title: Calcineurin and vacuolar-type H+-ATPase modulate macrophage effector functions.
abstract: While effector molecules produced by activated macrophages (including nitric oxide, tumor necrosis factor alpha, interleukin 1, etc.) help to eliminate pathogens, high levels of these molecules can be deleterious to the host itself. Despite their importance, the mechanisms modulating macrophage effector functions are poorly understood. This work introduces two key negative regulators that control the levels and duration of macrophage cytokine production. Vacuolar-type H+-ATPase (V-ATPase) and calcineurin (Cn) constitutively act in normal macrophages to suppress expression of inflammatory cytokines in the absence of specific activation and to inhibit macrophage cytokine responses induced by bacterial lipopolysaccharide (V-ATPase), interferon gamma (V-ATPase and Cn), and calcium (Ca2+) flux (Cn). Cn and V-ATPase modulate effector gene expression at the mRNA level by inhibiting transcription factor NF-kappaB. This negative regulation by Cn is opposite to its crucial positive role in T cells, where it activates NFAT transcription factor(s) leading to expression of interleukin 2, tumor necrosis factor alpha, and other cytokine genes. The negative effects of V-ATPase and Cn on NF-kappaB-dependent gene expression are not limited to the macrophage lineage, as similar effects have been seen with a murine fibroblast cell line and with primary astrocytes.
authors.affiliation: Department of Biological Sciences, Stanford University, Stanford, CA 94305-5020, USA.
authors.forename: I M
authors.initials: IM
authors.lastname: Conboy
authors.forename: D
authors.initials: D
authors.lastname: Manoli
authors.forename: V
authors.initials: V
authors.lastname: Mhaiskar
authors.forename: P P
authors.initials: PP
authors.lastname: Jones
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D019703:Calcineurin / Q000494:pharmacology / Q000502:physiology*; D002460:Cell Line; D002478:Cells, Cultured; D016207:Cytokines / Q000096:biosynthesis / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000378:metabolism; D005786:Gene Expression Regulation; D007306:Insecticides / Q000494:pharmacology; D007371:Interferon-gamma / Q000494:pharmacology; D018664:Interleukin-12 / Q000235:genetics; D007739:L Cells; D008070:Lipopolysaccharides / Q000494:pharmacology; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000276:immunology / Q000502:physiology*; D051379:Mice; D008815:Mice, Inbred Strains; D016328:NF-kappa B / Q000378:metabolism; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins / Q000378:metabolism; D006180:Proton-Translocating ATPases / Q000378:metabolism*; D011722:Pyrethrins / Q000494:pharmacology; D011994:Recombinant Proteins; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013601:T-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D016559:Tacrolimus / Q000494:pharmacology; D019284:Thapsigargin / Q000494:pharmacology; D014157:Transcription Factors / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics; D025262:Vacuolar Proton-Translocating ATPases
chemical_list: D016207:Cytokines; D004268:DNA-Binding Proteins; D007306:Insecticides; D008070:Lipopolysaccharides; D016328:NF-kappa B; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D011722:Pyrethrins; D011994:Recombinant Proteins; D014157:Transcription Factors; D014409:Tumor Necrosis Factor-alpha; D018664:Interleukin-12; C017160:cypermethrin; D019284:Thapsigargin; D007371:Interferon-gamma; D019703:Calcineurin; D025262:Vacuolar Proton-Translocating ATPases; D006180:Proton-Translocating ATPases; D016559:Tacrolimus