Accessory molecules and T cell activation. II. Antibody binding to L3T4a inhibits Ia-independent mouse T cell proliferation

Eur J Immunol. 1987 Mar;17(3):429-32. doi: 10.1002/eji.1830170321.


Monoclonal antibody (mAb) blocking assays using L3T4- and lymphocyte function-associated antigen-1 (LFA-1)-specific reagents were used as an approach to investigate the involvement of these accessory molecules in various T cell activation pathways. As previously reported, rat mAb to L3T4a and LFA-1A functional epitopes efficiently blocked antigen-driven T helper cell proliferation. In contrast, antigen- and Ia-independent T cell triggering induced by appropriate mAb to the Thy-1 or the T cell receptor molecules were found to be inhibitable by L3T4a- but not LFA-1A-specific mAb, although the extent of inhibition varied, depending on the cell type and the activating signal examined. These results provide further evidence that the inhibiting effects of L3T4-specific mAb on T cell responses may be due, in addition to an impairment of L3T4-class II major histocompatibility complex molecular interaction, to a down regulatory signal possibly transmitted by the L3T4 molecule itself.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Monoclonal / immunology
  • Antigen-Antibody Reactions
  • Antigen-Presenting Cells / immunology
  • Antigens, Differentiation, T-Lymphocyte
  • Antigens, Surface / immunology*
  • Conalbumin / immunology
  • Histocompatibility Antigens Class II / immunology*
  • Lymphocyte Activation*
  • Mice
  • Mice, Inbred Strains
  • Receptors, Antigen, T-Cell / immunology
  • T-Lymphocytes / immunology*


  • Antibodies, Monoclonal
  • Antigens, Differentiation, T-Lymphocyte
  • Antigens, Surface
  • Histocompatibility Antigens Class II
  • Receptors, Antigen, T-Cell
  • Conalbumin