Lentiviral Transduction of Dendritic Cells Confers Protective Antiviral Immunity In Vivo

Abstract

Control of a viral infection in vivo requires a rapid and efficient cytotoxic-T-lymphocyte response. We demonstrate that lentivirus-mediated introduction of antigen in dendritic cells confers a protective antiviral immunity in vivo in a lymphocytic choriomeningitis virus model. Therefore, lentiviral vectors may be excellent vaccine candidates for viral infections.The success of an antiviral vaccine depends on its capacity to induce strong and sustained antiviral immunity. While a number of methods are employed to achieve this goal, it is still unclear whether lentiviral vectors are able to induce efficient antiviral immunity in vivo. Introduction of antigen into dendritic cells (DC) by using lentiviral vectors leads to antigen presentation and activation of virus-specific cytotoxic T lymphocytes (CTL) in vitro in human and murine models, as well as in vivo in murine tumor models (4,5,7,10,20). However, due to rapid viral replication, the control of a viral infection in vivo requires strong T-cell responses, both qualitatively and quantitatively.The murine model of lymphocytic choriomeningitis virus (LCMV) infection is a well-defined system for studying protective CTL responses in vivo (1,11,15,16,19,21). Therefore, this experimental system is appropriate for addressing the question of whether lentiviral vectors are suitable tools for introducing antigen into DC in order to induce protective antiviral immunity in vivo.Our study demonstrates for the first time that third-generation lentiviral vectors are capable of introducing antigen into DC, which confer a strong protective antiviral immunity in vivo.Vaccination with LV-GFPUbigp33-transduced DC induces the expansion of antigen-specific T cells in vivo. We first asked whether LV-GFPUbigp33-transduced DC could prime LCMV glycoprotein-specific CD8 ϩ T cells in vitro and in vivo. LVGFPUbigp33 is a third-generation lentiviral vector that encodes the transgene GFPUbigp33 (immunodominant epitope of LCMV glycoprotein, positions 33 to 41 [gp33-41], fused with ubiquitin and enhanced green fluorescent protein [GFP] sequences) (17, 18). Bone marrow-derived DC from C57BL/6 mice (IFFA-Credo, L'Arbresle, France) were generated as published previously (20). Briefly, bone marrow cells were differentiated into DC by culturing in medium supplemented with murine granulocyte-macrophage colony stimulating factor (ImmunoKontact, Lugano, Switzerland), interleukin 4, and Flt3-L (R&D, Abingdon, United Kingdom) for 9 days. Thirdgeneration lentiviral vectors were transduced at day 3, after nonadherent cells were discarded from the culture. At day 7, DC were matured by adding 1 g/ml of lipopolysaccharide (Difco, Detroit, Mich.) in the presence of cytokines.When DC were transduced with LV-GFPUbigp33 at a multiplicity of infection of 5, the average transduction efficiency for LV-GFPUbigp33 was 18.5% (data not shown). At the same multiplicity of infection the efficiency of transduction of DC with lentiviral vectors encoding GFP was around 35% (20). Importantly, the design of the LV-GFPUbigp33 ...

Dendritic Cell Immunization Route Determines Integrin Expression and Lymphoid and Nonlymphoid Tissue Distribution of CD8 T Cells

“…A ppropriately activated dendritic cells (DC) 4 are potent APC, and exogenously administered Ag-pulsed DC induce specific CD8 ϩ T cell responses against viral and tumor Ags (1)(2)(3)(4). However, the cellular nature and migration properties of exogenous DC limit their distribution in lymphoid compartments in an injection route-dependent manner (3,(5)(6)(7)(8)(9), leading to regionally constrained immune responses (3,5).…”

Induction of HIV‐specific T and B cell responses with a replicating and conditionally infectious lentiviral vaccine

“…Upon vaccination with these transduced DC, we observed potent anti-gag T and B cell activation. Unlike most studies that have induced T cell responses against diverse antigens through a variety of lentiviral approaches [8, 11,30,31,36], the potent B cell response is novel.…”

“…Lentiviral vectors, especially ones based on HIV, that are used in mice have mammalian promoters to produced tumor-associated antigens [8, 10, 11,30,31]. The commonly used Balb/c mouse model should be deficient in the ability of our vector, which uses HIV's promoter system, to replicate and undergo second-round transduction, as a postintegration block to HIV replication in mice has been described (reviewed in [32]), although the above data showing p24 Gag protein and viral cores suggests that murine DC are capable of some level of protein production and virion formation.…”

“…Upon vaccination with these transduced DC, we observed potent anti-gag T and B cell activation. Unlike most studies that have induced T cell responses against diverse antigens through a variety of lentiviral approaches [8, 11,30,31,36], the potent B cell response is novel.While we were able to demonstrate second-round infection of DC in vitro, we could not demonstrate this in vivo and needed to reimmunize mice to obtain potent responses. This is likely due to the post-integration block to HIV replication in mice [32] that makes second-round transduction an inefficient process.…”

Recombinant lentivector as a genetic immunization vehicle for antitumor immunity

“…This is likely related to their capacity to transduce non-dividing cells, including DCs in vivo, and to enable persistent Ag presentation through high level expression of transgenes and low vector immunogenicity. Lentivector has recently been utilized in preclinical animal models for prevention of infectious diseases [21][22][23] and tumor immunotherapy. With improved bisosafety and better understanding of the basic mechanism of T cell priming induced by lentivector immunization, these vectors have great potential to effectively deliver Ag to induce potent T cell immunity against tumors.…”