[Inhibitory effect of anti-C II TA RNase P on MHC II expression in Jurkat cells]

This study was purposed to investigate the inhibitory effect of anti-C II TA M1-RNA on MHC II expression. The M1-RNA with guide sequences (GS) recognizing C II TA at 3408 site (M1-3408-GS) and C II TA target RNA (3176 - 3560) were constructed, then cloned into the pUC19 and pGEM-7zf (+) vector respectively. The recombinant M1-RNA and its target RNA were incubated in cell-free conditions. It showed that M1-3408-GS could exclusively cleave target RNA, then it was cloned into the psNAV vector. Stable transfectants of Jurkat cells with M1-3408-GS were analyzed for classical MHC II (HLA-DR, -DP, -DQ) induction in response to IFN-gamma by flow cytometry. The level of C II TA mRNA was measured by RT-PCR. The results showed that after IFN-gamma treatment, the expression of HLA-DR, HLA-DP, HLA-DQ on M1-3408-GS positive Jurkat cells decreased 83.17%, 94.12% and 84.31% respectively as compared with control. At the same time the mRNA contents of C II TA also markedly decreased (P < 0.05, t = 4.89). It is concluded that anti-C II TA M1-RNA (M1-3408-GS) inhibits C II TA, decreases itself mRNA content and so suppresses expression of MHC II molecules regulated by C II TA.