title: Effects of the mermithid nematode Ovomermis sinensis on the hemocytes of its host Helicoverpa armigera.
abstract: 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.
authors.affiliation: Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, 152 Luoyu Road, Wuhan 430079, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Li
authors.forename: Yalan
authors.initials: Y
authors.lastname: Sun
authors.forename: Guoxiu
authors.initials: G
authors.lastname: Wang
authors.forename: Xusheng
authors.initials: X
authors.lastname: Liu
mesh_terms: D000818:Animals; D002452:Cell Count; D003599:Cytoskeleton / Q000502:physiology; D006434:Hemocytes / Q000166:cytology / Q000276:immunology / Q000469:parasitology*; D006790:Host-Parasite Interactions; D008632:Mermithoidea / Q000502:physiology*; D009036:Moths / Q000276:immunology / Q000469:parasitology*