Expression of MHC class I and class I-like gene products on the cell membrane of mature and immature T cells.
Beta 2-microglobulin (beta 2m) constitutes the 12 kD light chain of the MHC-encoded 43-kD glycoprotein HLA-ABC molecules, which are expressed on most nucleated cells. The T6 (CD1a) antigen is expressed on thymocytes in reciprocal manner to HLA-ABC, having a similar structure to the HLA-ABC molecule. We have determined the expression of beta 2m, HLA-ABC and the T6 antigen on the cell-surface of CD1a+ and CD1a- thymocytes (defined by NA1/34 expression), and have shown that despite immunophenotypic differences between these two stages of thymic maturation, the quantity of beta 2m-associated molecules expressed was not significantly different. The nature of the heavy (alpha) chain associated with beta 2m, however, differed since HLA-ABC had largely replaced T6 on the surface of CD1a- thymocytes. We also determined the expression of beta 2m and HLA-ABC on the surface of peripheral blood CD4+ and CD8+ T-cells, and showed that the CD8+ population expressed higher levels of these antigens than CD4+ T-cells, with no detectable excess beta 2m over HLA-ABC for either subpopulation. In addition, thymocytes expressed fewer beta 2m-associated determinants than peripheral blood T-cells. These results indicate an increase in the expression of beta 2m-associated molecules with differentiation from thymic to peripheral T-cell, with a further increase in such molecules expressed on the CD8+ compared to the CD4+ peripheral T-cell subpopulation.
Jones
R A
RA
Department of Haematology, Cookridge Hospital, Leeds, U.K.
Scott
C S
CS
Child
J A
JA
D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis*; D002454:Cell Differentiation; D006680:HLA Antigens / Q000032:analysis*; D006801:Humans; D013601:T-Lymphocytes / Q000145:classification / Q000166:cytology / Q000276:immunology*; D001613:beta 2-Microglobulin / Q000032:analysis
D000945:Antigens, Differentiation, T-Lymphocyte; D006680:HLA Antigens; D001613:beta 2-Microglobulin