[Immune response of purified Plasmodium falciparum antigen on human peripheral blood T lymphocytes in vitro].

Objective: To explore the effects of the purified Plasmodiumfalciparum (P. f) antigen on the T lymphocytes of the peripheral blood of healthy people in vitro.

Methods: The peripheral blood mononuclear cells (PBMCs) isolated from healthy donators were cultured with purified P. fantigen (5 μg/ml) and normal RBC (nRBC) antigen (5 μg/ml), in addition, the group in which only IL-2 added was set as a negative control. After cultured for 12 d, the corresponding antigens were used to re-stimulated the activated T cells in the two stimulated groups for 20 h. Then the cells were collected, the proliferations of the T cells labeled by CFSE were analyzed, and the secretion condition of IL-4 and IFN-γ of the cells were detected by flow cytometry.

Results: After amplification, the proliferative index (PI) of CD4+ T cells that were stimulated with P. f antigen was significantly higher than those in the nRBC antigen group and the negative control group (both P <0.05), but there was no significant difference between the PIs of γδ T cells in the above three groups (P > 0.05). Meanwhile, the percentages of the CD4' T cells secreting IL-4+ in the P. f antigen group was significantly higher than those in the other two groups (both P <0.05), while the percentages of T cells secreting IFN-γ in the 3 groups had no significant difference (P > 0.05).

Conclusion: The purified P.fanti- gen could effectively stimulate the proliferation of CD4+ T cells in peripheral blood of healthy people, and the latter can play a role in immunoregulation through secreting IL-4 preferentially.