Various Stages of Immune Synapse Formation Are Differently Dependent on the Strength of the TCR Stimulus

International Journal of Molecular Sciences

卷:21

Pascal Blatt¹  Varsha Pattu¹  Xuemei Li¹  Michael Estl¹  Hsin-Fang Chang¹  Ute Becherer¹  Jens Rettig¹ 

[1]Cellular Neurophysiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), Saarland University, 66421 Homburg, Germany

关键词: cytotoxic T lymphocyte(s);    immune synapse;    supramolecular activation center;    cytotoxic granule(s);    lipid bilayers;    total internal reflection fluorescence microscopy;   

DOI  :  10.3390/ijms21072475

来源: DOAJ

【 摘 要 】

Cytotoxic T lymphocytes (CTL) are key players of the adaptive immune system that target tumors and infected cells. A central step to that is the formation of a cell–cell contact zone between the CTL and its target called an immune synapse (IS). Here, we investigate the influence of the initial T cell receptor (TCR) trigger of a cytolytic IS on the distinct steps leading to cytotoxic granule (CG) exocytosis. We stimulated primary CTLs from mouse using lipid bilayers with varying anti-CD3 but constant ICAM concentrations. We fluorescently labeled molecular markers of distinct IS zones such as actin, CD3, granzyme B, and Synaptobrevin2 in CTLs and imaged cytolytic IS formation by total internal reflection fluorescence microscopy (TIRFM). We found that an intermediate anti-CD3 concentration of 10 µg/mL induces the fastest adhesion of CTLs to the bilayers and results in maximal CG fusion efficiency. The latency of actin ring formation, dwell time, and maximum surface area at the IS exhibit different dependencies on the stimulatory anti-CD3 concentrations. The number and surface area of CD3 clusters at the IS seem to show a different dependency to the TCR trigger when compared to their dwell time. Finally, the mode of full CG exocytosis appears to be independent of the TCR trigger.

【 授权许可】

Unknown