[Effect of PvMSP1 on differentiation, maturation and function of dendritic cells].

Objective: To investigate the effects of Plasmodium vivax merozoite surface protein 1 (PvMSP1) on differentiation, maturation and function of dendritic cells (DC) and the mechanisms of PvMSP1 on the activation of DC via toll like receptors (TLR).

Methods: DCs were incubated with different doses of PvMSP1 (1.0, 10.0, 100.0 microg/ml) in vitro. The changes of CD83, CD86, and HLA-DR on DC were detected by flow cytometry (FCM); the expressions of cytokine IL-10 and IL-12 of DC were measured by ELISA; the expressions of TLR4 and TLR9 mRNA of DC were measured by RT-PCR; the proliferation induction to autologous lymphocytes of DC was measured by MTT. Meanwhile, the untreated DC and LPS inducing DC were as the negative control and positive control, respectively. All the data were analyzed statistically.

Results: Compared with the untreated DC, the proportions of CD83, CD86 and HLA-DR on DC induced by LPS and PvMSP1 increased significantly (all P < 0.05); the expressions of IL-10 and IL-12 of DC induced by LPS increased significantly (P < 0.01), and those induced by PvMSP1 also increased significantly (all P < 0.05). In the LPS inducing group, the TLR4 mRNA production increased (P < 0.05) and the TLR9 mRNA production had no significantly changes (P > 0.05). In the PvMSP1-treated group, the DC TLR4 mRNA production increased (P < 0.01) and the TLR9 mRNA production had no significantly changes (P > 0.05); DC stimulated the proliferation of autologous lymphocytes.

Conclusion: PvMSP1 enhances DC differentiation and maturation, and the mature DC induced by PvMSPI has the ability of antigen presenting. The route for PvMSP1 inducing DC maturation might be TLR4 pathway rather than TLR9 pathway.