CD164 is an endolysosomal host factor for entry of Clade A New World Arenaviruses

Abstract

Arenaviruses are divided into Old World (OW) and New World (NW) groups. OW arenaviruses enter cells through a pH-dependent receptor switch from a plasma-membrane factor to an endolysosomal receptor for subsequent membrane fusion, whereas clade B NW arenaviruses use transferrin receptor 1 without a secondary receptor. Using a vesicular stomatitis virus (VSV) chimera expressing the glycoprotein complex (GPC) of the clade A NW arenavirus Pichinde virus, we performed a genome-wide CRISPR loss-of-function screen and identified the endolysosomal sialomucin CD164 as an essential host factor. CD164 knockout cells were resistant to VSV chimeras bearing the GPCs of Pichinde, Parana, and Flexal viruses, and to authentic Pichinde and Parana virus, with susceptibility restored by complementation. The requirement mapped to the cysteine-rich domain of CD164, which bound GP1 in a pH-dependent manner through main-chain interactions. These findings define CD164 as an endolysosomal receptor for clade A NW arenaviruses expanding the receptor switching paradigm.