Activation probability of a single na ïve T cell upon TCR ligation is controlled by T cells interacting with the same antigen‐presenting cell

AbstractAccurate recognition of antigens by specific T cells is crucial for adaptive immunity to work properly. The activation of a T cell antigen ‐specific response by an antigen presenting cell (APC) has not been clearly measured at a single T cell level. It is also unknown whether the cell extrinsic environment alters antigen recognition by a T cell. To measure the activation probability of a single T cell by an APC, we performed a single cell live imaging assay and found that the activation probability changes depending not only on the antigens but also on the interactions of other T cells with the APC. We found that the specific reactivity of single naïve T cells was poor. However, their antigen‐specific reactivity increased dr astically when attached to an APC interacting with activated T cells. Activation of T cells was suppressed when regulatory T cells interacted with the APC. These findings suggest that although the ability of APCs to activate an antigen‐specific naïve T cell is low at a single cell level, the surr ounding environment of APCs improves the specificity of the bulk response.

Source: FEBS Letters - April 8, 2021 Category: Biochemistry Authors: Hiroaki Machiyama, Tomoyuki Yamaguchi, Tomonobu M Watanabe, Toshio Yanagida, Hideaki Fujita Tags: RESEARCH LETTER Source Type: research