Hamburger J, Kreier J P
Infect Immun. 1975 Aug;12(2):339-45. doi: 10.1128/iai.12.2.339-345.1975.
An infective preparation of extracellular blood forms (FP) of Plasmodium berghei was used to study some aspects of the interaction between protective antibodies and malaria parasites. FP but not infected erythrocytes (IRBC) were shown by the fluorescent antibody technique to be coated by antibodies after in vitro incubation with immune serum. Preincubation of both FP and IRBC with immune serum followed by their washing did not result in enhanced elimination of the parasites in vivo. However, FP preincubated with immune serum and subsequently washed were eliminated more efficiently than FP preincubated with normal serum if the preparations were injected with some immune serum. Such an increase in the efficiency of elimination was not detected with similarly pretreated IRBC. It is thus probable that protective antibodies acted in vivo against extracellular parasites rather than against parasites in erythrocytes. The interaction between parasites and antibodies may be of a highly reversible nature, and washing of the in vitro-treated parasites may cause elution of antibody from the sensitized parasites so that the amount of antibody on the parasite falls below the critical level required for in vivo elimination.
使用伯氏疟原虫细胞外血液形态（FP）的感染性制剂来研究保护性抗体与疟原虫之间相互作用的某些方面。荧光抗体技术显示，与免疫血清进行体外孵育后，被抗体包被的是FP而非感染红细胞（IRBC）。FP和IRBC与免疫血清预孵育后再洗涤，并不会导致体内寄生虫清除增强。然而，如果将制剂与一些免疫血清一起注射，与免疫血清预孵育并随后洗涤的FP比与正常血清预孵育的FP清除效率更高。用同样预处理的IRBC未检测到这种清除效率的提高。因此，保护性抗体可能在体内作用于细胞外寄生虫而非红细胞内的寄生虫。寄生虫与抗体之间的相互作用可能具有高度可逆性，体外处理后的寄生虫洗涤可能导致抗体从致敏寄生虫上洗脱，从而使寄生虫上的抗体量降至体内清除所需的临界水平以下。
