title: Three-dimensional co-culture of human monocytes and macrophages with tumor cells: analysis of macrophage differentiation and activation.
abstract: Here we report on an experimental system for generating TAM in vitro by culturing human MO and MO-derived macrophages (MAC) within 3-dimensional multicellular tumor spheroids (MCS). MO as well as MO-derived MAC migrate into tumor spheroids and spread throughout the entire spheroid within 16 hr. In contrast, fibroblast-spheroids were not infiltrated. The regular expression of MAC maturation-associated antigens on infiltrating MO was suppressed within MCS of the undifferentiated bladder carcinoma line J82 with regard to carboxypeptidase M (CPM), MAX.3 antigen and CD105. However, MAC within spheroids of highly differentiated papillary RT4 cells failed only the single antigen CD51, whereas MAC expressed the complete maturation-associated phenotype within non-tumorigenic HCV29 spheroids. Interestingly, the suppressive effect of J82 carcinoma cells could only be observed in 3-dimensional but not in monolayer cultures. The J82-MCS induced suppression of CPM and MAX.3 expression was only seen to be operative on infiltrating blood MO: MO first differentiated for 2 days and subsequently co-cultured with J82-MCS showed normal expression of MAX.3 and CPM within the spheroid. Besides the modulation of MAC phenotype, the cytokine response of intraspheroidal MAC was analyzed: upon co-culture MO secreted high IL-1beta and IL-6 but low amounts of TNF-alpha as compared to MAC. This MO typical cytokine pattern remained constant for up to 8 days in culture, again indicating a disturbed MO to MAC maturation within tumor spheroids. In conclusion, a 3-dimensional interaction with tumor cells in vitro results in significant changes in the phenotype and function of the spheroid-associated MO and MAC.
authors.affiliation: Department of Hematology and Oncology, University of Regensburg, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Konur
authors.forename: M
authors.initials: M
authors.lastname: Kreutz
authors.forename: R
authors.initials: R
authors.lastname: Knüchel
authors.forename: S W
authors.initials: SW
authors.lastname: Krause
authors.forename: R
authors.initials: R
authors.lastname: Andreesen
mesh_terms: D000951:Antigens, Neoplasm / Q000032:analysis; D001483:Base Sequence; D002454:Cell Differentiation / Q000502:physiology; D018920:Coculture Techniques; D016207:Cytokines / Q000096:biosynthesis; D058851:GPI-Linked Proteins; D006801:Humans; D008262:Macrophage Activation / Q000502:physiology*; D008264:Macrophages / Q000166:cytology* / Q000378:metabolism; D008666:Metalloendopeptidases / Q000032:analysis; D008969:Molecular Sequence Data; D009000:Monocytes / Q000166:cytology*; D010641:Phenotype; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D018874:Spheroids, Cellular; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis; D001749:Urinary Bladder Neoplasms / Q000473:pathology*
chemical_list: D000951:Antigens, Neoplasm; D016207:Cytokines; D058851:GPI-Linked Proteins; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; C058479:carboxypeptidase M; D008666:Metalloendopeptidases