CD81 expressed on human thymocytes mediates integrin activation and interleukin 2-dependent proliferation

J Exp Med. 1996 Nov 1;184(5):2055-60. doi: 10.1084/jem.184.5.2055.


Lymphocyte recognition of antigen by the antigen-specific T cell receptor (TCR) and coreceptor complexes rapidly alters the cell's adhesive properties facilitating high avidity cell-ligand interactions necessary for lymphocyte development and function. Here, we report the expression of CD81 (target of antiproliferative antigen [TAPA]-1) on human thymocytes and the physical association of CD81 with CD4 and CD8 T cell coreceptors. Antibody ligation of CD81 on thymocytes promotes the rapid induction of integrin-mediated cell-cell adhesion via lymphocyte function-associated molecule-1 (LFA-1). Cross-linking CD81 is also shown to be costimulatory with signaling through the TCR/CD3 complex inducing interleukin 2-dependent thymocyte proliferation. These data suggest that a CD81-mediated pathway in thymocytes is involved in the regulation of both cell adhesion and activation.

Publication types

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

MeSH terms

  • Antigens, CD / metabolism*
  • CD4 Antigens / metabolism
  • CD8 Antigens / metabolism
  • Cell Adhesion*
  • Cross-Linking Reagents
  • Humans
  • Interleukin-2 / pharmacology*
  • Lymphocyte Activation*
  • Lymphocyte Function-Associated Antigen-1 / metabolism*
  • Membrane Proteins*
  • Protein Binding
  • T-Lymphocytes / drug effects
  • T-Lymphocytes / immunology*
  • Tetraspanin 28
  • Thymus Gland / cytology
  • Thymus Gland / immunology


  • Antigens, CD
  • CD4 Antigens
  • CD8 Antigens
  • CD81 protein, human
  • Cross-Linking Reagents
  • Interleukin-2
  • Lymphocyte Function-Associated Antigen-1
  • Membrane Proteins
  • Tetraspanin 28