Intravital two-photon microscopy of the lymph nodes to understand the role of extracellular vesicles in immune system dynamics

Abstract

The presence of lymph node metastasis is a major prognostic factor affecting patients with head and neck squamous cell carcinoma (HNSCC). Although advances have been made in the field of regional metastasis, limited data are available for the molecular signals involved in this process. In our FAPESP post-doctorate project (Process 2015/19191-6), we identified a set of proteins in the primary tumor from HNSCC patients that is associated with lymph node metastasis and can be transported by oral cancer extracellular vesicles (EVs). We postulated that this group of EV proteins may be associated with changes in the normal lymph nodes that lead to metastasis. This BEPE project was designed to evaluate the role of tumor-derived EV proteins in lymph node immune cells dynamics using intravital two-photon microscopy (2P-IVM). 2P-IVM is a state-of-the-art technique that allows the visualization of biological processes in live animals. The development of 2P-IVM has allowed investigators to view the dynamics movements and interactions of individual cells within live lymph nodes both for the sessile and the motile compartments. We will test the role of selected EV proteins in the dynamics of lymph nodes cells, specifically dendritic cells and their cross talk with CD4+ T cells, using a C57BL/6 mouse model. This BEPE proposal will complement the data obtained in the FAPESP post-doctorate project in a mechanistically way and may further indicate therapeutic target that control lymph node metastasis onset in HNSCC.