Repression of B7.2 on self-reactive B cells is essential to prevent proliferation and allow Fas-mediated deletion by CD4(+) T cells.


Journal Article

Peripheral tolerance mechanisms normally prevent delivery of T cell help to anergic self-reactive B cells that accumulate in the T zones of spleen and lymph nodes. Chronic exposure to self-antigens desensitizes B cell antigen receptor (BCR) signaling on anergic B cells so that they are not stimulated into clonal expansion by CD4(+) T cells but instead are eliminated by Fas (CD95)-induced apoptosis. Because a range of BCR-induced signals and responses are repressed in anergic B cells, it is not known which of these are critical to regulate for Fas-mediated peripheral tolerance. Display of the costimulatory molecule, B7.2 (CD86), represents a potentially important early response to acute BCR engagement that is poorly induced by antigen on anergic B cells. We show here that restoring B7.2 expression on tolerant B cells using a constitutively expressed B7.2 transgene is sufficient to prevent Fas-mediated deletion and to trigger extensive T cell-dependent clonal expansion and autoantibody secretion in the presence of specific T cells. Dysregulated expression of B7.2 on tolerant B cells caused a more extreme reversal of peripheral tolerance than that caused by defects in Fas or Fas ligand, and resulted in T cell-dependent clonal expansion and antibody secretion comparable in magnitude to that made by foreign antigen-specific B cells. These findings demonstrate that repression of B7.2 is critical to eliminate autoreactive B cells by Fas in B cell-T cell interactions. The possible role of B7.2 dysregulation in systemic autoimmune diseases is discussed.

Full Text

Duke Authors

Cited Authors

  • Rathmell, JC; Fournier, S; Weintraub, BC; Allison, JP; Goodnow, CC

Published Date

  • August 17, 1998

Published In

Volume / Issue

  • 188 / 4

Start / End Page

  • 651 - 659

PubMed ID

  • 9705947

Pubmed Central ID

  • 9705947

International Standard Serial Number (ISSN)

  • 0022-1007

Digital Object Identifier (DOI)

  • 10.1084/jem.188.4.651


  • eng

Conference Location

  • United States