Dendritic cells & immunity in mycoplasma pneumonia

描述(由申请者提供)：该项目的广泛、长期目标是开发预防和治疗呼吸道疾病的方法。我们发现不同的T细胞群调节了小鼠肺炎支原体的炎症反应，决定T细胞反应类型的因素还需要了解。树突状细胞(DC)和其他抗原提呈细胞(如巨噬细胞)在支原体疾病中的作用尚不清楚，但由于T细胞在支原体疾病中起着至关重要的作用，树突状细胞和巨噬细胞可能在疾病发病机制中发挥作用，并影响保护性免疫的产生。我们假设，操纵DC可以预测地改变肺部对支原体感染的免疫反应的类型和强度，这将影响疾病的严重性和抵抗力。此外，肺巨噬细胞也可能通过支持Th1型反应而影响支原体免疫。需要比较肺树突状细胞和巨噬细胞活动的影响。在这个方案中，我们将解决以下问题：1)幼年或支原体感染小鼠肺内DC和巨噬细胞的变化是否影响激活和调节T细胞分化和激活的能力？2)支原体抗原致敏的DC或巨噬细胞是否能产生针对支原体的保护性或免疫病理反应？3)通过调节细胞因子改变DC功能是否会影响肺部免疫反应和支原体呼吸道疾病？4)DCβ-趋化因子ABCD-1和ABCD-2(TARC)是否在肺部抗支原体免疫中发挥作用？实验设计如下：1)检测支原体感染小鼠呼吸道树突状细胞和巨噬细胞对无关抗原(OVA)体外和体内T细胞反应的激活能力。2)用支原体抗原冲击树突状细胞和巨噬细胞，观察它们在气管内接种后产生抵抗或免疫病理的能力，以及随后与支原体攻击的能力。3)DC将在体外用调节性细胞因子IFNGamma、IL-12、IL-4、TGF-β或IL-10处理，并用支原体抗原冲击，其对支原体的抵抗力或免疫病理学的能力将通过其气管内接种来确定；4)支原体感染小鼠肺部的T细胞将检测ABCD-1和ABCD-2受体的表达及其对这些趋化因子的反应能力。小鼠将接受中和单抗治疗，以确定ABCD-1和ABCD-2在支原体保护性免疫和免疫病理反应中的作用。

DESCRIPTION (provided by applicant): The broad, long-term objectives of this project are to develop approaches to prevent and treat respiratory diseases. We found that different T cells populations modulate inflammatory responses of murine mycoplasma pneumonia, and the factors that determine the type of T cell responses need to be understood. The role of dendritic cells (DCs) and other antigen presenting cells, e.g. macrophages, in Mycoplasma disease is unknown, but because T cell responses in mycoplasma disease play such a critical role, DCs and macrophages likely impact on disease pathogenesis and influence the generation of protective immunity. We hypothesize that manipulating DC can predictably change the types and intensity of immune reactions in the lung against mycoplasma infection, and this will impact on the severity and resistance to disease. In addition, pulmonary macrophages may also impact on mycoplasma immunity, possibly through support of Th1-type responses. The impact of pulmonary DCs and macrophages activity needs to be compared. In this proposal, we will address the following questions: 1) Do changes in pulmonary DCs and macrophages from naive or mycoplasma-infected mice influence the ability to activate and modulate T cell differentiation and activation? 2) Can mycoplasma-antigen pulsed DCs or macrophages generate protective or immunopathologic responses against mycoplasma? 3) Can altering DC function with regulatory cytokines influence pulmonary immune responses and mycoplasma respiratory disease? 4) Do the DCbeta-chemokines, ABCD-1 and ABCD-2 (TARC), play a role in pulmonary immunity against mycoplasma? The experimental design is as follows: 1) DCs and macrophages from the respiratory tracts of mycoplasma-infected mice will be evaluated for their ability activate in vitro and in vivo T cell responses against an unrelated antigen (OVA). 2) DCs and macrophages will be pulsed with mycoplasma antigen and their ability to generate resistance or immunopathology after intratracheal inoculation and subsequent challenge with mycoplasma will be determined. 3) DC will be treated in vitro with regulatory cytokines, IFNgamma, IL-12, IL-4 TGF-beta or IL-10, and pulsed with mycoplasma antigen, and their ability to generate resistance or immunopathology against mycoplasma will be determined by their intratracheal inoculation; and 4) T cells from lungs of Mycoplasma infected mice will be examined for expression of receptors for ABCD-1 and ABCD-2 and their ability to respond to these chemokines. Mice will be treated with neutralizing monoclonal antibodies to determine the role of ABCD-1 and ABCD-2 in protective immunity and immunopathologic responses against mycoplasma.