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
View: Text | PDF
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

×

Figure 3

Direct injection of lentiviral vaccine protects against LCMV infection.

Options: View larger image (or click on image) Download as PowerPoint
Direct injection of lentiviral vaccine protects against LCMV infection. ...
(A) The structures of the lentiviral vaccine vector CD40L-GP33 expressing CD40L and LCMV MHCI epitope GP33-41 (left) are shown. Wild-type and SAMHD1-KO mice (n = 6) were injected i.v. or i.p. with 3 × 106 IU of the viruses, and after 1, 2, or 4 weeks, the mice were challenged with LCMV Armstrong virus (right). Virus load, TCR+CD8+ T cells, and cytolytic activity were measured 4 days postinfection. (B) LCMV RNA copy numbers in the spleen of the immunized mice were quantified by quantitative reverse transcription PCR (qRT-PCR) (n = 6) 4 days postinfection. (C) Splenocytes from mice challenged 2 weeks postimmunization were stained with GP33 tetramer and antibodies against CD3 and CD8. CD3+CD8+ cells were gated, and the number of tetramer+ cells was determined. The gating strategy is shown (above) and the percentage of tetramer+CD8+ T cells was quantified. (D) The proportion of splenic GP33+TCR+CD8+ T cells expressing IFN-γ was quantified by flow cytometry. (E) Cytolytic activity of splenocytes from the immunized mice (n = 6) was measured in vitro. LB27.4 target cells were stained with CFSE and pulsed with GP33 peptide and then incubated for 24 hours with different numbers of effector splenocytes. The cells were then stained with viability dye eFluor 450 and the dead cells quantified by flow cytometry. Statistical significance was determined by Kruskal-Wallis test with post hoc Dunn’s test. Confidence intervals are shown as the mean ± SD. (**P ≤ 0.01, ***P ≤ 0.001, ****P ≤ 0.0001.)