T Cell Autocrine Hyaluronan Forms Complex Structures in CD4 T Cell Cytoplasm and Plays a Critical Role in Formation of the Immune Synapse

作者：Robert B. Vernon, Michel D. Gooden, John A. Gebe, Inkyung Kang, Caroline Stefani, Gail Workman, Adam Lacy‐Hulbert, Paul L. Bollyky, Thomas N. Wight · 发表于：Journal of Histochemistry & Cytochemistry · 年份：2025 · DOI：10.1369/00221554251381874 · 被引用次数：1 · 研究领域：Proteoglycans and glycosaminoglycans research、Cancer Immunotherapy and Biomarkers、T-cell and B-cell Immunology

Summary This study examines the involvement of T cell autocrine hyaluronan (HA) with the immunological synapse (IS) that mediates T cell activation by antigen-presenting cells (APCs). Three-dimensional (3D) confocal images of mouse CD4 + T cells interacting with B cell lymphoma (A20) APCs in vitro showed HA to be primarily on the T cell side of the IS, appearing as a compact mass indenting the T cell nucleus. Similar 3D imaging of CD4 + T cells forming a pseudo-IS on anti-CD3 antibody-coated glass showed HA in the vicinity of the IS in dense masses or complex, arched, columnar structures. Affinity/immunofluorescence labeling studies confirmed the HA masses and columns were cytoplasmic, located beneath the cortical actin layer but outside the nucleus. In T cells forming a pseudo-IS, the HA-binding protein RHAMM was localized to cortical cytoplasm and had limited spatial overlap with cytoplasmic HA. Pre-exposure of T cells to the HA synthesis inhibitor 4-methylumbelliferone (4-MU) or to the HA-binding peptide Pep-1 inhibited IS formation with A20 APCs. Moreover, actin ring development in T cell pseudo-IS was inhibited by pre-exposure to 4-MU, but not by pre-exposure to Pep-1. Collectively, our previous and present studies suggest a complex role for cell surface and cytoplasmic T cell autocrine HA in IS formation and T cell receptor signaling: