Synergy of adoptive T-cell therapy and intratumoral suicide gene therapy is mediated by host NK cells.

Published

Journal Article

In situ tumor cell killing by the herpes simplex virus thymidine kinase (HSVtk) gene can effectively prime antitumor T-cell responses, at least in part through local induction of a pro-inflammatory environment. Therefore, we reasoned that tumor-associated HSVtk expression would significantly enhance the efficacy of adoptive T-cell transfer (ACT) of (tumor) antigen-specific T cells into tumor-bearing hosts. When B16ovaHSVtk tumors were treated with ganciclovir (GCV), along with suboptimal numbers of activated OT-1T cells, complete tumor regressions were observed where GCV, or ACT, alone was completely ineffective. To our surprise, analysis of regressing tumors showed no increases in intratumoral OT-1T cell trafficking. However, the intratumoral percentages of both OT-1 and endogenous natural killer (NK) cells were substantially increased over controls. Depletion of endogenous NK cells abrogated the efficacy of the combination therapy and reduced the percentages of interferon-gamma(IFNgamma)-secreting OT-1T cells in mice that received combined therapy to levels similar to those of control mice. These data suggest that even relatively low levels of gene transfer of suicide genes into tumors may have therapeutic value as an adjuvant for other T-cell therapies, by providing immunological signals that support T-cell activation and expansion in vivo.

Full Text

Duke Authors

Cited Authors

  • Sanchez-Perez, L; Gough, M; Qiao, J; Thanarajasingam, U; Kottke, T; Ahmed, A; Thompson, JM; Maria Diaz, R; Vile, RG

Published Date

  • July 2007

Published In

Volume / Issue

  • 14 / 13

Start / End Page

  • 998 - 1009

PubMed ID

  • 17443216

Pubmed Central ID

  • 17443216

International Standard Serial Number (ISSN)

  • 0969-7128

Digital Object Identifier (DOI)

  • 10.1038/sj.gt.3302935

Language

  • eng

Conference Location

  • England