GSE130424
Two distinct subsets are identified from the peritoneal myeloid mononuclear cells expressing both CD11c and CD115
The peritoneal cavity is home to various immune cells.  Previous studies have investigated the heterogenous nature of peritoneal myeloid mononuclear cells.  However, up to this date, there are no clear criteria to distinguish peritoneal macrophages and dendritic cells (DCs).  In the present study, we delineate the subsets of myeloid mononuclear cells in the mouse peritoneal cavity.  Considering phenotypical, functional, and ontogenic features, peritoneal myeloid mononuclear cells are divided into 5 subsets: large peritoneal macrophages (LPMs), small peritoneal macrophages (SPMs), DCs, and 2 MHCII+CD11c+CD115+ subpopulations (i.e., MHCII+CD11c+CD115+CD14-CD206- and MHCII+CD11c+CD115+CD14+CD206+).  Among them, 2 subsets of competent antigen presenting cells are demonstrated with distinct functional characteristics, one being DCs and the other being MHCII+CD11c+CD115+CD14-CD206- cells.  DCs are able to promote fully activated T cells and superior in expanding cytokine producing inflammatory T cells, whereas MHCII+CD11c+CD115+CD14-CD206- cells generate partially activated T cells and possess a greater ability to induce regulatory T cells under TGF-ß and retinoic acid conditions.  While the development of DCs and MHCII+CD11c+CD115+CD14-CD206- cells are responsive to the treatment of FLT3L and GM-CSF, the numbers of LPMs, SPMs, and MHCII+CD11c+CD115+CD14+CD206+ cells are only influenced by the injection of GM-CSF.  In addition, the analysis of transcriptomes reveals that the gene expression profile of MHCII+CD11c+CD115+CD14+CD206+ cells share high similarity with that of SPMs.  Collectively, our study identifies 2 distinct subpopulations of?MHCII+CD11c+CD115+?cells, (i) MHCII+CD11c+CD115+CD14-CD206- cells closely related to DCs and (ii) MHCII+CD11c+CD115+CD14+CD206+ cells to SPMs. Overall design: Global mRNA sequencing of MHCII+ peritoneal myeloid mononuclear cells