Pro- and anti-inflammatory cytokine production by autoimmune T cells against preproinsulin in HLA-DRB1*04, DQ8 Type 1 diabetes

Diabetologia. 2004 Mar;47(3):439-450. doi: 10.1007/s00125-003-1315-1. Epub 2004 Jan 24.

Abstract

Aims/hypothesis: Preproinsulin is a target T cell autoantigen in human Type 1 diabetes. This study analyses the phenotype and epitope recognition of preproinsulin reactive T cells in subjects with a high genetic risk of diabetes [HLA-DRB1*04, DQ8 with Ab+ (autoantibody-positive) or without islet autoantibodies (control subjects)], and in HLA-matched diabetic patients.

Methods: A preproinsulin peptide library approach was used to screen for cytokine profiles and epitope specificities in human peripheral blood lymphocytes, and CD4(+)CD45RA(-) and CD4(+)CD45RA(+) T cell subfractions, representing memory and naive and recently primed T cells respectively.

Results: In CD4(+) T cell subsets we identified immunodominant epitopes and cytokine production patterns that differed profoundly between patients, Ab+ subjects and non-diabetic HLA-matched control subjects. In Ab+ subjects, a C-peptide epitope C13-29 and insulin B-chain epitope B11-27 were preferentially recognised, whereas insulin-treated Type 1 diabetic patients reacted to native insulin and B-chain epitope B1-16. In peripheral blood lymphocytes of Ab+ subjects, an increase in T helper (Th) 1 (IFNgamma, IL-2) and Th2 (IL-4) cytokines was detectable, wheras in CD45RA(+) and CD45RA(-) subsets, IL-4 and IL-10 phenotypes dominated, compatible with the contribution of non-CD4 cells to IFNgamma content. In insulin-treated Type 1 diabetic patients, naive and recently primed CD4(+) cells were characterised by increasd IFNgamma, TNFalpha, and IL-5.

Conclusions/interpretation: Our data show that T cell reactivity to preproinsulin in CD45RA subsets is Th2-dominant in Ab+ subjects, challenging the Th1 paradigm in Type 1 diabetes. Characteristic immunodominant epitopes and cytokine patterns distinguish diabetic patients and Ab+ subjects from HLA-matched healthy individuals. This could prove useful in monitoring of T-cell immunity in clinical diabetes intervention trials.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Autoantibodies / blood
  • Autoimmunity
  • CD4-Positive T-Lymphocytes / immunology*
  • Child
  • Cytokines / biosynthesis
  • Diabetes Mellitus, Type 1 / blood
  • Diabetes Mellitus, Type 1 / immunology*
  • HLA-DQ Antigens / blood*
  • HLA-DR Antigens / blood*
  • HLA-DRB1 Chains
  • Histocompatibility Testing
  • Humans
  • Insulin
  • Leukocyte Common Antigens / immunology
  • Proinsulin / immunology*
  • Protein Precursors / immunology*
  • Protein Tyrosine Phosphatase, Non-Receptor Type 1
  • Reference Values
  • T-Lymphocytes / immunology*

Substances

  • Autoantibodies
  • Cytokines
  • HLA-DQ Antigens
  • HLA-DQ8 antigen
  • HLA-DR Antigens
  • HLA-DRB1 Chains
  • Insulin
  • Protein Precursors
  • preproinsulin
  • Proinsulin
  • Leukocyte Common Antigens
  • Protein Tyrosine Phosphatase, Non-Receptor Type 1