单克隆抗体对疟原虫子孢子感染鼠的保护作用

本研究通过一系列体内、外中和试验表明抗疟原虫子孢子单克隆抗体MS1—5均是保护性抗体,其抗虫机制为(1)抑制子孢子侵入肝细胞,经MS1作用后的子孢子能大量聚集在肝脏,但失去入侵肝细胞的能力。(2)中和子孢子感染力,使其失去引起宿主血液感染的能力,抗体的被动转移能使受者获得抗感染力,受保护的程度取决于子孢子的接种量及循环抗体的浓度。(3)循环抗体对子孢子的中和抑制是有限的,杂交瘤移梢鼠具有较高活性的保护性循环抗体,能完全抵抗2×10~3个子孢子的感染,但只有部分(47％)免疫鼠能抵抗10~4个子孢子的攻击。提示虫体负荷一旦超出抗体的中和能力就能逃避免疫,引起宿主的感染与发病。

Protection of Monoclonal Antibody in Mice from the Infection of Malarial Parasite

This study,using a series of neutralizing activity tests in vitro or in vivo, indicated that monoclonal antibodies against sporozoite MS1-5 were the protective antibodies, MSl-5 could confer prtotection to mice and rat against a non-lethal inoculation of P. yoelii by (1) inhibiting the invasion of sporoites into hepatocytes, the sporozoi-tes reacted with MSl-5 accumulated in the liver but couldn't invade the liver cell, and (2) abolishing parasite infectivity. Passive transformation of MSl-5 was effective in mediating protection on immunized mice. The extent of protective immunity depended on inoculation quantity of parasites and the concentration of antibody.