间日疟原虫重组蛋白Pvs25和Pvs28免疫小鼠应答机制观察

目的观察间日疟传播阻断疫苗候选抗原Pvs25和Pvs28的免疫应答机制。方法分别用与弗氏佐剂乳化后的Pvs25和Pvs28重组蛋白皮下免疫DBA/2小鼠;采用ELISA分别对各组小鼠脾细胞培养上清的IFN-γ、IL-4、IL-10动态检测;以ELISPOT方法检测小鼠脾脏IFN-γ+和IL-4+细胞数量。结果经重组蛋白免疫的两组小鼠脾细胞培养上清IFN-γ的含量于初次免疫后第14d升高,与对照组相比差异显著(P<0.01),但随后降至对照组水平;IL-4和IL-10均在初次免疫后第28d出现有意义的升高(P<0.01),后升高更为明显,分别直至免疫后期70d、56d出现下降,但直至112d仍明显高于免疫前的水平(P<0.01)。初次免疫后第70d?98d小鼠脾脏IFN-γ+和IL-4+细胞数量,与对照组相比IFN-γ+无明显变化,而IL-4+则明显增多(P<0.01)。结论Pvs25和Pvs28重组蛋白可诱导小鼠产生以Th2反应为主的免疫应答。

Mechanism of murine immune response to Plasmodium vivax Pvs25 and Pvs28 recombinant proteins

The mechanism of murine immune response to Pvs25 and Pvs28 recombinant protein (rPvs25 and rPvs28), the Plasmodium vivax malaria transmission blocking vaccine candidates, was investigated. Mice were injected subcutaneouly with rPvs25 or rPvs28 emulsified in Freund’s adjuvant. Level of IFN-γ, IL-10 and IL-4 in spleen cell culture supernatants derived from mice at different times before or after vaccination was assayed by ELISA kits. Numbers of IL-4+ and IFN-γ+ cells in murine spleen lymphocytes were detected by enzyme-linked immunospot assay (ELISPOT) on day 70,day 98 after first vaccination. It was found that level of IFN-γ elevated sharply at day 14 (P<0.01) and then dropped to the level of control group. Levels of IL-4 and IL-10 increased from day 28 after first vaccination and got further higher henceforth. Despite of its later decrease, the levels kept higher till day 112 compared with the control (P<0.01). Number of IL-4+ cells from mice spleen elevated on day 70 and day 98 (P<0.01), while that of IFN-γ+ cells didn’t change, compared with the control. It is suggested that rPvs25 and rPvs28 can induce murine immune response, predominantly the Th2 response.