Establishment of T cell lines to bovine beta-casein and beta-casein-derived epitopes in patients with type 1 diabetes

J Endocrinol. 2003 Jan;176(1):143-50. doi: 10.1677/joe.0.1760143.

Abstract

Enhanced cellular immune response to bovine beta-casein has been reported in patients with type 1 diabetes. In this study we aimed to establish beta-casein-specific T cell lines from newly diagnosed type 1 diabetic patients and to characterise these cell lines in terms of phenotype and epitope specificity. Furthermore, since sequence homologies exist between beta-casein and putative beta-cell autoantigens, reactivity to the latter was also investigated. T cell lines were generated from the peripheral blood of nine recent onset type 1 diabetic patients with different HLA-DQ and -DR genotypes, after stimulation with antigen pulsed autologous irradiated antigen presenting cells (APCs) and recombinant human interleukin-2 (rhIL-2). T cell line reactivity was evaluated in response to bovine beta-casein, to 18 overlapping peptides encompassing the whole sequence of beta-casein and to beta-cell antigens, including the human insulinoma cell line, CM, and a peptide from the beta-cell glucose transporter, GLUT-2. T cell lines specific to beta-casein could not be isolated from HLA-matched and -unmatched control subjects. beta-Casein T cell lines reacted to different sequences of the protein, however a higher frequency of T cell reactivity was observed towards the C-terminal portion (peptides B05-14, and B05-17 in 5/9 and 4/9 T cell lines respectively). Furthermore, we found that 1 out of 9 beta-casein-specific T cell lines reacted also to the homologous peptide from GLUT-2, and that 3 out of 4 of tested cell lines reacted also to extracts of the human insulinoma cell line, CM. We conclude that T cell lines specific to bovine beta-casein can be isolated from the peripheral blood of patients with type 1 diabetes; these cell lines react with multiple and different sequences of the protein particularly towards the C-terminal portion. In addition, reactivity of beta-casein T cell lines to human insulinoma extracts and GLUT-2 peptide was detected, suggesting that the potential cross-reactivity with beta-cell antigens deserves further investigation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Animals
  • Autoantigens / immunology
  • Case-Control Studies
  • Caseins / immunology*
  • Cattle
  • Cell Culture Techniques
  • Cell Line
  • Child
  • Cross Reactions
  • Diabetes Mellitus, Type 1 / immunology*
  • Epitopes / immunology*
  • Female
  • Genotype
  • Glucose Transporter Type 2
  • HLA-DQ Antigens
  • HLA-DQ beta-Chains
  • HLA-DR Antigens
  • HLA-DRB1 Chains
  • Histocompatibility Testing
  • Humans
  • Immunophenotyping
  • Insulinoma
  • Interferon-gamma / immunology
  • Interleukin-4 / immunology
  • Islets of Langerhans / immunology
  • Lymphocyte Activation
  • Male
  • Monosaccharide Transport Proteins / immunology
  • T-Lymphocytes / immunology*
  • Tumor Cells, Cultured

Substances

  • Autoantigens
  • Caseins
  • Epitopes
  • Glucose Transporter Type 2
  • HLA-DQ Antigens
  • HLA-DQ beta-Chains
  • HLA-DQB1 antigen
  • HLA-DR Antigens
  • HLA-DRB1 Chains
  • Monosaccharide Transport Proteins
  • Interleukin-4
  • Interferon-gamma