Reversal of CD45R isoform switching in CD8+ T cells.
Both CD4+ and CD8+ T cells express either CD45RA or CD45R0 isoform of CD45R in an exclusive way. Recent reports have shown that CD45RA+ T cells lose CD45RA and gain CD45R0 upon activation. This switching has been suggested to be irreversible although more recently, examples of reversal of CD45R isotype switching in CD4+ T cells have been reported. We report here that freshly isolated unprimed CD8+ T cells, when activated with PHA, temporarily lose CD45RA but reexpress an intermediate level of CD45RA 2-3 weeks after activation with PHA. This reversal seems to take place much more slowly in unprimed CD4+ T cells: the majority of CD4+ T cells that had lost CD45RA and gained CD45R0 remained CD45RA-CD45R0+ in 3 weeks after the stimulation. Also, long-term CD8+ CD45RA+ T cell lines stimulated with PHA or OKT3 showed even more rapid recovery of CD45RA while PPD-specific CD4+ T cell clones retained the original CD45R0 phenotype 3 weeks after stimulation with PPD or PHA.
Fujii
Y
Y
First Department of Surgery, Osaka University Medical School, Japan.
Okumura
M
M
Inada
K
K
Nakahara
K
K
D015703:Antigens, CD / Q000378:metabolism*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D016827:CD8 Antigens / Q000032:analysis; D002999:Clone Cells; D005434:Flow Cytometry; D006649:Histocompatibility Antigens / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D017493:Leukocyte Common Antigens; D008213:Lymphocyte Activation; D008212:Lymphocyte Depletion; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D013997:Time Factors
D015703:Antigens, CD; D016827:CD8 Antigens; D006649:Histocompatibility Antigens; D017493:Leukocyte Common Antigens