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

Collagen Specific T-Cell Repertoire and HLA-DR Alleles: Biomarkers of Active Refractory Rheumatoid Arthritis

Rheumatoid arthritis (RA) is characterized by chronic joint inflammation and associates with HLA-DRB1*04. The Collagen IIp_261-273-specific T cell repertoire in the peripheral blood of DR4 + patients at the onset of the disease shows a restricted TCR-beta chain usage among which the most frequent is TRBV25.

To define whether this group of DR4-restricted collagen-specific shared T cell could represent markers of active-severe disease and response to therapy, 90 subjects affected by early-RA were enrolled in the study; peripheral blood mononuclear cells were cultured with or without the human collagen II peptide p261-273 and were examined by immunoscope analysis for the usage of the previously identified shared TCR-beta chains.

We report that the presence of T cells carrying rearrangement TRBV25 associated with HLA-DR haplotype and disease activity. HLA-DRB1* haplotypes 04–04, 04–01 and 04–11 were significantly associated with usage of TRBV25, higher disease activity at the onset of disease and poor response to DMARDs.

Finally, the HLA-DRB1* haplotype appeared complementary with current serologic tools to predict good and poor responders in a treat to target strategy. The data reported here offer clues to predict the course of the disease and to foresee personalized treatments in RA patients.

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In DR4 + RA patients disease activity is associated with detection of Collagen_261-273-specific T cells carrying TRBV25.

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HLA-DR 04/04, 04/01 and 04/11 alleles were associated with TRBV25, DAS at the onset, and poor response to DMARDs.

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These findings could lead to tailor the treatment in the subgroup of patients with an active refractory disease.

In the era of costly medical care with monoclonal antibodies and new molecules, and of an increasing request of a personalized medicine, a relevant socio-economic problem in the management of Rheumatoid Arthritis patients is the possible identification of the subgroups of poor responders to treatment. Our study aimed to detect the refractory active patients using an HLA-DR test (available in most hospital centers) combined with a relatively new biomarker of active disease expressed on the cell surface of autoreactive T cells. These tests appear complementary tools to identify the best and the poor responders to a “treat to target strategy”.

Taming the TCR: antigen-specific immunotherapeutic agents for autoimmune diseases

Current treatments for autoimmune diseases are typically non-specific anti-inflammatory agents that affect not only the autoreactive cells but also the parts of the immune system that are required to maintain health. There is a need for the development of antigen-specific therapeutic agents that can effectively prevent the autoimmune attack while leaving the rest of the immune system functioning as normal. The simplest way to achieve this is using the autoantigen itself as a tolerizing agent; however, there is some risk involved with administering a potentially pathogenic antigen. In this review, we focus instead on the development and use of modified T cell receptor (TCR) ligands, in which the peptide ligand is modified to change the response by the T cell from a disease inducing to a protective response, and still retain the antigen-specificity necessary to target the autoreactive T cells. We review the use of modified TCR ligands as therapeutic agents in animal models of autoimmunity and in human autoimmune disease, and finally consider how they need to be improved in order to use them effectively in patients with autoimmune disease.

APL-2, an altered peptide ligand derived from heat-shock protein 60, induces interleukin-10 in peripheral blood mononuclear cell derived from juvenile idiopathic arthritis patients and downregulates the inflammatory response in collagen-induced arthritis model

Juvenile idiopathic arthritis (JIA) is a heterogeneous group of diseases characterized by autoimmune arthritis of unknown cause with onset before age of 16 years. Methotrexate provides clinical benefits in JIA. For children who do not respond to methotrexate, treatment with anti-tumor necrosis factor (TNF)-α is an option. However, some patients do not respond or are intolerant to anti-TNF therapy. Induction of peripheral tolerance has long been considered a promising approach to the treatment of chronic autoimmune diseases. We aimed to evaluate the potentialities of two altered peptide ligands (APLs) derived from human heat-shock protein 60, an autoantigen involved in the pathogenesis of autoimmune arthritis, in JIA patients. Interferon (IFN)-γ, TNF-α and interleukin (IL)-10 levels were determined in ex vivo assays using peripheral blood mononuclear cells (PBMC) from these patients. Wild-type peptide and one of these APLs increased IFN-γ and TNF-α levels. Unlike, the other APLs (called APL2) increased the IL-10 level without affecting IFN-γ and TNF-α levels. On the other hand, APL2 induces a marked activation of T cells since it transforms cell cycle phase's distribution of CD4+ T cells from these patients. In addition, we evaluated the therapeutic effect of APL2 in collagen-induced arthritis model. Therapy with APL2 reduced arthritis scores and histological lesions in mice. This effect was associated to a decrease in TNF-α and IL-17 levels. These results indicate a therapeutic potentiality of APL2 for JIA.

The pentapeptide PLNPK inhibits systemic lupus erythematosus-associated renal damage

OBJECTIVE

This study aimed to observe the therapeutic effect of pentapeptide PLNPK on systemic lupus erythematosus (SLE) in mice, and to study the inhibitory effect of PLNPK on activation of T cells in vivo.

METHODS

Murine SLE-like chronic graft-versus-host disease (cGVHD) was induced. After treatment with PLNPK (100, 200, 400 μg/kg per day) for 70 days, serum blood urea nitrogen, creatine, total cholesterol, triglyceride and albumin were tested, and serum levels of anti-dsDNA and anti-histone antibodies were detected by ELISA. The pathological damage and IgG deposition in the kidney were identified. Concanavalin A (ConA)-induced T lymphocyte proliferation in SLE mice was also tested.

RESULTS

PLNPK can reduce serum blood urea nitrogen, creatine, total cholesterol, triglyceride, and elevate serum albumin, and reduce levels of anti-dsDNA and anti-histone antibodies in the murine SLE model. Pathological damage and IgG deposition in the kidney were reduced in the PLNPK-treated group. PLNPK inhibited T lymphocyte infiltration in kidney tissues and ConA-induced T lymphocyte proliferation in SLE mice.

CONCLUSION

Our results demonstrate that PLNPK can suppress T cell function and reduce the production of autoantibodies, and may be a feasible and effective therapy in the SLE model.

CD167 acts as a novel costimulatory receptor in T-cell activation

Optimal T-cell activation requires both an antigen-specific and a costimulatory signal. CD167 is a tyrosine kinase receptor for native type I collagen, its physiologic functions include matrix homeostasis and cell growth, adhesion, branching, and migration, but the specific role of CD167 in T cells has not yet been characterized. In this study, we found that CD167 expression on T cells was up-regulated after activation. Cooperation of CD167 engagement with suboptimal TCR/CD3 signals induced T-cell proliferation, enhanced expression of activation markers such as CD25 and CD69, elevated intracellular calcium mobilization and tyrosine phosphorylation, and introduced a bias toward a TH1/Tc1 immune response. Cooperation of CD167 engagement also enhanced mixed lymphocyte responses to alloantigens. Moreover, CD167 rapidly localized to the aggregated lipid rafts upon T-cell activation, this provided a molecular base for the signaling machinery of CD167. Together these findings, we demonstrate for the first time that CD167 could serve as a novel costimulatory receptor for T-cell activation.

The good, the bad and the ugly: how altered peptide ligands modulate immunity

BACKGROUND

The basis of T cell immune responses is the specific recognition of an immunogenic peptide epitope by a T cell receptor. Peptide alterations of such T cell epitopes with single or few amino acid variations can have drastic effects on the outcome of this recognition. These altered peptide ligands can act as modulators of immune responses as they are capable of downregulating or upregulating responses.

OBJECTIVE/METHODS

We review how altered peptide ligands can have 'good' 'bad' and 'ugly' outcomes in treating diseases.

RESULTS/CONCLUSION

Altered peptide ligands have been used as immunotherapeutics in autoimmune (and allergic) diseases, infectious diseases and cancer. In the next five years we anticipate seeing a number of altered peptide ligands in clinical trials, progressing from contradictory classifications of good, bad or ugly, to the exciting outcome of 'useful'.

Mucosal administration of an altered CII263-272 peptide inhibits collagen-induced arthritis by suppression of Th1/Th17 cells and expansion of regulatory T cells

Rheumatoid arthritis (RA) is a systemic autoimmune disease mediated by T cells. Collagen type II (CII) is one of the autoantigens associated with RA. CII263-272 is a predominant CII antigenic peptide that can induce T-cell activation upon binding to MHC and interaction with the appropriate T-cell receptor (TCR). Altered CII263-272 peptides with substitution of specific amino acids could bind to RA-associated HLA-DR4/1 with no T cell stimulating effects and could inhibit T cell activation in RA. We performed this study to evaluate the effect of mucosal administration and to explore the mechanism of the inhibitory effect of altered CII263-272 peptide (267Q-->A, 270K-->A and 271G-->A) on collagen induced arthritis (CIA). CIA was induced in Lewis rats by immunization with bovine CII. Altered CII263-272 peptide was given intranasally beginning from arthritis onset. Wild CII263-272 peptide or PBS was administered as controls. Therapeutic effects were evaluated by arthritis scores, body weight change, and joint pathologic scores. The anti-CII antibody and its subtypes and the cytokines, IFN-gamma, IL-10, and IL-17 were measured with ELISA. Foxp3+CD4+CD25+ regulatory T cell induction was assessed by FACS analysis. Following treatment with the altered CII263-272 peptide, arthiritis scores were reduced and body weight was increased. The altered CII263-272 peptide could retard the histologic lesion of the joints. The titers of anti-CII antibodies IgG2a in altered CII263-272 peptide treated rats decreased markedly compared to PBS-treated rats. The serum levels of IFN-gamma in rats treated with altered peptide was lower than that of rats treated with wild CII263-272 peptide and PBS. No differences were observed in the levels of serum IL-10 among the three groups. The altered CII263-272 peptide could decrease serum level of IL-17 and increase peripheral Foxp3+CD4+CD25+ T cells at early stage of CIA. Mucosal administration of altered CII263-272 peptide could effectively inhibit the progression of CIA. Altered CII263-272 peptide could suppress Th17 cells and expand regulatory T cells in the early stage of the disease. The IgG2a subtype of anti-CII antibodies and IFN-gamma were reduced and in vivo Th1 responses were inhibited as a result of altered CII peptide treatment. Altered CII peptide is likely therapeutic in RA.

Novel therapies for rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic, systemic inflammatory disease that causes significant morbidity and mortality. The pathogenesis outlined to date in RA consists of a cascade of pro-inflammatory cytokines and chemokines leading to the recruitment of inflammatory cells and the self perpetuation of inflammation, ultimately leading to cartilage and bone destruction. The dramatic progress in understanding the molecular immunology in RA has led to a transition from conventional treatment with aggressive immune suppression to targeted biological-based therapies that control the inflammatory pathways associated with RA. This article reviews the current biological and small-molecule therapies approved for the treatment of RA and those in development, including antibodies, tolerising agents and vaccines.