title: Treatment of monocytes with interleukin (IL)-12 plus IL-18 stimulates survival, differentiation and the production of CXC chemokine ligands (CXCL)8, CXCL9 and CXCL10.
abstract: During inflammation, interleukin (IL)-12 and IL-18 are produced by macrophages and other cell types such as neutrophils (IL-12), keratinocytes and damaged endothelial cells (IL-18). To explore the role of IL-12 and IL-18 in inflammatory innate immune responses we investigated their impact on human peripheral blood monocytes and mature bronchoalveolar lavage (BAL) macrophages. IL-12 and IL-18 together, but not alone, prevented spontaneous apoptosis of cultured monocytes, promoted monocyte clustering and subsequent differentiation into macrophages. These morphological changes were accompanied by increased secretion of CXC chemokine ligands (CXCL)9, CXCL10 (up to 100-fold, P < 0.001) and CXCL8 (up to 10-fold, P < 0.001) but not CCL3, CCL4 or CCL5. Mature macrophages (from BALs) expressed high basal levels of CXCL8, that were no modified upon stimulation with IL-12 and IL-18. In contrast, the basal production of CXCL9 and CXCL10 by BALs was increased by 10-fold (P < 0.001) in the presence of either IL-12 or IL-18 alone and by 50-fold in the presence of both cytokines. In conclusion, our results indicate a relevant role for IL-12 and IL-18 in the activation and resolution of inflammatory immune responses, by increasing the survival of monocytes and by inducing the production of chemokines. In particular, those that may regulate angiogenesis and promote the recruitment of monocytes, activated T cells (CXCL9 and CXCL10) and granulocytes (CXCL8).
authors.affiliation: Fundació IrsiCaixa, Badalona, Spain.
authors.forename: G
authors.initials: G
authors.lastname: Coma
authors.forename: R
authors.initials: R
authors.lastname: Peña
authors.forename: J
authors.initials: J
authors.lastname: Blanco
authors.forename: A
authors.initials: A
authors.lastname: Rosell
authors.forename: F E
authors.initials: FE
authors.lastname: Borras
authors.forename: J A
authors.initials: JA
authors.lastname: Esté
authors.forename: B
authors.initials: B
authors.lastname: Clotet
authors.forename: L
authors.initials: L
authors.lastname: Ruiz
authors.forename: R M E
authors.initials: RM
authors.lastname: Parkhouse
authors.forename: M
authors.initials: M
authors.lastname: Bofill
mesh_terms: D000704:Analysis of Variance; D002454:Cell Differentiation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D054357:Chemokine CXCL10; D054370:Chemokine CXCL9; D019743:Chemokines, CXC / Q000096:biosynthesis*; D006801:Humans; D007113:Immunity, Innate; D018664:Interleukin-12 / Q000494:pharmacology*; D020382:Interleukin-18 / Q000494:pharmacology*; D016209:Interleukin-8; D016676:Macrophages, Alveolar / Q000276:immunology*; D009000:Monocytes / Q000276:immunology*; D010587:Phagocytosis; D050797:STAT4 Transcription Factor / Q000032:analysis; D013268:Stimulation, Chemical
chemical_list: C508606:CXCL8 protein, human; C080810:CXCL9 protein, human; D054357:Chemokine CXCL10; D054370:Chemokine CXCL9; D019743:Chemokines, CXC; D020382:Interleukin-18; D016209:Interleukin-8; D050797:STAT4 Transcription Factor; C494090:STAT4 protein, human; D018664:Interleukin-12