Quantitative nanoscale imaging shows peptide-MHC I complexes are monomeric and spatially regulated in human dendritic cells

• 成果类型: Article
• 署名作者: Jacobs, Olivia; Menche, Tanja; Hoper, Cindy; Gerhards, Frederic; Fucek, Ivica; Vascotto, Fulvia; Dietz, Marina S.; Heilemann, Mike; Tampe, Robert
• 署名单位: Goethe University Frankfurt; Goethe University Frankfurt; Johannes Gutenberg University of Mainz; Goethe University Frankfurt
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.2615838123
• 发表日期: 2026-09-01
• 页码: e2615838123
• 关键词: antigen processing; single-molecule microscopy; dendritic cells; peptide-MHC I complexes; T cell receptor; SINGLE-MOLECULE LOCALIZATION; superresolution microscopy; antigen presentation; dimers; pathways; capacity; DYNAMICS; binding; surface

摘要

Major histocompatibility complex class I (MHC I) molecules present antigenic peptides to cytotoxic T cells, a process central to immune surveillance. However, the nanoscale spatial organization of peptide-MHC I (pMHC I) on human dendritic cells (DCs), key initiators of cytotoxic T cell responses, remains largely unexplored. Here, we combine high-affinity soluble T cell receptors with DNA-based point accumulation for imaging in nanoscale topography (DNA-PAINT) to quantitatively map and count defined pMHC I complexes at single-molecule resolution on HLA-A*02:01-expressing cells and primary human monocyte-derived DCs. We found no evidence for higher-order pMHC I nanoclusters under conditions of extracellular peptide exchange or physiological intracellular loading. Instead, detected signals correspond to individual pMHC I complexes. Notably, DC differentiation and activation modulate pMHC I surface abundance and spatial compartmentalization. These findings refine current models of antigen presentation by emphasizing regulation through surface density and spatial distribution, and establish a quantitative framework for epitope-specific, single-molecule quantification of antigen presentation in human immune cells.