title: Antibody-dependent cellular cytotoxicity mediated by plasma obtained before secondary dengue virus infections: potential involvement in early control of viral replication.
abstract: BACKGROUND
  Preexisting dengue virus (DV)-specific antibodies from prior heterologous DV infection may have several effects in secondary DV infection. These antibodies may mediate protective effects by means of antibody-dependent cellular cytotoxicity (ADCC), in which virus-specific antibodies bind to the surface of heterologous DV-infected cells and mediate natural killer cell lysis. In the present study, we examined the ability of plasma obtained before secondary DV infection to induce ADCC of DV-infected cells.
  
  
  METHODS
  Plasma samples were obtained before DV2 or DV3 infection in a prospective cohort study of Thai schoolchildren. The ADCC activity in the plasma samples was measured by (51)Cr-release assay, using persistently DV2- or DV3-infected Raji cells as targets.
  
  
  RESULTS
  ADCC activity in plasma obtained before secondary infection directly correlated with neutralizing antibody titers, anti-DV immunoglobulin G1 levels, and a multitypic 50% plaque reduction neutralization test pattern. ADCC activity in pre-secondary DV3 infection plasma samples inversely correlated with plasma viremia levels, but no such correlation was seen in pre-secondary DV2 infection plasma samples. ADCC activity did not correlate with disease severity in subsequent secondary DV2 or DV3 infection but was lowest in plasma from patients with dengue hemorrhagic fever due to secondary DV3 infection.
  
  
  CONCLUSIONS
  ADCC may contribute to the early control of secondary DV3 viremia in vivo.
authors.affiliation: Center for Infectious Disease and Vaccine Research, University of Massachusetts Medical School, Worcester, MA 01655, USA.
authors.forename: Kamolwish
authors.initials: K
authors.lastname: Laoprasopwattana
authors.forename: Daniel H
authors.initials: DH
authors.lastname: Libraty
authors.forename: Timothy P
authors.initials: TP
authors.lastname: Endy
authors.forename: Ananda
authors.initials: A
authors.lastname: Nisalak
authors.forename: Supamit
authors.initials: S
authors.lastname: Chunsuttiwat
authors.forename: Francis A
authors.initials: FA
authors.lastname: Ennis
authors.forename: Alan L
authors.initials: AL
authors.lastname: Rothman
authors.forename: Sharone
authors.initials: S
authors.lastname: Green
mesh_terms: D000914:Antibodies, Viral / Q000097:blood* / Q000276:immunology; D000920:Antibody-Dependent Cell Cytotoxicity / Q000276:immunology*; D002648:Child; D015331:Cohort Studies; D003715:Dengue / Q000097:blood / Q000276:immunology* / Q000821:virology; D003716:Dengue Virus / Q000254:growth & development / Q000276:immunology* / Q000302:isolation & purification; D004306:Dose-Response Relationship, Immunologic; D006760:Hospitalization; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007694:Killer Cells, Natural / Q000276:immunology; D011446:Prospective Studies; D012008:Recurrence; D012703:Serotyping; D013223:Statistics as Topic; D014766:Viremia / Q000097:blood / Q000276:immunology; D014779:Virus Replication / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D007074:Immunoglobulin G