Effector and regulatory T cells roll at high shear stress by inducible tether and sling formation

The adaptive immune response involves T cell differentiation and migration to sites of inflammation. T cell trafficking is initiated by tethering and rolling on inflamed endothelium. Tethers and slings, discovered in neutrophils, facilitate cell rolling at high shear stress. Here we demonstrate that PSGL-1 binding to P- or E-selectins and the ability to form tethers and slings during rolling are highly inducible in T-helper-1 (Th1), Th17 and regulatory (Treg), but less in Th2 cells. In vivo, endogenous Tregs rolled stably in cremaster venules at physiological shear stress. Quantitative dynamic footprinting nanoscopy of Th1, Th17 and Tregs uncovered the formation of multiple tethers. Importantly, human Th1 cells also showed tethers and slings. RNA-Seq revealed that sling-forming cells induced genetic pathways related to cell motility. We conclude that differentiated CD4 T cells stabilize rolling by inducible tether and sling formation. These phenotypic changes approximate the adhesion phenotype of neutrophils and support CD4 T cell access to sites of inflammation in non-lymphoid tissues. Examination of mRNA expression profiles contributing to Tethers and Slings formation in CD4 T cell subsets by RNA-seq deep sequencing analysis by Hiseq 4000