title: HIV-1 Gag-specific immunity induced by a lentivector-based vaccine directed to dendritic cells.
abstract: Lentivectors (LVs) have attracted considerable interest for their potential as a vaccine delivery vehicle. In this study, we evaluate in mice a dendritic cell (DC)-directed LV system encoding the Gag protein of human immunodeficiency virus (HIV) (LV-Gag) as a potential vaccine for inducing an anti-HIV immune response. The DC-directed specificity is achieved through pseudotyping the vector with an engineered Sindbis virus glycoprotein capable of selectively binding to the DC-SIGN protein. A single immunization by this vector induces a durable HIV Gag-specific immune response. We investigated the antigen-specific immunity and T-cell memory generated by a prime/boost vaccine regimen delivered by either successive LV-Gag injections or a DNA prime/LV-Gag boost protocol. We found that both prime/boost regimens significantly enhance cellular and humoral immune responses. Importantly, a heterologous DNA prime/LV-Gag boost regimen results in superior Gag-specific T-cell responses as compared with a DNA prime/adenovector boost immunization. It induces not only a higher magnitude response, as measured by Gag-specific tetramer analysis and intracellular IFN-gamma staining, but also a better quality of response evidenced by a wider mix of cytokines produced by the Gag-specific CD8(+) and CD4(+) T cells. A boosting immunization with LV-Gag also generates T cells reactive to a broader range of Gag-derived epitopes. These results demonstrate that this DC-directed LV immunization is a potent modality for eliciting anti-HIV immune responses.
authors.affiliation: Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA 90089, USA.
authors.forename: Bingbing
authors.initials: B
authors.lastname: Dai
authors.forename: Lili
authors.initials: L
authors.lastname: Yang
authors.forename: Haiguang
authors.initials: H
authors.lastname: Yang
authors.forename: Biliang
authors.initials: B
authors.lastname: Hu
authors.forename: David
authors.initials: D
authors.lastname: Baltimore
authors.forename: Pin
authors.initials: P
authors.lastname: Wang
mesh_terms: D016915:AIDS Vaccines / Q000276:immunology*; D000818:Animals; D003713:Dendritic Cells / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005822:Genetic Vectors / Q000276:immunology*; D015497:HIV-1; D007111:Immunity, Cellular / Q000276:immunology*; D056724:Immunity, Humoral / Q000276:immunology*; D016086:Lentivirus; D051379:Mice; D008807:Mice, Inbred BALB C; D012845:Sindbis Virus / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology; D054301:gag Gene Products, Human Immunodeficiency Virus / Q000276:immunology*
chemical_list: D016915:AIDS Vaccines; D054301:gag Gene Products, Human Immunodeficiency Virus