Project B03 - Dendritic cell control of T cell differentiation and immune responses by exosomes
Extracellular vesicles (EVs) are thought to modulate immune responses, although there is still little direct evidence in vivo for such a mechanism. Here we present a novel deep-learning-trained image analysis workflow that analyses cells which were stained in vivo with a chimeric eGFP-tagged Milk Fat Globule-EGF Factor 8 protein (MFG-E8-eGFP) to discriminate phosphatidylserine (PS)+ apoptotic cells from PS+ EVs. Using this analysis pipeline, we will analyze EVs in infected mice and human yellow fever vaccinees, with a focus on effector T cells and other cells which strongly bind PS+ EVs. These EVs are mostly exosomes of antigen-presenting cell origin as they carry MHC and costimulatory molecules able to drive T cell-fate decisions. Hence, our new tools allow us for the first time to evaluate in vivo data on the roles for exosomes as mediators of T cell differentiation and we will analyze if and how EVs influence the T cell compartment during infection and vaccination.
