Induction of cell migration by transient Wolbachia pipientis infection in Aedes albopictus cell line

Wolbachia is a genus of maternally transmitted bacteria having an endosymbiotic relationship with arthropod and nematode species. These bacteria manipulate host development, sex-determination, and reproduction. In addition, they are known to potentially suppress vector-borne diseases by interfering with pathogen transmission. Although the occurrence of Wolbachia infection in insects has been known, the underlying mechanisms that mediate their interactions remain unclear. To examine the influence of Wolbachia adaptation on the host, we infected wAlbA and wAlbB strain from Aedes albopictus into the C6/36 cell line derived from Ae. albopictus. The transient Wolbachia infection was characterized by induction of cell migration without cell proliferation. The production of nitrite and reactive oxygen species (ROS) was induced by transient Wolbachia infection. Cells with transient Wolbachia infection exhibited elevated expression of Toll-like receptor 6 (TLR6) and myeloid differentiation primary response 88 (Myd88). Conversely, the expression of TLR2, TLR4, TLR7, Cactus, Ankyrin, and Argonaute2 (AGO2) was inhibited upon Wolbachia infection. These results suggest that Wolbachia has an influence on the cell migration ability as well as host innate immune response in vitro. Considering these results, transient Wolbachia strain transfer in C6/36 cells might be an important approach for studying Wolbachia-host interactions and might help gain a deeper understanding of the early adaptation of Wolbachia in the original host insect.