163P - Testing and analysis of fluorescent markers panel for T-cells’ multifunctionality in glioblastoma multiforme patients

Date 30 September 2012
Event ESMO Congress 2012
Session Poster presentation II
Topics Translational Research
Presenter Idan Ben-Horin
Authors I. Ben-Horin1, I. Volovitz2, Z. Ram3
  • 1Oncology Division, Tel Aviv Sourasky Medical Center-(Ichilov), 64239 - Tel Aviv/IL
  • 2Cancer Immunotherapy Lab, Tel-Aviv Sourasky Medical Center, Tel-Aviv/IL
  • 3Neurosurgery, Te-Aviv Sourasky Medical Center, Tel-Aviv/IL

Abstract

Introduction

Immunotherapy had only limited success in brain tumors as the brain is regarded as an immunologically privileged site. Recently published work on a rat model showed that when live, non-attenuated brain tumor cells are injected subcutaneously they are first accepted but are later spontaneously rejected. This immunologically mediated rejection of the brain tumors cells in peripheral sites leads to a similar intra-cranial tumor rejection. Objective: to characterize the different immune cell populations found in human glioblastoma multiforme (GBM) and in peripheral blood of GBM patients and to develop means to follow immune responses in the CNS to anti-tumor therapy.

Methods

Tumors were broken down and tumor cells isolated. Cultures of tumor cells with or without the respective patient's activated or non-activated lymphocytes were prepared, stained with a fluorescent markers panel for T-cells multifuncionality and analyzed using flow cytometry. The panel was constructed in our lab with markers for CD3 (total T-cells), CD4 (Th cells), CD8 (CTL), IFNγ, TNFα, IL-12 and ViViD – a viability marker.

Results

Our panel succeeded in characterizing the different immune cell populations. It also demonstrated that activation of CD4 T-cells increased IFNγ and IL12 expression and not TNFα's expression. CD8 T-cells demonstrated a smaller rise in IFNγ and IL12 expression and no expression of TNFα, before or after stimulation. Non-activated lymphocytes demonstrated no multifunctionality while activated cells exhibited low levels of IFNγ and IL12 joint expression. The extent of multifuncionality differed between CD4 and CD8 cells.

Conclusion

Our panel characterized the different T-cell populations in tumors. It demonstrated that only a small percentage of cells exhibited multifuncionality. To the best of our knowledge this is the first time T-cells multifunctionality in brain tumors has been described. This phenomenon is of importance as it correlates with vaccines' potency. Future work will characterize the difference between peripheral and intratumoral T-cells and their interaction with other immune cells populations as we aim to understand tumor induced immune system inhibition.

Disclosure

All authors have declared no conflicts of interest.