[Study of reduction rat T-lymphocytes activation and proliferation by inhibition inducible co-stimulator gene...

To observe the change of activation and proliferation ability of rat T-lymphocytes after suppress ICOS gene expression by RNA interference.

Four interference sites targeting at rat ICOS gene were designed and four pairs of oligonucleotide fragments were cloned into the pSilencer 4.1-CMV neo plasmid vectors then transfected into rat lymphocytes with cationic liposome. The expression of mRNA and protein of ICOS was detected by RT-PCR and flow cytometry. The alteration of lymphocyte proliferation ability was evaluated by mix lymphocyte reaction, and the secretion levels of IFN-gamma and IL-4 were measured by ELISA procedure.

After transfection, the expression of mRNA and protein of ICOS in test groups were lower than that in control groups (P < 0.05). The ability of T-lymphocytes in proliferation was poor and the levels of IFN-gamma and IL-4 were reduced with ICOS gene shut down.

RNA interference plasmid vector can suppress ICOS expression in rat T-lymphocytes significantly, and it may be useful for further study on transplantation immunity tolerance.