Impact of thymosin-α1 upon proliferation of human peripheral blood T lymphocytes and expression of co-stimulatory molecules CD28 and CD152

Objective To elucidate the effects of thymosin- α 1 on the proliferation of human peripheral blood T lymphocytes and the mechanisms. Methods Membrane dyes PKH26 stain and fluorescent special antibody combined with flow cytometry were used to evaluate the effects of thymosin-α1 on human peripheral blood T lymphocytes proliferation and the expression of co- stimulatory molecules. Results After stimulation with thymosin- α 1 for 5 days, flow cytometric analysis showed that the proliferation index of thymosin- α1 group was significantly higher than that of control group (2.15±1.09 vs 1.67±0.55, P= 0.04). The percentage of positive co-stimulatory molecule CD28 in the thymosinα1 group was significantly higher than that in the control group [(27.63±12.36)% vs (22.62±10.12)%, P= 0.04)]. But there was no difference in the percentage of co-stimulatory molecule CD152 between thymosin-α1 group and control group [(3.54±1.58)% vs (0.91±0.41)%, P= 0.46]. Conclusion In vitro thymosin-α1 can obviously promote human peripheral blood T lymphocytes proliferation, and its mechanism may be related to up-regulation on expression level of co-stimulatory molecule CD28 by thymosin-α1. Key words: Thymosin-α1;  T-lymphocytes;  Cell proliferation;  Antigens, CD28;  CD152antigens