86P - Impairment of membrane TNF_ expression reduces cytotoxic activity of dendritic cells against autologous tumor cells in high-grade glioma patients (...

Date 08 December 2017
Event ESMO Immuno-Oncology Congress 2017
Session Lunch & Poster Display session
Topics Soft Tissue Sarcomas
Gynaecologic Malignancies
Presenter Tamara Tyrinova
Citation Annals of Oncology (2017) 28 (suppl_11): xi6-xi29. 10.1093/annonc/mdx711
Authors T. Tyrinova1, O. Leplina1, S. Mishinov2, M. Tikhonova1, A. Kalinovskiy3, S. Chernov3, V. Stupak2, A. Ostanin1, E. Chernykh1
  • 1Laboratory Of Cellular Immunotherapy, Scientific Research Institute of Fundamental and Clinical immunology, 630079 - Novosibirsk/RU
  • 2Neurosurgery Department, Novosibirsk Research Institute of Traumatology and Orthopedics them. Y.L.Tsivyana, 630079 - Novosibirsk/RU
  • 3Neurooncology Department, Federal Neurosurgical Center, 630079 - Novosibirsk/RU

Abstract

Background

Besides initiation of tumor-specific T cell immunity, dendritic cells (DCs) are endowed with direct tumoricidal activity. DC cytotoxicity can facilitate tumor antigen uptake by DCs and results in earlier induction of anti-tumor immune response. Previously, we showed monocyte-derived DCs of high-grade glioma patients generated in the presence of IFNα (IFN-DCs) have impaired cytotoxic activity against TNFα-sensitive tumor HEp-2 cells, that is associated with poor survival. The present study focuses on TNFα-dependent tumoricidal activity of glioma patient DCs.

Methods

The study was conducted in 28 donors and 45 high-grade glioma patients (Grade III-IV). DCs were generated by culturing of plastic-adherent peripheral blood mononuclear cells in the presence of GM-CSF and IFN-α followed by the addition of LPS. The tumor cell lines were obtained from tissues of 11 patients with Grade IV. DC cytotoxicity against tumor cells was studied using MTT-assay. mTNFα expression was determined by flow cytometry, TNFα gene expression – by RT-PCR, TNFα-converting enzyme (TACE) activity – by spectrofluorimetric analysis of DC lysates.

Results

The impairment of cytotoxic activity of patient IFN-DCs against TNFα-sensitive HEp-2 cells was associated with low level of membrane TNFα (mTNFα) and mRNA TNFα expression and tendency to high activity of TACE. Blocking TACE with TAPI-0 enhances mTNFα expression on patient IFN-DCs and significantly increases their cytotoxicity against HEp-2 cells. As for tumor cell lines obtained from glioma patient tissues, donor IFN-DC lysis of glioma cells had high values (≥ 40%). Blocking of TNFα/TNF-R1-signaling pathway by treating of donor IFN-DCs with soluble rhTNFR1 receptor led to partial decrease of DC cytotoxicity against most glioma cell lines (Δ up to 24-40%). Cytotoxic activity of patient IFN-DCs with decreased mTNFα expression against autologous tumor cells sensitive to TNFα/TNF-R1-signaling pathway was lower on average by 30% compared with control (donor) values.

Conclusions

The current study shows an important role of mTNFα as mediator of DC tumoricidal activity and as molecular targets for the regulation of DC cytotoxicity.

Clinical trial identification

Legal entity responsible for the study

Ethics Committees of Institute of Fundamental and Clinical Immunology, Institute of Traumatology and Orthopedics, Federal Neurosurgical Center and Institute of Cytology and Genetics

Funding

Russian Foundation for basic research

Disclosure

All authors have declared no conflicts of interest.