Normal B lymphocyte development but impaired T cell maturation in CD45-exon6 protein tyrosine phosphatase-deficient mice

Cell. 1993 Jul 16;74(1):143-56. doi: 10.1016/0092-8674(93)90302-7.


The transmembrane tyrosine phosphatase CD45 is expressed in multiple isoforms on all nucleated hematopoietic cells, resulting from alternative splicing of variable exons. We generated mice with a mutation in the variable CD45 exon 6, using homologous recombination. In mice homozygous for the CD45-exon6 mutation, B cells and most T cells did not express CD45. Development of B cells appeared normal, although Ig mu-induced proliferation was completely abrogated. Thymocyte maturation was blocked at the transitional stage from immature CD4+CD8+ to mature CD4+ or CD8+ cells, and only a few T cells could be detected in peripheral lymphoid organs. Clonal deletion of superantigen-reactive T cells still occurred. Cytotoxic T cell responses to lymphocytic choriomeningitis virus were absent in CD45-exon6-/- mice. These data imply that CD45 is differentially required for the development and function of B and T lymphocytes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • B-Lymphocytes / cytology
  • B-Lymphocytes / immunology*
  • CD4 Antigens / immunology
  • CD8 Antigens / immunology
  • Cell Differentiation / genetics
  • Cell Differentiation / immunology
  • Exons
  • Immunoglobulin mu-Chains
  • Leukocyte Common Antigens / genetics*
  • Mice
  • Protein Tyrosine Phosphatases / deficiency*
  • Protein Tyrosine Phosphatases / genetics
  • T-Lymphocytes / cytology
  • T-Lymphocytes / immunology*
  • T-Lymphocytes, Cytotoxic / immunology


  • CD4 Antigens
  • CD8 Antigens
  • Immunoglobulin mu-Chains
  • Leukocyte Common Antigens
  • Protein Tyrosine Phosphatases