MLR3 molecule is an activation antigen shared by human B, T lymphocytes and T cell precursors

Eur J Immunol. 1989 Feb;19(2):323-8. doi: 10.1002/eji.1830190216.


MLR3 molecule is a membrane glycoprotein (mol. mass range 28-34 kDa) present on activated, but not resting human peripheral T cells, B cells and thymocytes. Its kinetics of appearance on the cell surface (3 h after the addition of the inductive signal to the cells) suggests that it is an early activation antigen. The proliferative response of cultured T and B lymphocytes and thymocytes to different activation signals is inhibited by the addition of MLR3 monoclonal antibody. Moreover the antibody in combination with non-mitogenic doses of phorbol myristate acetate leads to proliferation of thymocytes and resting B and T lymphocytes. In the latter, synthesis of interleukin 2 is also induced. Biochemical analysis of MLR3 antigen indicates that it is a phosphorylated protein with N-linked sugar moieties. Together these data suggest a role for MLR3 antigen in the signal transduction process during activation, both for mature lymphocytes and for T cell precursors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, Surface / immunology*
  • Antigens, Surface / isolation & purification
  • B-Lymphocytes / analysis
  • B-Lymphocytes / immunology*
  • Humans
  • Lymphocyte Activation*
  • Membrane Glycoproteins / immunology*
  • Membrane Glycoproteins / isolation & purification
  • Membrane Glycoproteins / metabolism
  • Mice
  • Palatine Tonsil
  • Phosphorylation
  • Receptors, Antigen, T-Cell / physiology
  • Signal Transduction
  • Stem Cells / analysis
  • Stem Cells / immunology*
  • T-Lymphocytes / analysis
  • T-Lymphocytes / immunology*
  • T-Lymphocytes / metabolism
  • Thymus Gland


  • Antigens, Surface
  • MLR3 activation antigen
  • Membrane Glycoproteins
  • Receptors, Antigen, T-Cell