title: Differential effects of malignant mesothelioma cells on THP-1 monocytes and macrophages.
abstract: Malignant mesothelioma (MM) is a highly fatal tumor arising from inner body membranes, whose extensive growth is facilitated by its week immunogenicity and by its ability to blunt the immune response which should arise from the huge mass of leukocytes typically infiltrating this tumor. It has been reported that the inflammatory infiltrate found in MM tissues is characterized by a high prevalence of macrophages. Thus, in this work we evaluated the ability of human MM cells to modulate the inflammatory phenotype of human THP-1 monocytes and macrophages, a widely used in vitro model of monocyte/macrophage differentiation. Furthermore, we tested the hypothesis that the exposure to MM cells could alter the differentiation of THP-1 monocytes favoring the development of alternatively activated, tumor-supporting macrophages. Our data prove for the first time that MM cells can polarize monocytes towards an altered inflammatory phenotype and macrophages towards an immunosuppressive phenotype. Moreover, we demonstrate that monocytes cocultivated with MM cells 'keep a memory' of their encounter with the tumor which influences their differentiation to macrophages. On the whole, we provide evidence that MM cells exert distinct, cell-specific effects on monocytes and macrophages. The thorough characterization of such effects may be of a crucial importance for the rational design of new immunotherapeutic protocols.
authors.affiliation: Department of Experimental Medicine and Biochemical Sciences, University of Rome Tor Vergata, I-00133 Rome, Italy. valerioizzi@libero.it
authors.forename: Valerio
authors.initials: V
authors.lastname: Izzi
authors.forename: Valerio
authors.initials: V
authors.lastname: Chiurchiù
authors.forename: Fabiola
authors.initials: F
authors.lastname: D'Aquilio
authors.forename: Camilla
authors.initials: C
authors.lastname: Palumbo
authors.forename: Ilaria
authors.initials: I
authors.lastname: Tresoldi
authors.forename: Andrea
authors.initials: A
authors.lastname: Modesti
authors.forename: Patrizia M
authors.initials: PM
authors.lastname: Baldini
mesh_terms: D016718:Arachidonic Acid / Q000378:metabolism; D002454:Cell Differentiation; D002460:Cell Line; D003094:Collagen / Q000378:metabolism; D015232:Dinoprostone / Q000378:metabolism; D006801:Humans; D016753:Interleukin-10 / Q000378:metabolism; D008264:Macrophages / Q000166:cytology* / Q000473:pathology / Q000502:physiology; D008654:Mesothelioma / Q000473:pathology*; D009000:Monocytes / Q000166:cytology* / Q000473:pathology / Q000502:physiology; D009569:Nitric Oxide / Q000378:metabolism; D010587:Phagocytosis; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D016718:Arachidonic Acid; D009569:Nitric Oxide; D003094:Collagen; D015232:Dinoprostone