Smith Elizabeth C, Taylor-Robinson Andrew W
School of Biology, University of Leeds, Clarendon Way, Leeds LS2 9JT, UK.
Parasitol Res. 2003 Jan;89(1):26-33. doi: 10.1007/s00436-002-0687-3. Epub 2002 Aug 24.
Production of parasite-specific antibodies is an important component of immunity to blood stage malaria infection, as shown by several previous studies in rodent models. However, no study has addressed the induction of humoral immunity by different parasites in a genetically homogeneous host population. Here, levels of parasite-specific immunoglobulin isotypes were measured during primary infections of Plasmodium chabaudi and of Plasmodium yoelii in inbred NIH mice inoculated with cloned lines of either avirulent or virulent erythrocytic parasites. Non-lethal infections were characterized by early and late significant upregulation of IgG2a and IgG1, respectively. In contrast, for lethal infections, a slower, reduced IgG2a response correlated with a rapidly fatal outcome prior to any significant synthesis of IgG1. It is proposed that the sequential upregulated synthesis of parasite-specific IgG2a (cytophilic) and IgG1 (non-cytophilic) is associated with protective immunity to blood stage malaria infections in mice. This may provide an immunological framework for examining humoral immunity to malaria in humans.
正如之前在啮齿动物模型中的多项研究所表明的，产生寄生虫特异性抗体是对血期疟疾感染免疫的重要组成部分。然而，尚无研究探讨在基因同质的宿主群体中不同寄生虫对体液免疫的诱导作用。在此，对接种了无毒或有毒红细胞寄生虫克隆株的近交NIH小鼠，在感染查巴迪疟原虫和约氏疟原虫的初次感染期间，测量了寄生虫特异性免疫球蛋白同种型的水平。非致死性感染的特征分别是IgG2a和IgG1在早期和晚期显著上调。相比之下，对于致死性感染，IgG2a反应较慢且减弱，这与在IgG1显著合成之前迅速致命的结果相关。有人提出，寄生虫特异性IgG2a（嗜细胞性）和IgG1（非嗜细胞性）的顺序上调合成与小鼠对血期疟疾感染的保护性免疫有关。这可能为研究人类对疟疾的体液免疫提供一个免疫学框架。
