Behnke J M, Ali N M, Jenkins S N
Ann Trop Med Parasitol. 1984 Oct;78(5):509-17. doi: 10.1080/00034983.1984.11811857.
Large, single-pulse laboratory infections with Trichuris muris are rejected by mice before patency, but low-level infections of fewer than 20 worms survive for long periods. Data are presented to show that the threshold at which an effective immune response takes place is significantly higher in mice concurrently infected with Nematospiroides dubius. In control CFLP mice trickle infections did not survive to maturity but in the slower responder C57 Bl10 mice egg production began on Day 35 and continued for a further seven weeks, with some mature worms present at autopsy. Concurrent infection with N. dubius resulted in trickle infections, T. muris surviving much better than in control mice, although these still showed some resistance to T. muris. It is suggested that the results support the hypothesis that T. muris elicits concomitant immunity in the host. Thus, the first worms to establish survive to patency at which time they can no longer be removed by the host, but once the immunological threshold has been exceeded incoming larvae are rejected by the host. Such a survival strategy would be very useful to T. muris in the wild.
用小鼠鞭虫进行的大型单脉冲实验室感染在感染成熟前会被小鼠排斥，但感染少于20条虫的低水平感染会长期存活。数据表明，同时感染双盲肠线虫的小鼠产生有效免疫反应的阈值显著更高。在对照CFLP小鼠中，点滴感染无法存活至成熟，但在反应较慢的C57 Bl10小鼠中，产卵于第35天开始，并持续了另外七周，尸检时发现有一些成熟虫体。同时感染双盲肠线虫导致点滴感染，小鼠鞭虫的存活情况比对照小鼠好得多，尽管对照小鼠对小鼠鞭虫仍有一定抵抗力。研究表明，这些结果支持小鼠鞭虫在宿主体内引发伴随免疫的假说。因此，最初建立感染的虫体存活至感染成熟，此时宿主无法再将其清除，但一旦超过免疫阈值，宿主就会排斥新进入的幼虫。这种生存策略对野外的小鼠鞭虫非常有用。
