An experimental study on the role of CTLA4Ig gene transfected DCs in the induction of immune tolerance / 中华器官移植杂志

ABSTRACT

Objective To investigate the possibility of DCs transfected with CTLA4Ig cDNA by retrovirus vector to induce antigen specific hyporesponsiveness.Methods The modified DCs(CTLA4Ig-DCs) were prepared by transferring the DCs from cultured rat BM cells with the constructed retro-virus CTLA4Ig vector.The CTLA4Ig gene expression was detected on the prepared DCs by RT-PCR and Dot-ELISA methods.The influence of the modified DCs on mixed lymphocyte reaction(MLR) intensity was determined by T cell proliferation.Results The CTLA4Ig gene could be transferred successfully to DCs by retrovirus vector,which was confirmed by RT-PCR and Dot-ELISA methods.As compared with control group,DCsRev could significantly and antigen-specifically inhibit MLR in vitro in a dose-and time-dependent manner.The number of DCRev from 10~(3) to 10~(4) could reach the maximal inhibition by(69.12 %).On the other hand,the inhibition capacity of DCsRev was increased from(48 h) to 12 h prior to adding stimulating cells and the maximal inhibition was(98.3 %) at(12 h).Analysis of T cell proliferation revealed that donor-specific inhibition could be induced by DCsRev in an ex-vivo model.But this kind of inhibition was not lifetime.Conclusions The CTLA4Ig gene could be transferred successfully to DCs by retrovirus vector.This kind of DCs lost capacity of stimulating MLR,and could inhibit T cell proliferation,which might be responsible for the antigen-specific suppression induced by DCsRev.