title: The acute phase of Chikungunya virus infection in humans is associated with strong innate immunity and T CD8 cell activation.
abstract: BACKGROUND
  Rapidly spreading to new regions, including the islands of the Indian Ocean, Central Africa, and Europe, Chikungunya fever is becoming a major problem of public health. Unlike other members of the alphavirus genus, immune responses to Chikungunya virus (CHIKV) have been poorly investigated.
  
  
  METHODS
  We conducted a large ex vivo multiplex study of 50 cytokine, chemokine, and growth factor plasma profiles in 69 acutely infected patients from the Gabonese outbreak of 2007. We also assessed a phenotypic study of T lymphocyte responses during human acute CHIKV infection.
  
  
  RESULTS
  CHIKV infection in humans elicited strong innate immunity involving the production of numerous proinflammatory mediators. Interestingly, high levels of Interferon (IFN) α were consistently found. Production of interleukin (IL) 4, IL-10, and IFN-γ suggested the engagement of the adaptive immunity. This was confirmed by flow cytometry of circulating T lymphocytes that showed a CD8+ T lymphocyte response in the early stages of the disease, and a CD4+ T lymphocyte mediated response in the later stages. For the first time to our knowledge, we found evidence of CD95-mediated apoptosis of CD4+ T lymphocytes during the first 2 days after symptoms onset, ex vivo.
  
  
  CONCLUSIONS
  Together, our findings suggest that strong innate immunity is required to control CHIKV infection.
authors.affiliation: Centre International de Recherches Médicales de Franceville, BP769, Gabon. nadia.wauquier@gmail.com
authors.forename: Nadia
authors.initials: N
authors.lastname: Wauquier
authors.forename: Pierre
authors.initials: P
authors.lastname: Becquart
authors.forename: Dieudonné
authors.initials: D
authors.lastname: Nkoghe
authors.forename: Cindy
authors.initials: C
authors.lastname: Padilla
authors.forename: Angélique
authors.initials: A
authors.lastname: Ndjoyi-Mbiguino
authors.forename: Eric M
authors.initials: EM
authors.lastname: Leroy
mesh_terms: D000328:Adult; D018354:Alphavirus Infections / Q000453:epidemiology / Q000276:immunology / Q000473:pathology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D065632:Chikungunya Fever; D002646:Chikungunya virus / Q000276:immunology* / Q000472:pathogenicity; D016207:Cytokines / Q000097:blood; D004196:Disease Outbreaks; D005260:Female; D005681:Gabon / Q000453:epidemiology; D006801:Humans; D007113:Immunity, Innate; D008297:Male; D008875:Middle Aged
chemical_list: D016207:Cytokines