title: Pollen-induced oxidative stress influences both innate and adaptive immune responses via altering dendritic cell functions.
abstract: It has been demonstrated that pollen grains contain NAD(P)H oxidases that induce oxidative stress in the airways, and this oxidative insult is critical for the development of allergic inflammation in sensitized mice. On the basis of this observation, we have examined whether pollen grain exposure triggers oxidative stress in dendritic cells (DCs), altering their functions. To test this hypothesis, human monocyte-derived DCs were treated with ragweed pollen grains. Our findings show that exposure to pollen grains induces an increase in the intracellular levels of reactive oxygen species in DCs. Our data also indicate that besides the NAD(P)H oxidases, other component(s) of pollen grains contributes to this phenomenon. Elevated levels of intracellular reactive oxygen species triggered the production of IL-8 as well as proinflammatory cytokines, such as TNF-alpha and IL-6. Treatment with pollen grains initiated the maturation of DCs, strongly upregulated the membrane expression of CD80, CD86, CD83, and HLA-DR, and caused only a slight increase in the expression of CD40. The pollen-treated DCs induced the development of naive T lymphocytes toward effector T cells with a mixed profile of cytokine production. Antioxidant inhibited both the phenotypic and functional changes of DCs, underlining the importance of oxidative stress in these processes. Collectively, these data show that pollen exposure-induced oxidative stress may contribute to local innate immunity and participate in the initiation of adaptive immune responses to pollen Ags.
authors.affiliation: Institute of Immunology, Medical and Health Science Center, University of Debrecen, Debrecen H-4012, Hungary.
authors.forename: Aniko
authors.initials: A
authors.lastname: Csillag
authors.forename: Istvan
authors.initials: I
authors.lastname: Boldogh
authors.forename: Kitti
authors.initials: K
authors.lastname: Pazmandi
authors.forename: Zoltan
authors.initials: Z
authors.lastname: Magyarics
authors.forename: Peter
authors.initials: P
authors.lastname: Gogolak
authors.forename: Sanjiv
authors.initials: S
authors.lastname: Sur
authors.forename: Eva
authors.initials: E
authors.lastname: Rajnavolgyi
authors.forename: Attila
authors.initials: A
authors.lastname: Bacsi
mesh_terms: D031164:Ambrosia / Q000276:immunology; D015703:Antigens, CD / Q000378:metabolism; D018122:B7-1 Antigen / Q000378:metabolism; D051940:B7-2 Antigen / Q000378:metabolism; D019013:CD40 Antigens / Q000378:metabolism; D049109:Cell Proliferation; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D006684:HLA-DR Antigens / Q000378:metabolism; D006801:Humans; D007136:Immunoglobulins / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000378:metabolism; D018384:Oxidative Stress; D011058:Pollen / Q000276:immunology*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D000097802:CD83 Antigen
chemical_list: D015703:Antigens, CD; D018122:B7-1 Antigen; D051940:B7-2 Antigen; D019013:CD40 Antigens; D006684:HLA-DR Antigens; D007136:Immunoglobulins; D015850:Interleukin-6; D016209:Interleukin-8; D008562:Membrane Glycoproteins; D017382:Reactive Oxygen Species; D014409:Tumor Necrosis Factor-alpha; D000097802:CD83 Antigen