Effects of CIITA antisense RNA on the expression of HLA class II molecules

To study the effect of the major histocompatibility complex class II (MHC I I) transactivator (CIITA) antisense RNA on the expression of the human leuk emia (HLA) class II molecules, 5' end cDNA sequence of CIITA gene was clone d, and antisense RNA expression vector pcDNA-II was constructed. HeLa cells transfected with pcDNA-II and pcDNA3 were induced by IFN-gamma for 3 d. Th e expression of HLA class Il molecules on HeLa/pcDNA-II cells was significa ntly decreased, while it has no effect on the expression of HLA class I mol ecules. This result suggests that the CIITA antisense RNA can inhibit the e xpression of HLA class II molecules in HeLa cells. It also implies a promis ing approach to generate immune tolerance in graft transplantation.