Type II collagen-induced arthritis. Studies with purified anticollagen immunoglobulin

Microbiota-dependent indole production is required for the development of collagen-induced arthritis

Altered tryptophan catabolism has been identified in inflammatory diseases like rheumatoid arthritis (RA) and spondyloarthritis (SpA), but the causal mechanisms linking tryptophan metabolites to disease are unknown. Using the collagen-induced arthritis (CIA) model we identify alterations in tryptophan metabolism, and specifically indole, that correlate with disease. We demonstrate that both bacteria and dietary tryptophan are required for disease, and indole supplementation is sufficient to induce disease in their absence. When mice with CIA on a low-tryptophan diet were supplemented with indole, we observed significant increases in serum IL-6, TNF, and IL-1β; splenic RORγt+CD4+ T cells and ex vivo collagen-stimulated IL-17 production; and a pattern of anti-collagen antibody isotype switching and glycosylation that corresponded with increased complement fixation. IL-23 neutralization reduced disease severity in indole-induced CIA. Finally, exposure of human colon lymphocytes to indole increased expression of genes involved in IL-17 signaling and plasma cell activation. Altogether, we propose a mechanism by which intestinal dysbiosis during inflammatory arthritis results in altered tryptophan catabolism, leading to indole stimulation of arthritis development. Blockade of indole generation may present a novel therapeutic pathway for RA and SpA.

Complement in the Initiation and Evolution of Rheumatoid Arthritis

The complement system is a major component of the immune system and plays a central role in many protective immune processes, including circulating immune complex processing and clearance, recognition of foreign antigens, modulation of humoral and cellular immunity, removal of apoptotic and dead cells, and engagement of injury resolving and tissue regeneration processes. In stark contrast to these beneficial roles, however, inadequately controlled complement activation underlies the pathogenesis of human inflammatory and autoimmune diseases, including rheumatoid arthritis (RA) where the cartilage, bone, and synovium are targeted. Recent studies of this disease have demonstrated that the autoimmune response evolves over time in an asymptomatic preclinical phase that is associated with mucosal inflammation. Notably, experimental models of this disease have demonstrated that each of the three major complement activation pathways plays an important role in recognition of injured joint tissue, although the lectin and amplification pathways exhibit particularly impactful roles in the initiation and amplification of damage. Herein, we review the complement system and focus on its multi-factorial role in human patients with RA and experimental murine models. This understanding will be important to the successful integration of the emerging complement therapeutics pipeline into clinical care for patients with RA.

Extracellular matrix-blood composite injection reduces post-traumatic osteoarthritis after anterior cruciate ligament injury in the rat

The objective of this study was to determine if an injection of a novel extracellular matrix scaffold and blood composite (EMBC) after anterior cruciate ligament (ACL) injury would have a mitigating effect on post-traumatic osteoarthritis (PTOA) development in rat knees. Lewis rats underwent unilateral ACL transection and were divided into three groups as follows: (1) no further treatment (ACLT; n = 10); (2) an intra-articular injection of EMBC on day 0 (INJ0; n = 11); and (3) an intra-articular injection of EMBC on day 14 (INJ14; n = 11). Ten additional animals received capsulotomy only (n = 10, SHAM group). The OARSI histology scoring of the tibial cartilage and micro-CT of the tibial epiphysis were performed after 35 days. The ratio of intact/treated hind limb forces during gait was determined using a variable resistor walkway. The OARSI cartilage degradation sum score and total degeneration width were significantly greater in the ACLT group when compared to the INJ0 (p = 0.031, and p = 0.005) and INJ14 (p = 0.022 and p = 0.04) group. Weight bearing on the operated limb only decreased significantly in the ACLT group (p = 0.048). In the rat ACL transection model, early or delayed injection of EMBC ameliorated the significant decrease in weight bearing and cartilage degradation seen in knees subjected to ACL transection without injection. The results indicate that the injection of EMBC may slow the process of PTOA following ACL injury and may provide a promising treatment for PTOA. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:995-1003, 2016.

Rodent preclinical models for developing novel antiarthritic molecules: comparative biology and preferred methods for evaluating efficacy

Rodent models of immune-mediated arthritis (RMIA) are the conventional approach to evaluating mechanisms of inflammatory joint disease and the comparative efficacy of antiarthritic agents. Rat adjuvant-induced (AIA), collagen-induced (CIA), and streptococcal cell wall-induced (SCW) arthritides are preferred models of the joint pathology that occurs in human rheumatoid arthritis (RA). Lesions of AIA are most severe and consistent; structural and immunological changes of CIA best resemble RA. Lesion extent and severity in RMIA depends on experimental methodology (inciting agent, adjuvant, etc.) and individual physiologic parameters (age, genetics, hormonal status, etc.). The effectiveness of antiarthritic molecules varies with the agent, therapeutic regimen, and choice of RMIA. All RMIA are driven by overactivity of proinflammatory pathways, but the dominant molecules differ among the models. Hence, as with the human clinical experience, the efficacy of various antiarthritic molecules differs among RMIA, especially when the agent is a specific cytokine inhibitor.

Enhanced susceptibility to low-dose collagen-induced arthritis in CR1/2-deficient female mice--possible role of estrogen on CR1 expression

The influence of complement receptor 1 and 2 (CR1/2) was investigated on the susceptibility to low-dose collagen-induced arthritis (CIA) in wild-type (WT) and CR1/2-deficient DBA/1 mice. Significantly enhanced CIA was observed in female CR1/2-deficient mice compared with WT female mice, while male mutant and WT mice showed similar arthritis development. The enhanced CIA was accompanied with higher complement levels and a prolonged IgM anti-collagen type II response. When investigating whether estrogen contributed to the different arthritis susceptibility, we found that ovariectomy rendered WT females more sensitive to low-dose CIA and to the same extent as CR1/2-deficient females, while CR1/2-deficient mice were unaffected by ovariectomy. Notably, the ovariectomized WT mice displayed reduced CR1(+) B220(+) B-cell numbers and CR1 expression compared with sham-operated WT mice, suggesting a stimulatory effect of estrogen on CR1. In accordance, a significant correlation was observed between reduced CR1 expression in B cells and increased age in healthy female blood donors but not in male donors. Our findings demonstrate an important role of CR1/2 in suppressing CIA in female mice under low-antigen conditions. The data suggest that estrogen promote CR1 expression in B cells. These findings provide insight to the increased frequency of rheumatoid arthritis in postmenopausal women.

Quantitative dynamic models of arthritis progression in the rat

PURPOSE

This comparison employs mathematical disease progression models to identify a rat model of arthritis with the least inter-animal variability and features lending to better study designs.

METHODS

Arthritis was induced with either collagen (CIA) or mycobacterium (AIA) in either Lewis or Dark Agouti (DA) rats. Disease progression was monitored by paw edema and body weight. Models with production, loss, and feedback components were constructed and population analysis using NONMEM software was employed to identify inter-animal variability in the various disease progression parameters.

RESULTS

Onset time was the only parameter different within all four groups (DA-AIA 11.5 days, DA-CIA 16.5 days, Lewis-AIA 11.9 days, Lewis-CIA 13.9 days). The loss-of-edema rate constant was 20% slower in DA (0.362 h(-1)) than Lewis (0.466 h(-1)) rats. Most models exhibited peak paw edema 20 days post-induction. Edema in CIA returned to 150% of the initial value after the disease peaked. DA rats displayed more severe overall responses.

CONCLUSIONS

No statistical differences between groups were observed for inter-animal variation in disease onset, progression and severity parameters. Onset time varies and should be noted in the design of future studies. DA rats may offer a more dynamic range of edema response than Lewis rats.

Targeting phosphoinositide 3-kinase: moving towards therapy

Phosphoinositide 3-kinases (PI3K) orchestrate cell responses including mitogenic signaling, cell survival and growth, metabolic control, vesicular trafficking, degranulation, cytoskeletal rearrangement and migration. Deregulation of the PI3K pathway occurs by activating mutations in growth factor receptors or the PIK3CA locus coding for PI3Kalpha, by loss of function of the lipid phosphatase and tensin homolog deleted in chromosome ten (PTEN/MMAC/TEP1), by the up-regulation of protein kinase B (PKB/Akt), or the impairment of the tuberous sclerosis complex (TSC1/2). All these events are linked to growth and proliferation, and have thus prompted a significant interest in the pharmaceutical targeting of the PI3K pathway in cancer. Genetic targeting of PI3Kgamma (p110gamma) and PI3Kdelta (p110delta) in mice has underlined a central role of these PI3K isoforms in inflammation and allergy, as they modulate chemotaxis of leukocytes and degranulation in mast cells. Proof-of-concept molecules selective for PI3Kgamma have already successfully alleviated disease progress in murine models of rheumatoid arthritis and lupus erythematosus. As targeting PI3K moves forward to therapy of chronic, non-fatal disease, safety concerns for PI3K inhibitors increase. Many of the present inhibitor series interfere with target of rapamycin (TOR), DNA-dependent protein kinase (DNA-PK(cs)) and activity of the ataxia telangiectasia mutated gene product (ATM). Here we review the current disease-relevant knowledge for isoform-specific PI3K function in the above mentioned diseases, and review the progress of >400 recent patents covering pharmaceutical targeting of PI3K. Currently, several drugs targeting the PI3K pathway have entered clinical trials (phase I) for solid tumors and suppression of tissue damage after myocardial infarction (phases I,II).

Blockade of PI3Kgamma suppresses joint inflammation and damage in mouse models of rheumatoid arthritis

Phosphoinositide 3-kinases (PI3K) have long been considered promising drug targets for the treatment of inflammatory and autoimmune disorders as well as cancer and cardiovascular diseases. But the lack of specificity, isoform selectivity and poor biopharmaceutical profile of PI3K inhibitors have so far hampered rigorous disease-relevant target validation. Here we describe the identification and development of specific, selective and orally active small-molecule inhibitors of PI3Kgamma (encoded by Pik3cg). We show that Pik3cg(-/-) mice are largely protected in mouse models of rheumatoid arthritis; this protection correlates with defective neutrophil migration, further validating PI3Kgamma as a therapeutic target. We also describe that oral treatment with a PI3Kgamma inhibitor suppresses the progression of joint inflammation and damage in two distinct mouse models of rheumatoid arthritis, reproducing the protective effects shown by Pik3cg(-/-) mice. Our results identify selective PI3Kgamma inhibitors as potential therapeutic molecules for the treatment of chronic inflammatory disorders such as rheumatoid arthritis.

Antibodies against the CB10 fragment of type II collagen in rheumatoid arthritis

Antibodies against intact type II collagen (CII) are a feature of rheumatoid arthritis (RA) but have limited diagnostic value. Here we assess whether either of the two major cyanogen bromide fragments of CII, namely CB10 or CB11, are more sensitive substrates for the detection of antibodies in RA. Cleavage of bovine CII with cyanogen bromide yielded CB10 and CB11; these were purified by column chromatography for use in an enzyme-linked immunosorbent assay. Serum antibodies were measured in patients with RA, psoriatic arthritis (PsA), osteoarthritis (OA) and blood donors. Results were compared with those using intact CII. Antibodies against CB10 were found in as many as 88% of 96 patients with long-standing RA, but only 12% of 33 patients with PsA, 6% of 34 patients with OA and 3% of 93 control sera. Lower frequencies for these diseases were obtained on testing for antibodies against CB11: 50%, 6%, 21% and 2%, respectively. The sensitivity of detection in RA of antibodies against CB10 compared with antibodies against intact CII (88% versus 24%) was not at the expense of specificity, which remained high at 94%. The much higher frequency of antibodies against CB10 in RA than in other rheumatic diseases or control sera indicates that CB10 is clearly a more sensitive substrate than the intact collagen molecule and, combined with other assays (rheumatoid factor, anti-cyclic citrullinated peptide [anti-CCP]), might comprise a panel with a highly reliable predictive value. Moreover, our findings should encourage renewed interest in the role of collagen autoimmunity in the pathogenesis of RA.

Prevention of collagen-induced arthritis in mice transgenic for the complement inhibitor complement receptor 1-related gene/protein y

The objective of these studies was to examine collagen-induced arthritis (CIA) in C57BL/6 mice transgenic for the rodent complement regulatory protein complement receptor 1-related gene/protein y (Crry) (Crry-Tg), a C3 convertase inhibitor. The scores for clinical disease activity and for histological damage in the joints were both significantly decreased in Crry-Tg mice in comparison to wild-type (WT) littermates. The production of both IgG1 and IgG2a anti-collagen Abs was reduced in the Crry-Tg mice, although spleen cell proliferation in response to collagen type II was not altered. The production of IFN-gamma, TNF-alpha, and IL-1beta by LPS-stimulated spleen cells was decreased, and IL-10 was increased, in cells from Crry-Tg mice in comparison to WT. The steady-state mRNA levels for IFN-gamma, TNF-alpha, and IL-1beta were all decreased in the joints of Crry-Tg mice in comparison to WT. The synovium from Crry-Tg mice without CIA contained the mRNA for the Crry transgene, by RT-PCR, and the synovium from transgenic mice with CIA exhibited little deposition of C3 protein by immunohistological analysis. These results suggest that suppression of CIA in Crry-Tg mice may be due to enhanced synthesis of Crry locally in the joint with decreased production of proinflammatory cytokines.

Mechanisms of effects of complement inhibition in murine collagen-induced arthritis

OBJECTIVE

To determine the mechanisms of amelioration of collagen-induced arthritis (CIA) in DBA/1J mice by inhibition of complement activation.

METHODS

Mice received 2 intradermal injections of bovine type II collagen (CII), on days 0 and 21. From day 21 (immediately after the second injection of CII) through day 35, mice received intraperitoneal injections of either phosphate buffered saline (PBS), a monoclonal mouse antibody to murine C5 (anti-C5 antibody), or the C3 convertase inhibitor Crry-Ig.

RESULTS

On days 30 and 32, the clinical disease activity score was lower in mice treated with anti-C5 antibody than in those treated with Crry-Ig. Histopathologic evidence of joint damage was 75% lower in the mice treated with anti-C5 antibody than in those treated with either PBS or Crry-Ig. Spleen cells from mice receiving either form of complement inhibition exhibited decreased CII-stimulated proliferation, whereas increased proliferative responses were exhibited by lymph node cells from mice treated with Crry-Ig. Treatment with anti-C5 antibody decreased production of IgG1 anticollagen antibody, while production of IgG2a antibody was inhibited by both complement inhibitory treatments. CII-stimulated spleen cells from anti-C5-treated mice produced lower levels of tumor necrosis factor alpha (TNFalpha) and interleukin-10 (IL-10) compared with those from mice treated with Crry-Ig. Lower steady-state messenger RNA (mRNA) levels for TNFalpha, interferon-gamma (IFNgamma), IL-18, and IL-6 were observed in the joints of anti-C5-treated mice, and for IFNgamma and IL-6 in mice receiving Crry-Ig, all in comparison with PBS-treated mice. However, mRNA levels for IL-1beta and TNFalpha were lower in the joints after treatment with anti-C5 compared with Crry-Ig.

CONCLUSION

These results indicate that inhibition of complement in CIA leads to decreased production of IgG2a antibody and suppressed CII-induced spleen cell proliferation. The greater inhibitory effects on CIA of anti-C5 antibody in comparison with Crry-Ig may be attributable primarily to decreased levels of IL-1beta and TNFalpha mRNA in the joints.

Reduced susceptibility to collagen-induced arthritis in DBA/1J mice expressing the TSG-6 transgene

OBJECTIVE

Expression of TSG-6 (tumor necrosis factor-stimulated gene 6) is induced by proinflammatory cytokines. This study was undertaken to examine the effects of local expression of TSG-6 in arthritic joints of TSG-6 transgenic mice, in the collagen-induced arthritis (CIA) model.

METHODS

We generated transgenic mice that harbored the TSG-6 gene under the control of the T cell-specific lck promoter. Arthritis was induced by immunization with bovine type II collagen (CII), and its progression was monitored based on the incidence of arthritis, the arthritis index, and footpad swelling. Anti-CII antibodies and cytokine production were determined by enzyme-linked immunosorbent assay. Gene expression arrays were used to compare gene expression profiles of transgenic and control mice at various stages of CIA.

RESULTS

TSG-6 was expressed in limbs of transgenic mice after immunization with CII, while its expression in nontransgenic animals was insignificant. The incidence of CIA was reduced in TSG-6 transgenic animals, its onset delayed, and all parameters of clinical arthritis significantly reduced. However, the immune response against CII was not significantly inhibited in TSG-6 transgenic mice.

CONCLUSION

TSG-6 expression has been demonstrated in patients with rheumatoid and other forms of arthritis. Our data show that local expression of TSG-6 at sites of inflammation results in potent inhibition of inflammation and joint destruction in a model of autoimmune arthritis in mice. Therefore, it is likely that TSG-6 plays a similar modulatory role in human rheumatoid arthritis and related diseases and may have potential for the treatment of autoimmune arthritis in humans.

H2-Mbeta 1 and H2-Mbeta 2 heterodimers equally promote clip removal in I-A(q) molecules from autoimmune-prone DBA/1 mice

Antigen-presenting cells degrade endocytosed antigens, e.g. collagen type II, into peptides that are bound and presented to arthritogenic CD4(+) helper T cells by major histocompatibility complex (MHC) class II molecules. Efficient loading of many MHC class II alleles with peptides requires the assistance of H2-M (HLA-DM in humans), a heterodimeric MHC class II-like molecule that facilitates CLIP removal from MHC class II molecules and aids to shape the peptide repertoire presented by MHC class II to CD4(+) T cells. In contrast to the HLA-DM region in humans, the beta-chain locus is duplicated in mice, with the H2-Mb1 beta-chain distal to H2-Mb2 and the H2-Ma alpha-chain gene. H2-M alleles appear to be associated with the development of autoimmune diseases. Recent data showed that Mbeta1 and Mbeta2 isoforms are differentially expressed in isolated macrophages and B cells, respectively. The tissue expression and functional role of these heterodimers in promoting CLIP removal and peptide selection have not been addressed. We utilized the human T2 cell line, which lacks part of chromosome 6 encompassing the MHC class II and DM genes, to construct transgenic cell lines expressing the MHC class II heterodimer I-A(q) alone or in the presence of H2-Malphabeta1 or H2-Malphabeta2 heterodimers. Both H2-M isoforms facilitate the exchange of CLIP for cognate peptides on I-A(q) molecules from arthritis-susceptible DBA/1 mice and induce a conformational change in I-A(q) molecules. Moreover, I-A(q) cell-surface expression is not absolutely dependent on H2-M molecules. These data suggest that I-A(q) exhibits a high affinity for CLIP since virtually all I-A(q) molecules on T2 cells were found to be associated with CLIP in the absence of both H2-M isoforms.

Amelioration of collagen-induced arthritis in DBA/1J mice by recombinant TSG-6, a tumor necrosis factor/interleukin-1-inducible protein

OBJECTIVE

To examine the effect of recombinant TSG-6 on collagen-induced arthritis (CIA) in DBA/1J mice. TSG-6 is a tumor necrosis factor (TNF)/ interleukin-1 (IL-1)-inducible hyaluronan-binding protein produced by synovial cells and chondrocytes that is present in synovial fluids of patients with rheumatoid arthritis.

METHODS

To determine the effect of TSG-6 on chronic inflammatory joint disease, we induced CIA in DBA/1J mice by immunization with bovine type II collagen. Animals were treated with 12 intraperitoneal doses of 200 microg of recombinant TSG-6, beginning 3 days before the expected onset of disease symptoms. Progression of arthritis was monitored by determining the disease incidence, arthritis index, and footpad swelling. Levels of IgG1, IgG2a, and IgG2b antibodies against bovine and murine type II collagen and serum concentrations of IL-6 were determined at various time points. Histologic examination of affected joints was performed approximately 20 days after the onset of arthritis.

RESULTS

Treatment with recombinant TSG-6 protein had a potent ameliorative effect, manifested by decreases in the disease incidence, arthritis index, and footpad swelling. Histologic examination of affected joints in TSG-6-treated animals revealed little pannus formation and cartilage erosion, features which were conspicuous in control mice. Animals treated with recombinant TSG-6 developed significantly reduced levels of IgG1, IgG2a, and IgG2b antibodies against bovine and murine type II collagen.

CONCLUSION

The antiinflammatory effect of the TNF/IL-1-inducible TSG-6 protein in murine CIA suggests a role for this protein as an endogenous regulator of the inflammatory process.

Effects of maitake (Grifola frondosa) polysaccharide on collagen-induced arthritis in mice

We recently reported the anti-hepatitis effect of a polysaccharide, designated as the D-fraction, extracted from maitake. Its effect includes immuno-regulating activities. We investigated the effect of the glucan in collagen-induced arthritis (CIA). The D-fraction was administered to CIA mice for 30 consecutive days. Arthritis development was observed from the 4th day after the second immunization. The D-fraction did not have any influence on anti-type II collagen antibodies in blood serum or activated B cells. To determine how cellular immunity may be involved in the development of CIA, ratios of CD4+ T cells and their activated form in the axillary and inguinal lymph node T cells were detected by flow cytometry analysis. The ratios were not different between the D-fraction group and the control group. However, interleukin-1beta, granulocyte-macrophage colony-stimulating factor and tumor necrosis factor-alpha productions from splenic macrophages were significantly increased to 2.0, 4.7 and 1.9 times the control group level, respectively. The ratio of macrophages in the whole spleen cells was 2.3 times that of the control group, and their migrating ability was 1.9 times higher. Based on these results, we concluded that the arthritis development induced by D-fraction administration is attributable to the activation of splenic macrophages.

Bacterial lipopolysaccharide acts as an adjuvant to induce autoimmune arthritis in mice

We investigated the ability of lipopolysaccharide (LPS) as an adjuvant to induce autoimmune arthritis. LPS from Escherichia coli was intraperitoneally injected into DBA/1J mice together with the joint cartilage component type II collagen (CII) on day 0. Thereafter, the injection of CII and LPS was continued every 2 weeks up to day 56. The results showed that mice injected with CII plus LPS had signs of arthritis on day 55 and the joint inflammation reached a peak on day 75. Injection of CII or LPS alone induced no arthritis. Histologically, marked oedema of synovium and intense infiltration of inflammatory cells, including neutrophils, were observed 3 days after the onset of joint inflammation. Twenty-one days later, there were marked proliferation of synovial tissues with many mononuclear cells and destruction of cartilage. Anti-CII immunoglobulin G (IgG) and IgG2a antibodies were markedly produced in mice injected with CII plus LPS. Pronounced secretion of cytokines, including interleukins-12 and -1beta, interferon-gamma and tumour necrosis factor-alpha, was also observed in these animals. Arthritis was passively transferred into naive syngeneic mice with sera but not with lymphoid cells from mice given CII with LPS. Other types of LPS from Salmonella enteritidis, Salmonella typhimurium and Klebsiella pneumoniae as well as lipid A from E. coli, induced inflammation in joints when administered with CII. Polymixin B sulphate mixed with LPS or lipid A blocked the induction of joint inflammation. These results indicate that LPS appears to play an important role as an adjuvant in the induction of arthritis in which autoimmunity to CII is involved.

Antibodies to type II collagen and HLA disease susceptibility markers in rheumatoid arthritis

OBJECTIVE

To seek associations between antibodies to native and denatured type II collagen (NCII and DCII) and HLA in rheumatoid arthritis (RA).

METHODS

One hundred fourteen patients with clinically well-defined RA were HLA-DR and DQ typed. Those who were DR4 positive were subtyped for DRB1*0401-*0408 alleles by polymerase chain reaction using allele-specific oligonucleotide probes. Antibodies to human NCII and DCII (heat-denatured) were measured by enzyme-linked immunosorbent assay. The frequency of HLA alleles was compared in patients grouped according to the presence and absence of antibodies to NCII and DCII.

RESULTS

Twenty-seven patients (24%) were positive for antibodies to NCII. There was a significant increase in the frequency of HLA-DR7 in anti-NCII-positive patients compared with anti-NCII-negative patients (30% versus 9%; P = 0.019) and a significant decrease in HLA-DR3 (7% versus 28%; P = 0.044). Repeating the analyses after excluding the 16 patients who were DR7 positive revealed a significant increase in the frequency of HLA-DR1 in anti-NCII-positive patients compared with anti-NCII-negative patients (63% versus 27%; P = 0.045). Moreover, antibodies to NCII were associated with the third hypervariability region susceptibility sequence QRRAA that is present in DRB1*0101, *0404, *0405, and *0408 (84% versus 47%; P = 0.0085); 24 of 27 anti-NCII-positive patients were positive for either DR7, DR1, or DRB1*0404 or *0408. Thirty patients (26%) were positive for antibodies to DCII. There was a significant increase in the frequency of HLA-DR3 in anti-DCII-positive patients compared with anti-DCII-negative patients (40% versus 18%; P = 0.028).

CONCLUSION

The genetic associations between HLA-DR alleles and antibodies to CII in RA patients is in keeping with the collagen-induced arthritis model and implicates autoimmunity to CII as a major component in the multifactorial pathogenesis of RA.

Venoms, copper, and zinc in the treatment of arthritis

This article discusses the use of venoms, copper, and zinc in the treatment of arthritis. The author examines the history and effectiveness of viper, bee, and ant venoms in order to determine whether these natural ingredients in anti-inflammatory medications help relieve a patient's symptoms. Copper and zinc studies may offer therapeutic benefits, but there is still no solid consensus on the potential role of these elements in treating arthritis.

Intranasal administration of denatured type II collagen and its fragments can delay the onset of collagen-induced arthritis

Collagen-induced arthritis (CIA) is an autoimmune animal model for some types of human rheumatoid arthritis (RA). We have evaluated the effectiveness of intranasal administration of antigen in inhibiting CIA in DBA/1 mice. The intranasal administration of heat-denatured or trypsin-digested bovine type II collagen (CII) before immunization with CII strongly delayed the onset of CIA, whereas administration of native CII did not do so. The mice administered denatured or digested CII possessed much lower titers of anti-CII IgG2a than the control mice, whereas titers of anti-CII IgG1 and IgG2b were unchanged or slightly decreased. Responding to CII and peptides containing immunodominant T cell determinants, lymph node cells from mice administered denatured CII produced less IFN-gamma. These results suggest that intranasal administration of antigen downregulated preferentially Th1-type responses, whereas an enhanced Th2-type response was not observed. We demonstrate that the methods shown here are a possible treatment for rheumatoid arthritis.

Treatment with an Anti-IL-4 Monoclonal Antibody Blocks Suppression of Collagen-Induced Arthritis in Mice by Oral Administration of Type II Collagen

Oral administration of type II collagen (CII) has been shown to suppress collagen-induced arthritis (CIA) in experimental animals. However, the exact mechanism by which CIA is suppressed following administration of CII remains to be investigated, although it was demonstrated that active suppression by regulatory T cells might be involved in the suppression. Therefore, we have examined whether the inhibitory cytokine IL-4 plays a role in the suppression of CIA, by using an anti-IL-4 mAb (11B11 mAb). Mice were fed daily with CII over a period of 10 days before immunization with CII. 11B11 mAb was i.p. injected 30 min before each oral administration of CII. The results showed that treatment with 11B11 mAb markedly blocked suppression of CIA by the oral Ag. The blockade of suppression of CIA by the anti-IL-4 mAb was associated with the blockade of augmentation of IL-4 secretion in CII-fed mice. The treatment with 11B11 mAb also resulted in the prevention of decreases in anti-CII IgG2a Ab production, DTH responses to CII, proliferation of lymphoid cells to CII, and IFN-γ secretion in mice given CII orally. Thus, the neutralization of IL-4 by an anti-IL-4 Ab appears to be effective in blocking suppression of CIA by oral administration of CII, suggesting that IL-4 may be critically involved in its suppression.

Effect of a monoclonal antibody against interleukin-4 on collagen-induced arthritis in mice

1 The present study was undertaken to investigate the effect of a monoclonal antibody (11B11 mAb) against interleukin-4 (IL-4) on collagen-induced arthritis (CIA) in mice. 2 11B11 mAb was daily injected intraperitoneally over a period of 10 days, commencing on the day of immunization with type II collagen (CII). 3 The results showed that the anti-IL-4 mAb markedly augmented both the incidence and the severity of CIA. The augmentation of the disease was associated with a significant increase in anti-CII IgG2a antibody production, proliferative responses of lymph node cells to CII and interferon-gamma (IFN-gamma) secretion from the lymphoid cells. The production of anti-CII IgG1 antibodies the secretion of IL-4 was markedly reduced in the mAb-treated mice. 4 Thus, the neutralization of IL-4 by 11B11 mAb appears to be effective in augmenting CIA.

Novel synthetic retinoic acid inhibits rat collagen arthritis and differentially affects serum immunoglobulin subclass levels

Retinoids affect many biological processes such as cell proliferation, differentiation and morphogenesis, but their effects on arthritic patients and animal models of arthritis are controversial. We tested the effect of a novel synthetic retinoic acid, Am-80 (4-[(5,6,7,8-tetrahydro-5,5,8,8,-tetramethyl-2-naphthalenyl) carbamoyl] benzoic acid), on type-II collagen (CII)-induced arthritis (CIA) in rats. Am-80 markedly suppressed the incidence of arthritis, hindpaw swelling and bone destruction. In contrast, 13-cis-retinoic acid (13-cis-RA) hardly inhibited these CIA symptoms. Moreover, Am-80, but not 13-cis-RA, strongly reduced the serum level of anti-CII antibody and differentially affected the levels of immunoglobulin (Ig) subclasses in vivo: IgG1 and IgG2a levels were decreased, while IgA level was increased without any change in the IgM level. These findings indicate that Am-80 may be one of the lead retinoic acids of a new class of anti-inflammatory agents.

Immunomodulating effects of the new anti-rheumatic drug tenidap on collagen-induced arthritis

We investigated the in vivo action of the newly developed anti-rheumatic agent tenidap, CP-66,248 (Pfizer Inc., New York), on arthritis in collagen-induced arthritic mice. The inhibitory effect of tenidap on the development of arthritis was statistically more significant than piroxicam. The serum anti-type II collagen antibody titer was markedly inhibited in the mice treated by tenidap. These results suggest that, unlike NSAIDs, tenidap inhibits the progress of collagen-induced arthritis through its immunomodulating effect.

Agalactosyl glycoforms of IgG autoantibodies are pathogenic

The glycosylation of IgG results in many different glycoforms. A large body of correlative data (including remission of arthritis during pregnancy) has suggested that IgG molecules lacking galactose were associated with rheumatoid arthritis. We now demonstrate that agalactosyl IgG glycoforms are directly associated with pathogenicity in murine collagen-induced arthritis. We show that passive transfer of an acute synovitis in T-cell-primed mice can be enhanced by using IgG containing autoantibodies to type II collagen when the antibodies are present as the agalactosyl glycoform. Thus, nonpathogenic doses of autoantibodies can be made pathogenic by altering their glycosylation state.

Germline-encoded IgG antibodies bind mouse cartilage in vivo: epitope- and idiotype-specific binding and inhibition

Autoantibodies specific for type-II collagen (CII) occur in mice and rats with collagen-induced arthritis (CIA). The binding in vitro and in vivo of mouse monoclonal antibodies (MoAbs) specific for separate epitopes in CII have been investigated. Two-day-old mice were injected intraperitoneally (i.p.) with the anti-CII antibody CIID3 in both unlabelled and biotinylated form. It was found that antibodies binding to the same epitope in CII in vivo can inhibit others from binding in an epitope-specific fashion. The binding in vivo and in vitro of anti-CII antibodies could be inhibited also by an anti-idiotypic rat antiserum produced against the D3 antibody. The anti-idiotypic antiserum inhibited the binding of the antibody D3 and the idiotypically related antibody C2. The cDNA's of anti-CII antibodies D3, C2, and F4 were sequenced and found to contain germline encoded V-genes, apparently without somatic mutations. The variable heavy chain of D3 and C2 both expressed the same VH rearrangement, confirming that they share idiotypes. This report demonstrates that CII-specific germline-encoded IgG autoantibodies bind specifically to normal cartilage in vivo via their combining site.

Resistance to collagen-induced arthritis in rats and rhesus monkeys after immunization with attenuated type II collagen

Immunization of susceptible rodent or primate species with type II collagen (b-CII) from bovine origin induces type II collagen-induced arthritis (CIA). The disease is characterized as a systemic polyarthritis associated with humoral and cellular autoimmunity to CII and shares similarity with human arthritic diseases. The objective of this study was to develop a procedure for induction of resistance to CIA in animals, which possess a certain major histocompatibility complex phenotype that makes them prone to develop CIA (susceptible). It is shown that by immunization with an attenuated form of CII, in which arthritogenic epitopes have been destroyed by heat denaturation, disease resistance is induced in a susceptible inbred rat strain (RT-1u) and in an outbred population of susceptible rhesus monkeys (lacking the Mamu-A26 allele). In both species the disease resistance is connected with modulation of anti-CII autoantibodies of the IgM isotype. This protocol may provide a basis for effective and safe methods to induce protection to autoimmune arthritis in those subjects that are genetically prone to develop such a disease.

Anti-tumor necrosis factor ameliorates joint disease in murine collagen-induced arthritis

There is considerable evidence implicating tumor necrosis factor alpha (TNF-alpha) in the pathogenesis of rheumatoid arthritis. This evidence is based not only on the universal presence of TNF-alpha in arthritic joints accompanied by the upregulation of TNF-alpha receptors but also on the effects of neutralizing TNF-alpha in joint cell cultures. Thus, neutralization of TNF-alpha in vitro results in inhibition of the production of interleukin 1, which like TNF-alpha, is believed to contribute to joint inflammation and erosion. To determine the validity of this concept in vivo, the effect of administering TNF-neutralizing antibodies to mice with collagen-induced arthritis has been studied. This disease model was chosen because of its many immunological and pathological similarities to human rheumatoid arthritis. TN3-19.12, a hamster IgG1 monoclonal antibody to murine TNF-alpha/beta, was injected i.p. into mice either before the onset of arthritis or after the establishment of clinical disease. Anti-TNF administered prior to disease onset significantly reduced paw swelling and histological severity of arthritis without reducing the incidence of arthritis or the level of circulating anti-type II collagen IgG. More relevant to human disease was the capacity of the antibody to reduce the clinical score, paw swelling, and the histological severity of disease even when injected after the onset of clinical arthritis. These results have implications for possible modes of therapy of human arthritis.

Adjuvant composition determines the induction of type II collagen-induced arthritis

In this study we have investigated the influence of adjuvant composition on the development of collagen-induced arthritis and of anti-collagen type II specific B- and T-cell responses following immunization with type II collagen. DBA/l mice immunized with bovine collagen type II emulsified in complete Freund's adjuvant (CFA) containing Mycobacterium tuberculosis strain H37Ra developed footpad swelling indicative of arthritis. Animals immunized with collagen type II plus CFA containing Mycobacterium butyricum, or incomplete Freund's adjuvant showed no significant increase in footpad width. Induction of anti-CII specific T-cell proliferation was also dependent upon immunization with CII plus CFA containing M. tb H37RA. In contrast, ovalbumin-reactive T-cell proliferation was unaffected by the species of mycobacteria, indicating that the difference in adjuvant activity of the mycobacterial species is specific for anti-collagen type II T-cell responses. Antibody response to collagen type II, unlike T-cell responses, was not significantly different using the two adjuvants. This study therefore demonstrates that murine collagen-induced arthritis requires immunization with collagen type II together with complete Freund's adjuvant containing Mycobacterium tuberculosis H37RA. Since only this combination of antigen and adjuvant induces detectable arthritis and T-cell responses against collagen type II, while antibody synthesis does not have such stringent adjuvant requirements, this suggests that the development of the full pattern of the collagen-induced arthritis disease requires synergistic activation of both humoral and cell-mediated responses.

Interactions between anticollagen antibodies and chondrocytes

OBJECTIVE

To investigate the interactions between anticollagen antibodies and living chondrocytes.

METHODS

Mouse monoclonal anti-type II collagen (anti-CII) antibodies, rabbit anti-human CII, and rat anti-CII, anti-CIV, anti-CV, anti-CVI, and anti-CIX were studied in vitro to determine their ability to bind to the plasma membrane of living bovine chondrocytes.

RESULTS

Mouse monoclonal anti-CII, rabbit anti-CII, and rat anti-CII, anti-CV, and anti-CIX were shown to bind in vitro to the plasma membrane of bovine chondrocytes. Antibody binding was not observed with anti-CIV, or with chondrocytes previously incubated with bacterial collagenase. A significant increase in chondrocyte caseinase and collagenase secretion was observed following sequential incubation with the monoclonal antibodies and a source of activating cytokines.

CONCLUSION

These results suggest that collagen autoantibodies may exert some of their pathogenic effects on cartilage through interactions with resident chondrocytes, leading to modulation of the rate of secretion of cartilage matrix-degrading enzymes.

Anti-T cell receptor antibody treatment of rats with established autologous collagen-induced arthritis: suppression of arthritis without reduction of anti-type II collagen autoantibody levels

Activation of T cells is critical for the development of type II collagen (CII)-induced arthritis (CIA). However, the relative importance of T cells in their delivery of help to B cells, promoting autoantibody formation or acting as inflammatory initiating cells, is unclear. The effect of a monoclonal antibody directed to the alpha/beta T cell receptor (TcR) on the development of autologous CIA was studied. Two weeks after immunization with autologous CII the onset of severe arthritis occurred, followed by a chronic arthritis activity in the peripheral joints. Anti-TcR treatment before immunization suppressed the incidence of arthritis and the autoantibody response to CII. Treatment given immediately before the expected onset delayed the appearance of arthritis. Treatment given to already arthritic rats reduced the severity. In the latter two groups the serum levels of anti-CII autoantibodies were not affected. The duration of the ameliorating effect was limited and with the return of arthritis a concomitant antibody response towards the injected mouse anti-TcR antibody was observed. These results show that the role of T cells in both the induction and perpetuation of CIA is essential and not limited to the triggering of production of pathogenic anti-CII autoantibodies.

Down-regulation of adoptive adjuvant-induced arthritis by suppressor factor(s)

We recently described a method for inducing immunologic tolerance to trinitrochlorobenzene (TNCB), a hapten that generates suppressor cells capable of down-regulating the efferent phase of TNP-specific contact hypersensitivity in rats. Peritoneal exudate cells (PEC) of such tolerized rats, upon being triggered by specific hapten, suppressed contact hypersensitivity to another hapten elicited at the same time. This implied that cells that mediate delayed-type hypersensitivity of any specificity might be down-regulated, provided that the suppressor cells are activated with specific antigen and that the unrelated delayed-type hypersensitivity is elicited in parallel. To rigorously test this possibility, we examined the ability of TNP-specific suppressor lymphoid cell factors to affect cells that mediate adoptively transferable adjuvant-induced arthritis (AIA) in rats. To induce arthritis, spleen cells from Freund's complete adjuvant-injected rats were stimulated with concanavalin A and administered to naive recipients. Prior to adoptive transfer, the cells were exposed for brief intervals to supernatants of lymphoid cells from control and hapten-tolerized rats. Supernatants of PEC and lymph node cells from hapten-tolerized rats were found to markedly reduce the effectiveness of cells that mediate AIA. The hapten-tolerized cells required reexposure to hapten prior to preparation of the supernatants. Supernatants of spleen cells from hapten-tolerized rats that had been hapten-painted as well as hapten-triggered and supernatants of lymph node cells and of PEC from only hapten-painted or hapten-triggered rats were ineffective in altering the AIA. Thus, factors from suppressor cells induced toward hapten-coupled self-antigens have been found to adversely affect the function of lymphoid cells that mediate a totally unrelated inflammatory response, namely, AIA. The clinical implications of these findings are discussed.

Multiple epitopes on cartilage type II collagen are accessible for antibody binding in vivo

Monoclonal mouse antibodies specific for the major epitopes on mouse type II collagen (CII) were biotinylated and injected into neonatal and adult mice. Anti-CII antibodies, specific for four different epitopes on the CII molecule, could be shown to bind specifically to joint surfaces in the paws of 2-day-old syngeneic DBA/1 mice after an intraperitoneal injection of 100 micrograms of biotinylated antibody. The anti-CII antibodies did not bind to cartilage from DBA/1 mice in vitro, unless the sections were pretreated with hyaluronidase or the specimens decalcified prior to freezing, showing that the epitopes are accessible in vivo but not in vitro. By analyzing the in vivo binding capacity for a number of monoclonal anti-CII antibodies which represented different IgG subclasses, it could be demonstrated that binding to the same epitopes occurred independent of IgG subclass. However, one epitope (denoted "B1") was only weakly detected, possibly due to the fact that the antibody used (CIIB1) crossreacts with type I collagen and C1q. Monoclonal anti-CII antibodies, injected into neonates or adult mice, bound specifically to most, but not all, tissues containing CII; including hyaline joint cartilage, fibrous sternal and costal cartilage, tracheal cartilage and fibrous cartilage in the spine but not to CII-containing structures in the eye. The finding that CII, while present in cartilage, is accessible for antibody binding in vivo may have important implications for the availability of CII for the immune system and for the understanding of the development of pathological autoimmunity leading to collagen-induced arthritis in mice.

Characterization of collagen-specific T cells derived from pathogenic and nonpathogenic rat T cell lines

Rat/mouse T-T hybridomas have been developed from an arthritogenic and a nonarthritogenic T cell line. These hybridomas express alpha beta TCR and are CD4+, CD8-, and MRC OX-22-. They have type II collagen reactivity as assessed by an IL-2 release assay. Southern blot analysis of DNA extracted from these hybridomas demonstrates that each T cell line contains at least three different collagen-reactive clones. The data suggest that the spectrum of TCR beta gene rearrangements is limited, as one hybridoma from the nonpathogenic line shares an identically sized productive TCR beta gene rearrangement with two hybridomas from the pathogenic line. Both cell lines as well as one hybridoma from the pathogenic line are autoreactive to rat type II collagen. The anti-collagen responses of all the hybridomas are restricted to the rat class II MHC RT1.B gene loci. The hybridomas, like their parental cell lines, do not respond preferentially to either native or denatured type II collagen. These hybridomas recognize a specific type II collagen epitope and not repetitive collagen-like sequence motifs. They require antigen processing to respond to both native and denatured type II collagen.

Studies on the homing of Mycobacterium-sensitized T lymphocytes to the synovium during passive adjuvant arthritis

The migration of intravenously administered adjuvant sensitized T lymphocytes to the knee synovium of recipient rats undergoing passive adjuvant arthritis has been followed. Using fluorescein isothiocyanate (FITC)-labeled adjuvant-sensitized T cells and anticollagen IgG, the present studies demonstrate the presence of fluorescent cells in the inflamed knee synovium of recipient rats undergoing passive arthritis. Proliferation studies indicate that synovial cells from these rats respond to Mycobacterium tuberculosis (MT). Since cross-reactivity between Mycobacterial antigens and cartilage proteoglycans has been previously demonstrated, it is suggested that adjuvant-sensitized T cells that are injected into naive rats migrate to the synovium, proliferate in response to cartilage proteoglycan, and initiate passive arthritis.

Specificity of antibodies to type II collagen in rheumatoid arthritis

To reassess the role of autoantibodies to type II collagen in the pathogenesis of diseases, we studied antibodies from patients with rheumatoid arthritis (RA) and from patients with relapsing polychondritis for species specificity and collagen type specificity, using an improved enzyme-linked immunosorbent assay. Antibodies were found in the sera of 15% of the RA patients and 50% of the relapsing polychondritis patients, as well as in the cartilage of 69% of the RA patients examined. Reaction with both homologous and heterologous type II collagens was common. Analysis of 19 selected RA sera revealed that autoantibodies were generally associated with specific antibodies to some species of heterologous type II collagen. In contrast, antibodies found in 4% of the non-RA controls were specific for either bovine or chick type II collagen. These findings indicate that autoantibody formation in RA and relapsing polychondritis may occur as a result of an immune response to heterologous type II collagen. However, since RA and relapsing polychondritis patient sera differed in their reactivity with the cyanogen bromide-digested peptides, it is possible that the clinical manifestation of collagen autoimmunity might be influenced by the epitope specificity of the antibodies.

Cartilage proteoglycan-induced arthritis in BALB/c mice. Antibodies that recognize human and mouse cartilage proteoglycan and can cause depletion of cartilage proteoglycan with little or no synovitis

Human fetal cartilage proteoglycan (PG) induces the development of an erosive polyarthritis and spondylitis in BALB/c mice. We have examined the properties of 3 monoclonal antibodies (MAb) to human fetal cartilage PG isolated from immunized mice that cross-react with mouse cartilage PG. Compared with sera from arthritic mice, which contain antibodies reactive with keratan sulfate, MAb 202 (IgG1) reacted only with a protein-related epitope that is distributed on both hyaluronic acid-binding and chondroitin sulfate-attachment regions. MAb 813 (IgG1) reacted with the same fragments and recognized an epitope with the immunologic characteristics of keratan sulfate. MAb 945 (IgM) remains to be further characterized. Introduction of hybridomas secreting MAb 202 and MAb 945 into irradiated mice resulted in the loss of PG from articular cartilage and from growth plate cartilage (with MAb 202 only), as revealed by a loss of staining with toluidine blue. There was no synovial hyperplasia with MAb 202, but some hyperplasia and mononuclear cell infiltration was seen with MAb 945. This was accompanied by the binding of immunoglobulins to articular cartilage, as demonstrated by immunofluorescence. The hybridoma secreting MAb 813 produced no cartilage changes or synovitis, and there was no immunoglobulin binding to cartilage. Polymorphonuclear leukocyte infiltration was never observed with these antibodies. These studies indicate that MAb reactive with mouse cartilage PG can cause the depletion of PG from hyaline cartilage by mechanisms that may be both complement dependent and complement independent. Antibodies may serve to release and expose PG antigen to immune cells, as well as causing a loss of the mechanical properties of cartilage that are PG dependent.

Homologous type II collagen-induced arthritis in rats. Characterization of the disease and demonstration of clinically distinct forms of arthritis in two strains of rats after immunization with the same collagen preparation

Arthritis was induced in Lewis and DA rat strains after immunization with native homologous type II collagen (CII). Differences were noted in the clinical signs of arthritis in the 2 rat strains, which were immunized with the same arthritogenic preparation of CII. DA rats showed disease onset characterized by symmetric involvement of the interphalangeal joints of the hind feet. Lewis rats showed disease onset characterized by involvement of only the ankle or knee joints. Moreover, the arthritis tended to be chronic (i.e., persistent and variable redness and swelling seen in interphalangeal joints) in DA rats, but not in Lewis rats. Analysis of the delayed-type hypersensitivity reaction to CII and anti-CII autoantibody production demonstrated the presence of T cell, as well as B cell, reactivity to rat CII in both strains of rat. A spontaneous T cell reactivity to CII, as measured by rat CII-induced ear swelling, was observed in nonimmunized DA rats, but not in nonimmunized Lewis rats. The demonstration that clinical features of arthritis induced with identical arthritogenic stimuli are different depending on the genetic background of the affected animal may be relevant in understanding the heterogeneity of the clinical features of human inflammatory joint disease.

Methylacetylenic putrescine (MAP), an inhibitor of polyamine biosynthesis, prevents the development of collagen-induced arthritis

The objective of the present investigation was to examine the effects of an irreversible inhibitor of ornithine decarboxylase (2R,5R)-6-heptyne-2,5,diamine (methylacetylenic putrescine, MAP) on experimentally induced arthritis in mice. MAP (0.5-0.05%) was administered in drinking water to DBA/1 mice immunized with native chick type II collagen (CII). The development of arthritis was inhibited only in those mice receiving 0.5% MAP; lower doses were ineffective. Putrescine and spermidine levels were decreased and spermine levels were increased in spleen and lymph node cells from drug-treated mice compared to control arthritic mice. Furthermore, when control mice were developing arthritis, serum anti-CII antibody levels were lower in the MAP-treated group. MAP inhibited antibody production early in the immune response to CII; there was an association between inhibition of antibody production and inhibition of the development of arthritis. When MAP was discontinued, the nonarthritic, drug-treated mice did not develop the disease. Late administration of MAP (beginning 19 days after CII immunization) did not affect the incidence or the severity of the arthritis. Cyclophosphamide treatment begun at the same time significantly inhibited the development of the disease. In vitro T cell responses to denatured type II collagen (dCII) in untreated and MAP-treated mice were examined 14 days after immunization with CII. This is a time of peak T cell responsiveness in untreated animals. MAP treatment had no effect on the T cell response to dCII. These results indicate that MAP can prevent the development of CII-induced arthritis, possibly by inhibiting the autoantibody response. Therefore, inhibitors of polyamine biosynthesis deserve further investigation as potential immunosuppressive agents.

Arthritis in DBA/1 mice induced with passively transferred type II collagen immune serum. Immunohistopathology and serum levels of anti-type II collagen auto-antibodies

Arthritis was induced in DBA/1 mice by passive transfer of syngeneic anti-type II collagen (CII) serum concentrate. After transfer of serum containing 0.2 or 0.5 mg anti-CII auto-antibodies the first clinical signs of arthritis appeared 48 h after injection. Severe clinical arthritis was detected 96 h after injection. Immunohistochemical analyses of joints 48 h after serum injection revealed synovial foci in intercarpal and metacarpophalangeal joints of macrophage-like cells, expressing C3bi-receptors and major histocompatibility complex class II molecules, and infiltration of few CD4+ lymphocytes. Later (96 h after injection), the inflamed synovia were dominated by C3bi-receptor+ polymorphonuclear cells. In contrast to conventionally induced collagen arthritis (CIA), the inflammatory infiltrates, filling joint spaces and synovial tissue, were extensively dominated by polymorphonuclear cells, whereas macrophage-like cells expressing class II molecules and a few T cells were seen only in the periphery of the developing pannus. The anti-CII serum induced arthritis may be used as a model for studies of humoral mediated mechanisms operating in conventionally induced CIA as well as in rheumatoid arthritis.

Immune deposits in articular cartilage of patients with rheumatoid arthritis have a granular pattern not seen in osteoarthritis

Frozen sections of articular cartilage, obtained from patients with rheumatoid arthritis (RA) or osteoarthritis (OA) undergoing joint replacement, were stained with fluoresceinated specific antisera to IgG, IgM, IgA, C1q, C4, and C3. Specimens positive for IgG were examined for IgG subclasses using mouse monoclonal antibodies. IgG was present in 22 of 34 cartilage specimens obtained from patients with RA, and in 14 of these 22 patients, a granular pattern was present. IgM, IgA, C1q, and C3 when present showed a similar granular pattern. In articular cartilage of patients with RA, all IgG subclasses tended to be present. The remaining eight specimens positive for IgG from patients with RA had staining patterns also seen in patients with OA. IgG staining was present in 31 of 117 cartilage specimens obtained from patients with OA and none had the granular pattern seen in RA. Intermittent linear staining at the surface was the most common pattern seen in cartilage from patients with OA. The different patterns of immune deposits in articular cartilage in RA and OA suggest that antibodies with different specificities are present or that different mechanisms of immune deposit formation exist in these disorders.

Collagen induced arthritis as an experimental model for rheumatoid arthritis. Immunogenetics, pathogenesis and autoimmunity

The type II collagen (CII) induced arthritis animal model (CIA) provides opportunities to study the nature of autoimmune reactions leading to arthritis and may be used as a model for rheumatoid arthritis (RA). Thus, in similarity with RA, the CIA model, when induced with autologous CII, shows a chronic and progressive disease course. The susceptibility to both RA and CIA are correlated to the expression of certain MHC class II allotype genes. In both diseases are autoantibodies to CII and rheumatoid factors produced. Immunohistopathology of affected joints show in both diseases a dominance of activated macrophages/fibroblasts with a significant infiltration of activated T cells and an infiltration of granulocytes. We do here suggest that both RA and CIA are dependent on a synergy between delayed type hypersensitivity and immune complex mediated inflammatory mechanisms and that CIA provides opportunities for studies of immunospecific reactions leading to arthritis.

Sex-linked differences in susceptibility of cynomolgus monkeys to type II collagen-induced arthritis. Evidence that epitope-specific immune suppression is involved in the regulation of type II collagen autoantibody formation

To determine whether sex-linked factors are important in the susceptibility and resistance of cynomolgus monkeys to type II collagen-induced arthritis, we immunized 5 males and 10 females with chick type II collagen (CII) and studied their clinical and immune responses. All 10 females developed overt arthritis and produced antibodies to CII and cross-reactive antibodies to monkey type II collagen (MkII). In contrast, only 1 male monkey developed arthritis, which was transient and mild in severity. Examination of antisera obtained from the male monkeys disclosed high titers of antibody to CII, but little antibody to MkII. The cyanogen bromide peptide recognition patterns varied markedly from animal to animal, implying that monkeys are capable of recognizing multiple arthritogenic determinants on CII.

Induction of erosive arthritis in mice after passive transfer of anti-type II collagen antibodies

The passive transfer of concentrated immunoglobulins or affinity-purified anti-collagen antibodies from sera of mice with type II collagen-induced arthritis can induce erosive arthritis in recipient animals. In both cases, the incidence of arthritis was over 60% and the inflammation persisted for at least two weeks. Radiography revealed bone destruction and apposition of a newly formed material while histologic examination showed cartilage and bone degradation, accompanied with synovitis and periarthritis. Inflammatory infiltrates were composed of polymorphonuclear leucocytes and lymphocytes, and were associated with a proliferation of connective tissue cells.

Collagen arthritis in rats: the importance of humoral immunity in the initiation of the disease and perpetuation of the disease by suppressor T cells

Arthritis could be passively transferred with a serum concentrate from collagen arthritic rats to nude rats and cyclosporin-treated, type II collagen-tolerant rats. These findings suggest that collagen arthritis could be inducible by humoral immunity alone in the absence of cellular immunity to type II collagen or functional T cells. In addition, passive arthritis induced by anticollagen antibody is a mild, transient disease from which the animals normally recover and the rats that have recovered from passive arthritis are resistant to develop a second phase of arthritis following a second administration of anticollagen antibody or the subsequent challenge with type II collagen. However, when a serum concentrate was transferred while cyclosporin was administered continuously, transferred arthritis in cyclosporin-treated, type II collagen-tolerant rats lasted as long as cyclosporin treatment and arthritis was significantly enhanced compared to those of naive recipients. Further, enhancement and prolongation of passively transferred arthritis in nude rats was observed. Furthermore, treatment with cyclophosphamide reversed acquired resistance to collagen arthritis subsequent to recovery from passive arthritis. These findings suggest that suppressor T cells might, at least in part, affect the clinical course of collagen arthritis and reverse acquired resistance to arthritis.

Passive collagen arthritis induced by anticollagen IgG

Studies conducted in rats and mice indicate that passive arthritis can be transferred to naive recipients with anticollagen IgG. The passively transferred disease is less severe and is transient. Rats that recover from passive arthritis are resistant to a second phase of clinical disease when administered either anticollagen IgG or type II collagen. Suppressor T cells appear to be responsible for this resistance. Passive arthritis induced by anticollagen IgG is a complement dependent lesion. Deposition of IgG on the cartilage and host complement C3 and C5 activation are essential for the induction of passive disease. Inflammatory cells are necessary for the demonstration of passive arthritis; mice deficient in inflammatory cells or defective in this cell population are resistant to passive arthritis. Monoclonal antibodies reactive to type II collagen or to a renatured TCA fragment can also induce passive arthritis. The disease is subclinical and can be detected only after histological analysis of the joints.