Blitvich Bradley J, Wang Tian, Saxena Vandana, Zeng Shemin, Harmon Karen M, Raymond Matthew D, Goins Kenneth M, Reed Cynthia R, Mullins Robert F, Greiner Mark A
Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa.
Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas.
Am J Trop Med Hyg. 2016 Nov 2;95(5):1185-1191. doi: 10.4269/ajtmh.16-0256. Epub 2016 Sep 26.
The purpose of this study was to determine the in vitro and ex vivo susceptibility of human corneal cells to West Nile virus (WNV) infection and evaluate the ability of the virus to disseminate to the corneas of infected mice. Human corneal epithelial cells were challenged with WNV, incubated for 1-6 days, and tested for evidence of WNV infection. Viral RNA and antigen were detected at every time point, and the virus reached a peak titer of 2.5 × 10 plaque-forming units (pfu)/mL at 3 days postinoculation (PI). Corneas procured from donors were incubated in culture dishes containing WNV for 1-5 days and tested for evidence of WNV. Viral RNA and antigen were detected, and the virus reached a mean peak titer of 4.9 × 10 pfu/mL at 5 days PI. Mice were inoculated intraperitoneally with WNV, and their eyes were harvested at 2, 5, and 8 days PI and tested for evidence of WNV. Viral RNA was detected in corneas of four of nine systemically infected mice as early as 2 days PI. We conclude that human corneal cells support WNV replication in vitro and ex vivo, and WNV may disseminate into the corneas of experimentally infected mice. These findings indicate that corneal transmission cannot be ruled out as a novel mode of human-to-human WNV transmission and additional experiments should be conducted to assess this risk further.
本研究的目的是确定人角膜细胞对西尼罗河病毒（WNV）感染的体外和离体易感性，并评估该病毒传播至感染小鼠角膜的能力。用人角膜上皮细胞感染WNV，孵育1 - 6天，并检测WNV感染的证据。在每个时间点均检测到病毒RNA和抗原，接种后3天（PI）病毒滴度达到峰值2.5×10蚀斑形成单位（pfu）/mL。从供体获取的角膜在含有WNV的培养皿中孵育1 - 5天，并检测WNV感染的证据。检测到病毒RNA和抗原，接种后5天病毒平均峰值滴度达到4.9×10 pfu/mL。给小鼠腹腔接种WNV，在接种后2天、5天和8天采集其眼睛并检测WNV感染的证据。早在接种后2天，在9只全身感染小鼠中的4只小鼠的角膜中检测到病毒RNA。我们得出结论，人角膜细胞在体外和离体条件下支持WNV复制，并且WNV可能传播至实验感染小鼠的角膜。这些发现表明，不能排除角膜传播作为WNV人传人新途径的可能性，应开展更多实验以进一步评估这种风险。
