naive T vs conA treated sample

Although T cell activation is closely linked to internalization of the T cell antigen receptor (TCR), relatively few studies have examined the release of TCRs via shedding of T cell microvilli following physical interaction with cognate antigen-presenting cells. In this study, we investigated the physiological implications of the release of TCRs and other external membrane components. We term this event “trogocytic molting”, as it occurs through a combined process of trogocytosis and enzymatic vesiculation of microvillar membrane structures. Surprisingly, in contrast to TCR internalization, this event leads to rapid upregulation of surface TCRs and remarkable metabolic reprogramming of cholesterol and fatty acids synthesis to meet the demands of clonal expansion, which drives multiple rounds of division and cell survival. These findings suggest that, contrary to the long-standing paradigm that emphasizes the importance of TCR internalization, external membrane loss, including TCRs, is a significant mechanism for clonal expansion In mouse CD3 T cells, we analyzed gene expression in each stimulation at three time points: 0 h (NT), 3 h, and 24 h time point.