Department of Pathology and Microbiology, Division of Microbiology, Nihon University School of Medicine, Tokyo 173-8610, Japan.
Viruses. 2022 May 27;14(6):1169. doi: 10.3390/v14061169.
We recently published an article about myelin oligodendrocyte glycoprotein-independent rubella infection of keratinocytes in vitro, in which first-trimester trophoblast cells were shown as rubella virus (RuV)-resistant. Given an incident rate as high as 90% of congenital rubella syndrome in the first eight weeks of pregnancy, the RuV infection of first-trimester trophoblasts is considered key to opening the gate to transplacental transmission mechanisms. Therefore, with this study, we aimed to verify the susceptibility/resistance of first-trimester trophoblast cell lines, HTR-8/SVneo and Swan.71, against RuV. Cells cultured on multi-well plates were challenged with a RuV clinical strain at a multiplicity of infection from 5 to 10 for 3 h. The infectivity was investigated by immunofluorescence (IF) assay and flow cytometry (FCM) analysis. Supernatants collected during the post-infection period were used to determine virus-progeny production. The scattered signaling of RuV infection of these cells was noted by IF assay, and the FCM analysis showed an average of 4-5% of gated cells infected with RuV. In addition, a small but significant production of virus progeny was also observed. In conclusion, by employing appropriate approaches, we determined the low infectivity of RuV in first-trimester trophoblast cell lines but not resistance as in our previous report.
我们最近发表了一篇关于体外培养的角质形成细胞中髓鞘少突胶质细胞糖蛋白非依赖性风疹病毒感染的文章，其中显示早孕滋养层细胞对风疹病毒（RuV）具有抗性。鉴于妊娠头 8 周先天性风疹综合征的发生率高达 90%，因此，早孕滋养层细胞的 RuV 感染被认为是打开胎盘传播机制的关键。因此，本研究旨在验证早孕滋养层细胞系 HTR-8/SVneo 和 Swan.71 对 RuV 的易感性/抗性。将细胞接种在多孔板上，用 5 至 10 的感染复数（MOI）感染临床分离株 RuV 3 小时。通过免疫荧光（IF）检测和流式细胞术（FCM）分析来检测感染性。在感染后的时间段内收集上清液以确定病毒产量。IF 检测显示这些细胞的 RuV 感染呈现散在信号，FCM 分析显示平均有 4-5%的门控细胞被 RuV 感染。此外，还观察到少量但显著的病毒产物生成。总之，通过采用适当的方法，我们确定了 RuV 在早孕滋养层细胞系中的低感染性，但与我们之前的报告不同，没有抗性。
