Dwinger R H, Luckins A G, Murray M, Rae P, Moloo S K
Parasite Immunol. 1986 Jul;8(4):293-305. doi: 10.1111/j.1365-3024.1986.tb00847.x.
When domestic ruminants cyclically infected with Trypanosoma congolense are superinfected with a different serodeme of the same species, an interference phenomenon occurs which delays the development of the second cyclical infection. Experiments were carried out to investigate the influence of the time interval between the two infections on the degree of interference and to follow the course of the superinfection clinically, serologically and histologically. Goats infected with tsetse-transmitted T. congolense IL 1587 were either infected simultaneously or 7, 14, 18, 28 or 35 days later with a different serodeme, T. congolense IL 1180. Skin reactions due to superinfection were either absent or smaller in size and delayed in onset compared with control animals undergoing a primary infection with T. congolense IL 1180 which had been initiated by tsetse fly bites. All animals were treated with the trypanocidal drug Berenil 21 days after superinfection and 3 weeks later challenged with T. congolense IL 1180 using tsetse flies. The goats that had been infected simultaneously with the two serodemes were immune to the homologous challenge, but 11 (85%) of the animals that had been superinfected were not. The effect of interference on the host immune response to T. congolense IL 1180 was most marked in animals superinfected at day 7; thereafter there was evidence that the ability to respond immunologically against secondary infection was gradually recovered. Histological examination of skin removed 7 days after a simultaneous infection of goats with two serodemes, showed trypanosomes and a cellular reaction similar to that following infection with a single serodeme. In skin removed 7 days after superinfection of goats that had been infected for 7 days, the cellular response was less pronounced and trypanosomes were not seen, although by 14 to 16 days numerous trypanosomes were present and there was a marked cellular infiltrate. It is postulated that the presence or absence of a factor induced shortly after initiation of a trypanosome infection in the skin of goats might delay parasite development when metacyclic trypanosomes are deposited by tsetse following superinfection.
当周期性感染刚果锥虫的家养反刍动物被同一物种的不同血清型再次感染时，会出现一种干扰现象，这种现象会延迟第二次周期性感染的发展。进行了实验以研究两次感染之间的时间间隔对干扰程度的影响，并从临床、血清学和组织学方面追踪再次感染的进程。感染采采蝇传播的刚果锥虫IL 1587的山羊，要么同时被不同血清型的刚果锥虫IL 1180感染，要么在7、14、18、28或35天后被感染。与通过采采蝇叮咬初次感染刚果锥虫IL 1180的对照动物相比，再次感染引起的皮肤反应要么不存在，要么尺寸较小且发作延迟。所有动物在再次感染21天后用杀锥虫药物贝尼尔治疗，3周后用采采蝇对其进行刚果锥虫IL 1180攻击。同时感染两种血清型的山羊对同源攻击具有免疫力，但11只（85%）再次感染的动物没有免疫力。干扰对宿主针对刚果锥虫IL 1180免疫反应的影响在第7天再次感染的动物中最为明显；此后有证据表明，对二次感染产生免疫反应的能力逐渐恢复。对同时感染两种血清型的山羊皮肤在感染7天后进行组织学检查，发现有锥虫以及类似于单一血清型感染后的细胞反应。在感染7天后再次感染的山羊皮肤在7天后切除的样本中，细胞反应不太明显，未发现锥虫，尽管到14至16天时出现了大量锥虫且有明显的细胞浸润。据推测，山羊皮肤中锥虫感染开始后不久诱导产生的一种因子的存在与否，可能会在再次感染后采采蝇传播循环后期锥虫时延迟寄生虫的发育。
