title: Loss of SOCS3 in myeloid cells prolongs survival in a syngeneic model of glioma.
abstract: In glioma, microglia and macrophages are the largest population of tumor-infiltrating cells, referred to as glioma associated macrophages (GAMs). Herein, we sought to determine the role of Suppressor of Cytokine Signaling 3 (SOCS3), a negative regulator of Signal Transducer and Activator of Transcription 3 (STAT3), in GAM functionality in glioma. We utilized a conditional model in which SOCS3 deletion is restricted to the myeloid cell population. We found that SOCS3-deficient bone marrow-derived macrophages display enhanced and prolonged expression of pro-inflammatory M1 cytokines when exposed to glioma tumor cell conditioned medium in vitro. Moreover, we found that deletion of SOCS3 in the myeloid cell population delays intracranial tumor growth and increases survival of mice bearing orthotopic glioma tumors in vivo. Although intracranial tumors from mice with SOCS3-deficient myeloid cells appear histologically similar to control mice, we observed that loss of SOCS3 in myeloid cells results in decreased M2 polarized macrophage infiltration in the tumors. Furthermore, loss of SOCS3 in myeloid cells results in increased CD8+ T-cell and decreased regulatory T-cell infiltration in the tumors. These findings demonstrate a beneficial effect of M1 polarized macrophages on suppressing glioma tumor growth, and highlight the importance of immune cells in the tumor microenvironment.
authors.affiliation: Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA.
authors.forename: Braden C
authors.initials: BC
authors.lastname: McFarland
authors.affiliation: Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA.
authors.forename: Margaret P
authors.initials: MP
authors.lastname: Marks
authors.affiliation: Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA.
authors.forename: Amber L
authors.initials: AL
authors.lastname: Rowse
authors.affiliation: Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA.
authors.forename: Samuel C
authors.initials: SC
authors.lastname: Fehling
authors.affiliation: Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA.
authors.forename: Magda
authors.initials: M
authors.lastname: Gerigk
authors.affiliation: Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA.
authors.forename: Hongwei
authors.initials: H
authors.lastname: Qin
authors.affiliation: Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA.
authors.forename: Etty N
authors.initials: EN
authors.lastname: Benveniste
mesh_terms: D000818:Animals; D017209:Apoptosis; D001932:Brain Neoplasms / Q000235:genetics / Q000276:immunology / Q000473:pathology*; D049109:Cell Proliferation; D005910:Glioma / Q000235:genetics / Q000276:immunology / Q000473:pathology*; D051379:Mice; D018345:Mice, Knockout; D022423:Myeloid Cells / Q000276:immunology / Q000378:metabolism / Q000473:pathology*; D000071223:Suppressor of Cytokine Signaling 3 Protein / Q000502:physiology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology / Q000378:metabolism / Q000473:pathology*; D014407:Tumor Cells, Cultured; D059016:Tumor Microenvironment / Q000276:immunology
chemical_list: C491411:Socs3 protein, mouse; D000071223:Suppressor of Cytokine Signaling 3 Protein
keywords: GL261; JAK/STAT; SOCS3; glioblastoma; macrophage