Department of Biochemistry and Biophysics, University of California, San Franciscogrid.266102.1, San Francisco, California, USA.
University of California, Berkeley-University of California, San Francisco Graduate Program in Bioengineering, University of California, San Francisco, San Francisco, California, USA.
mBio. 2022 Jun 28;13(3):e0020522. doi: 10.1128/mbio.00205-22. Epub 2022 May 3.
Lymphocytic choriomeningitis virus (LCMV) is a well-studied mammarenavirus that can be fatal in congenital infections. However, our understanding of LCMV and its interactions with human host factors remains incomplete. Here, host determinants affecting LCMV infection were investigated through a genome-wide CRISPR knockout screen in A549 cells, a human lung adenocarcinoma line. We identified and validated a variety of novel host factors that play a functional role in LCMV infection. Among these, knockout of the sialomucin CD164, a heavily glycosylated transmembrane protein, was found to ablate infection with multiple LCMV strains but not other hemorrhagic mammarenaviruses in several cell types. Further characterization revealed a dependency of LCMV entry on the cysteine-rich domain of CD164, including an N-linked glycosylation site at residue 104 in that region. Given the documented role of LCMV with respect to transplacental human infections, CD164 expression was investigated in human placental tissue and placental cell lines. CD164 was found to be highly expressed in the cytotrophoblast cells, an initial contact site for pathogens within the placenta, and LCMV infection in placental cells was effectively blocked using a monoclonal antibody specific to the cysteine-rich domain of CD164. Together, this study identifies novel factors associated with LCMV infection of human tissues and highlights the importance of CD164, a sialomucin that previously had not been associated with viral infection. Lymphocytic choriomeningitis virus (LCMV) is a human-pathogenic mammarenavirus that can be fatal in congenital infections. Although frequently used in the study of persistent infections in the field of immunology, aspects of this virus's life cycle remain incomplete. For example, while viral entry has been shown to depend on a cell adhesion molecule, DAG1, genetic knockout of this gene allows for residual viral infection, implying that additional receptors can mediate cell entry. The significance of our study is the identification of host factors important for successful infection, including the sialomucin CD164, which had not been previously associated with viral infection. We demonstrated that CD164 is essential for LCMV entry into human cells and can serve as a possible therapeutic target for treatment of congenital infection.
淋巴细胞性脉络丛脑膜炎病毒(Lymphocytic choriomeningitis virus,LCMV)是一种研究充分的沙粒病毒,可在先天性感染中致命。然而,我们对 LCMV 及其与人类宿主因素的相互作用的理解仍不完整。在这里,通过在人类肺腺癌细胞系 A549 细胞中的全基因组 CRISPR 敲除筛选,研究了影响 LCMV 感染的宿主决定因素。我们鉴定并验证了多种新型宿主因子,它们在 LCMV 感染中发挥功能作用。在这些因子中,敲除高度糖基化的跨膜蛋白唾液酸粘蛋白 CD164,可消除多种 LCMV 株的感染,但不会消除其他出血性沙粒病毒在几种细胞类型中的感染。进一步的特征分析显示,LCMV 进入依赖于 CD164 的富含半胱氨酸结构域,包括该区域中残基 104 处的一个 N 连接糖基化位点。鉴于 LCMV 在胎盘人类感染方面的已有作用,我们研究了人胎盘组织和胎盘细胞系中的 CD164 表达。发现 CD164 在滋养细胞中高度表达,滋养细胞是病原体在胎盘内的初始接触部位,并且使用针对 CD164 的富含半胱氨酸结构域的单克隆抗体有效阻断了胎盘细胞中的 LCMV 感染。总之,这项研究确定了与人类组织中 LCMV 感染相关的新型因素,并强调了 CD164 的重要性,CD164 是一种以前与病毒感染无关的唾液酸粘蛋白。淋巴细胞性脉络丛脑膜炎病毒(Lymphocytic choriomeningitis virus,LCMV)是一种对人类具有致病性的沙粒病毒,在先天性感染中可能致命。尽管它经常在免疫学领域中用于研究持续性感染,但该病毒生命周期的某些方面仍不完整。例如,虽然已经表明病毒进入依赖于细胞粘附分子 DAG1,但该基因的基因敲除允许残留的病毒感染,这意味着其他受体可以介导细胞进入。我们研究的意义在于鉴定对成功感染至关重要的宿主因素,包括以前与病毒感染无关的唾液酸粘蛋白 CD164。我们证明 CD164 是 LCMV 进入人类细胞所必需的,并且可以作为治疗先天性感染的潜在治疗靶标。