A Novel HLA-DRB1*10:01-Restricted T Cell Epitope From Citrullinated Type II Collagen Relevant to Rheumatoid Arthritis

Arthritis Rheumatol. 2016 May;68(5):1124-35. doi: 10.1002/art.39553.


Objective: Antibodies against citrullinated type II collagen (Cit-CII) are common in the sera and synovial fluid of patients with rheumatoid arthritis (RA); however, the known T cell epitope of CII is not dependent on citrullination. The aim of this study was to identify and functionally characterize the Cit-CII-restricted T cell epitopes that are relevant to RA.

Methods: Peripheral blood mononuclear cells (PBMCs) from HLA-DRB1*10:01-positive patients with RA and healthy donors were stimulated in vitro with candidate CII peptides. CD154 up-regulation was measured as a marker of antigen-specific activation, and anti-HLA-DR-blocking experiments confirmed HLA restriction. Cytokine production was measured using a Luminex technique. Direct peptide-binding assays using HLA-DRB1*10:01 and HLA-DRB1*04:01 monomeric proteins were performed. The T cell receptor (TCR) β-chain of CD154-enriched antigen-specific T cells was analyzed using high-throughput sequencing.

Results: A novel Cit-CII peptide was identified based on its ability to activate CD4+ T cells from HLA-DRB1*10:01-positive individuals. When stimulated in vitro, Cit-CII autoreactive T cells produced proinflammatory cytokines. Cit-CII(311-325) bound (with low affinity) to HLA-DRB1*10:01 but not to HLA-DRB1*04:01, while the native form was unable to bind either protein. In addition, highly expanded clones were identified in the TCRβ repertoire of Cit-CII(311-325) -stimulated PBMCs.

Conclusion: These results illustrate the ability of the citrullination process to create T cell epitopes from CII, a cartilage-restricted protein that is relevant to RA pathogenesis. The exclusive binding of Cit-CII(311-325) to HLA-DRB1*10:01 suggests that recognition of citrullinated epitopes might vary between individuals carrying different RA-associated HLA-DR molecules.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Arthritis, Rheumatoid / immunology*
  • Case-Control Studies
  • Citrulline / immunology*
  • Citrulline / metabolism
  • Collagen Type II / immunology*
  • Collagen Type II / metabolism
  • Cytokines / immunology
  • Epitopes, T-Lymphocyte / immunology*
  • Female
  • HLA-DRB1 Chains / immunology*
  • High-Throughput Nucleotide Sequencing
  • Humans
  • In Vitro Techniques
  • Leukocytes, Mononuclear / immunology
  • Male
  • Middle Aged
  • Receptors, Antigen, T-Cell, alpha-beta / genetics
  • Sequence Analysis, DNA


  • Collagen Type II
  • Cytokines
  • Epitopes, T-Lymphocyte
  • HLA-DRB1 Chains
  • HLA-DRB1*04:01 antigen
  • Receptors, Antigen, T-Cell, alpha-beta
  • Citrulline