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CD 80(B7-1) expression on human tumor cell lines and its costimulatory signals for T cell proliferation and cytokine production.

OBJECTIVE
To investigate CD 80 expression on human tumor cell lines and establish stable CD 80 expression transfectants to illustrate CD 80 costimulation on the T cell proliferation and cytokine production.


METHODS
Raji, MDA-453, MCF-7, Hela, 3AO, MKN-45 and EBV transformed B cell were detected for CD 80 expression by RT-PCR. CD 80 cDNA subcloned to retrovirus vector pLXSN, with them stable CD 80 transfectanants were established. With specific mAb BB1 and FACS assay, the expression of CD 80 were detected. Anti-CD3 induced T lymphocyte proliferation and IL-2, IFN-r production were performed to evaluate CD 80 costimulatory activity in the presence of calcium ionophore A23187 and phorbol ester PMA.


RESULTS
CD 80 (B7-1) expression of MDA-453, MCF-7, Hela, 3AO, MKN-45 was negative, and that of Raji and EBV transformed B cell was positive by RT-PCR and FACS methods. Cocultured with CD 80 transfected human breast carcinoma cell line MDA-453, anti-CD3 induced T cells proliferation and cytokine production were significantly increased in the presence of A23187 and PMA, but not with parental MDA-453.


CONCLUSIONS
CD 80 expression is absent on most human tumor cell line except for Raji and EBV transformed B cell. Full activation of T cell needs CD 80 costimulation. Influence of CD 80 costimulation on cytokine production is mainly regulated via IL-2 and IFN-r.