Human monoclonal antibody with T-cell-like specificity recognizes MHC class I self-peptide presented by HLA-DR1 on activated cells

Tissue Antigens. 1998 Mar;51(3):258-69. doi: 10.1111/j.1399-0039.1998.tb03100.x.


Alloreactive T cells recognize peptides presented in the binding groove of major histocompatibility complex molecules (MHCs), whereas B cells mainly recognize the MHCs independent of bound peptides. Here, we demonstrate that the human B-cell repertoire comprises B cells which can be stimulated during pregnancy to produce antibodies reacting with MHCs in a way similar to T cells. The human monoclonal antibody UL-5A1 recognizes DR1(DRA/DRB1*0101) molecules on lymphoblastoid cell lines only if they co-express HLA-A2 or if they have been loaded with HLA-A2-derived peptides. The effect of the HLA-A2 peptide 105-117 on UL-5A1 reactivity was specific, time and dose-dependent. Reactivity increased when naturally processed peptides were removed from DR1 molecules before the HLA-A2 peptide 105-117 was loaded. UL-5A1 reacted specifically with cells that had been activated. The results imply a role of activation of cells in peptide processing and/or loading.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Antibodies, Monoclonal / immunology*
  • Antibody Specificity / immunology*
  • Antigen Presentation / immunology*
  • Cell Line, Transformed
  • Complement System Proteins / immunology
  • Epitopes, T-Lymphocyte
  • Female
  • HLA-A2 Antigen / immunology
  • HLA-DR Antigens / immunology
  • HLA-DR1 Antigen / immunology*
  • HLA-DRB1 Chains
  • Histocompatibility Antigens Class I / immunology*
  • Histocompatibility Antigens Class II / immunology
  • Humans
  • Leukocytes, Mononuclear / immunology
  • Lymphocyte Activation
  • Male
  • Molecular Sequence Data
  • Peptides
  • Precipitin Tests
  • Pregnancy
  • T-Lymphocyte Subsets / immunology
  • T-Lymphocytes / immunology*


  • Antibodies, Monoclonal
  • Epitopes, T-Lymphocyte
  • HLA-A2 Antigen
  • HLA-DR Antigens
  • HLA-DR1 Antigen
  • HLA-DRB1 Chains
  • Histocompatibility Antigens Class I
  • Histocompatibility Antigens Class II
  • Peptides
  • Complement System Proteins