Directly injected lentiviral vector–based T cell vaccine protects mice against acute and chronic viral infection
Takuya Tada, Thomas D. Norton, Rebecca Leibowitz, Nathaniel R. Landau
Takuya Tada, Thomas D. Norton, Rebecca Leibowitz, Nathaniel R. Landau
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Research Article Immunology Vaccines

Directly injected lentiviral vector–based T cell vaccine protects mice against acute and chronic viral infection

Abstract

Lentiviral vector–based dendritic cell vaccines induce protective T cell responses against viral infection and cancer in animal models. In this study, we tested whether preventative and therapeutic vaccination could be achieved by direct injection of antigen-expressing lentiviral vector, obviating the need for ex vivo transduction of dendritic cells. Injected lentiviral vector preferentially transduced splenic dendritic cells and resulted in long-term expression. Injection of a lentiviral vector encoding an MHC class I–restricted T cell epitope of lymphocytic choriomeningitis virus (LCMV) and CD40 ligand induced an antigen-specific cytolytic CD8+ T lymphocyte response that protected the mice from infection. The injection of chronically infected mice with a lentiviral vector encoding LCMV MHC class I and II T cell epitopes and a soluble programmed cell death 1 microbody rapidly cleared the virus. Vaccination by direct injection of lentiviral vector was more effective in sterile alpha motif and HD-domain containing protein 1–knockout (SAMHD1-knockout) mice, suggesting that lentiviral vectors containing Vpx, a lentiviral protein that increases the efficiency of dendritic cell transduction by inducing the degradation of SAMHD1, would be an effective strategy for the treatment of chronic disease in humans.

Authors

Takuya Tada, Thomas D. Norton, Rebecca Leibowitz, Nathaniel R. Landau

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Figure 4

Adoptively transferred CD8+ T cells and DCs suppress virus loads.

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Adoptively transferred CD8+ T cells and DCs suppress virus loads. (A) As...
(A) As diagrammed, wild-type or SAMHD1-KO mice were immunized by i.p. injection of CD40L-GP33 or control CD40L virus. Five days postimmunization, the mice were sacrificed, and splenic CD8+/– T cells, DCs, and B cells were isolated on magnetic beads. The cell populations were injected i.v (n = 5) into wild-type or SAMHD1-KO mice, and 3 days later, the mice were challenged with LCMV Armstrong. (B) Isolated CD8+/– T cells, DCs, and B cell populations from SAMHD1-KO mice were stained with antibodies against CD8, CD11c, and CD19 analyzed by flow cytometry. (C) Wild-type (left) and SAMHD1-KO (right) mice (n = 5) were adoptively transferred with total splenocytes, CD8+ T cells, CD8– T cells, DCs, and B cells from mice immunized with CD40L or CD40L-GP33 virus. Controls included mice that were not adoptively transferred and mice that were not infected. LCMV RNA copy numbers were quantified day 4 postinfection by qRT-PCR. (D) Five days after adoptive transfer, CD8+/– T cells, DCs, and B cells were isolated from the SAMHD1-KO spleen, and cytolytic activity was measured in vitro. Effector cells were incubated with CFSE-stained, GP33-coated LB27.4 target cells for 24 hours. The number of dead target cells was quantified by flow cytometry. Statistical significance was determined by 2-tailed, unpaired t test. Confidence intervals are shown as the mean ± SD. (*P ≤ 0.05, **P ≤ 0.01, ***P ≤ 0.001, ****P ≤ 0.0001.)