title: Sequence variation occurs in CD4 epitopes during early HIV infection.
abstract: OBJECTIVE
  To determine whether viral sequence variation occurs in HIV-specific CD4 epitopes during early HIV infection.
  
  
  METHODS
  Gag, Nef, and integrase (Int) sequences were obtained from the plasma of 7 subjects identified during acute HIV-1 infection. Changes in the viral sequence were determined based on comparison of sequences obtained at 2 time points during early infection. Peptide-specific CD4+ T-cell responses were measured at matched time points using interferon-gamma enzyme-linked immunosorbent spot assays to identify CD4 epitopes.
  
  
  RESULTS
  An average of 4 mutations were identified per subject. The majority of the mutations were nonsynonymous and resulted in a total of 6 amino acid changes in Gag, 7 changes in Nef, and 6 changes and a deletion in Int. Half of the sequence changes were within recognized CD4 epitopes. Mutations within CD4 epitopes were coincident with changes in the peptide-specific CD4 response.
  
  
  CONCLUSIONS
  These data indicate that sequence variation occurs within recognized CD4 epitopes during early HIV infection. Furthermore, it suggests that mutations within HIV-specific CD4 epitopes may affect T helper cell function.
authors.affiliation: Partners AIDS Research Center, Massachusetts General Hospital, Boston, MA 02114, USA.
authors.forename: Jenna
authors.initials: J
authors.lastname: Rychert
authors.forename: Suzanne
authors.initials: S
authors.lastname: Saindon
authors.forename: Sarah
authors.initials: S
authors.lastname: Placek
authors.forename: Demetre
authors.initials: D
authors.lastname: Daskalakis
authors.forename: Eric
authors.initials: E
authors.lastname: Rosenberg
mesh_terms: D000293:Adolescent; D000328:Adult; D001483:Base Sequence; D015704:CD4 Antigens / Q000235:genetics*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D015750:Genes, gag; D015754:Genes, nef; D014644:Genetic Variation; D015658:HIV Infections / Q000235:genetics* / Q000276:immunology; D006650:Histocompatibility Testing; D006801:Humans; D019426:Integrases / Q000235:genetics; D008212:Lymphocyte Depletion; D008297:Male; D008875:Middle Aged; D009154:Mutation
chemical_list: D015704:CD4 Antigens; D019426:Integrases