T cell microvilli particles are generated during the contact with antigen presenting cells

Abstract

The role of T cell microvilli has been suggested to search the antigen on the surface of antigen presenting cell (APC) and involve in adhesion under flow. However, the biological role of T cell microvilli during T cell activation has been largely unknown. In this study, we show that T cell microvilli convey the T cell receptors (TCRs) to c-SMAC at all stage of the Immune synapse (IS) and release TCR-enriched microvilli derived particles (TMPs) at IS or behind moving T cells. And also, we found that T cell in kinapse mode release the large size of TMPs (L-TMPs) and The rod- shaped L-TMP are undergone the fragmentation to the small size of TMP (S-TMPs). The direct plasma- membrane budding (DPMB) complex components, such as arrestin-domain-containing protein-1 (Arrdc1), transport-1 component tumor-susceptibility gene 101 (TSG101), and ATPase vacuolar protein-sorting-associated protein 4 (Vps4 a/b), involve in the fragmentation of L-TMPs to S-TMPs. To observe the generation for TMPs in more physiological condition, we adapted the 3D-polyvinyl Alcohol (PVA) nanofiber hydrogel. The 3D-live imaging by using the PVA hydrogel may suggest that TMPs can generate during the formation of IS in vivo condition. Concluding this study, we show that T cell microvilli involve in the conveyer for TCR to c-SMAC during the formation of IS. And we demonstrate the mechanism on the generation of TMPs.