Activation-dependent expression of low affinity IgG receptors Fc gamma RII(CD32) and Fc gamma RIII(CD16) in subpopulations of human T lymphocytes

Immunobiology. 1995 Apr;192(5):297-320. doi: 10.1016/s0171-2985(11)80172-5.

Abstract

Receptors for IgG (Fc gamma R) are expressed by small subpopulations of peripheral blood T lymphocytes. Our studies demonstrate that T lymphocytes can be induced in vitro to express two different low-affinity Fc gamma R. Mitogen activation of peripheral blood T lymphocytes obtained from eight healthy individuals leads to considerable augmentation of the Fc gamma RIII+ (CD32) T cell subpopulation. The highest percentage of CD32 expressing T lymphocytes could be detected after three days of activation. The T cell subpopulation which transiently express the CD32 antigen, encompasses CD4+ and CD8+ cells. Molecular cloning of the CD32 antigen by reverse transcription and polymerase chain reaction demonstrates that activated human T lymphocytes express the Fc gamma RIIIb2 isoform. The percentage of the Fc gamma RIII+ (CD16) T cell subpopulation was significantly increased only in the lymphocyte populations obtained from three out of eight volunteers immediately after mitogen activation. However, during short-term cell culture the CD16 expressing CD8+ T cell subset increased in the T cell population from all individuals investigated. During this time, the IL-2 receptor alpha-chain (CD25) expression level decreased as a function of time. In contrast to the CD8+CD16+ T cells, the percentage of the non-MCH-restricted CD56+CD16+ T cells was not influenced by mitogen activation and time of cell cultivation. We could show that CD16 in T cells is able to mediate a stimulus leading to proliferation of the CD8+CD56-CD16+ T cells but not that of the CD56+CD16+ T cell subset. This discrepancy cannot be explained by the expression of different Fc gamma RIII isoforms, because both T cell subsets express Fc gamma RIIIA alpha, as we demonstrate in this report.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Monoclonal / immunology
  • Base Sequence
  • CD3 Complex / immunology
  • Cells, Cultured
  • Cloning, Molecular
  • Humans
  • Lymphocyte Activation / immunology*
  • Molecular Sequence Data
  • Receptors, IgG / analysis*
  • Receptors, IgG / biosynthesis
  • T-Lymphocyte Subsets / immunology*
  • T-Lymphocyte Subsets / metabolism

Substances

  • Antibodies, Monoclonal
  • CD3 Complex
  • Receptors, IgG