A single immunization with a minute dose of a lentiviral vector‐based vaccine is highly effective at eliciting protective humoral immunity against West Nile virus

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AIDS vaccination has a pressing need for more potent vaccination vectors capable of eliciting strong, diversified, and long-lasting cellular immune responses against human immunodeficiency virus (HIV). Lentiviral vectors have demonstrated efficiency not only as gene delivery vehicles for gene therapy applications but also as vaccination tools. This is likely due to their ability to transduce nondividing cells, including dendritic cells, enabling sustained endogenous antigen presentation and thus the induction of high proportions of specific cytotoxic T cells and long-lasting memory T cells. We show in a first proof-of-concept pilot study that a prime/boost vaccination strategy using lentiviral vectors pseudotyped with a glycoprotein G from two non-cross-reactive vesicular stomatitis virus serotypes elicited robust and broad cellular immune responses against the vector-encoded antigen, simian immunodeficiency virus (SIV) GAG, in cynomolgus macaques. Vaccination conferred strong protection against a massive intrarectal challenge with SIVmac251, as evidenced both by the reduction of viremia at the peak of acute infection (a mean of over 2 log 10 fold reduction) and by the full preservation of the CD28 ؉ CD95 ؉ memory CD4 ؉ T cells during the acute phase, a strong correlate of protection against pathogenesis. Although vaccinees continued to display lower viremia than control macaques during the early chronic phase, these differences were not statistically significant by day 50 postchallenge. A not-optimized SIV GAG antigen was chosen to show the strong potential of the lentiviral vector system for vaccination. Given that a stronger protection can be anticipated from a modern HIV-1 antigen design, gene transfer vectors derived from HIV-1 appear as promising candidates for vaccination against HIV-1 infection.

Section: Resultsmentioning

confidence: 99%

“…Vector HIV-1 p24 contents were measured by enzyme-linked immunosorbent assay (ELISA; Perkin-Elmer Life Sciences), and gene transfer titers were determined by real-time PCR on cell lysates from transduced 293T cells and expressed as transduction unit (TU)/ml or by flow cytometry (24).…”

Section: Methodsmentioning

confidence: 99%

Lentiviral Vector-Based Prime/Boost Vaccination against AIDS: Pilot Study Shows Protection against Simian Immunodeficiency Virus SIVmac251 Challenge in Macaques

Beignon

Mollier

Liard

et al. 2009

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“…ϩ T-cell and antibody responses to the human tumor antigen NY-ESO-1 (9,17,22), induce protective humoral immunity to West Nile virus (13), and generate T-cell and antibody responses to human immunodeficiency virus (HIV) (14,20). The clinically relevant subcutaneous injection route is thought to be particularly good at inducing T-cell responses, because lentivectors transduce skin-derived dendritic cells, which migrate to the draining lymph node and present antigen to T cells (11).…”

mentioning

confidence: 99%

Nonintegrating Lentivector Vaccines Stimulate Prolonged T-Cell and Antibody Responses and Are Effective in Tumor Therapy

Karwacz

Mukherjee²,

Apolonia³

et al. 2009

؉ T-cell and antibody responses to the secreted hepatitis B virus (HBV) surface antigen expressed from a nonintegrating lentivector injected intramuscularly. The induction, specificity, and kinetics of antibody production closely mimicked those of natural HBV infection. In this case, both the vector genome and the immune response were maintained for at least 2 months. Together, our data indicate that nonintegrating lentivectors can be employed to generate effective vaccines.

“…Briefly, 1/50 (pol) or 1/10 (2-LTR) of total-cell DNA was used for real-time PCR carried out in triplicate for each reaction in a 20-l mixture containing 1ϫ LightCycler FastStart DNA master hybridization probes (Roche Diagnostics), 4 mM MgCl 2 , 300 nM each primer, and 200 nM each probe. Results were normalized to cell number based on the amplification of the CD3 gene as previously described (21).…”

mentioning

confidence: 99%

Nuclear Import Defect of Human Immunodeficiency Virus Type 1 DNA Flap Mutants Is Not Dependent on the Viral Strain or Target Cell Type

Arhel

Munier

Souque

et al. 2006

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We conducted a detailed analysis of virus infectivity using the provirus clones provided by the authors and analogous target cells. In contrast to published data, our results show that all cPPT mutant viruses exhibit reduced infectivity corresponding to a nuclear import defect irrespective of the viral genetic background or target cell.The unique ability of human immunodeficiency virus type 1 (HIV-1) and other lentiviruses to replicate efficiently in nondividing cells implies the use of an active nuclear import strategy allowing the DNA genome to cross the nuclear membrane of an interphasic nucleus so as to gain access to, and integrate into, the cellular chromatin. The mitosis-independent replication of lentiviruses was the key feature for the generation of lentivirus-derived gene transfer vectors with promising therapeutic applications. Their capacity to transduce nonmitotic cells overcame one major limitation of the applicability of oncovirus-derived retrovirus vectors to gene therapy.The search for the lentivirus determinants of mitosis-independent replication has constituted an active but strongly controversial field of investigation. An early premise, though unfounded, was that replication of a nuclear import-defective virus should be altered specifically in nondividing cells but not in dividing cells, where mitosis was expected to provide an alternative nuclear entry pathway for the HIV-1 preintegration complex (PIC). Based on the search for putative nuclear localization signals (NLS) within HIV-1 proteins that could account for active nuclear import of the PIC, a complex model involving several redundant factors has been drawn.A first putative NLS was identified within the HIV-1 matrix protein (MA) and proposed as the critical determinant for viral genome nuclear import (8). However, the demonstration that replication was not affected in nondividing cells with identical MA mutants cast doubt on these first findings (14). It was then proposed that nuclear import was achieved by both MA and Vpr in a redundant manner (20) and that mutation of only one of the two determinants had no effect on HIV-1 genome nuclear import. Since myristoylated MA protein is expected to localize at the plasma membrane after fusion of the viral membrane with target cells, it was claimed that phosphorylation of the MA C-terminal tyrosine residue (Y132) acted to release from the plasma membrane a small fraction of the MA protein, which subsequently would interact, by virtue of a novel protein-protein interaction, with a central domain of the HIV-1 integrase (IN), thus allowing the nuclear import of the HIV-1 PIC (16,17). However, the implication of the MA C-terminal tyrosine in the Vpr/MA model received no further confirmation, and the HIV-1 MA Y132F mutant demonstrated wildtype infection efficiency in nondividing primary macrophages (15). HIV-1 IN was then proposed as a third determinant of HIV-1 genome nuclear import (5, 18), and this time a replication defect was found in both dividing and nondividing cells (5), but there was no...