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Cancer Immunol Res. 2015 Aug;3(8):915-25. doi: 10.1158/2326-6066.CIR-14-0220-T. Epub 2015 May 14.

Adenovirus Improves the Efficacy of Adoptive T-cell Therapy by Recruiting Immune Cells to and Promoting Their Activity at the Tumor.

Author information

1
Cancer Gene Therapy Group, Department of Pathology and Transplantation Laboratory, Haartman Institute, University of Helsinki, Helsinki, Finland.
2
Laboratory of Radiochemistry, Department of Chemistry, University of Helsinki, Helsinki, Finland.
3
Cancer Gene Therapy Group, Department of Pathology and Transplantation Laboratory, Haartman Institute, University of Helsinki, Helsinki, Finland. TILT Biotherapeutics Ltd, Helsinki, Finland.
4
Laboratory of Radiochemistry, Department of Chemistry, University of Helsinki, Helsinki, Finland. Centre for Drug Research, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland.
5
Cancer Gene Therapy Group, Department of Pathology and Transplantation Laboratory, Haartman Institute, University of Helsinki, Helsinki, Finland. TILT Biotherapeutics Ltd, Helsinki, Finland. Department of Oncology, Helsinki University Central Hospital, Helsinki, Finland. akseli.hemminki@helsinki.fi.

Abstract

Despite the rapid progress in the development of novel adoptive T-cell therapies, the clinical benefits in treatment of established tumors have remained modest. Several immune evasion mechanisms hinder T-cell entry into tumors and their activity within the tumor. Of note, oncolytic adenoviruses are intrinsically immunogenic due to inherent pathogen-associated molecular patterns. Here, we studied the capacity of adenovirus to overcome resistance of chicken ovalbumin-expressing B16.OVA murine melanoma tumors to adoptive ovalbumin-specific CD8(+) T-cell (OT-I) therapy. Following intraperitoneal transfer of polyclonally activated OT-I lymphocytes, control of tumor growth was superior in mice given intratumoral adenovirus compared with control mice, even in the absence of oncolytic virus replication. Preexisting antiviral immunity against serotype 5 did not hinder the therapeutic efficacy of the combination treatment. Intratumoral adenovirus injection was associated with an increase in proinflammatory cytokines, CD45(+) leukocytes, CD8(+) lymphocytes, and F4/80(+) macrophages, suggesting enhanced tumor immunogenicity. The proinflammatory effects of adenovirus on the tumor microenvironment led to expression of costimulatory signals on CD11c(+) antigen-presenting cells and subsequent activation of T cells, thus breaking the tumor-induced peripheral tolerance. An increased number of CD8(+) T cells specific for endogenous tumor antigens TRP-2 and gp100 was detected in combination-treated mice, indicating epitope spreading. Moreover, the majority of virus/T-cell-treated mice rejected the challenge of parental B16.F10 tumors, suggesting that systemic antitumor immunity was induced. In summary, we provide proof-of-mechanism data on combining adoptive T-cell therapy and adenovirotherapy for the treatment of cancer.

PMID:
25977260
DOI:
10.1158/2326-6066.CIR-14-0220-T
[Indexed for MEDLINE]
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