Differential regulation of CD27 expression on subsets of CD4 T cells.
Our earlier studies showed that although CD27 was stably expressed on the CD45RA(+)-CD45RO-CD29low subset of CD4 T cells, its expression on the CD45RA-CD45RO+CD29high subset of CD4 T cells was gradually lost within 3 weeks after PHA activation. In the present study, we further determined the mechanisms by which the CD27 expression was differentially regulated on the subsets of CD4 T cells. We showed that disappearance of CD27 from the surface of the CD45RA-CD45RO+ subset of CD4 T cells was not solely due to the shedding of the CD27 molecule from the cell surface since the release of a soluble form of the CD27 molecule from the CD45RO+ CD4 T cells was consistently less than that from CD45RA+ CD4 T cells. Although the surface CD27 expression was undetectable on long-term cultured T cell lines originally derived from CD45RO+ CD4 T cells, some of these cells still expressed intracellular CD27 and CD27 mRNA. Moreover, restimulation could not induce CD27 expression on such cells. Further analysis of CD27 protein and mRNA expression at a clonal level showed that cloned cells derived from CD45RO+ CD4 T cells having lost cell surface expression of CD27 were of two types: one expressed intracellular CD27 mRNA and protein whereas the second lacked both intracellular CD27 mRNA and protein.
Kurosawa
K
K
Dana-Farber Cancer Institute, Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115.
Kobata
T
T
Tachibana
K
K
Agematsu
K
K
Hirose
T
T
Schlossman
S F
SF
Morimoto
C
C
D015152:Blotting, Northern; D015153:Blotting, Western; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D002999:Clone Cells; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D005786:Gene Expression Regulation / Q000276:immunology; D006801:Humans; D017493:Leukocyte Common Antigens / Q000097:blood; D008213:Lymphocyte Activation / Q000276:immunology; D012333:RNA, Messenger / Q000097:blood; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7 / Q000096:biosynthesis*
D012333:RNA, Messenger; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7; D017493:Leukocyte Common Antigens