Université de Bordeaux 2, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France.
INRA, Centre de Bordeaux-Aquitaine, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France.
Microbiology (Reading). 2010 Apr;156(Pt 4):1097-1107. doi: 10.1099/mic.0.035063-0. Epub 2009 Dec 17.
Successful transmission of Spiroplasma citri by its leafhopper vector requires a specific interaction between the spiroplasma surface and the insect cells. With the aim of studying these interactions at the cellular and molecular levels, a cell line, named Ciha-1, was established using embryonic tissues from the eggs of the S. citri natural vector Circulifer haematoceps. This is the first report, to our knowledge, of a cell line for this leafhopper species and of its successful infection by the insect-transmissible strain S. citri GII3. Adherence of the spiroplasmas to the cultured Ciha-1 cells was studied by c.f.u. counts and by electron microscopy. Entry of the spiroplasmas into the insect cells was analysed quantitatively by gentamicin protection assays and qualitatively by double immunofluorescence microscopy. Spiroplasmas were detected within the cell cytoplasm as early as 1 h after inoculation and survived at least 2 days inside the cells. Comparing the insect-transmissible GII3 and non-insect-transmissible 44 strains revealed that adherence to and entry into Ciha-1 cells of S. citri 44 were significantly less efficient than those of S. citri GII3.
柑橘螺原体的成功传播需要其叶蝉媒介与昆虫细胞之间的特定相互作用。为了在细胞和分子水平上研究这些相互作用，我们使用柑橘螺原体天然媒介柑橘红蜘蛛的胚胎组织建立了一个名为 Ciha-1 的细胞系。据我们所知，这是首次为该叶蝉物种建立细胞系，并成功感染了昆虫可传播的螺原体 GII3 株。通过 c.f.u. 计数和电子显微镜研究了螺原体对培养的 Ciha-1 细胞的粘附。通过庆大霉素保护试验进行定量分析和双重免疫荧光显微镜进行定性分析，研究了螺原体进入昆虫细胞的情况。在接种后 1 小时，螺原体就已在细胞质中被检测到，并在细胞内至少存活了 2 天。比较昆虫可传播的 GII3 株和非昆虫可传播的 44 株发现，柑橘螺原体 44 株对 Ciha-1 细胞的粘附和进入能力明显低于柑橘螺原体 GII3 株。
