Cunningham D S, Brewer T E, Kuhn R E, Craig W H
J Parasitol. 1981 Aug;67(4):475-80.
Trypanosoma cruzi releases a factor (SCAF) when grown in vitro which decomplements normal mouse, human, and guinea pig sera. The production and potency of SCAF was dependent on the density of cultured parasites, parasite viability and proliferative capacity, and duration of culture. The in vitro interaction between SCAF and serum complement (C') occurred rapidly and was complete within 30 min of mixing. The administration of SCAF to normal mice resulted in up to 50% reduction in hemolytic C' activity, whereas SCAF had no effect on the C' levels in mice infected wit T. cruzi for more than 10 days. The active moiety of SCAF was shown to be a nonproteinaceous substance(s) with a molecular weight of approximately 23,000 daltons.
克氏锥虫在体外培养时会释放一种因子（SCAF），该因子可使正常小鼠、人类和豚鼠血清的补体失活。SCAF的产生和效力取决于培养寄生虫的密度、寄生虫的活力和增殖能力以及培养时间。SCAF与血清补体（C'）在体外的相互作用迅速发生，混合后30分钟内即可完成。给正常小鼠注射SCAF可使溶血C'活性降低多达50%，而SCAF对感染克氏锥虫超过10天的小鼠的C'水平没有影响。SCAF的活性部分被证明是一种分子量约为23,000道尔顿的非蛋白质物质。
