[Studies on HLA-class I and class II antigen expression in cultured choriocarcinoma cell lines]

Eight choriocarcinoma cell lines (Two SCH and IMa, were established from non-gestational choriocarcinoma and the other six BeWo, JaR, JEG-3, GCH-1, NUC-1, and HCCM-5, were from gestational one) were investigated for HLA-Class I and Class II antigen expression by the immunofluorescence method using rabbit anti HLA-ABC serum, and by a radioimmunoassay inhibition best using monoclonal antibodies (W6/32: anti HLA-ABC, 7B6: anti HLA-Class II, and D1-4-10: anti HLA-DR). With respect to HLA-Class I antigen expression, only non-gestational SCH (gastric origin) showed a clear positive finding. The other non-gestational IMa (ovarian origin) was negative. Cell lines from gestational choriocarcinoma showed a slightly positive finding (negative by immunofluorescence but slightly positive by inhibition test), except for JaR which was negative. All cell lines examined in the present study were negative for HLA-Class II antigen. The present results show that the majority of the gestational choriocarcinoma cell lines may express very slight HLA-Class I antigens.