title: IgE production in CD40/CD40L cross-talk of B and mast cells and mediator release via TGase 2 in mouse allergic asthma.
abstract: TGase 2 is over-expressed in a variety of inflammatory diseases including allergic asthma. This study aimed to investigate the role of TGase 2 on IgE production and signaling pathways in mast cell activation related to OVA-induced allergic asthma. Bone marrow-derived mast cells (BMMCs) isolated from WT or TGase 2(-/-) mice were activated with Ag/Ab (refer to act-WT-BMMCs and act-KO-BMMCs, respectively). B cells isolated from splenocytes were activated with anti-mouse IgM (act-B cells), and B cells were co-cultured with BMMCs. WT and TGase 2(-/-) mice were sensitized and challenged with OVA adsorbed in alum hydroxide. Intracellular Ca(2+) ([Ca(2+)]i) levels were determined by fluorescence intensity; IgE, mediators and TGase 2 activity by ELISA; the CD138 expression by FACS analyzer; cell surface markers and signal molecules by Western blot; NF-κB by EMSA; co-localization of mast cells and B cells by immunohistochemistry; Fcε RI-mediated mast cell activation by PCA test; expression of cytokines, MMPs, TIMPs, TLR2 and FcεRI by RT-PCR. In vitro, act-KO-BMMCs reduced the [Ca(2+)]i levels, NF-κB activity, expression of CD40/CD40L, plasma cells, total IgE levels and TGase 2 activity in act-B cells co-cultured with act-BMMCs, expression of inflammatory cytokines and MMPs2/9, release of mediators (TNF-α, LTs and cytokines), and activities of signal molecules (PKCs, MAP kinases, I-κB and PLA2), which were all increased in act-WT-BMMCs. TGase 2 siRNA transfected/activated-BMMCs reduced all responses as same as those in act-KO-BMMCs. In allergic asthma model, TGase 2(-/-) mice protected against PCA reaction, OVA-specific IgE production and AHR, and they reduced co-localization of mast cells and B cells or IgE in lung tissues, expression and co-localization of surface molecules in mast cells (c-kit and CD40L) and B cells (CD23 and CD40), inflammatory cells including mast cells, goblet cells, amounts of collagen and mediator release in BAL fluid and/or lung tissues, which were all increased in WT mice. TLR expression in TGase 2(-/-) mice did not differ from those in WT mice. Our data suggest that TGase 2 expression and Ca(2+) influx required by bidirectional events in mast cell activation facilitate IgE production in B cells via up-regulating mast cell CD40L expression, and induce the expression of numerous signaling molecules associated with airway inflammation and remodeling in allergic asthma.
authors.affiliation: Department of Pharmacology and Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea.
authors.forename: Gwan Ui
authors.initials: GU
authors.lastname: Hong
authors.forename: Bum Soo
authors.initials: BS
authors.lastname: Park
authors.forename: Jung Won
authors.initials: JW
authors.lastname: Park
authors.forename: Soo Youl
authors.initials: SY
authors.lastname: Kim
authors.forename: Jai Youl
authors.initials: JY
authors.lastname: Ro
mesh_terms: D000818:Animals; D001249:Asthma / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D001402:B-Lymphocytes / Q000166:cytology / Q000378:metabolism*; D001854:Bone Marrow Cells / Q000166:cytology / Q000378:metabolism; D019013:CD40 Antigens / Q000378:metabolism*; D023201:CD40 Ligand / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D018920:Coculture Techniques; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D005260:Female; D019204:GTP-Binding Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D007073:Immunoglobulin E / Q000378:metabolism*; D008168:Lung / Q000378:metabolism; D008407:Mast Cells / Q000166:cytology / Q000378:metabolism* / Q000473:pathology; D020782:Matrix Metalloproteinases / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism; D015398:Signal Transduction; D019714:Tissue Inhibitor of Metalloproteinases / Q000235:genetics / Q000378:metabolism; D011503:Transglutaminases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D019013:CD40 Antigens; D016207:Cytokines; D034741:RNA, Small Interfering; D019714:Tissue Inhibitor of Metalloproteinases; D014409:Tumor Necrosis Factor-alpha; D023201:CD40 Ligand; D007073:Immunoglobulin E; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D011503:Transglutaminases; D020782:Matrix Metalloproteinases; D019204:GTP-Binding Proteins; D002118:Calcium