Lysophosphatidic acid signaling supports Coxsackievirus infection through lipid metabolism

Viruses rely on cellular metabolism for efficient replication, and lipids are one class of these metabolites that function at nearly every stage in virus replication. Coxsackievirus B3 (CVB3) is an enterovirus that uses lipids for entry, replication, and egress, using lipids as both structural and energy resources. We performed an unbiased metabolomic analysis of Huh7 and Vero E6 cells infected with CVB3, which highlighted that lipids of diverse classes were upregulated during viral infection. Using an inhibitor panel of small molecules targeting lipids, we identified lysophosphatidic acid (LPA) signaling as a key factor in CVB3 infection. LPA functions as a signaling lipid, functioning through its receptor, LPA receptor 1 (LPAR1), a G-protein -coupled receptor that mediates cellular growth, survival, and differentiation. Inhibiting LPA signaling through the small molecule inhibitor AM095 or genetically through siRNA knockdown reduces CVB3 infection by upwards of 100-fold. We find that LPA mediates CVB3 genome replication and that AM095 treatment reduces complete genome synthesis. We also find that LPA signaling through LPAR1 facilitates infection by mediating cellular lipid synthesis, primarily by regulating the expression of key enzymes in lipid synthesis, like fatty acid synthase (FASN) and acetyl CoA carboxylase 1 (ACC1). In cells treated with AM095, cellular lipid droplets are depleteddepleted, and cells exhibit a quiescent-like phenotype, as measured by Seahorse XF assay. Overall, we find that the signaling lipid LPA is key to CVB3 infection at the stage of viral replication, putatively by mediating lipid synthesis and supporting cellular respiration and glycolysis.