关键词: 免疫血清, 治疗血清, 约氏疟原虫, 裂殖子, 有效成分, 原虫血症, 裂殖体, 被动转移, 抗原, 感染红细胞

Abstract: Sera were collccted from mice immunized separately with schizonts, merozoitcs or different parasite stages, or from mice which had been recovered from Plasmodium yoelii yoelii infection. The effect of protection of cach serum against P. y. infection was assayed by passivc transfer technique. It was shown that only sera collected from mice which either had been trcated with chloroquine or had been naturally recovcred from P. y. infections can transfer certain dcgree of resistance to normal mice. The cffectivc sera delayed the appearance and the peak of parasitemia, and prolonged the survival time of the challenged mice. After these sera were fractionatcd by 50%(NH4)2SO4 precipitation, the prccipitated fraction showed similar degree of protection as the non-fractionated sera. Chloroquine-treated serum was shown to be able to inhibit the invasion of new erythrocytes by marozoite in vitro. 35S-methionine-labelcd antigens were precipitated by protective or non-protective sera and the bands were compared on SDS-PAGE and autoradiogram. Since thc antigcn bands of 245, 210, 190, 156 and 130 KD can only bc precipitated by protective sera but not by non-protectivc sera, it is possible that the protection of chloroquine-treated serum is induced by the specific antibodies against the above antigens.