Phosphorylation of mouse thymocyte CD4 and CD8: regulation of surface expression
Tagawa, M.; Koike, T.; Griffith, L.C.
Biochemistry International 24(4): 739-747
1991
ISSN/ISBN: 0158-5231 PMID: 1799373 Document Number: 382813
Murine T cell surface antigens, CD4 and CD8 are phosphorylated in response to phorbol 12-myristate 13-acetate, a protein kinase C activator, but not phosphorylated after concanavalin A, Ca2+ ionophore or dibutyryl-cAMP treatment. We examined the cell surface expression of both antigens and show that surface CD4 on CD4+CD8+ and CD4+CD8- thymocytes is rapidly decreased after PMA treatment, while CD8 expression is unaffected. Prolonged PMA treatment, which down-regulates protein kinase C, allows CD4 reexpression only in the CD4+CD8- population, suggesting that different mechanisms of cell surface antigen expression are operating in the two thymocyte subpopulations.