title: Distinct populations of metastases-enabling myeloid cells expand in the liver of mice harboring invasive and preinvasive intra-abdominal tumor.
abstract: The liver is the most common site of adenocarcinoma metastases, even in patients who initially present with early disease. We postulated that immune-suppressive cells in the liver of tumor-bearing hosts inhibit anti-tumor T cells, thereby accelerating the growth of liver metastases. Using models of early preinvasive pancreatic neoplasia and advanced colorectal cancer, aims of this study were to determine immune phenotype, stimulus for recruitment, inhibitory effects, and tumor-enabling function of immune-suppressive cells in the liver of tumor-bearing hosts. We found that in mice with intra-abdominal malignancies, two distinct CD11b(+)Gr1(+) populations with divergent phenotypic and functional properties accumulate in the liver, becoming the dominant hepatic leukocytes. Their expansion is contingent on tumor expression of KC. These cells are distinct from CD11b(+)Gr1(+) populations in other tissues of tumor-bearing hosts in terms of cellular phenotype and cytokine and chemokine profile. Liver CD11b(+)Gr1(+) cells are highly suppressive of T cell activation, proliferation, and cytotoxicity and induce the development of Tregs. Moreover, liver myeloid-derived suppressor cells accelerate the development of hepatic metastases by inactivation of cytotoxic T cells. These findings may explain the propensity of patients with intra-abdominal cancers to develop liver metastases and suggest a promising target for experimental therapeutics.
authors.affiliation: S. Arthur Localio Laboratory, Department of Surgery, New York University School of Medicine, New York, NY 10016, USA.
authors.forename: Michael K
authors.initials: MK
authors.lastname: Connolly
authors.forename: Jon
authors.initials: J
authors.lastname: Mallen-St Clair
authors.forename: Andrea S
authors.initials: AS
authors.lastname: Bedrosian
authors.forename: Ashim
authors.initials: A
authors.lastname: Malhotra
authors.forename: Valery
authors.initials: V
authors.lastname: Vera
authors.forename: Junaid
authors.initials: J
authors.lastname: Ibrahim
authors.forename: Justin
authors.initials: J
authors.lastname: Henning
authors.forename: H Leon
authors.initials: HL
authors.lastname: Pachter
authors.forename: Dafna
authors.initials: D
authors.lastname: Bar-Sagi
authors.forename: Alan B
authors.initials: AB
authors.lastname: Frey
authors.forename: George
authors.initials: G
authors.lastname: Miller
mesh_terms: D000008:Abdominal Neoplasms / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D000818:Animals; D039481:CD11b Antigen / Q000096:biosynthesis / Q000276:immunology; D049109:Cell Proliferation; D054360:Chemokine CXCL1 / Q000096:biosynthesis / Q000276:immunology; D015972:Gene Expression Regulation, Neoplastic / Q000276:immunology; D007108:Immune Tolerance; D008099:Liver / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D008213:Lymphocyte Activation / Q000276:immunology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008822:Mice, Transgenic; D022423:Myeloid Cells / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000276:immunology; D010190:Pancreatic Neoplasms / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology / Q000378:metabolism / Q000473:pathology
chemical_list: D039481:CD11b Antigen; D054360:Chemokine CXCL1; C475895:Cxcl1 protein, mouse; D009363:Neoplasm Proteins