Transit and Function of T Cells Revealed in Vivo
Mikael Pittet, Director of the Cellular Imaging Program, Harvard Medical School

Seminar • 12 December 2004 • BM.2.131

More Info ...Abstract
T cells provide a complex means of defense against pathogens and cancer. To trigger an efficient immune response, rare T cells capable of recognizing pathogen- or tumor- derived peptides should divide rapidly in lymph nodes and then transit to the disease site where they display immediate effector functions. However, T cell transit to infected tissues or tumors as well as T cell function at the target sites remain largely unexplored, particulalrly in complex in vivo environments. We are employing novel imaging modalities (including fluorescent protein tomography and intravital confocal/two-photon microscopy) for non-invasive in vivo visualization of T cells and tumor cells in various clinical settings. We aim at obtaining insights into (i) the dynamics of T cell trafficking into tumors, and (ii) the functional capacity of T cells to kill tumor cells in vivo. Because anti-tumor T cell responses that develop in cancer patients rarely result in tumor eradication, we are assessing the impact of different immunotherapeutic modalities that may promote homing to tumors as well as effector functions of tumor-specific T cells in vivo.