APCs present A beta(k)-derived peptides that are autoantigenic to type B T cells

J Immunol. 2003 Apr 15;170(8):4155-60. doi: 10.4049/jimmunol.170.8.4155.

Abstract

Type B T cells recognize peptide provided exogenously but are ignorant of the same epitope derived from intracellular processing. In this study, we demonstrate the existence of type B T cells to an abundant autologous peptide derived from processing of the I-A(k) beta-chain. T cell hybridomas raised against this peptide fail to recognize syngeneic APC despite abundant presentation of the naturally processed epitope but react in a dose-dependent manner to exogenous peptide. Moreover, these hybridomas respond to Abeta(k) peptide extracted from the surface of I-A(k)-expressing APC. This peptide was isolated from B cell lines where it was found in high abundance; it was also present in lines lacking HLA-DM, but in considerably lower amounts. Therefore, type B T cells exist in the naive repertoire to abundant autologous peptides. We discuss the implications of these findings to the potential biological role of type B T cells in immune responses and autoimmune pathology.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antigen Presentation / immunology*
  • Antigen-Presenting Cells / immunology*
  • Antigen-Presenting Cells / metabolism
  • Autoantigens / administration & dosage
  • Autoantigens / biosynthesis
  • Autoantigens / immunology*
  • Autoantigens / metabolism
  • B-Lymphocyte Subsets / classification
  • B-Lymphocyte Subsets / immunology
  • B-Lymphocyte Subsets / metabolism
  • Cell Line
  • Cell Membrane / immunology
  • Cell Membrane / metabolism
  • Epitopes, T-Lymphocyte / immunology
  • Epitopes, T-Lymphocyte / metabolism
  • Histocompatibility Antigens Class II / administration & dosage
  • Histocompatibility Antigens Class II / biosynthesis
  • Histocompatibility Antigens Class II / immunology*
  • Histocompatibility Antigens Class II / metabolism
  • Hybridomas
  • Mice
  • Mice, Inbred C57BL
  • Molecular Sequence Data
  • Multigene Family / immunology
  • Peptide Fragments / administration & dosage
  • Peptide Fragments / biosynthesis
  • Peptide Fragments / immunology*
  • Peptide Fragments / metabolism
  • Protein Processing, Post-Translational / immunology
  • T-Lymphocyte Subsets / immunology*
  • T-Lymphocyte Subsets / metabolism

Substances

  • Autoantigens
  • Epitopes, T-Lymphocyte
  • Histocompatibility Antigens Class II
  • I-A(b) antigen, mouse
  • I-Ak antigen
  • Peptide Fragments