Phosphatidylserine (PS) is an anionic phospholipid that is usually localized in the inner leaflets of the plasma membrane. However, the enzyme scramblase catalyzes the externalization of PS on the outer leaflet of the plasma membrane during apoptosis or cellular stress. This event prompts the recognition of PS displaying cells by phagocytes leading to “apoptotic clearance.” Multiple PS receptors (PSRs) mediate this process including members from the TAM (Tyro3, Axl, Mertk) receptor Tyrosine kinases (RTKs) by interacting with PS via bridging proteins like Gas6 and ProS1. Ironically, this network (PS/TAM) that evolved for boosting cellular health through clearance of apoptotic and necrotic cells, has been manoeuvred by pathogens and tumor cells using “apoptotic mimicry.” Enveloped viruses, responsible for most of the lethal epidemics and pandemics including the current SARS-CoV2 outbreak, have employed apoptotic mimicry to their advantage. In the current chapter, we summarize the existing knowledge regarding the involvement of PS/Gas6, ProS1/TAM in facilitating infectivity in a diverse set of cell lines, animals as well as organoids. This network executes a largely proviral role in facilitating infection as seen with Zika, Ebola, Influenza and Dengue viruses. However, this response varies with strains and the cells infected, and in some cases, this same signaling displays an antiviral function. We also report multiple studies that have used neutralizing antibodies and small molecule inhibitors in successfully reducing viral replication and ameliorating pathogenicity. Knowledge about this unique signaling pathway and measures that can be taken to inhibit it is most valuable now given how enveloped viruses lead to plagues on the entire globe.

磷脂酰丝氨酸 (PS) 是一种阴离子磷脂，通常位于质膜的内小叶中。然而，在细胞凋亡或细胞应激期间，加扰酶催化质膜外小叶上 PS 的外化。该事件促使吞噬细胞识别显示 PS 的细胞，从而导致“细胞凋亡清除”。多个 PS 受体 (PSR) 介导这一过程，包括来自TAM 的成员（Tyro 3、Axl、Mertk) 受体酪氨酸激酶 (RTK) 通过桥接蛋白（如 Gas6 和 ProS1）与 PS 相互作用。具有讽刺意味的是，这种通过清除凋亡和坏死细胞来促进细胞健康的网络 (PS/TAM) 已被病原体和肿瘤细胞使用“凋亡模拟”操纵。包膜病毒是造成包括当前 SARS-CoV2 爆发在内的大多数致命流行病和大流行病的罪魁祸首，它们利用了凋亡模拟来发挥自己的优势。在本章中，我们总结了有关 PS/Gas6、ProS1/TAM 参与促进多种细胞系、动物和类器官感染的现有知识。正如寨卡病毒、埃博拉病毒、流感病毒和登革热病毒所见，该网络在促进感染方面发挥着主要的前病毒作用。然而，这种反应因菌株和感染的细胞而异，在某些情况下，这种相同的信号显示出抗病毒功能。我们还报告了多项使用中和抗体和小分子抑制剂成功减少病毒复制和改善致病性的研究。考虑到包膜病毒如何导致全球瘟疫，关于这种独特的信号通路和可以采取的抑制措施的知识现在最有价值。