Study on the regulatory effect of FK506 on T cell subgroups and the co-stimulator expression of allo-liver recipients

Objective Through observing the influence of FK506 on T cell subgroups and the expression of co-stimulators CD28,CD152 and inducible costimulator(ICOS) in patients receiving allo-liver transplantation and FK506 treatment,to explore the effect of FK506 on T cell signal transduction. Methods The T cell subgroups and the expression of CD28,CD152 and ICOS on peripheral T cells in healthy-control group,disease-control group and treatment group were determined by flowcytometry. Results The total number of T lymphocytes were not significantly different among three groups.Compared with disease-control group,the number of CD4~+ T cell of the treatment group was much lower and the number of CD8~+T cell was much higher;The expressions of CD28 and ICOS significantly decreased while the CD152 expression obviously increased. Conclusions FK506 plays an important role in the quick correction of the turbulence of T cell subgroup balance.Through inhibiting the expression of positive costimulators and promoting the expression of negative costimulator CD152,FK506 blocks the activating signal transduction at the upper stream of T cell immune signal pathway and thus inhibits the activation of T cell.