Chalenko Yaroslava, Kolbasova Olga, Pivova Elena, Abdulkadieva Mariam, Povolyaeva Olga, Kalinin Egor, Kolbasov Denis, Ermolaeva Svetlana
Laboratory of Ecology of Pathogenic Bacteria, Gamaleya Research Center of Epidemiology and Microbiology, Moscow, Russia.
Federal Research Center for Virology and Microbiology (FRCVM), Volginsky, Russia.
Front Microbiol. 2022 Feb 7;13:825076. doi: 10.3389/fmicb.2022.825076. eCollection 2022.
The facultative intracellular pathogen is of major veterinary importance in small ruminants. Nevertheless, details of interactions with cells of small ruminants are not fully established. To study the potential of to infect sheep cells, we used the finite sheep kidney cell line (shKEC), which was infected with the wild-type strain EGDe. The invasion efficiency was 0.015 ± 0.004%. The invasion factor InlB was critically important for invasion, and inlB gene deletion almost prevented invasion into shKEC cells. Comparison of the potential of phylogenetically defined InlB isoforms to restore the invasive phenotype of the EGDeΔinlB strain demonstrated that although all InlB isoforms restored invasion of the EGDeΔinlB strain into shKEC cells, the InlB isoforms typical of highly virulent ruminant strains of the clonal complexes CC1 and CC7 were more efficient than isoforms typical of CC2 and CC9 strains (which are less virulent toward ruminants) in supporting invasion. effectively multiplied with a doubling of time in about 90 min after they entered the sheep cells. Intracellular bacteria moved using the well-known actin polymerization mechanism. Cell-to-cell spreading was restricted to the infection of a few tens of neighboring cells for 7 days. Overall, the obtained results demonstrated that (i) InlB is required for invasion into sheep cells, (ii) InlB isoforms might be important for hypervirulence of certain clonal groups toward ruminants, and (iii) effectively multiplies in ovine cells once entered.
这种兼性细胞内病原体对小型反刍动物具有重要的兽医意义。然而，其与小型反刍动物细胞相互作用的细节尚未完全明确。为了研究其感染绵羊细胞的潜力，我们使用了有限的绵羊肾细胞系（shKEC），并用野生型菌株EGDe对其进行感染。侵袭效率为0.015±0.004%。侵袭因子InlB对侵袭至关重要，inlB基因缺失几乎阻止了其侵袭shKEC细胞。对系统发育定义的InlB亚型恢复EGDeΔinlB菌株侵袭表型的潜力进行比较表明，尽管所有InlB亚型都恢复了EGDeΔinlB菌株对shKEC细胞的侵袭，但克隆复合体CC1和CC7的高毒力反刍动物菌株典型的InlB亚型在支持侵袭方面比CC2和CC9菌株（对反刍动物毒力较低）典型的亚型更有效。它们进入绵羊细胞后，大约在90分钟内有效增殖，倍增时间约为90分钟。细胞内细菌利用著名的肌动蛋白聚合机制移动。细胞间传播在7天内仅限于感染几十相邻细胞。总体而言，获得的结果表明：（i）侵袭绵羊细胞需要InlB；（ii）InlB亚型可能对某些克隆群对反刍动物的高毒力很重要；（iii）一旦进入绵羊细胞，它就能有效增殖。
