biostudies-literatureUnknown13(1)Hossain MCIHRCanadian Cancer Society Research InstituteEmerging evidence suggests that resident macrophages within tissues are enablers of tumor growth. However, a second population of resident macrophages surrounds all visceral organs within the cavities and nothing is known about these GATA6⁺ large peritoneal macrophages (GLPMs) despite their ability to invade injured visceral organs by sensing danger signals. Here, we show that GLPMs invade growing metastases that breach the visceral mesothelium of the liver via the "find me signal", ATP. Depleting GLPMs either by pharmacological or genetic tools, reduces metastases growth. Apoptotic bodies from tumor cells induces programmed cell death ligand 1 (PD-L1) upregulation on GLPMs which block CD8⁺ T cell function. Direct targeting of GLPMs by intraperitoneal but not intravenNature communications4406https://www.ebi.ac.uk/biostudies/studies/S-EPMC9338095biostudies-literatureGata6⁺ resident peritoneal macrophages promote the growth of liver metastasis.PMC9338095Shim RLee WYKubes PSharpe AHHossain MfalseGata6⁺ resident peritoneal macrophages promote the growth of liver metastasis.Emerging evidence suggests that resident macrophages within tissues are enablers of tumor growth. However, a second population of resident macrophages surrounds all visceral organs within the cavities and nothing is known about these GATA6⁺ large peritoneal macrophages (GLPMs) despite their ability to invade injured visceral organs by sensing danger signals. Here, we show that GLPMs invade growing metastases that breach the visceral mesothelium of the liver via the "find me signal", ATP. Depleting GLPMs either by pharmacological or genetic tools, reduces metastases growth. Apoptotic bodies from tumor cells induces programmed cell death ligand 1 (PD-L1) upregulation on GLPMs which block CD8⁺ T cell function. Direct targeting of GLPMs by intraperitoneal but not intraven2022-01-01T00:00:00Z2022 Jul2025-04-26T16:13:14.734Z2025-04-06T15:10:23.433ZS-EPMC93380953590620210.1038/s41467-022-32080-y