title: Chikungunya virus adaptation to Aedes albopictus mosquitoes does not correlate with acquisition of cholesterol dependence or decreased pH threshold for fusion reaction.
abstract: BACKGROUND
  Chikungunya virus (CHIKV) is a mosquito transmitted alphavirus that recently caused several large scale outbreaks/epidemics of arthritic disease in tropics of Africa, Indian Ocean basin and South-East Asia. This re-emergence event was facilitated by genetic adaptation (E1-A226V substitution) of CHIKV to a newly significant mosquito vector for this virus; Aedes albopictus. However, the molecular mechanism explaining the positive effect of the E1-A226V mutation on CHIKV fitness in this vector remains largely unknown. Previously we demonstrated that the E1-A226V substitution is also associated with attenuated CHIKV growth in cells depleted by cholesterol.
  
  
  METHODS
  In this study, using a panel of CHIKV clones that varies in sensitivity to cholesterol, we investigated the possible relationship between cholesterol dependence and Ae. albopictus infectivity.
  
  
  RESULTS
  We demonstrated that there is no clear mechanistic correlation between these two phenotypes. We also showed that the E1-A226V mutation increases the pH dependence of the CHIKV fusion reaction; however, subsequent genetic analysis failed to support an association between CHIKV dependency on lower pH, and mosquito infectivity phenotypes.
  
  
  CONCLUSIONS
  the E1-A226V mutation probably acts at different steps of the CHIKV life cycle, affecting multiple functions of the virus.
authors.affiliation: Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA. kotsetsa@utmb.edu
authors.forename: Konstantin A
authors.initials: KA
authors.lastname: Tsetsarkin
authors.forename: Charles E
authors.initials: CE
authors.lastname: McGee
authors.forename: Stephen
authors.initials: S
authors.lastname: Higgs
mesh_terms: D000220:Adaptation, Biological; D000330:Aedes / Q000821:virology*; D019943:Amino Acid Substitution / Q000235:genetics; D000818:Animals; D002646:Chikungunya virus / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D002784:Cholesterol / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D014759:Viral Envelope Proteins / Q000235:genetics / Q000378:metabolism; D053586:Virus Internalization
chemical_list: D014759:Viral Envelope Proteins; D002784:Cholesterol