Ebolavirus Requires Acid Sphingomyelinase Activity and Plasma Membrane Sphingomyelin for Infection

Abstract

Acid sphingomyelinase (ASMase) converts the lipid sphingomyelin (SM) to phosphocholine and ceramide and has optimum activity at acidic pH. Normally, ASMase is located in lysosomes and endosomes, but membrane damage or the interaction with some bacterial and viral pathogens can trigger its recruitment to the plasma membrane. Rhinovirus and measles viruses each require ASMase activity during early stages of infection. Both sphingomyelin and ceramide are important components of lipid rafts and are potent signaling molecules. Each plays roles in mediating macropinocytosis, which has been shown to be important for ebolavirus (EBOV) infection. Here, we investigated the role of ASMase and its substrate, SM, in EBOV infection. The work was performed at biosafety level 4 with wild-type virus with specificity and mechanistic analysis performed using virus pseudotypes and virus-like particles. We found that virus particles strongly associate with the SM-rich regions of the cell membrane and depletion of SM reduces EBOV infection. ASM-specific drugs and multiple small interfering RNAs strongly inhibit the infection by EBOV and EBOV glycoprotein pseudotyped viruses but not by the pseudotypes bearing the glycoprotein of vesicular stomatitis virus. Interestingly, the binding of virus-like particles to cells is strongly associated with surface-localized ASMase as well as SM-enriched sites. Our work suggests that ASMase activity and SM presence are necessary for efficient infection of cells by EBOV. The inhibition of this pathway may provide new avenues for drug treatment.

Elevation of Serum Acid Sphingomyelinase Activity in Children with Acute Respiratory Syncytial Virus Bronchiolitis

“…Infection of human epithelial cells by several rhinovirus strains was found to trigger a rapid activation of the ASM and the resulting ceramide-enriched membrane platforms were shown to be significant for rhinovirus entry (Grassmé et al 2005). Another study reported that ASM activity and sphingomyelin presence are necessary for efficient infection of cells by ebolavirus (Miller et al 2012). Thus far, ASM has not been reported to be associated with RSV infection; however, our results suggest that ASM could play a critical role in RSV infection.…”

Switching head group selectivity in mammalian sphingolipid biosynthesis by active-site engineering of sphingomyelin synthases

“…NBDC6CPE (NBDCPE) was gener ously provided by Philippe Devaux (Institut de Biologie Physico Chimique, Paris). WEPRO2240 wheat germ extract was from Cell-Free Sciences, Accudenz from Accurate Chemicals and [1,[2][3][4][5][6][7][8][9][10][11][12][13][14] C]ethanolamine hydrochloride (100 Ci/ml, 100-115 mCi/ mmol) from BioTrend. EndoH was from New England Biolabs.…”

Lipid Involvement in Viral Infections: Present and Future Perspectives for the Design of Antiviral Strategies

“…Along this line, ebolavirus requires the activity of acid sphingomyelinase, the enzyme that converts sphingomyelin to phosphocholine and ceramide for infection, and depletion of sphingomyelin reduces its infection [206]. A dependence on sphingomyelin for HCV replication has also been documented [130].…”