title: Envelope lipid-packing as a critical factor for the biological activity and stability of alphavirus particles isolated from mammalian and mosquito cells.
abstract: Alphaviruses are enveloped arboviruses. The viral envelope is derived from the host cell and is positioned between two icosahedral protein shells (T = 4). Because the viral envelope contains glycoproteins involved in cell recognition and entry, the integrity of the envelope is critical for the success of the early events of infection. Differing levels of cholesterol in different hosts leads to the production of alphaviruses with distinct levels of this sterol loaded in the envelope. Using Mayaro virus, a New World alphavirus, we investigated the role of cholesterol on the envelope of alphavirus particles assembled in either mammalian or mosquito cells. Our results show that although quite different in their cholesterol content, Mayaro virus particles obtained from both cells share a similar high level of lateral organization in their envelopes. This organization, as well as viral stability and infectivity, is severely compromised when cholesterol is depleted from the envelope of virus particles isolated from mammalian cells, but virus particles isolated from mosquito cells are relatively unaffected by cholesterol depletion. We suggest that it is not cholesterol itself, but rather the organization of the viral envelope, that is critical for the biological activity of alphaviruses.
authors.affiliation: Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21341-902 RJ, Brazil.
authors.forename: Ivanildo P
authors.initials: IP
authors.lastname: Sousa
authors.forename: Carlos A M
authors.initials: CA
authors.lastname: Carvalho
authors.forename: Davis F
authors.initials: DF
authors.lastname: Ferreira
authors.forename: Gilberto
authors.initials: G
authors.lastname: Weissmüller
authors.forename: Gustavo M
authors.initials: GM
authors.lastname: Rocha
authors.forename: Jerson L
authors.initials: JL
authors.lastname: Silva
authors.forename: Andre M O
authors.initials: AM
authors.lastname: Gomes
mesh_terms: D000330:Aedes / Q000166:cytology / Q000821:virology*; D000524:Alphavirus / Q000502:physiology*; D000818:Animals; D002522:Chlorocebus aethiops; D002784:Cholesterol / Q000378:metabolism; D006224:Cricetinae; D008563:Membrane Lipids / Q000378:metabolism*; D013045:Species Specificity; D014709:Vero Cells; D014759:Viral Envelope Proteins / Q000378:metabolism*; D019065:Virus Assembly / Q000502:physiology*; D053586:Virus Internalization
chemical_list: D008563:Membrane Lipids; D014759:Viral Envelope Proteins; C050629:viral envelope lipids; D002784:Cholesterol