Elliott Salenna R, Payne Paul D, Duffy Michael F, Byrne Timothy J, Tham Wai-Hong, Rogerson Stephen J, Brown Graham V, Eisen Damon P
Department of Medicine, The University of Melbourne, Royal Melbourne Hospital, Victoria, Australia.
Am J Trop Med Hyg. 2007 May;76(5):860-4.
Antibodies to variant surface antigens (VSA) including Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) have been associated with protective antimalarial immunity that appears to be variant-specific. This study of adult returned travelers with a single acute P. falciparum infection investigated whether a primary antibody response includes IgG specific for heterologous VSA. We found that 11 of 14 patients had IgG reactive with up to six P. falciparum lines expressing different heterologous PfEMP1 variants, measured by flow cytometry (reactivity greater than two times the mean of the negative control sera was defined as "positive"), with high reactivity (greater than four times the mean of the negative controls) detected in three patients. The dominant variant(s) recognized differed between seropositive individuals. Despite previous evidence that antibody responses to heterologous VSA are short-lived, seven patients had detectable IgG at > 20 weeks post-infection. Together these data suggest that a single P. falciparum infection can be sufficient to induce antibodies reactive with several PfEMP1 variants, although the repertoire of target epitopes they recognize may still be restricted.
针对包括恶性疟原虫红细胞膜蛋白1（PfEMP1）在内的可变表面抗原（VSA）的抗体，与似乎具有变体特异性的保护性抗疟免疫相关。这项针对单次急性恶性疟原虫感染的成年归国旅行者的研究，调查了初次抗体反应是否包括针对异源VSA的IgG。我们发现，14名患者中有11名的IgG与多达6种表达不同异源PfEMP1变体的恶性疟原虫株发生反应，通过流式细胞术检测（反应性大于阴性对照血清平均值的两倍被定义为“阳性”），3名患者检测到高反应性（大于阴性对照平均值的四倍）。血清阳性个体识别的主要变体有所不同。尽管先前有证据表明对异源VSA的抗体反应是短暂的，但7名患者在感染后20周以上仍可检测到IgG。这些数据共同表明，单次恶性疟原虫感染可能足以诱导与几种PfEMP1变体发生反应的抗体，尽管它们识别的靶表位库可能仍然有限。
