Article Cite This: ACS Infect. Dis. XXXX, XXX, XXX−XXX
pubs.acs.org/journal/aidcbc
Dissecting the Components of Sindbis Virus from Arthropod and Vertebrate Hosts: Implications for Infectivity Differences Carmen A. Dunbar,† Vamseedhar Rayaprolu,‡ Joseph C.-Y. Wang,§ Christopher J. Brown,† Emma Leishman,∥ Sara Jones-Burrage,‡ Jonathan C. Trinidad,† Heather B. Bradshaw,∥ David E. Clemmer,† Suchetana Mukhopadhyay,‡ and Martin F. Jarrold*,† ACS Infect. Dis. Downloaded from pubs.acs.org by CALIFORNIA STATE UNIV BAKERSFIELD on 04/16/19. For personal use only.
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Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States Department of Biology, Indiana University, Jordan Hall, 1001 East Third Street, Bloomington, Indiana 47405, United States § Department of Molecular and Cellular Biochemistry, Indiana University, Simon Hall, 212 South Hawthorne Drive, Bloomington, Indiana 47405, United States ∥ Department of Psychological and Brain Sciences, Indiana University, 1101 East Tenth Street, Bloomington, Indiana 47405, United States ‡
S Supporting Information *
ABSTRACT: Sindbis virus (SINV) is an enveloped, single-stranded RNA virus, which is transmitted via mosquitos to a wide range of vertebrate hosts. SINV produced by vertebrate, baby hamster kidney (BHK) cells is more than an order of magnitude less infectious than SINV produced from mosquito (C6/ 36) cells. The cause of this difference is poorly understood. In this study, charge detection mass spectrometry was used to determine the masses of intact SINV particles isolated from BHK and C6/36 cells. The measured masses are substantially different: 52.88 MDa for BHK derived SINV and 50.69 MDa for C6/36 derived. Further analysis using several mass spectrometry-based methods and biophysical approaches indicates that BHK derived SINV has a substantially higher mass than C6/36 derived because in the lipid bilayer, there is a higher portion of lipids containing long chain fatty acids. The difference in lipid composition could influence the organization of the lipid bilayer. As a result, multiple stages of the viral lifecycle may be affected including assembly and budding, particle stability during transmission, and fusion events, all of which could contribute to the differences in infectivity. KEYWORDS: alphavirus, mass spectrometry, lipid, glycan
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Alphaviruses are arboviruses which are transmitted by an arthropod vector, primarily a mosquito, to a vertebrate host. Virus particles produced in vertebrate cell cultures (avian or mammalian) typically have a specific infectivity between 0.001 and 0.0125, in other words,
