Abstract: 　Objective] To observe the anti P.berghei ability of C57BL/6 mice after infected with Nippostrongylus brasiliensis alterations in T helper cell subsets in the course of Plasmodium infection, and the effect of the alteration on host′s prognoses. [Methods] C57BL/6 mice were infected with Nippostrongylus brasiliensis subcutaneously, 3 wk later, the mice were injected with Plasmodium berghei intraperitoneally. The parasitemia was monitored daily. On days 0,3 and 9, RNA from the spleens of infected mice was prepared for PT PCR to analyse the changes of IFN γ and IL 4 mRNA during the infection course.[Results] Compared with control group, the peak reaching time of parasitemia in the experiment group was delayed, and the bearing capacity of mice to malaria infection and the surviving time increased obviously. The IL 4 level in the experiment group was higher than that in the control group on day 0 of P.berghei infection, but all raised abnormally in both groups at the early stage of the infection; while IFN γ level in the experiment group was higher than that in the control group on day 3 after infection, and then began to reduce to some extent on day 9 of the infection in the experiment group. [Conclusion] T helper cell subsets play an important role in antimalarial immunoregulation in mice.

Key words: T helper cell, immunity, Plasmodium berghei, Nippostrongylus braslilensis