Journal Article

GM-CSF drives myelopoiesis, recruitment and polarisation of tumour-associated macrophages in cholangiocarcinoma and systemic blockade facilitates antitumour immunity

Kuhlers, Peyton C, Hernandez-Alejandro, Roberto, De Las Casas, Luis, Belt, Brian A, Nywening, Timothy M, Qin, Shuyang S, Georger, Mary, Linehan, David C, Dale, Benjamin S, Lesinski, Gregory B, Jackson, Katherine M, Ullman, Nicholas A, Juviler, Peter G, O'Dell, Michael R, Yeh, Jen Jen, Keilson, Jessica Millian, Morrison, Ashley B, Figueroa Guilliani, Nathania M, Hezel, Aram F, Burchard, Paul R, Jewell, Rachel, Calvi, Laura M, Ruffolo, Luis I

2022

Overview

ObjectiveIntrahepatic cholangiocarcinoma (iCCA) is rising in incidence, and at present, there are limited effective systemic therapies. iCCA tumours are infiltrated by stromal cells, with high prevalence of suppressive myeloid populations including tumour-associated macrophages (TAMs) and myeloid-derived suppressor cells (MDSCs). Here, we show that tumour-derived granulocyte–macrophage colony-stimulating factor (GM-CSF) and the host bone marrow is central for monopoiesis and potentiation of TAMs, and abrogation of this signalling axis facilitates antitumour immunity in a novel model of iCCA.MethodsBlood and tumours were analysed from iCCA patients and controls. Treatment and correlative studies were performed in mice with autochthonous and established orthotopic iCCA tumours treated with anti-GM-CSF monoclonal antibody.ResultsSystemic elevation in circulating myeloid cells correlates with poor prognosis in patients with iCCA, and patients who undergo resection have a worse overall survival if tumours are more infiltrated with CD68+ TAMs. Mice with spontaneous iCCA demonstrate significant elevation of monocytic myeloid cells in the tumour microenvironment and immune compartments, and tumours overexpress GM-CSF. Blockade of GM-CSF with a monoclonal antibody decreased tumour growth and spread. Mice bearing orthotopic tumours treated with anti-GM-CSF demonstrate repolarisation of immunosuppressive TAMs and MDSCs, facilitating T cell response and tumour regression. GM-CSF blockade dampened inflammatory gene networks in tumours and TAMs. Human tumours with decreased GM-CSF expression exhibit improved overall survival after resection.ConclusionsiCCA uses the GM-CSF-bone marrow axis to establish an immunosuppressive tumour microenvironment. Blockade of the GM-CSF axis promotes antitumour T cell immunity.

• Publisher: BMJ Publishing Group Ltd and British Society of Gastroenterology,BMJ Publishing Group LTD,BMJ Publishing Group
• Subject: Animals / Antibodies, Monoclonal / Bone marrow / Cholangiocarcinoma / Colony-stimulating factor / Granulocyte-macrophage colony-stimulating factor / Granulocyte-Macrophage Colony-Stimulating Factor - metabolism / Granulocyte-Macrophage Colony-Stimulating Factor - pharmacology / Hepatology / Humans / Immune response / Immunity / immunotherapy / Inflammation / inflammatory mediators / Lymphocytes T / macrophages / Medical prognosis / Mice / Microenvironments / Monoclonal antibodies / Monocytes / Myeloid cells / Myelopoiesis / Patients / Stromal cells / Suppressor cells / Tumor Microenvironment / Tumor-Associated Macrophages / Tumors