Selective expression of class II MHC isotypes by MLC-activated human T lymphocytes

Hum Immunol. 1990 Mar;27(3):208-19. doi: 10.1016/0198-8859(90)90051-p.


Although activated human T cells express class II MHC molecules, the biologic significance of this event is not understood. Using two-color flow cytometry, we have analyzed the expression of HLA-DR, -DQ, and -DP isotypes by T cells following activation by allogeneic lymphoblastoid B-cell lines. Within the CD3+ population, transient expression was observed at 1 day following initiation of culture, which preceded a dramatic and sustained increase around 6-7 days. DR expression was always highest, followed by DP and DQ with DP expression usually somewhat higher than DQ. At day 8, three populations were observed consisting of DR+DP+DQ+ (60%), DR+DP+ (69%), and DR+ (75%) T cells. Interestingly, DQ+ or DP+ but DR- T cells were not observed. These patterns of class II isotype expression were similar in CD2+, CD4+, and CD8+ subgroups and suggest that class II molecules are selectively expressed on T cells and may play a role in the regulation of T-cell responses to alloantigens.

Publication types

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

MeSH terms

  • Antibodies, Monoclonal / immunology
  • Cell Division
  • Cell Line, Transformed
  • Cell Separation
  • Cells, Cultured
  • Flow Cytometry
  • Fluorescence
  • Histocompatibility Antigens Class II / biosynthesis*
  • Humans
  • Interleukin-2 / pharmacology
  • Kinetics
  • Leukocytes / immunology
  • Lymphocyte Activation
  • T-Lymphocytes / immunology*


  • Antibodies, Monoclonal
  • Histocompatibility Antigens Class II
  • Interleukin-2