Wang Hsuan-Yuan, Taher Husam, Kreklywich Craig N, Schmidt Kimberli A, Scheef Elizabeth A, Barfield Richard, Otero Claire E, Valencia Sarah M, Crooks Chelsea M, Mirza Anne, Woods Kelsey, Burgt Nathan Vande, Kowalik Timothy F, Barry Peter A, Hansen Scott G, Tarantal Alice F, Chan Cliburn, Streblow Daniel N, Picker Louis J, Kaur Amitinder, Früh Klaus, Permar Sallie R, Malouli Daniel
bioRxiv. 2023 Jun 16:2023.06.15.545169. doi: 10.1101/2023.06.15.545169.
Congenital cytomegalovirus (cCMV) infection is the leading infectious cause of neonatal neurological impairment but essential virological determinants of transplacental CMV transmission remain unclear. The pentameric complex (PC), composed of five subunits, glycoproteins H (gH), gL, UL128, UL130, and UL131A, is essential for efficient entry into non-fibroblast cells . Based on this role in cell tropism, the PC is considered a possible target for CMV vaccines and immunotherapies to prevent cCMV. To determine the role of the PC in transplacental CMV transmission in a non-human primate model of cCMV, we constructed a PC-deficient rhesus CMV (RhCMV) by deleting the homologues of the HCMV PC subunits UL128 and UL130 and compared congenital transmission to PC-intact RhCMV in CD4+ T cell-depleted or immunocompetent RhCMV-seronegative, pregnant rhesus macaques (RM). Surprisingly, we found that the transplacental transmission rate was similar for PC-intact and PC-deleted RhCMV based on viral genomic DNA detection in amniotic fluid. Moreover, PC-deleted and PC-intact RhCMV acute infection led to similar peak maternal plasma viremia. However, there was less viral shedding in maternal urine and saliva and less viral dissemination in fetal tissues in the PC-deleted group. As expected, dams inoculated with PC-deleted RhCMV demonstrated lower plasma IgG binding to PC-intact RhCMV virions and soluble PC, as well as reduced neutralization of PC-dependent entry of the PC-intact RhCMV isolate UCD52 into epithelial cells. In contrast, binding to gH expressed on the cell surface and neutralization of entry into fibroblasts by the PC-intact RhCMV was higher for dams infected with PC-deleted RhCMV compared to those infected with PC-intact RhCMV. Our data demonstrates that the PC is dispensable for transplacental CMV infection in our non-human primate model.
Congenital CMV transmission frequency in seronegative rhesus macaques is not affected by the deletion of the viral pentameric complex.
先天性巨细胞病毒（cCMV）感染是新生儿神经功能障碍的主要感染原因，但经胎盘传播CMV的关键病毒学决定因素仍不清楚。由糖蛋白H（gH）、gL、UL128、UL130和UL131A五个亚基组成的五聚体复合物（PC）对于有效进入非成纤维细胞至关重要。基于其在细胞嗜性中的这一作用，PC被认为是CMV疫苗和免疫疗法预防cCMV的一个可能靶点。为了在cCMV的非人灵长类动物模型中确定PC在经胎盘传播CMV中的作用，我们通过删除HCMV PC亚基UL128和UL130的同源物构建了一种PC缺陷型恒河猴巨细胞病毒（RhCMV），并在CD4 + T细胞耗竭或免疫功能正常的RhCMV血清阴性的怀孕恒河猴（RM）中，将先天性传播与PC完整的RhCMV进行比较。令人惊讶的是，基于羊水病毒基因组DNA检测，我们发现PC完整和PC缺失的RhCMV经胎盘传播率相似。此外，PC缺失和PC完整的RhCMV急性感染导致的母体血浆病毒血症峰值相似。然而，PC缺失组母体尿液和唾液中的病毒脱落较少，胎儿组织中的病毒传播也较少。正如预期的那样，接种PC缺失型RhCMV的母猴血浆IgG与PC完整的RhCMV病毒粒子和可溶性PC的结合较低，以及对PC完整的RhCMV分离株UCD52依赖PC进入上皮细胞的中和作用降低。相比之下，与感染PC完整的RhCMV的母猴相比，感染PC缺失型RhCMV的母猴对细胞表面表达的gH的结合以及对PC完整的RhCMV进入成纤维细胞的中和作用更高。我们的数据表明，在我们的非人灵长类动物模型中，PC对于经胎盘CMV感染是可有可无的。
血清阴性恒河猴中先天性CMV传播频率不受病毒五聚体复合物缺失的影响。
