Li Qiang, Sun Yalan, Wang Guoxiu, Liu Xusheng
Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, 152 Luoyu Road, Wuhan 430079, China.
J Insect Physiol. 2009 Jan;55(1):47-50. doi: 10.1016/j.jinsphys.2008.10.005. Epub 2008 Nov 26.
Little is known about the mechanism by which mermithid nematodes avoid encapsulation responses of insect hosts. In this study, we investigated the influence of the mermithid nematode Ovomermis sinensis on host Helicoverpa armigera hemocyte number, encapsulation activity, spreading behavior and cytoskeleton. Parasitism by O. sinensis caused a significant increase in the total hemocyte counts (THC) and plasmatocyte numbers of H. armigera. However, in vivo encapsulation assays revealed that hemocyte encapsulation abilities of H. armigera were suppressed by O. sinensis. Moreover, parasitism by O. sinensis changed the spreading behavior and cytoskeletons of the host hemocytes. The results suggested that O. sinensis could actively suppress the hemocyte immune response of its host, possibly by destroying the host hemocyte cytoskeleton. This is the first report of a possible mechanism by which mermithid nematodes suppress encapsulation responses of insect hosts.
对于索线虫避免昆虫宿主包囊化反应的机制，我们了解甚少。在本研究中，我们调查了中华卵索线虫对宿主棉铃虫血细胞数量、包囊化活性、铺展行为和细胞骨架的影响。中华卵索线虫寄生导致棉铃虫的总血细胞计数（THC）和浆血细胞数量显著增加。然而，体内包囊化试验表明，中华卵索线虫抑制了棉铃虫血细胞的包囊化能力。此外，中华卵索线虫寄生改变了宿主血细胞的铺展行为和细胞骨架。结果表明，中华卵索线虫可能通过破坏宿主血细胞骨架来主动抑制其宿主的血细胞免疫反应。这是关于索线虫抑制昆虫宿主包囊化反应可能机制的首次报道。
