title: Increased antigen presentation and T(h)1 polarization in genetically histamine-free mice.
abstract: Histamine is a well-known inflammatory mediator exerting various immunomodulatory effects and affecting the development of antigen-specific immune responses. Dendritic cells (DCs) are the most potent antigen-presenting cells specialized for capture, uptake, transport, processing and presentation of antigens to T cells. Using a genetically histamine-free [histidine decarboxylase knockout (HDC-/-)] mouse model, we examined the effects of histamine on DC-mediated antigen presentation. Applying an in vitro antigen presentation assay, we found that spleen DCs, derived from HDC-/- mice, display a higher efficiency in antigen presentation compared with wild-type cells. Flow cytometric characterization of DCs disclosed that this difference was not due to an altered distribution of DCs between or within the major functional sub-populations (assessed by CD11b and CD4 as myeloid and CD8alpha and DEC205 as lymphoid DC markers) or major changes in the co-stimulatory molecule profile (CD40, CD80, CD86). However, real-time PCR analysis of in vivo CFA-induced IL-12p35, IFNgamma, IL-10 and IL-4 expression showed that DCs matured in a histamine-free environment exhibit significantly elevated levels of IL-12p35 and IFNgamma mRNA. In vitro investigations confirmed that isolated DCs, developed in the absence of histamine, exhibit indeed a predominantly T(h)1-polarized cytokine pattern, as they show elevated levels of IFNgamma mRNA upon LPS stimulation. Similar difference was found at the protein level by ELISA, as well. Our study demonstrates that histamine interferes with antigen presentation and alters the cytokine profile of DCs.
authors.affiliation: Department of Genetics, Cell and Immunobiology, Semmelweis University, Nagyvárad tér 4, H-1089 Budapest, Hungary.
authors.forename: Ivett
authors.initials: I
authors.lastname: Jelinek
authors.forename: Valéria
authors.initials: V
authors.lastname: László
authors.forename: Edit
authors.initials: E
authors.lastname: Buzás
authors.forename: Eva
authors.initials: E
authors.lastname: Pállinger
authors.forename: Balázs
authors.initials: B
authors.lastname: Hangya
authors.forename: Zsuzsanna
authors.initials: Z
authors.lastname: Horváth
authors.forename: András
authors.initials: A
authors.lastname: Falus
mesh_terms: D000818:Animals; D017951:Antigen Presentation / Q000276:immunology; D015703:Antigens, CD / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism; D003713:Dendritic Cells / Q000187:drug effects / Q000276:immunology*; D005434:Flow Cytometry; D006632:Histamine / Q000502:physiology; D006640:Histidine Decarboxylase / Q000235:genetics*; D007371:Interferon-gamma / Q000235:genetics; D053765:Interleukin-12 Subunit p35 / Q000235:genetics; D008070:Lipopolysaccharides / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D013154:Spleen / Q000166:cytology; D018417:Th1 Cells / Q000276:immunology*
chemical_list: D015703:Antigens, CD; D016207:Cytokines; D053765:Interleukin-12 Subunit p35; D008070:Lipopolysaccharides; D012333:RNA, Messenger; D006632:Histamine; D007371:Interferon-gamma; D006640:Histidine Decarboxylase