title: Negative regulatory effect of histamine in DNFB-induced contact hypersensitivity.
abstract: Histamine plays an important role in the regulation of various immunological functions. To evaluate the role of histamine in contact hypersensitivity, contact dermatitis was induced with dinitrofluorobenzene (DNFB) in histidine decarboxylase knockout (HDC-/-) histamine-deficient and wild-type mice. The DNFB-induced increase of the ear thickness was significantly higher in HDC-/- mice than in wild-type mice. Using flow cytometry, significantly lower percentages of CD4+ Th and CD8+ Tc cells, and significantly higher percentages of CD45R+ B cells were observed in the regional lymph nodes in HDC-/- mice than in wild-type mice. In the ear specimens of both groups, the majority of the infiltrating cells were neutrophils and macrophages at 24 and 48 h after challenge. Using immunohistochemistry, we observed significantly more CD45+ leukocytes in HDC-/- mice than in wild-type mice. The expression of Th1 (IL-2, IFN-gamma, TNF-alpha) and Th2 (IL-4) mRNAs was examined by quantitative real time RT-PCR in the ear samples. The levels of Th1 cytokine mRNAs both at 24 and 48 h after challenge and IL-4 mRNA at 48 h showed a significantly higher increase in HDC-/- mice than in wild-type mice. These results suggest that histamine plays a negative immunoregulatory role in DNFB-induced contact hypersensitivity.
authors.affiliation: Department of Dermatology and Allergology, University of Szeged, Hungary. egaraczi@yahoo.com
authors.forename: Edina
authors.initials: E
authors.lastname: Garaczi
authors.forename: Márta
authors.initials: M
authors.lastname: Széll
authors.forename: Tamás
authors.initials: T
authors.lastname: Jánossy
authors.forename: Andrea
authors.initials: A
authors.lastname: Koreck
authors.forename: Andor
authors.initials: A
authors.lastname: Pivarcsi
authors.forename: Edit
authors.initials: E
authors.lastname: Buzás
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Pos
authors.forename: András
authors.initials: A
authors.lastname: Falus
authors.forename: Attila
authors.initials: A
authors.lastname: Dobozy
authors.forename: Lajos
authors.initials: L
authors.lastname: Kemény
mesh_terms: D000818:Animals; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D017449:Dermatitis, Allergic Contact / Q000276:immunology*; D004139:Dinitrofluorobenzene; D004423:Ear / Q000473:pathology; D015870:Gene Expression; D006632:Histamine / Q000235:genetics / Q000502:physiology*; D006640:Histidine Decarboxylase / Q000235:genetics; D007371:Interferon-gamma / Q000235:genetics / Q000378:metabolism; D007376:Interleukin-2 / Q000235:genetics / Q000378:metabolism; D015847:Interleukin-4 / Q000235:genetics / Q000378:metabolism; D017493:Leukocyte Common Antigens / Q000032:analysis; D007962:Leukocytes / Q000276:immunology; D051379:Mice; D018345:Mice, Knockout; D009154:Mutation / Q000235:genetics; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D016207:Cytokines; D007376:Interleukin-2; D014409:Tumor Necrosis Factor-alpha; D015847:Interleukin-4; D006632:Histamine; D007371:Interferon-gamma; D004139:Dinitrofluorobenzene; D017493:Leukocyte Common Antigens; D006640:Histidine Decarboxylase