Lung megakaryocytes are immune modulatory cells

Although platelets are the cellular mediators of thrombosis, they also immune cells. Platelets interact both directly and indirectly with cells, impacting their activation differentiation, as well all phases response. Megakaryocytes (Mks) cell source circulating platelets, until recently Mks were typically only considered bone marrow–resident (BM-resident) However, platelet-producing reside in lung, lung express greater levels molecules compared BM Mks. We therefore sought to define functions Using single-cell RNA sequencing myeloid-enriched we found that Mks, which term MkL, had gene expression patterns similar antigen-presenting This was confirmed using imaging conventional flow cytometry. The phenotype plastic driven by tissue environment, evidenced having an MkL-like under influence pathogen receptor challenge lung-associated molecules, such IL-33. Our vitro vivo assays demonstrated MkL internalized processed antigenic proteins bacterial pathogens. Furthermore, induced CD4+ T MHC II–dependent manner vivo. These data indicated key regulatory roles dictated part environment.