Abstract 4795: Kupfer-type immunological synapse characteristics do not predict anti-brain tumor cytolytic T-cell function in vivo

Abstract

Abstract To analyze the in vivo structure of antigen-specific immunological synapses during an effective immune response, we established brain tumors expressing the surrogate tumor antigen ovalbumin, and labeled antigen-specific anti-glioma T cells using specific tetramers. Using these techniques we determined that a significant amount of antigen-specific T cells were localized to the brain tumor and surrounding brain tissue, and a large percentage could be induced to express IFNγ when exposed to the specific ovalbumin-derived peptide epitope SIINFEKL. Detailed morphological analysis of T cells immunoreactive for tetramers in direct physical contact with tumor cells expressing ovalbumin, indicated that the interface between T cells and target tumor cells displayed various morphologies, including Kupfer-type immunological synapses. Quantitative analysis of adjacent confocal optical sections was performed to determine if the higher frequency of antigen-specific anti-glioma T cells present in animals that developed an effective anti tumor immune response, could be correlated with a specific immunological synaptic morphology. Detailed in vivo quantitative analysis failed to detect an increased proportion of immunological synapses displaying the characteristic Kupfer-type morphology, in animals mounting a strong and effective anti-tumor immune response, compared to those experiencing a clinically ineffective one. We conclude that an effective cytolytic immune response is not dependent on an increased frequency of Kupfer-type immunological synapses Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4795.