| Bronchial asthma is one of the chronic airway diseases which incidence is high, andin different regions and countries the disease affects5-16%of the population.The diseaseis a heavy burden to patients, families and society. To treat, control or even overcome thisdisease, over the past centuries, scientists and clinicians have been always exploring itsmechanisms and treatment.Currently, Th2cell-dependent and IgE involved is the most classic mechanism theoryof bronchial asthma, and in the process dendritic cells also play as a important role.Dendritic cells (DC) carrying antigens express costimulatory molecules and a number ofhigh level MHC Ⅱ when they reach the mediastinal lymph node, and the costimulatorymolecules and MHC Ⅱinduce proliferation and differentiation of T cell. Because theimportant role of the dendritc cells for asthma, the studies exploring the mechanism ofthem were more and more.Mesenchymal stem cells are beginning studied for asthma treatment these years. Inour former studies, we found mesenchymal stem cells could improve the condition of theasthma mice, and the function might play through the cytokines they released, and alsodendritic cells might play important role too. When we separated and extractedmesenchymal stem cells of different mouse, we found the function of Fcgr2b deficientmesenchymal stem cells were weaker than the wide type cells. Why is this so? We didsome pre-experiments, and then, we think this may be related to COX-2and PGE2, whichplay important role in asthma and the mature of dendritic cells.ObjectiveDiscuss the difference function to asthma and dendritic cells between FcgmmaRdeficient and wide type mesenchymal stem cells, and find the reason.MethodsA. Experiments in vitro: after separating and extracting MSCs from Fcgr2b deficientand normal mice, identified them and did the follow experiments.1. Co-cultrued DC different MSCs stimulating with LPS:(1) detecting the CD11c,I-Ab and CD86using Flow Cytometry;(2) ELISA for IL-12of the supernatant;(3) mixed lymphocyte culture with different DC, and then detected the proliferation of T cells.2. Analysising MSCs:(1) extracted mRNA from different MSCs, did reversetranscription and Q-PCR;(2) extracted protein from different MSCs, did Western-Blot;(3)ELISA for PGE2of the supernatant.B. Experiments in vivo:1. grouped and made acute asthma models: NC (na ve control group), AC (asthmacontrol group), T1(asthma mice treated with wide type MSCs group) and T2(asthma micetreated with Fcγ-deficient MSCs group);2. Detected serum IgE, bronchoalveolar lavage fluid (BALF) cells, BALF IL-4,BALF IL-13, BALF IL-10, BALF PGE2; lung pathology (using HE).ResultsA. Experiments in vitro: MSCs express high level of Fcgr2bII; Fcgr2bII2B-/-MSC isless effective in supressing DC maturation; Fcgr2bII deficient MSC is less potent insupressing antigen-specific T cell response; Fcgr2bII deficient MSCs produce less amountof PGE2.B. Experiments in vivo:1. AC-IgE was higher than NC-IgE (p<0.001), T1-IgE and T2-IgE were lower thanAC-IgE (p<0,05), and T1-IgE was lower than T2-IgE (p<0.1);2. BALF cells: AC was higher than NC (p<0.001), T1and T2were lower than AC(p<0,05), and T1was lower than T2(p<0.05);3. BALF IL-4and IL-13: AC was higher than NC (p<0.001), T1and T2were lowerthan AC (p<0,05), and T1was lower than T2(p<0.05);4. BALF IL-10: AC-IL-10was higher than NC-IL-10(p<0.001), T1-IL-10andT2-IL-10were higher than AC (p<0,05), and T1-IL-10was higher than T2-IL-10(p<0.05);5. BALF PGE2: T1-PGE2and T2-PGE2were higher than AC-PGE2(p<0,001), andT1-PGE2was higher than T2-PGE2(p<0.05);6. HE staining: NC normal, AC the worst, T1and T2better than AC, and T1betterthan T2.ConclusionMSCs could suppress the maturation of DC then suppressing the proliferation of Tcells, and could improve the condition of asthma mice. Wide type MSCs produced higher level of COX-2and PGE2than Fcgr2bII deficient ones, and the suppressive function ofDC, T cells and the ability to improve asthma condition of wt-MSCs were stronger thanFcgr2bII deficient ones. |
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