Anti-CD40 Ab- or 8-oxo-dG-enhanced Treg cells reduce development of experimental autoimmune encephalomyelitis via down-regulating migration and activation of mast cells.

This study investigated whether anti-CD40 Ab and 8-oxo-dG attenuate mast cell migration and EAE development. Anti-CD40 Ab and 8-oxo-dG reduced EAE scores, mast cell numbers, expression of adhesion molecules, OX40L and Act1, levels of TNF-α, LTs, expression of cytokines, and co-localization of Treg cells and mast cells, all of which are increased in EAE-brain tissues. Each treatment enhanced Treg cells, expression of OX40, and cytokines related to suppressive function of Treg cells in EAE brain tissues. Act-BMMCs with Treg cells reduced expression of OX40L and CCL2/CCR2, VCAM-1, PECAM-1, [Ca²⁺]i levels, release of mediators, various signaling molecules, Act1 related to IL-17a signals versus those in act-BMMCs without Treg cells. The data suggest that IL-10- and IL-35-producing Foxp3⁺-Treg cells, enhanced by anti-CD40 Ab or 8-oxo-dG, suppress migration of mast cells through down-regulating the expression of adhesion molecules, and suppress mast cell activation through cell-to-cell cross-talk via OX40/OX40L in EAE development.

Hong GU ，Kim NG ，Jeoung D ，Ro JY ... -  《-》

IgE production in CD40/CD40L cross-talk of B and mast cells and mediator release via TGase 2 in mouse allergic asthma.

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.

Hong GU ，Park BS ，Park JW ，Kim SY ，Ro JY ... -  《-》

Signaling pathways in the activation of mast cells cocultured with astrocytes and colocalization of both cells in experimental allergic encephalomyelitis.

Kim DY ，Jeoung D ，Ro JY 《-》

IgE and IgA produced by OX40-OX40L or CD40-CD40L interaction in B cells-mast cells re-activate FcεRI or FcαRI on mast cells in mouse allergic asthma.

Mast cells are major effector cells of allergic diseases related to IgE. This study was undertaken to determine whether IgE or IgA, produced by CD40-CD40L or OX40-OX40L interactions between B cells and mast cells, re-activate FcεRI or FcαRI on mast cell surface. C57BL mice were sensitized and subjected to OVA challenge to induce asthma. Bone marrow-derived mast cells (BMMCs) and primary B cells were co-cultured. Mast cell recruitment into airways was stained by May-Grünwald Giemsa, the expression of markers or signaling molecules were determined by immunohistochemistry or Western blotting, and co-localization of B cells and mast cells by immunofluorescence. Anti-CD40 plus anti-OX40L Abs synergistically reduced IgE and IgA production, and mediators (histamine, LTs and cytokines) released in mast cells, and additively reduced other responses, such as, numbers of mast cells, the expression of markers (tryptase, mMCP5, B220 and CD19), surface molecules (CD40, CD40L, OX40 and OX40L), FcεRI or FcαRI and the co-localization of BMMCs and B cells, and IgE- or IgA-producing cells, as compared with individual blocking Ab treatment which reducedresponses in BAL cells or lung tissues of OVA-challenged mice or in co-culture of B and mast cells. The data suggest that IgE and IgA, produced by OX40-OX40L or CD40-CD40L interaction between B cells and mast cells, may re-activate receptors of FCεRI and FcαRI on mast cell surfaces, followed by more mediator release, and furthermore, that treatment with anti-CD40 plus anti-OX40L Abs offers a potential treatment for allergic asthma.

Hong GU ，Lim JY ，Kim NG ，Shin JH ，Ro JY ... -  《-》

Foxp3(+)-Treg cells enhanced by repeated low-dose gamma-irradiation attenuate ovalbumin-induced allergic asthma in mice.

Park BS ，Hong GU ，Ro JY 《-》