title: Gag-specific immune responses after immunization with p17/p24:Ty virus-like particles in HIV type 1-seropositive individuals.
abstract: Gag-specific immune responses and changes in HIV-1 RNA levels were evaluated in eight HIV-1-infected persons, in order to assess the immunotherapeutic potential HIV-1 p17/p24: Ty virus-like particles (p24-VLP). All treated subjects showed transient and dose-dependent proliferative responses to the Ty-VLP carrier (stimulation index [SI], 2.0-119.5). Three of four individuals who received either 500 or 1,000 micrograms of p24-VLP also showed proliferative responses to p17 or p24 (SI, 2.0-15.7). In 2 subjects who were treated with either 500 or 1,000 micrograms of p24-VLP, enhanced Gag-specific CTL precursor (CTLp) frequencies were observed after immunization (10- to 14-fold). Both subjects had low baseline Gag-specific CTL activity (< 25 cTLp/10(6) PBMCs). In the other participants studied no significant boosting of preexisting Gag-specific CTL responses was observed. Short-term elevation of HIV-1 RNA levels at weeks 2 and 4 was observed in two subjects treated with the highest dose of p24-VLP. However, HIV-1 RNA levels at week 24 did not significantly differ from those found in the placebo group. In conclusion, p24-VLP induced marginal Gag-specific immune responses in limited numbers of HIV-1-seropositive individuals, with some showing transient elevation of HIV-1 viral load. Further studies are needed to establish potential clinical effects of these observations.
authors.affiliation: Department of Clinical Viro-Immunology, Central Laboratory of The Netherlands Red Cross Blood Transfusion Service, Amsterdam, The Netherlands.
authors.forename: M R
authors.initials: MR
authors.lastname: Klein
authors.forename: J
authors.initials: J
authors.lastname: Veenstra
authors.forename: A M
authors.initials: AM
authors.lastname: Holwerda
authors.forename: M T
authors.initials: MT
authors.lastname: Roos
authors.forename: I
authors.initials: I
authors.lastname: Gow
authors.forename: G
authors.initials: G
authors.lastname: Patou
authors.forename: R A
authors.initials: RA
authors.lastname: Coutinho
authors.forename: F
authors.initials: F
authors.lastname: De Wolf
authors.forename: F
authors.initials: F
authors.lastname: Miedema
mesh_terms: D016915:AIDS Vaccines / Q000276:immunology* / Q000627:therapeutic use / Q000633:toxicity; D000276:Adjuvants, Immunologic; D000328:Adult; D000536:Aluminum Hydroxide; D004311:Double-Blind Method; D005260:Female; D015683:Gene Products, gag / Q000276:immunology*; D016655:HIV Core Protein p24 / Q000276:immunology* / Q000627:therapeutic use / Q000633:toxicity; D015658:HIV Infections / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012367:RNA, Viral / Q000097:blood; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology
chemical_list: D016915:AIDS Vaccines; D000276:Adjuvants, Immunologic; D015683:Gene Products, gag; D016655:HIV Core Protein p24; D012367:RNA, Viral; C065031:p24-VLP vaccine; D000536:Aluminum Hydroxide