同一克隆两个不同变异体的伊氏锥虫在兔体内抗原变异研究

STUDY ON ANTIGENIC VARIATION OF DIFFERENT VATS TRYPANOSOMA EVANSI DERIVING FROM A CLONE STOCK IN RABBITS

为了解伊氏锥虫在兔体内感染后期抗原变异的情况及比较同一克隆不同变异体锥虫在兔体内抗原变异情况,用伊氏锥虫安徽株单虫克隆ShTat1.2感染兔,在兔体30天中每隔3天及感染后51、54、57天(兔58天死亡)分离兔血中锥虫并克隆,获得13个克隆锥虫群体,经间接免疫荧光试验和ABC酶标记试验鉴定为10个抗原性互不相同的抗原变异体(VariableAntigenType,VAT),其中早期(感染锥虫30天内)9个,后期1个;早期锥虫一般3天发生1次抗原变异,后期7天内无变异。用同样的血清学方法检测,得知ShTat1.2锥虫感染早期的VATS中的6个与ShTat1.1锥虫在同种动物体内同期获得的VATS相同,但VATS出现次序不同。结果表明伊氏锥虫感染早期比感染后期抗原变异频繁,同一克隆锥虫不同变异体在兔体内变异次序不相同。

In order to understand antigenic variation in Trypanosoma evansi in 1ast course of infection in rabbit and compare the antigenic variation of different variable antigen types (VATS) deriving from a cloned stock in rabbit,a rabbit was infected with a clone ShTat1.2 from Anhui stock of T.eveansi , blood was collected from the rabbit every three days during the first 30 days and the 51th, 54th, 57th day after infection,13 cloned trypanosome populations were gotten.Ten VATS were monitored and characterized from those populations by indirect immunoflurescence test (IFT) and avidin biotin enzyme immunoassay (ABC EIA),9 of 10 VATS were in the first 30 days and 1 in last 7days after infection.The Trypanosomes often changed their antigen every three days in the early stage,but didn’t in the last 7 days after infection.By the two tests,the result also showed 6 of 9 VATS of trypanosome ShTat1.2 during the early time of infection were appeared in the rabbit infected with the trypanosome ShTat1.1 during the same time,but the sequences of VATS of ShTat1.1 was different from that of ShTat1.2. It is concluded that antigenic variation of T.evansi in early stage of infection is higher than in 1ast stage,and the sequences of two VATS deriving from a clone of T.evensi differ.