Viral apoptotic mimicry and the role of phosphatidylserine receptors

In our 2021 mSphere of Influence article (M. A. Brindley, mSphere 6:e00034-21, 2021, https://doi.org/10.1128/mSphere.00034-21), we discussed the concept of viral apoptotic mimicry and how the seminal study by Mercer and Helenius proposed a new paradigm in how viruses can gain entry into cells (J. Mercer and A. Helenius, Science 320:531-535, 2008, https://doi.org/10.1126/science.1155164). Building on the observation that enveloped viral lipids can mediate viral entry, subsequent studies have expanded these observations and further defined the lipids that can initiate infection, the cellular receptors involved, as well as started to explore how viruses obtain their membrane and potentially alter the lipid environment to enhance infection. Exploring the role viral apoptotic mimicry plays in the host has proven more difficult, as many of the receptors that interact with viral lipids also play key roles in immune signaling. This Full Circle review summarizes the lipids and receptors that are involved with viral apoptotic mimicry, the viruses that use them, as well as examines the studies that attempt to explore the role apoptotic mimicry plays in a host.