Trogocytosis-Mediated Intracellular Signaling in CD4+ T Cells Drives TH2-Associated Effector Cytokine Production and Differentiation

CD4 + T cells have been observed to acquire APC-derived membrane and membrane-associated molecules through trogocytosis in diverse immune settings. Despite this, the consequences of trogocytosis on the recipient T cell remain largely unknown. We previously reported that trogocytosed molecules on CD4 + T cells engage their respective surface receptors, leading to sustained TCR signaling and survival after APC removal. Using peptide-pulsed bone marrow-derived dendritic cells and transfected murine fibroblasts expressing antigenic MHC:peptide complexes as APC, we show that trogocytosis-positive CD4 + T cells display effector cytokines and transcription factor expression consistent with a T H 2 phenotype. In vitro-polarized T H 2 cells were found to be more efficient at performing trogocytosis than T H 1 or nonpolarized CD4 + cells, whereas subsequent trogocytosis-mediated signaling induced T H 2 differentiation in polarized T H 1 and nonpolarized cells. Trogocytosis-positive CD4 + T cells generated in vivo also display a T H 2 phenotype in both TCR-transgenic and wild-type models. These findings suggest that trogocytosis-mediated signaling impacts CD4 + T cell differentiation and effector cytokine production and may play a role in augmenting or shaping a T H 2-dominant immune response.