不同毒力疟原虫感染早期根治性治疗对再感染体液免疫应答的影响

Effect of Radical Cure in Early Phase of Primary Infection with Different Virulent Plasmodia on Humoral Immune Response to Homologous Reinfection

为探讨不同毒力疟原虫感染早期根治性治疗对再感染体液免疫应答的影响,用致死型和非致死型约氏疟原虫感染DBA/2小鼠,感染后3 d进行根治性治疗,并于初次感染后90 d进行再感染。计数红细胞感染率和检测再感染前(0 d)和再感染后(1、3、5 d)不同时间点脾细胞中活化性B细胞百分率以及血清中IgG、IgG1和IgG2 a水平,结果显示,再感染后2组小鼠均出现短暂的低水平虫体血症,再感染后第3天活化性B细胞、IgG、IgG1和IgG2 a均出现有意义的升高,但在每一相同检测时间点,2组小鼠的虫体血症、活化性B细胞百分率、IgG、IgG1和IgG2 a水平均没有显著差异。这些结果表明,不同毒力疟原虫感染早期的根治性治疗并不影响宿主在再感染时产生有效的体液免疫应答,强毒株原虫感染也能获得与弱毒株相同的可抵御再感染的能力。

In order to investigate the effect of radical cure in early phase of primary infection with different virulent plasmodia（Vp） on humoral immune response to homologous reinfection,DBA/2 mice were infected respectively with P.y17XL and P.y17XNL parasited erythrocytes,and radically cured on 3 d after infection.The mice were reinfected respectively with P.y17XL and P.y17XNL on 90 d after primary infection,then the level of parasitemia and specific IgG,IgG1 and IgG2a in sera as well as percentage of activated B cells in spleen cells were observed.The results showed that parasitemia in post-reinfection mice was transient and extremely low,and the percentage of activated B cells,specific IgG,IgG1 and IgG2a in these mice began to increase on 3 d of post-reinfection,however,in each testing time point the levels of parasitemia,IgG,IgG1 and IgG2a as well as the percentage of activated B cells from two groups of mice were not significantly different.These results suggested that radical cure in early phase of primary infection with different Vp had less effect on humoral immune response to homologous reinfection,Vp infection,being similar to low Vp infection,could also get the ability to resist reinfection.