恶性疟原虫单克隆抗体保护性机制的实验研究

用体外抑制试验、调理试验和细胞毒试验等方法,对抗恶性疟原虫红内期McAb之功能特性进行了研究。17株McAb中有7株对同步化培养的恶性疟原虫的体外增殖具有明显的抑制作用;抑制强度取决于剂量和作用时间。在McAb—IgG浓度为0.6mg/ml时,上述7株McAb的抑制活性均在94％以上。在6株McAb中,有4株能促进巨噬细胞吞噬疟原虫而发挥调理作用。在7株McAb中,有4株能加强腹腔细胞杀伤和杀死疟原虫而表现出细胞毒活性。结果提示,恶性疟原虫McAb似有“多功能”、“双功能”和”单功能”之分,用“多功能性McAb”纯化的疟疾抗原,在制备疟疾亚单位疫苗方面可能更有意义。

Inhibitory, opsonic, and cytotoxic activities of monoclonal antibodies against asexual erythrocytic stages of Plasmodium Falciparum

A range of monoclonal antibodies specific for P. falciparum were tested in vitro for their abilities to inhibit the multiplication of a partially synchronized culture of P. falciparum, to augment the phagocytosis of the parasites by macro-phages, and to enhance the killing of parasites by peritoneal cells depleted of adherent cells. Seven of 17 monoclonal antibodies, ranging from culture supernatant and ascitic fluid to purified IgG, were shown to have a dose-and time-dependent inhibition of the parasite growth in vitro. At a concentration of 0.6mg/ml, the inhibitory capacity of these monoclonal IgG were above 94% over a 3-day culture period, much higher than that of the relevant polyclonal TgG. Four of six monoclonal antibodies tested augmented the phagocytosis of the parasites by macrophages, which occurred as a result of the opsonization of the parasites.Four of seven monoclonal antibodies examined showed cytotoxic activity on malaria parasites. Peritoneal cells depleted of adherent cells were capable of killing the parasites in the presence of monoclonal antibodies. The results indicate that there may be "monofunction", bifunction",and "multifunction" types of monoclonal antibodies against P. falci-parum.The putative protective antigen of malaria parasite purified by"multifunctio-nal monoclonal antibody" affinity chromatography may have potential interest as a vaccine against the parasite.