Research Projects

Chronic T cell stimulation and tumor-derived T cell inhibitory signals in the tumor microenvironment (TME) often lead to the exhaustion of tumor antigen-specific CD8+ T cells (Tex), which are characterized by overexpression of several T cell inhibitory receptors, diminished effector functions, and lower cytotoxic potential. Tex are also found in the peripheral blood of cancer patients, with an increase in the frequency of circulating T cells over-expressing exhaustion-related markers recorded in non-small-cell lung carcinoma (NSCLC) and multiple myeloma patients. The frequency of circulating Tex correlates with clinical outcomes of different therapeutic approaches in cancer patients, underlining the importance of monitoring circulating Tex as a therapeutic endpoint. Clinical studies with checkpoint blockade immunotherapy have shown that frequencies of circulating Tex in patients can predict non-responders to specific therapeutic interventions. This study proposes establishing Raman scattering microscopy for label-free detection of Tex from heterogeneous cell populations using murine tumor models. Tex will be induced in vitro by repeated stimulation of TCR transgenic T cells, subjected to Raman spectral analysis, and analyzed using principal component analysis and hierarchical cluster analysis. The frequency of Tex will be assessed using statistical methods. This work will help establish Raman scattering microscopy as a label-free detection method of clinically relevant Tex, preventing labeling-induced changes in cellular physiology and erroneous readings.