title: Long-lasting humoral immune response induced in HIV-1-infected patients by a synthetic peptide (AT20) derived from the HIV-1 matrix protein p17 functional epitope.
abstract: A therapeutic vaccination based on a synthetic peptide (AT20) representative of the HIV-1 matrix protein p17 (p17) functional region, coupled to keyhole limpet hemocyanin (KLH) AT20-KLH was capable of inducing the production of high-avidity antibodies (Abs) toward a previous untargeted p17 hotspot of functional activity in highly active antiretroviral therapy (HAART)-treated HIV-1-infected patients. Since avidity of Abs after immunization and the retention of antigens are important in sustaining the long-lasting production of specific humoral responses, we asked whether AT20-KLH vaccination would result in development of a long-lived immune response.
  
  
  
  The long-term duration of Ab response to AT20-KLH has been evaluated in 10 patients previously enrolled for the AT20-KLH vaccination trial at day 898 post-immunization. Ab titer and their avidity was assessed using specifically designed ELISA assays, whereas their neutralizing capacity was estimated in vitro using a 'wound sealing assay'.
  
  
  
  Data obtained show that high titers of specific anti-AT20 Abs were maintained at more than 2 years after the last immunization. Furthermore, these Abs were capable to neutralize exogenous p17, as assessed by ability of sera derived from AT20-KLH-immunized patients to block the ability of p17 to promote cell migration in vitro.
  
  
  
  This finding attests for a successful AT20-KLH vaccine molecule formulation and for an effective HAART-dependent Ab persistence.
authors.forename: Emanuele
authors.initials: E
authors.lastname: Focà
authors.forename: Maria Luisa
authors.initials: ML
authors.lastname: Iaria
authors.forename: Francesca
authors.initials: F
authors.lastname: Caccuri
authors.forename: Simona
authors.initials: S
authors.lastname: Fiorentini
authors.forename: Davide
authors.initials: D
authors.lastname: Motta
authors.forename: Cinzia
authors.initials: C
authors.lastname: Giagulli
authors.forename: Francesco
authors.initials: F
authors.lastname: Castelli
authors.forename: Arnaldo
authors.initials: A
authors.lastname: Caruso
mesh_terms: D000276:Adjuvants, Immunologic; D000328:Adult; D023241:Antiretroviral Therapy, Highly Active; D000939:Epitopes; D005260:Female; D015658:HIV Infections / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology*; D006433:Hemocyanins / Q000276:immunology*; D006801:Humans; D056724:Immunity, Humoral; D008297:Male; D008875:Middle Aged; D010455:Peptides / Q000276:immunology*; D011446:Prospective Studies; D055815:Young Adult
chemical_list: D000276:Adjuvants, Immunologic; D000939:Epitopes; D010455:Peptides; D006433:Hemocyanins; C032808:keyhole-limpet hemocyanin
keywords: AT20,; HIV-1,; Long-lasting humoral response; Matrix protein p17,; Therapeutic vaccine,