Pattern of humoral reactivity to type II collagen in rheumatoid arthritis

Humoral immunity directed against type II collagen (CII) is a common although not specific feature of rheumatoid arthritis (RA). We have shown that 10 to 15% of the sera either from RA patients (n = 88) or from healthy controls (n = 149) reacted with native human CII. Conversely, autoantibodies to the alpha-1 (II) chains were significantly more frequent in the RA group (26.1% versus 6.0%, P<0.001), suggestingthatdenaturedCII may bean autoantigenin RA. Thus, human CII was cleaved with cyanogen bromide (CB), and immunoblotting techniques were performed on 19 RA and 21 normal sera. Among the four major CB peptides, CB10 and CB11 were recognized by most of the sera tested without distinction between normal or RA sera. Inhibition experiments using an ELISA have shown that: (i) antibodies to the native CII molecule did not cross-react with those recognizing the CB peptides, and vice-versa; (ii) the binding of the sera to native CII was partially inhibited by pre-incubation with alpha-1 (II) chains, and vice-versa; (iii) pre-incubation of the sera with CB peptides partially blocked the binding to alpha-1 (II) chains, whereas pre-incubation of the sera with alpha-1 (II) chains totally inhibited the reactivity against CB peptides; and (iv) a substantial proportion of the epitopes recognized by anti-CII autoantibodies was neither species specific nor type specific. Taken together, these findings reveal the existence of several populations of anti-CII autoantibodies: some antibodies react exclusively with conformational determinants of the CII molecule, and others are directed towards linear structures of alpha-1 (II) chains.     

The expression of collagenase 3 (MMP-13) mRNA in the synovial tissue is associated with histopathologic type II synovitis in rheumatoid arthritis

The histopathologic analysis of the synovial tissue is important to distinguish rheumatoid arthritis (RA) from other forms of synovitis and to provide information about prognosis and therapeutic strategies at early stages of the disease. In this context, the present study was performed to investigate the correlation between immunohistopathological and morphological features of synovitis and the expression of collagenase 3 (MMP-13) known to contribute significantly to cartilage degradation in RA. In the histopathologic scoring system used in this study, type I synovitis is characterized by B lymphocyte infiltration and an intact lining, and is only mild destructive to cartilage and bone. Type II shows marked diffuse infiltrations of macrophages and T lymphocytes, an ulcerated lining, fibrin exudation, and invasive growth into cartilage and bone tissue. Investigating 36 patients with RA, 21 patients (58%) were positive for the expression of collagenase 3 mRNA in the synovial tissue. Among these patients, 19 showed a histopathologic type II synovitis and only 2 patients had undifferentiated synovitis. In contrast, synovial tissue samples from patients without collagenase 3 mRNA expression were characterized in 6 cases by type I, in 5 cases by type II and in 4 cases by undifferentiated synovitis. The analysis of the clinical data revealed that RA patients with a histopathologic type II synovitis and synovial tissue collagenase 3 mRNA expression had elevated levels of systemic markers of inflammation and received stronger therapies. The data suggest, that collagenase 3 expression and the histopathologic type II synovitis are associated with a severe and destructive course of RA.     

The expression of collagenase 3 (MMP-13) mRNA in the synovial tissue is associated with histopathologic type II synovitis in rheumatoid arthritis

The histopathologic analysis of the synovial tissue is important to distinguish rheumatoid arthritis (RA) from other forms of synovitis and to provide information about prognosis and therapeutic strategies at early stages of the disease. In this context, the present study was performed to investigate the correlation between immunohistopathological and morphological features of synovitis and the expression of collagenase 3 (MMP-13) known to contribute significantly to cartilage degradation in RA. In the histopathologic scoring system used in this study, type I synovitis is characterized by B lymphocyte infiltration and an intact lining, and is only mild destructive to cartilage and bone. Type II shows marked diffuse infiltrations of macrophages and T lymphocytes, an ulcerated lining, fibrin exudation, and invasive growth into cartilage and bone tissue. Investigating 36 patients with RA, 21 patients (58%) were positive for the expression of collagenase 3 mRNA in the synovial tissue. Among these patients, 19 showed a histopathologic type II synovitis and only 2 patients had undifferentiated synovitis. In contrast, synovial tissue samples from patients without collagenase 3 mRNA expression were characterized in 6 cases by type I, in 5 cases by type II and in 4 cases by undifferentiated synovitis. The analysis of the clinical data revealed that RA patients with a histopathologic type II synovitis and synovial tissue collagenase 3 mRNA expression had elevated levels of systemic markers of inflammation and received stronger therapies. The data suggest, that collagenase 3 expression and the histopathologic type II synovitis are associated with a severe and destructive course of RA.     

Anti-type II collagen antibodies in rheumatoid arthritis

Antibodies to native chick and bovine Type II collagen were measured by radio immunoassay, in 83 rheumatoid arthritis (RA) patients and 14 normal controls. Anti-chick Type II collagen and anti-bovine Type II collagen antibodies were found in 48% and 43% of RA patients, respectively. A strong correlation of antibodies to chick and antibodies to bovine collagen was described, suggesting cross-reactivity between different collagen species. There was an association between the presence of anti-native Type II collagen antibody and the expression of HLA-DR2. It is suggested that the production of anti-collagen antibody may be under genetic control in RA, but not associated with the major genetic marker of disease susceptibility, HLA-DR4.     

Type II collagen autoimmunity in a mouse model of human rheumatoid arthritis

Type II collagen (CII) is expressed exclusively in the joint articular. Although the relationship between anti-CII immunity and human rheumatoid arthritis (RA) has been studied for a long time, definitive conclusions have not been reached. CII, as an autoantigen, has been studied extensively in small animal models, such as mice, and the collagen-induced arthritis (CIA) model has increased our understanding of the pathogenesis of human RA. In the present report, we summarize the available information on anti-CII immunity and discuss recent updates regarding pathogenesis in the CIA model, including the role of Th17 cells.     

Humoral immune response to citrullinated collagen type II determinants in early rheumatoid arthritis

Collagen type II (CII) is a relevant joint-specific autoantigen in the pathogenesis of rheumatoid arthritis (RA). Whereas the reasons for the breakage of self tolerance to this major cartilage component are still enigmatic, T cell responses to glycosylated CII determinants in RA patients indicate that post-translational modifications play a role. Since the conversion of arginine into citrulline by peptidylarginine deiminases (PAD) in some non-joint-specific antigens such as filaggrin or fibrin has been shown to give rise to RA-specific humoral immune responses, we investigated whether PAD modification of cartilage-specific CII might affect its recognition by circulating autoantibodies in early RA. In vitro treatment with purified PAD led to arginine deimination of native CII or of synthetic CII peptides as evidenced by amino acid analysis. The citrullination resulted in modified recognition of the immunodominant CII epitope C1(III) (amino acid residues 359-369) by murine and human antibodies. In a cohort of early RA patients (n=286), IgG antibodies directed toward a synthetic citrullinated C1(III) peptide (citC1(III)-P) were detectable with a prevalence of 40.4%. The partial autoantibody cross-reactivity between citC1(III)-P and citrullinated peptides mimicking epitopes of the cytoskeletal autoantigen filaggrin suggests that autoimmunity to cartilage-specific modified self might be a critical intermediate bridging recognition of PAD-modified extra-articular autoantigens with the disruption of tolerance to native cartilage constituents.     

Rheumatoid arthritis is auto-immunoreaction to collagen II in cartilage happened in synovial tissue

Rheumatoid arthritis is complex and not clear on the mechanism of pathogenesis. On the basis of analysis of the symptom and pathology of rheumatoid arthritis patients, we raised a new hypothesis. The content of the hypothesis is as follows: (A) Collagen II or collagen II-Iike substance in human cartilage is the cross-autoantigen of some infecting virus or bacteria because of the structure's similarity. (B) The inflammation in synovial tissue is auto-immunoreaction to collagen II in cartilage. (C) The proliferation and attachment of synovial tissue to the surface of cartilage is due to the chemotaxis of collagen II in cartilage for the immunocytes in synovial tissue. (D) The collagenase secreted from synovial cells and immunocytes are the direct elements in the destruction of cartilage. The fallen collagen II from cartilage is one of the most important inducer on the synovial cells and immunocytes for the production of collagenase.     

Altered collagen II peptides inhibited T-cell activation in rheumatoid arthritis

It has been reported that collagen II (CII)-derived peptide induced T-cell activation via its amino acids responsible for T-cell receptor (TCR) recognition. In this study, three altered CII263-272 peptide ligands (APL) containing multiple substitutions of TCR contact residues were synthesized. Their roles in inhibition of T-cell activation were evaluated in peripheral blood lymphocytes (PBL) of rheumatoid arthritis (RA) in vitro. It was shown that 41% (25/61) of RA patients were responsive to the wild-type antigenic CII263-272. In contrast, marginal or silent T-cell responses to the three APLs were found, accompanied by inhibitory effects on secretion of Th1 type cytokines and expression of cell surface markers, CD69 and CD25. In addition, T-cell activation induced by the wild-type antigenic CII263-272 was inhibited by all the three APLs in a dose-dependent manner. It is demonstrated that APLs with substitutions of TCR contact residues are capable of down-regulating T-cell responses in PBLs of RA, suggesting that the CII-derived APLs are potentially therapeutic in RA.     

类风湿关节炎模型大鼠滑膜组织中证实有髓样细胞诱发受体2的表达

背景：髓样细胞诱发受体2在类风湿关节炎活动期患者滑膜组织呈高表达,但其在类风湿关节炎发病机制中发挥的作用,目前并不清楚。 目的：观察髓样细胞诱发受体2在牛源性Ⅱ型胶原诱导的关节炎大鼠模型滑膜组织中的表达。 方法：制备胶原诱导关节炎模型大鼠,动态观察大鼠各项关节炎的活动指标和滑膜组织的病理学改变,RT-PCR法检测滑膜组织中髓样细胞诱发受体2、肿瘤坏死因子α、白细胞介素1β、白细胞介素10 mRNA的表达,Western blot及免疫组织化学法分别检测关节滑膜组织中髓样细胞诱发受体2的蛋白表达及定位。 结果与结论：模型组大鼠免疫13 d后出现足爪红肿,关节炎指数评分逐渐升高(P < 0.01),炎症高峰期在19-25 d,苏木精-伊红染色可见诱导性关节炎大鼠滑膜组织增生及炎性细胞浸润、软骨骨质破坏。与对照组相比,模型组大鼠关节滑膜髓样细胞诱发受体2的mRNA和蛋白的表达、肿瘤坏死因子α、白细胞介素1β mRNA表达均明显升高(P < 0.05或P < 0.01),白细胞介素10 mRNA表达显著降低(P < 0.05)。结果证实,髓样细胞诱发受体2可能是类风湿关节炎模型大鼠发病过程中一个重要的炎症调节递质,其反应性升高在类风湿关节炎模型大鼠发病中发挥着重要作用。 中国组织工程研究杂志出版内容重点：肾移植;肝移植;移植;心脏移植;组织移植;皮肤移植;皮瓣移植;血管移植;器官移植;组织工程全文链接：     

Studies on type II collagen induced arthritis in mice

A consistent and reproducible polyarthritis was induced in mice by immunizing them with type II collagen in Complete Freunds adjuvant (CFA) and Bacillus Calmette-Guerin (BCG) vaccine. Several inbred strains of mice were investigated for the ability to develop collagen induced arthritis (CIA). DBA/1 mice (H-2q) produced the highest incidence and the most severe arthritis of all the strains examined. Viable BCG vaccine was essential for the induction of a reproducible disease in this strain. The effects of some anti-inflammatory and anti-rheumatic compounds were examined on the developing and established lesions of CIA. These effects were determined by assessing the paw inflammation using a subjective scoring system and measuring foot weight. Furthermore, levels of serum amyloid P component (SAP) were also determined.Benoxaprofen, cyclophosphamide, indomethacin and prednisolone inhibited the paw inflammation in the developing disease whilst the anti-rheumatic compounds auranofin and D-penicillamine exacerbated the paw inflammation. Cyclophosphamide and prednisolone inhibited the established lesions but only prednisolone prevented the development of further lesions in the established disease. The SAP levels in the prednisolone treated group were also reduced. Auranofin treatment exacerbated the inflammation of both the established and the developing lesions in the same animal. D-penicillamine was inactive in the established disease.     

Immunogenetics of type II collagen autoimmunity and susceptibility to collagen arthritis.

The MHC restriction of the antibody response and development of arthritis after immunization with autologous or heterologous type II collagens in mice have been investigated. Mice from three different H-2q-carrying strains (DBA/1, NFR/N and B10.G) with different non-MHC genes, as well as B10-congenic strains carrying wild type H-2q-related or H-2r haplotypes, were susceptible for collagen arthritis. All strains tested developed an antibody response cross-reacting with autologous type II collagen after immunization with heterologous type II collagen; H-2q predisposes for a high response against chick, rat and bovine type II collagen, H-2r and H-2b for a high response against bovine type II collagen. Only mouse strains with H-2q, H-2r, H-2w3 or H-2w17 were responders to mouse type II collagen, and only these strains developed arthritis after immunization with heterologous or autologous type II collagens. These findings indicate that the ability to mount an immune response against autologous type II collagen is a prerequisite for the susceptibility to collagen arthritis. A cross-reactive autoimmune response after immunization with various heterologous type II collagen may enhance further the development of arthritis.     

TGF-beta type I receptor kinase inhibitor down-regulates rheumatoid synoviocytes and prevents the arthritis induced by type II collagen antibody

Rheumatoid arthritis (RA) is characterized by hypertrophic synovial tissues comprising excessively proliferating synovial fibroblasts and infiltrating inflammatory cells. Transforming growth factor-beta (TGF-beta) is a multifunctional cytokine that regulates cell growth, inflammation and angiogenesis by acting on various cell types. In RA synovial tissues, TGF-beta is expressed at high levels. However, the precise role of TGF-beta in RA remains unclear. We herein demonstrated a causal link between the TGF-beta-induced RA synovial cell proliferation and induction of platelet-derived growth factor (PDGF)-AA. In addition, TGF-beta induced IL-6 and vascular endothelial growth factor (VEGF) production by RA synovial fibroblasts associated with nuclear factor-kappa B activation. These effects of TGF-beta on RA synovial fibroblasts were suppressed by TGF-beta type I receptor kinase inhibitor HTS466284. Furthermore, HTS466284 significantly prevented anti-collagen type II antibody-induced arthritis in mice according to the clinical manifestations, histology, tumor necrosis factor-alpha, PDGF and VEGF expression and 5-bromo-2'-deoxyuridine incorporation. These in vitro and in vivo results suggest that TGF-beta plays a role in the development of synovial hyperplasia consisting of synovial cell proliferation, inflammation and angiogenesis. The blockade of TGF-beta signaling may thus become an additional strategy for the treatment of RA.     

Role of human fetal tissue transplantations in rheumatoid arthritis

Cell-mediated immunity is studied in 15 patients with rheumatoid arthritis. Fetal therapy increases the absolute count of actively phagocytizing neutrophils, stimulates their functional activity, and increases the percentage of mature neutrophils.     

Granulocyte‐augmented chemokine production induced by type II collagen containing immune complexes is mediated via TLR4 in rheumatoid arthritis patients

Rheumatoid arthritis (RA) patients with early elevations of antibodies against collagen type II (CII) have a distinct acute onset phenotype, associated with cytokine induction by surface‐bound anti‐CII‐containing immune complexes (ICs) and high C‐reactive protein (CRP) and erythrocyte sedimentation rate (ESR). Polymorphonuclear granulocytes (PMNs) and peripheral blood mononuclear cells (PBMCs) are abundant in the vicinity of CII in RA joints, and both PMN and PBMC reactivity against anti‐CII IC individually relate to early joint destruction and early elevation of CRP and ESR in RA. We searched for CII‐dependent mechanisms that might attract PMNs and PBMCs to RA joints. Human PBMCs and PMNs were stimulated with anti‐CII ICs and control ICs, either individually or in cocultures. Cocultured PMNs and PBMCs stimulated with anti‐CII ICs synergistically augmented production of the chemokines CXCL8, RANTES and MCP‐1, whereas downregulation was seen with control IC. This upregulation was unique to chemokines, as TNF‐α, IL‐1β, and GM‐CSF were downregulated in anti‐CII IC‐stimulated cocultures. The coculture‐associated chemokine upregulation depended on endogenous TLR4 ligand(s) and functionally active PMN enzymes, and was partially mediated by GM‐CSF. As anti‐CII levels peak around the time of RA diagnosis, this mechanism can attract inflammatory cells to joints in early RA and intensify the anti‐CII‐associated acute onset RA phenotype.     

PD-L2 is expressed on activated human T cells and regulates their function

T-cell activation and proliferation are regulated by cosignaling adhesion molecules involved in positive or negative signals. Programmed death (PD)-1 is one of immune inhibitory molecules that is expressed in activated T cells and is a promising target for immunotherapy. Both PD-1 ligands, PD-L1 and PD-L2 are expressed on antigen presenting cells (APCs) involved in the dialogue between a T cell and an APC. Here, we analysed the expression of these ligands, especially for PD-L2, on T cells. PD-L2 appears to be expressed on activated CD4 and CD8T cell subsets. Moreover, as PD-1 molecule, PD-L2 engagement at the surface of T cells is able to down-modulate cytokine production and cell proliferation. These observations indicate that PD-L2 is expressed following activation and is involved in the regulation of T cell function, highlighting the level of complexity in the T cell cosignaling network.     

PD-L2 is expressed on activated human T cells and regulates their function

T-cell activation and proliferation are regulated by cosignaling adhesion molecules involved in positive or negative signals. Programmed death (PD)-1 is one of immune inhibitory molecules that is expressed in activated T cells and is a promising target for immunotherapy. Both PD-1 ligands, PD-L1 and PD-L2 are expressed on antigen presenting cells (APCs) involved in the dialogue between a T cell and an APC. Here, we analysed the expression of these ligands, especially for PD-L2, on T cells. PD-L2 appears to be expressed on activated CD4 and CD8T cell subsets. Moreover, as PD-1 molecule, PD-L2 engagement at the surface of T cells is able to down-modulate cytokine production and cell proliferation. These observations indicate that PD-L2 is expressed following activation and is involved in the regulation of T cell function, highlighting the level of complexity in the T cell cosignaling network.     

Antibodies to type I and II collagen in rheumatoid arthritis and chronic cicatricial stenosis of the larynx and trachea in children

Enzyme immunoassay with highly purified human collagen preparations and low (1:10) dilutions of sera detected an increased specific immune reaction mostly on collagen denaturated forms in 50% of 49 patients with rheumatoid arthritis. No correlation was detected between the level of humoral immune response and the major clinical parameters except those reflecting the disease progress. Similar investigation of sera from children with chronic cicatricial stenoses has revealed a group of patients with significantly elevated level of anticollagen humoral immune response, though in these patients this response is probably not specifically associated with collagen.