Lentiviral vectors with CMV or MHCII promoters administered in vivo: immune reactivity versus persistence of expression

Mol Ther. 2007 Jul;15(7):1390-9. doi: 10.1038/sj.mt.6300180. Epub 2007 May 1.

Abstract

Lentiviral vectors (LVs) are potential tools for genetic vaccination. To improve the safety of LV vaccines, we evaluated the selectivity, bio-distribution, persistence of expression, and immune potency of vesicular stomatitis virus G (VSV-G)-pseudotyped vectors transcriptionally targeted to antigen presenting cells (APCs) through a major histocompatibility complex class II (MHCII) promoter. Control vectors contained the ubiquitous cytomegalovirus (CMV) promoter. Bio-distribution studies after intravenous injections of LVs expressing green fluorescent protein (GFP) or luciferase were conducted by a combination of flow cytometry, immunofluorescence, real-time quantitative polymerase chain reaction (RT-Q-PCR) and whole-body bioluminescence analyses. GFP-expressing vectors showed selective expression in MHCII(+) cells of spleen and LV-CMV-GFP administration produced noticeable spleen inflammation, whereas LV-MHCII-GFP did not. Long-term optical imaging analyses of C57BL/6 mice injected with LV-CMV-LUC showed diminishing luciferase expression in the liver and spleen over time. Vaccination/boost with LV-CMV expressing the melanoma antigen tyrosinase-related protein 2 (TRP2) yielded dose-dependent antigen-specific CD8(+) T-cell reactivity and high protection against B16 melanoma challenge. Unexpectedly, administration of LVs containing the MHCII promoter resulted in persistence of luciferase expression and viral integration in MHCII(+) splenocytes and virtually no CD8(+) T-cell responses against TRP2. These studies reveal that APC transduction by LVs could lead to immune reactivity (LV-CMV) or persistence of transgene expression (LV-MHCII), providing a relevant paradigm for vaccination and gene replacement approaches.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CD8-Positive T-Lymphocytes / immunology
  • CD8-Positive T-Lymphocytes / metabolism
  • Cell Line, Tumor
  • Cytomegalovirus / genetics*
  • Female
  • Gene Expression / genetics*
  • Genetic Vectors / administration & dosage
  • Genetic Vectors / genetics*
  • Histocompatibility Antigens Class II / genetics*
  • Histocompatibility Antigens Class II / immunology*
  • Histocompatibility Antigens Class II / metabolism
  • Lentivirus / genetics*
  • Liver / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Mice, Nude
  • Neoplasm Transplantation
  • Promoter Regions, Genetic / genetics*
  • Sensitivity and Specificity
  • Spleen / immunology
  • Spleen / metabolism
  • Survival Rate
  • Transgenes / genetics
  • Vaccination
  • Virus Internalization

Substances

  • Histocompatibility Antigens Class II