Myeloid regulatory cells in allergic airway inflammation

描述(申请人提供)：假设：髓系衍生调节细胞(MDRC)在过敏性呼吸道炎症反应(如哮喘)中被招募到肺中，通过调节包括一氧化氮(NO)和超氧化物(02-)在内的反应性自由基的生物利用度来帮助控制组织炎症水平。具体目的：(1)检验抗原激发后招募到致敏小鼠肺内的髓系亚群是否会产生并调节过敏性呼吸道炎症过程中反应性自由基的关键平衡；(2)在小鼠模型上，确定MDRC是否通过使用反应性自由基来减轻哮喘的炎症反应。实验方法：对C57BL/6、iNOS-/-或B6(CG)-Ncf1m1 J/J小鼠进行腹腔致敏，并用鼻腔抗原卵清蛋白(OVA)攻击。取肺泡灌洗液和肺组织检测(1)MDRC的募集动态；(2)MDRC的吞噬功能，以及MDRC产生细胞因子和自由基类物质。此外，我们将研究(3)MDRC是否通过iNOS、精氨酸酶或NADPH氧化酶途径在体外介导对T细胞增殖的抑制；(4)MDRC是否在体内过继转移后介导对T细胞增殖的抑制以及NO和02-在这种作用中的作用；以及(5)过继转移的MDRC是否在呼吸道炎症模型中调节气道高反应性。理论基础：在过敏性呼吸道炎症反应中，先天细胞被招募到肺，而不是适应性免疫细胞。我们提供的初步数据表明：(1)产生O2-和NO的MDRC的两个亚群被招募到肺中，(2)MDRC通过依赖自由基的机制抑制T细胞的增殖，表明这些细胞有可能减轻体内的炎症。与公共卫生和NHLBI使命的相关性：拟议的研究将直接测试MDRC抑制哮喘疾病严重性的潜力，潜在地确定抗哮喘治疗的新靶点。

DESCRIPTION (provided by applicant): Hypothesis: Myeloid derived regulatory cells (MDRC), recruited to the lung during allergic airway inflammatory responses such as asthma, help to control the level of tissue inflammation by regulating the bioavailability of reactive free radicals, including nitric oxide (NO) and superoxide (02-). Specific Aims: (1) To test the hypothesis that myeloid subpopulations recruited to the lung of sensitized mice following antigen challenge generate and regulate the critical balance of reactive free radicals during allergic airway inflammation (2) Determine whether MDRC attenuate the asthmatic inflammatory response by mechanisms using reactive free radical species in a mouse model. Experimental Approach: C57BL/6, INOS-/- or B6 (Cg)-Ncf1m1 J/J mice will be sensitized intraperitoneally and challenged with the intranasal antigen, ovalbumin (OVA). Bronchoalveolar lavage (BAL) fluid and lung tissue will be examined for (1) dynamics of recruitment of MDRC (2) function of MDRC including phagocytic ability, and generation of cytokines and free radical species by MDRC. In addition, we will investigate (3) whether MDRC mediate suppression of T cell proliferation in vitro via iNOS, Arginase or NADPH oxidase pathways (4) whether MDRC mediate suppression of T cell proliferation following adoptive transfer in vivo and the role of NO and 02- in this effect, and (5) whether the adoptively transferred MDRC modulate airway hyper-responsiveness in a model of airway inflammation. Rationale: During allergic airway inflammatory responses, innate cells are recruited to the lung prior to adaptive immune cells. We present preliminary data to show (1) that two subsets of MDRC which generate O2- and NO are recruited to the lungs, and (2) MDRC suppress T cell proliferation via mechanisms that depend on free radicals, suggesting the potential for these cells to attenuate inflammation in vivo. Relevance to Public Health and the NHLBI Mission: The proposed studies will test directly the potential of MDRC to suppress asthma disease severity, potentially identifying novel targets for anti-asthmatic therapy.