Mechanism of Mycoplasma-Induced Mast Cell Il-4 Synthesis

本项目的总体目标是确定先天性和适应性免疫机制，肺炎支原体通过该机制促进慢性气道高反应性和炎症的发展，重点是肥大细胞的作用。 具体目的1：克隆并表达M. pneumoniae在E. coli，并获得突变体M.该分子缺陷的肺炎菌株。P1粘附素或参与肥大细胞IL-4应答的选择片段将被克隆并在E.杆菌利用转座子诱变技术，获得了一株P1基因缺陷的M.将产生用于肥大细胞刺激实验和感染的小鼠模型的肺炎链球菌。 具体目标二：为了鉴定和表征肥大细胞上对P1糖蛋白诱导IL-4产生至关重要的表面分子，检查肺微环境中其他分子的调节作用，验证使用人肥大细胞观察到的作用，并表征M.肥大细胞系中的肺炎链球菌细胞因子应答。M的靶分子。肺炎诱导的肥大细胞细胞因子的产生将被鉴定和表征，突变缺失的作用将被检查，介质在肺微环境中的调节作用将被分析，M.将研究新的人肥大细胞系中的肺炎链球菌。 目的3：确定是否存在呼吸道支原体感染。肺炎链球菌诱导TH 2 CD 4+淋巴细胞向气道的募集，并使用依赖于肥大细胞衍生的IL-4或其它肥大细胞产物的机制来确定这是否发生。M的能力。将使用抗原特异性T细胞的过继转移来研究肺炎链球菌在肥大细胞诱导的TH 2细胞向肺和气道的募集中的协同作用。 具体目标4：在M.肺炎链球菌和肥大细胞的表达已经被消除或其中肥大细胞IL-4的产生被阻止。P1缺陷株M.将在小鼠中测试肺炎链球菌对慢性感染模型中的气道高反应性的影响。目的探讨肥大细胞靶分子在M.将研究肺炎诱导的细胞因子产生 突变品系的小鼠。

The overall goals of this project are to define innate and adaptive immune mechanisms by which Mycoplasma pneumoniae contributes to the development of chronic airway hyperreactivity and inflammation, focusing on the role of mast cells. Specific Aim 1: To clone and express the P1 adhesin of M. pneumoniae in E. coli and to produce a mutant M. pneumoniae strain deficient in that molecule. The P1 adhesin or select fragments involved in the mast cell IL-4 response will be cloned and expressed in E. coli. Using transposon mutagenesis, a P1-deficient strain of M. pneumoniae will be produced for use in mast cell stimulation experiments and the mouse model of infection. Specific Aim 2: To identify and characterize surface molecules on mast cells that are essential for induction of IL-4 production by P1 glycoprotein, examine modulating effects of other molecules in the pulmonary microenvironment, validate the effects observed using human mast cells, and characterize the effects of knockdown of expression of specific molecules involved in the M. pneumoniae cytokine response in mast cell lines. Target molecules for M. pneumoniae-induced mast cell cytokine production will be identified and characterized and the effects of mutational deletion examined, modulating effects of mediators in the pulmonary microenvironment will be analyzed, and effects of M. pneumoniae in a new human mast cell line will be studied. Specific Aim 3: To determine if respiratory tract infection by M. pneumoniae induces the recruitment to the airways of TH2 CD4 + lymphocytes, and to determine if this occurs using a mechanism that is dependent on mast cell-derived IL-4 or other mast cell products. The ability of M. pneumoniae to cooperate in the mast cell-induced recruitment of TH2 cells to the lungs and airways will be studied using adoptive transfer of antigen specific T cells. Specific Aim 4: To characterize the effects of infection in a mouse model under conditions in which interactions between M. pneumoniae and mast cells have been abrogated or in which mast cell IL-4 production is prevented. P1 deficient strain(s) of M. pneumoniae will be tested in mice for effects on airway hyperreactivity in a chronic infection model. The role of target molecules on the mast cells for M. pneumoniae-induced cytokine production will be studied in mutant strains of mice.