title: Regulation of the class II MHC pathway in primary human monocytes by granulocyte-macrophage colony-stimulating factor.
abstract: GM-CSF stimulates the growth and differentiation of hematopoietic progenitors and also affects mature cell function. These effects have led to the use of GM-CSF as a vaccine adjuvant with promising results; however, the mechanisms underlying GM-CSF-mediated immune potentiation are incompletely understood. In this study, we investigated the hypothesis that the immune stimulatory role of GM-CSF is in part due to effects on class II MHC Ag presentation. We find that, in primary human monocytes treated for 24-48 h, GM-CSF increases surface class II MHC expression and decreases the relative level of the invariant chain-derived peptide, CLIP, bound to surface class II molecules. GM-CSF also increases expression of the costimulatory molecules CD86 and CD40, but not the differentiation marker CD1a or CD16. Furthermore, GM-CSF-treated monocytes are better stimulators in a mixed leukocyte reaction. Additional analyses of the class II pathway revealed that GM-CSF increases total protein and RNA levels of HLA-DR, DM, and DOalpha. Expression of class II transactivator (CIITA) types I and III, but not IV, transcripts increases in response to GM-CSF. Furthermore, GM-CSF increases the amount of CIITA associated with the DR promoter. Thus, our data argue that the proinflammatory role of GM-CSF is mediated in part through increased expression of key molecules involved in the class II MHC pathway via induction of CIITA.
authors.affiliation: Department of Pediatrics, School of Medicine, Stanford University, CCSR Room 2120, 269 Campus Drive, Stanford, CA 94305, USA. hornell@stanford.edu
authors.forename: Tara M C
authors.initials: TM
authors.lastname: Hornell
authors.forename: Guy W
authors.initials: GW
authors.lastname: Beresford
authors.forename: Alyssa
authors.initials: A
authors.lastname: Bushey
authors.forename: Jeremy M
authors.initials: JM
authors.lastname: Boss
authors.forename: Elizabeth D
authors.initials: ED
authors.lastname: Mellins
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology; D017951:Antigen Presentation / Q000276:immunology; D015703:Antigens, CD / Q000096:biosynthesis; D000944:Antigens, Differentiation, B-Lymphocyte / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D051940:B7-2 Antigen; D019013:CD40 Antigens / Q000096:biosynthesis; D002454:Cell Differentiation / Q000276:immunology; D002462:Cell Membrane / Q000276:immunology / Q000378:metabolism; D002478:Cells, Cultured; D015536:Down-Regulation / Q000235:genetics / Q000276:immunology; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology*; D006681:HLA-D Antigens / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D006684:HLA-DR Antigens / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D059805:HLA-DR alpha-Chains; D000949:Histocompatibility Antigens Class II / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis / Q000494:pharmacology; D016753:Interleukin-10 / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D008562:Membrane Glycoproteins / Q000096:biosynthesis; D009000:Monocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000096:biosynthesis; D011994:Recombinant Proteins; D015398:Signal Transduction / Q000235:genetics / Q000276:immunology*; D014158:Transcription, Genetic / Q000276:immunology; D015854:Up-Regulation / Q000235:genetics / Q000276:immunology
chemical_list: D000276:Adjuvants, Immunologic; D015703:Antigens, CD; D000944:Antigens, Differentiation, B-Lymphocyte; D051940:B7-2 Antigen; D019013:CD40 Antigens; C497964:CD86 protein, human; D006681:HLA-D Antigens; C084245:HLA-DM antigens; C046148:HLA-DO antigens; D006684:HLA-DR Antigens; D059805:HLA-DR alpha-Chains; D000949:Histocompatibility Antigens Class II; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; C045084:invariant chain; D016753:Interleukin-10; D007371:Interferon-gamma; D016178:Granulocyte-Macrophage Colony-Stimulating Factor