. The policies of this ministry seem to be based on a genuine concern for the well being of the citys informal residents and with the aim of finding a lasting solution for this problem. However, these policies are in sharp contrast with actual practice revealed in the evictions documented in this report.
In 2004 the government passed a new land law. This law was an important step towards regulating the use of urban land and contains some safeguards for persons at risk of eviction. However, the law had no immediate practical consequences, as the necessary implementing regulations were not introduced and government agencies continued to forcibly evict Angolans contrary to the provisions of the law even after it was passed.
The 2004 Land Law also establishes a three-year period for regularization of informal land tenure, but does not set out how the government will effectively process regularization requests. According to the law, the onus is on individual citizens to seek regularization. If, after the three-year period, individuals have not submitted a regularization request to the authorities, the government is authorized to obtain the land they occupy, including by forcible meansregardless of whether or not the government took the necessary measures to inform citizens about the need and process for regularization and to ensure the timely processing of the requests. Unless the Angolan government takes deliberate steps to approve the remaining regulations and prioritize resources to ensure effective land registration for all those requiring regularization, insecurity of tenure will continue to be prevalent in Luanda and the citys urban poor will remain vulnerable to forced evictions such as those described in this report.
For its part, the Angolan Government has, at times, simply denied that it has carried out forced evictions. Most often the government has justified the evictions on the grounds that it needs the land for public interest development projects, or that it is removing alleged trespassers from state land. Many of the evictees interviewed for this report, however, lived on these lands for years or, in some cases, for generations. Others who settled more recently did so according to custom, with the consent of previous residents and small farmers. While the government claims that it is trying to improve living conditions in Luanda, it is, in fact, making such conditions worse for the most economically vulnerable by evicting thousands of them and by depriving them of the necessary assistance to help the evictees reestablish elsewhere.
Human Rights Watch calls on the government of Angola to investigate the allegations of excessive use of force and other human rights abuses related to the evictions described in this report, and to provide compensation to victims of past forced evictions. The government should also genuinely consult with communities and ensure due process where the involuntary removal of communities has been suspended due to complaints by the residents and where it plans to develop public interest projects in the future. To prevent further forced evictions in violation of international human rights law and standards, it is crucial that the government takes decisive and urgent action to address insecurity of tenure in Luanda.

domain: news


text:
[JURIST] UN Human Rights Chief Zeid Ra'ad al-Hussein [official profile] stated on Monday that Syrian factions should not offer amnesty for any committed war crimes as opposing sides meet in Geneva to discuss a possible end to the country's ongoing civil war. Hussein stated to the press [UN News report] that war crimes are crimes against humanity and referenced the deliberate starvation of Syrians in seized cities such as Madaya where civilians continue to suffer and die of malnutrition [Al Jazeera report], despite consistent efforts to provide aid. Hussein's comments follow a recent struggle to arrange negotiations between the Syrian government and the opposing High Negotiations Committee (HNC). Though the parties were scheduled to discuss issues of air bombings with UN Special Envoy Staffan de Mistura, the HNC has refused to join the talks until the government releases political prisoners and ends current bombings and sieges. Mistura expects that the talks will proceed as planned [UN News report] for six months with the goal of achieving a broad ceasefire, humanitarian aid, opposition against the ISIL threat and new governmental changes within the near future.
The conflict in Syria [JURIST backgrounder] has continued for five years in a civil war based around the legitimacy of President Bashar al-Assad [BBC backgrounder]. According to the UN more than 250,000 Syrians have died, and about 10.5 million have fled their homes. These refugees have attempted to flee the fighting by entering Europe, prompting UN officials to urge a global response [JURIST report] to the crisis. In January UnN humanitarian agencies called for continued aid [JURIST report] to Syrians due to the "deteriorating conditions" in the area of Deir-Ez-Zor. In December the UN Security Council adopted [JURIST report] a resolution outlining 15 steps for peace in Syria. The conflict has been highlighted by countless human rights violations and use of chemical weaponry, which has created mounting pressure among the international community to find an end to the conflict.

domain: politics


text:
2016 New Rochelle Youth Tackle League Online Registration Is Open and FREE.
Since 1957, New Rochelle Youth Tackle League has been dedicated to the youth in our community who participate in Pop Warner Football & Cheer. Our mission is to help nurture positive values, self-esteem, self discipline, and team work through the enjoyment of athletics. We thank you for your continued support of NRYTL. Joe Fosina - President
Lebron James and Khalil Edney 2013@2013 ESPY Awards
The 2016 RCPWL Season is Upon Us!
Thank you to everyone who has joined New Rochelle Youth Tackle League for our 60th season! Those who signed up via League One will
receive an introduction e-mail this weekend. In the meantime view our 'Frequently Asked Questions ' document that we have put together. General questions can be sent to email@example.com . LET'S GO NEWRO'
( 2014 )Former YTLer Jackson-Allen sets Mamaroneck HS record (lohud.com) (AGAIN)
The numbers were simply unimaginable.
"It's all just surreal," said the senior running back who needed only 16 carries to break a record set in 2002 by Tigers assistant Maurice Murray. "That is the kind of thing you do in a video game. It feels amazing. It was a crazy night." Read more
**side note Maurice Murray (former NRYTLer) - all time leading rusher for Northeastern University Football.
POP WARNER & YOUTH FOOTBALL NEWS
Advertise or support us @ Joe Fosina Field with signage! Contact us for details.

domain: sports


text:
OLDER AUSTRALIANS are being urged to return unwanted medicines to the pharmacy, with thousands of seniors and children at risk of hospitalisation due to medical poisoning every year.
More than 1000 people aged over 65 required hospitalisation due to medicine poisonings across Australia in 2010. As well as older Australians, older medicines in homes also pose a health hazard for children, with more than 5000 ending up in hospital due to medicine poisoning every year, according to the Australian Poisons Information Centre.
A new awareness campaign has been launched by the Return Unwanted Medicines project - a Government-funded initiative that provides Australians with a free and convenient way to dispose of expired and unwanted household medicines.
It is estimated that there are millions of medicines sitting in Australian homes - either out-of-date or no longer needed - posing a danger of accidental poisonings and medication mismanagement.
Project manager and community pharmacist Toni Riley said last year over 700 tonnes of medicines were collected and safely disposed of by the RUM Project, preventing it from ending up in waterways or landfill.
"If that's only medicines collected from around 20 per cent of the population, imagine how many more are hiding in bathroom cabinets and kitchen drawers across the country," she said.
Keeping medicines that are out-of-date poses a great risk to seniors who, on average, take more medicines than other age cohorts. This creates a greater chance for medication confusion or mismanagement that can result in accidental poisoning.
A recent Griffith University study of over 4,300 Australians found more than 80 per cent of people don't know about the RUM Project or how to dispose of unwanted medicines safely and appropriately.
Research has also found seniors are more severely affected by medical poisoning than younger age groups, requiring longer hospital visits, and resulting in higher mortality rates, and that cases of unintentional self-poisoning in seniors increases with age.
The Griffith University study also revealed that two thirds of respondents said they disposed of unwanted medicines with the usual household garbage; followed by being poured down the drain or toilet (23.3 per cent) and less than a quarter (23 per cent) actually disposed of their medication by returning it to a pharmacy.
"By following three simple steps of "Read, Remove and Return" Australians can minimise the risk of unintended poisonings and medication mix-ups, and do their bit to protect the environment," said Ms Riley.
- To find out how to return unwanted medicine go to www.returnmed.com.au or talk to your local pharmacist.

domain: medical


NOAA’s Joint Polar Satellite System-1 spacecraft and a host of small satellites known as CubeSats are beginning their missions following this morning’s successful launch aboard a United Launch Alliance Delta II rocket. The on-time liftoff occurred at 1:47:36 a.m. PST (4:47:36 EST) from Space Launch Complex 2 at Vandenberg Air Force Base in California.
“Things went absolutely perfect today. The weather cooperated, the upper-level winds cooperated, and so did the vehicle, spacecraft and range instruments,” said NASA Launch Manager Omar Baez after launch and ascent activities were complete. “We couldn’t ask for better.”
JPSS-1 is the first in NOAA’s series of four, next-generation operational environmental satellites designed to circle the Earth in a polar orbit. JPSS represents significant technological and scientific advancements in observations used for severe weather prediction and environmental monitoring. This data is used by NOAA’s National Weather Service for numerical forecast models, ultimately helping emergency managers make timely decisions on life-saving early warnings and evacuations. JPSS-1 was Ball Aerospace and Technologies Corp. of Boulder, Colorado.
“The nation has another wonderful weather asset in space,” Baez said.
All CubeSats have been deployed! P-POD 1 released EagleSat-1, RadFXSat and MakerSat-0; Buccaneer deployed from P-POD 2; and MiRaTA deployed from P-POD 3. The CubeSats all are flying solo to begin their missions.
Flying 440 nautical miles over the Indian Ocean, NOAA’s Joint Polar Satellite System-1 spacecraft has separated from the second stage of the United Launch Alliance Delta II rocket that delivered it to orbit this morning.
The next major milestone will be the third burn of the Delta II second stage – a quick burn lasting about 18 seconds – to prepare for deployment of the P-PODs, releasing the five CubeSats.
NOAA’s Joint Polar Satellite System-1 launched aboard a United Launch Alliance Delta II rocket at 1:47 a.m. PST (4:47 a.m. EST) from Vandenberg Air Force Base in California. The flight has proceeded smoothly and at this time, the vehicle is in a coast phase.
Here’s a look back at liftoff captured from NASA TV.
The Delta II rocket’s second-stage engine has cut off, finishing its first burn. This marks the beginning of a coast phase lasting just over 40 minutes. The engine will reignite for its second burn at 2:38 a.m. PST (5:38 a.m. EST).
Main engine cutoff occurred on time, the first and second stages separated as planned and the second-stage engine has started its first burn. The payload fairing that protected the JPSS-1 satellite during the first minutes of ascent has jettisoned as expected.
Booster ignition and liftoff! NOAA’s Joint Polar Satellite System-1 spacecraft is on its way into polar orbit aboard a United Launch Alliance Delta II rocket. The vehicle is rising up and away from Space Launch Complex 2, its light piercing the darkened skies over California’s Vandenberg Air Force Base.


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Alright One Direction, I am really into this song. I mean all of their new music has been pretty incredible, that’s for sure. Everyone is saying that this song was a response to Taylor Swift’s song ‘Style’ and I totally see that. It also reminds me of ‘Blank Space’ a little, which I don’t hate.
Honestly this band has really grown on me from their last album to the songs they have been releasing from their newest album that is coming out. It is a damn shame they are breaking up. I mean that they are taking a break, whatever you want to call it.
I really do love their more adult sound and Liam Payne is an absolute babe so it makes it even better.
I have to admit since Zayn is gone I really think their sound is even better than before.
And if you like cameras flashing every time we go out
And if you’re looking for someone to write your breakup songs about
Baby, I’m perfect
Click here and tell me what you think of the video!


text:
Located directly in the tourist area of Sanxenxo and just 5 minutes from the town centre, this hotel is also directly near to the beach. Public transport links can be found just 150 m from the hotel and shopping facilities, nightclubs as well as bars, cafés and restaurants are all just a 5-minute walk away. The hotel was built in 1999. Guests are welcomed at the accommodation, which has a total of 130 rooms. Most storeys can be reached by lift. Amenities include a safe. Wireless internet access in public areas allows travellers to stay connected. Among the culinary options available at the establishment are a restaurant, a dining area, a café and a bar. There is also a garden. Those arriving in their own vehicles can leave them in the car park of the hotel. Guests can also use the bicycle storage facilities. Additional services include medical assistance, room service and a laundry service. Each of the rooms is appointed with air conditioning, central heating and a bathroom. The basic features of most rooms include a balcony. The rooms each feature a double bed. A safe and a minibar are also available. Guests will also find a mini fridge included as standard. Little extras, including internet access, a telephone, a TV, a stereo system and WiFi, contribute to a great stay. The bathroom offers convenient facilities including a bathtub. A hairdryer is also available. The accommodation offers non-smoking rooms. A refreshing dip in the indoor or outdoor pool is an enjoyable way to cool down on hot days. A terrace, sun loungers and parasols are available. The hot tub is the perfect place to relax. The poolside bar serves a selection of refreshing drinks. Active travellers can enjoy tennis. Sport and leisure facilities at the establishment include a gym and billiards. Various wellness options are available at the hotel, including a spa, a sauna, a steam bath, a hammam, massage treatments, hydrotherapy applications and a solarium. Additional services include an entertainment programme for children, offering numerous activities. Copyright GIATA 2004 - 2016. Catering options available at the accommodation include bed and breakfast, half board and full board. Guests can choose to book options such as breakfast, lunch or dinner. The following credit cards are accepted at the establishment: American Express, VISA, Diners Club and MasterCard.
Wondeful value for money at a great beach resort in Galicia.
Comfortable room, excellent food, helpfull staff.
Good food in the main restaurant Poor quality of food in room service.Spa facilities for women not complete e g no facials, etc Main problem was air conditioning in the room was faulty.
Lovely hotel, excellent facilities, efficient and helpful staff, great breakfast in a very nice seaside resort with an excellent beach. None

domain: travel


text:
Another Quinn administration jobs initiative is drawing headlines for wasting taxpayer dollars and failing to provide marketable job training skills.
This time, it’s the Urban Weatherization Initiative, started in 2009 with the intent to train workers in predominantly African-American neighborhoods in weatherization and other energy efficiency trades.
Coming just days after a bipartisan legislative commission took two days of testimony on Governor Pat Quinn’s failed Neighborhood Recovery Initiative, a Chicago-based reform group is highlighting the failures of the massive weatherization training program that was supposed to create skilled workers and provide low-cost services to homeowners across the state.
A Better Government Association (BGA) investigation has found that five years into the program, more than $16 million has been spent, with just 183 homes upgraded and only a handful of persons actually working. The program is also the subject of a Chicago Sun-Times report, and the newspaper editorialized that the program is a “boondoggle.”
That works out to more than $87,000 for each home weatherized. But, that per-home figure is inflated because very little of the money has actually gone into home repairs and upgrades. Instead, $13 million of the $16 million spent went toward administrative costs and training.
The program claims to have trained 1,900 persons, but the state agency charged with overseeing the program says it does not have figures on how many trainees found jobs or are currently working. The BGA investigation found few former trainees who had found permanent work.
One of the finds of the BGA investigation was the training costs have been inflated because the program pays trainees at a rate that, if annualized, can equal more than $100,000 a year. Trainees are paid up to $49 an hour due to the state’s Prevailing Wage Act, nearly two and a half times more than originally predicted.
That’s because the “prevailing wage” rate used is not one for unskilled weatherization trainees, but rather for skilled carpenters. When it was first developed, the program anticipating paying trainees at a still-generous rate of $20 an hour.
Investigators also found that the wife of one of the program’s legislative supporters was hired by Quinn to run the program at a rate of more than $100,000 a year.
The controversy is just the latest to hit the Quinn administration, which has been on the hot seat for its administration of a 2010 anti-violence and job training program – the Neighborhood Recovery Initiative.
That initiative has been the subject of a scathing audit earlier this year, two days of testimony from former Quinn administration officials before the bipartisan Legislative Audit Commission and several criminal investigations

domain: law