The role of the T cell costimulator B7-1 in autoimmunity and the induction and maintenance of tolerance to peripheral antigen

Immunity. 1994 May;1(2):155-66. doi: 10.1016/1074-7613(94)90109-0.


T cell tolerance to peripheral antigens is believed to result mainly from the inability of parenchymal cells to present antigens in an immunogenic form due to the lack of expression of T cell costimulator. We found, however, that transgenic expression of the T cell costimulator B7-1 on the islets of Langerhans is not sufficient to abolish the in vivo tolerance to islets antigen. Here, we present evidence indicating that the level of major histocompatibility complex (MHC) antigen expressed by islet cells plays a critical role. Mice coexpressing the B7-1 transgene and high levels of the class II MHC antigen I-E on the islets develop an autoimmune destruction of the beta cells of the pancreas. By contrast, expression of the I-E molecule by islets, in the absence of T cell costimulator, leads to specific tolerance of these autoreactive T cells that cannot be reversed by costimulation with B7-1.

Publication types

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

MeSH terms

  • Animals
  • Antigens
  • Autoimmunity*
  • B7-1 Antigen / genetics
  • B7-1 Antigen / immunology*
  • Base Sequence
  • DNA Primers / genetics
  • Glucagon / metabolism
  • Histocompatibility Antigens Class II
  • Humans
  • Immune Tolerance*
  • Insulin / metabolism
  • Islets of Langerhans / immunology
  • Islets of Langerhans / metabolism
  • Islets of Langerhans / pathology
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Molecular Sequence Data
  • T-Lymphocytes / immunology*


  • Antigens
  • B7-1 Antigen
  • DNA Primers
  • Histocompatibility Antigens Class II
  • Insulin
  • Glucagon