Effect of radical treatment in early phase of primary infection with different toxicity plasmodium on cellular immune response to homologous reinfection

To investigate the effect of radical treatment in early phase of primary infection with different toxicity plasmodium on cellular immune response to homologous reinfection,DBA/2 mice were infected respectively with Py17XL and Py17XNL parasited erythrocytes,and radically treated on day 3 after infection.The mice were reinfected respectively with Py17XL and Py17XNL on day 90 after primary infection,then the level of parasitemia was observed by mean of the Giemsa staining of thin blood smears,and applying flow cytometry to quantitively analyze the percentage of actived T cells in spleen T cells on days 0,1,3 and 5 post-reinfection,respectively,the levels of IFN-γ,TNF-α,IL-4 and IL-10 in spleen cell culture supernatant were also measured by ELISA at the same time.Results showed that parasitemia in two groups of radically treated mice post-reinfection was all transient and extremely low,and percentage of actived T cells,levels of IFN-γ,TNF-α,IL-10 and IL-4 began to rise from day 1 to day 5 after reinfection,respectively,in each testing time point,however,the levels of parasitemia and percentage of actived T cells as well as levels of these cytokines from two groups of mice were not significantly different.These results suggest that host radically treated in early phase of primary infection with different toxicity malarial parasite may produce a similar pattern and intensity of cellular immune responses to homologous reinfection.