Characterization of mouse peritoneal macrophages using novel flow cytometry antibodies

Abstract Peritoneal resident macrophages are one of the most extensively studied macrophage populations in mouse. These cells can be divided into at least two discrete populations: small peritoneal macrophages (SPM) and large peritoneal macrophages (LPM). Under steady state conditions the monocyte-derived SPM constitute a minor population. They have a F4/80 (low) MHC-II (high) phenotype and constitutively produce cytokine RELM-alpha, known to be involved in anti-helminth response. LPM originate from embryonic progenitors and are normally more abundant. They express high levels of F4/80 and low levels of MHCII, and constitutively produce the B-cell attracting chemokine CXCL13. Here, we examined the homogeneity of each of the populations in C57Bl/6 and Balb/c mice. Our flow cytometric analysis with an array of novel antibodies, including anti-VSIG4 (CRIg), arginase 1, CD206, and CD163, revealed diversity within the LPM population. This phenotypic diversity most likely reflects differences in function and activation status, and will need further investigation.