特异性IgG抗体在异种/同种异株疟原虫感染治愈后P.y17XL再感染中的保护作用

为探讨特异性IgG抗体在异种/同种异株疟原虫治愈后再感染过程中的作用,用不同种/株疟原虫感染BALB/c小鼠,经治愈后用P.y17XL再感染。通过计数红细胞感染率和检测再感染后血清中特异性IgG抗体的水平变化,发现P.y17XNL感染治愈组小鼠几乎不出现原虫血症,其余异种疟原虫感染治愈组小鼠出现了不同程度的虫血症发生时相延迟和水平降低,部分生存率有所延长;不同虫种/株感染治愈后P.y17XL再感染的小鼠IFN-γ水平均明显低于同时间点P.y17XL初次感染的小鼠;P.v、P.y17XNL感染治愈小鼠血清中P.y17XL特异性IgG抗体水平出现显著增加(P<0.05),且以IgG1亚类升高为主。表明特异性IgG抗体可在宿主抗同源疟原虫再感染中发挥着重要作用,而对异种疟原虫再感染保护性有限。

Protective Effects of Specific IgG Antibody on Re-Infection of P.y17XL in Healed Homo-/Hetero-Generous Plasmodium Primarily Infected BALB/c Mice

In order to explore the effect of specific IgG antibodies during the re-infection process by homo-/hetero-generous Plasmodium primarily infected and cured BALB/c mice,different species/strains plasmodium were used to infect BALB/C mice and re-infect by P.y17XL after cure.The changes of RBC infection rate and specific IgG level in serum after the re-infection through counting,almost no parasitemia were found in P.y17XNL infected-and-cured（IAC） mice while other plasmodium IAC mice developed a relative delay and low levels of parasitemia.A significant lower IFN-γ levels were found in all IAC mice compared that of P.y17XL primarily infected mice.Specific IgG levels in P.v and P.y17XNL IAC mice sera appeared significant increment（P0.05）,increased mainly on sub-kind of IgG1.Indicated that specific IgG play an important role on prevention of re-infection of homo-geneous Plasmodium,but the prevention of re-infection of hetero-geneous Plasmodium was limited.