Ambient TLR Ligand Exposures and the Genesis of Asthma

描述（由申请人提供）：在婴儿期和幼儿期，一部分具有容许基因型的儿童发生吸入性过敏原超敏反应和哮喘，而其他儿童则不会。流行病学和实验室研究表明，生命早期暴露于Toll样受体（TLR）配体可能对哮喘的发生有深远的影响。因此，我们建议在成年和2周龄小鼠中确定气道暴露于纯化的TLR配体和室内灰尘提取物（HDE）中的TLR配体如何影响先天性和适应性免疫以及随后对气道变应原激发的反应。（PGN; TLR 2）、LPS（TLR 4）和免疫刺激序列寡脱氧核苷酸（ISS-ODN; TLR 9）影响先天性和适应性免疫以及气道过敏原耐受性-TLR 2，TLR 4，和TLR 9配体是普遍存在的，并诱导不同的免疫应答。因此，我们将比较PGN、LPS和ISS-ODN诱导的肺相关DC的成熟及其随后在免疫突触中与幼稚CD 4细胞的功能。体外和体内模型将用于成年和2周龄小鼠的比较分析。在另外的实验中，小鼠将被i.n.用单独的OVA或用PGN、LPS或ISS-ODN免疫，并分析免疫和气道过敏原攻击应答。SA-2：表征早期气道暴露于室内灰尘提取物（HDE）中所含TLR配体如何影响先天性和适应性免疫以及气道过敏原耐受性-使用纯化PGN、LPS和ISS-ODN的研究将有助于确定其在肺部的独特免疫活性。然而，在真实的世界中，潜在的哮喘婴儿和幼儿可能同时暴露于多种TLR配体和潜在的其他免疫刺激元素。因此，为了用纯化的TLR配体补充研究，我们将首先测量来自耐受性家庭（有牲畜、狗和猫等的家庭）的t-HDE的LPS和革兰氏阳性和阴性细菌DNA含量。和允许Th 2偏向的气道过敏原超敏反应的家庭（没有动物暴露的家庭）。然后，在与SA-1中提出的研究类似的研究中，我们将确定来自致耐受性和哮喘允许家庭的HDE如何影响成年和2周龄小鼠的气道DC成熟、CD 4细胞分化和宿主对空气变应原超敏反应的易感性。

DESCRIPTION (provided by applicant): During infancy and early childhood a subset of children with permissive genotypes develop aeroallergen hypersensitivities and asthma, while others do not. Epidemiological and laboratory investigations suggest that early life exposures to toll like receptor (TLR) ligands may have a profound impact on the genesis of asthma. Therefore, we propose to determine how airway exposures to purified TLR ligands and TLR ligands within house dust extracts (HDEs) impact on innate and adaptive immunity and subsequent responses to airway allergen challenge, in adult and 2-week old mice SA-I: Characterize how early life airway exposures to peptidoglycan (PGN; TLR2), LPS (TLR4) and immunostimulatory sequence oIigodeoxynucleotide (ISS-ODN; TLR9) influence innate and adaptive immunity and airway allergen tolerance- TLR2, TLR4, and TLR9 ligands are known to be ubiquitous and to induce divergent immunological responses. Therefore, we will compare PGN, LPS, and ISS-ODN induced maturation of lung associated DCs and their subsequent functionality in the immunological synapse with naive CD4 cells. In vitro and in vivo models will be utilized in comparative analyses of adult and 2-week old mice. In additional experiments, mice will be i.n. immunized with OVA alone or with PGN, LPS, or ISS-ODN, and immune and airway allergen challenge responses will be analyzed. SA-2: Characterize how early life airway exposures to TLR ligands contained in house dust extracts (HDEs) influence innate and adaptive immunity and airway allergen tolerance- Studies with purified PGN, LPS, and ISS-ODN will help define their unique immunological activities in the lungs. However, in the real world, potential asthmatic infants and toddlers are likely to have simultaneous exposures to a variety of TLR ligands and potentially other immunostimulatory elements, as well. Therefore, to complement studies with purified TLR ligands, we will first measure the LPS and Gram positive and negative bacterial DNA content of t-HDEs from homes that are tolerance (homes with livestock, dogs and cats etc.) and homes permissive for Th2 biased airway allergen hypersensitivities (homes without animal exposures). Then in studies analogous to those proposed in SA-1, we will determine how HDEs from tolerogenic and asthma permissive homes influence airway DC maturation, CD4 cell differentiation, and host susceptibility towards aeroallergen hypersensitivities in adult and 2 week old mice.