Distribution and prognostic impact of microglia/macrophage subpopulations in gliomas

• Published in: Brain pathology (Zurich, Switzerland) Vol. 29; no. 4; pp. 513 - 529
• Main Authors: Zeiner, Pia S., Preusse, Corinna, Golebiewska, Anna, Zinke, Jenny, Iriondo, Ane, Muller, Arnaud, Kaoma, Tony, Filipski, Katharina, Müller‐Eschner, Monika, Bernatz, Simon, Blank, Anna‐Eva, Baumgarten, Peter, Ilina, Elena, Grote, Anne, Hansmann, Martin L., Verhoff, Marcel A., Franz, Kea, Feuerhake, Friedrich, Steinbach, Joachim P., Wischhusen, Jörg, Stenzel, Werner, Niclou, Simone P., Harter, Patrick N., Mittelbronn, Michel
• Format: Journal Article
• Language: English
• Published: Switzerland John Wiley & Sons, Inc 01.07.2019; John Wiley and Sons Inc
• Subjects: Adaptive immunity; Adult; Aged; Animals; Astrocytoma; Astrocytoma - pathology; Brain; Brain cancer; Brain Neoplasms - pathology; Brain tumors; Carbon tetrachloride; CD11b antigen; CD163 antigen; Cell Line, Tumor; Central nervous system; Female; Gene expression; Glioblastoma; Glioblastoma - pathology; Glioma; Glioma - immunology; Glioma - metabolism; Glioma - pathology; glioma‐associated microglia and macrophages; Humans; immune polarization; Immune response; Immune system; Immunocytochemistry; Immunohistochemistry; Impact resistance; Inflammation; Interleukin 1; Interleukin 10; Macrophages; Macrophages - immunology; Macrophages - pathology; Male; Markers; Mice; Microglia; Microglia - immunology; Microglia - pathology; Middle Aged; Monocyte chemoattractant protein 1; Patients; Phagocytes; Prognosis; Survival; Tumor Microenvironment; Tumors; Xenograft Model Antitumor Assays; immune polarization; glioma; tumor microenvironment; glioma-associated microglia and macrophages
• ISSN: 1015-6305; 1750-3639; 1750-3639
• DOI: 10.1111/bpa.12690

While the central nervous system is considered an immunoprivileged site and brain tumors display immunosuppressive features, both innate and adaptive immune responses affect glioblastoma (GBM) growth and treatment resistance. However, the impact of the major immune cell population in gliomas, represented by glioma‐associated microglia/macrophages (GAMs), on patients’ clinical course is still unclear. Thus, we aimed at assessing the immunohistochemical expression of selected microglia and macrophage markers in 344 gliomas (including gliomas from WHO grade I–IV). Furthermore, we analyzed a cohort of 241 IDH1R132H‐non‐mutant GBM patients for association of GAM subtypes and patient overall survival. Phenotypical properties of GAMs, isolated from high‐grade astrocytomas by CD11b‐based magnetic cell sorting, were analyzed by immunocytochemistry, mRNA microarray, qRT‐PCR and bioinformatic analyses. A higher amount of CD68‐, CD163‐ and CD206‐positive GAMs in the vital tumor core was associated with beneficial patient survival. The mRNA expression profile of GAMs displayed an upregulation of factors that are considered as pro‐inflammatory M1 (eg, CCL2, CCL3L3, CCL4, PTGS2) and anti‐inflammatory M2 polarization markers (eg, MRC1, LGMN, CD163, IL10, MSR1), the latter rather being associated with phagocytic functions in the GBM microenvironment. In summary, we present evidence that human GBMs contain mixed M1/M2‐like polarized GAMs and that the levels of different GAM subpopulations in the tumor core are positively associated with overall survival of patients with IDH1R132H‐non‐mutant GBMs.