Protective Immune Responses to Blastomyces Dermatitidis

芽生菌病是主要的全身性真菌病之一，经常引起进行性肺部疾病，但在皮肤芽生菌感染期间导致免疫失败和抵抗的因素尚不明确。 我们创造了一个WI-1淘汰B。在原发性肺部感染的鼠模型中减弱和控制的皮肤炎。 给老鼠注射疫苗可以防止再次感染，并引起杀菌免疫。 我们建议在这里使用的同基因减毒和野生型菌株和小鼠模型，在最后一个资助期，以确定在实验性肺芽生菌病的免疫失败和耐药性的细胞和分子基础。我们假设：B。皮肤炎破坏非免疫宿主中免疫T细胞的产生，导致进行性感染。 在接种疫苗的宿主中，T细胞介导抗性，并在T细胞亚群的需求中显示出可塑性，以产生和维持疫苗免疫力和记忆。我们的具体目标是：（1）解读免疫抑制细胞因子转化生长因子-β（TGF-β）在进行性原发性感染期间T细胞免疫失败中的作用，以及CTLA-4（T细胞活化的负调节剂）在TGF-β诱导的细胞免疫抑制期间的参与。 (2)描述不同的机制-细胞因子（IFN-γ、TNF-α）、细胞溶解和直接抗微生物活性-通过这些机制，CD 4+和CD 8 + T细胞介导疫苗对B的免疫。皮肤炎，以及在产生和维持这些回忆免疫应答中对CD 28共刺激和IL-12信号传导的需要。 (3)从B的表达产物中鉴定和克隆保护性T细胞在体外识别的抗原。Dermatitis cDNA文库中，以及在粗品、保护性细胞壁膜抗原的T细胞免疫印迹中，并证明克隆的重组抗原在体内赋予对B的保护性免疫。皮肤炎了解免疫失败和抵抗真菌的机制将有助于规划疫苗和治疗策略，在健康的人，并在宿主防御功能受损的患者，如艾滋病。

Blastomycosis, one of the principal systemic mycoses, often produces a progressive pulmonary disease, but the factors that account for immune failure and resistance during infection with Blastomyces dermatitidis infection are ill defined. We created a WI-1 knockout of B. dermatitidis that is attenuated and controlled in a murine model of primary pulmonary infection. Its administration to mice vaccinates them against re-infection and evokes sterilizing immunity. We propose here to use the isogenic attenuated and wild-type strains and mouse models developed in the last funding period to define the cellular and molecular bases of immune failure and resistance in experimental pulmonary blastomycosis. We hypothesize: that B. dermatitidis subverts generation of immune T-cells in a nonimmune host, leading to progressive infection. In a vaccinated host, T-cells mediate resistance, and show plasticity in the requirements of T-cell subsets for generation and maintenance of vaccine immunity and memory. Our specific aims are to: (1) Decipher the role of the immunosuppressive cytokine transforming growth factor-beta (TGF- beta) in failure of T-cell immunity during progressive primary infection, and the participation of CTLA-4, a negative regulator of T-cell activation, during TGF-beta-induced cellular immune suppression. (2) Delineate differential mechanisms - cytokines (IFN-gamma, TNF-alpha), cytolysis, and direct antimicrobial activity - by which CD4+ and CD8+ T-cells mediate vaccine immunity to B. dermatitidis, and requirements for CD28 co- stimulation and IL-12 signaling in generating and maintaining these recall immune responses. (3) Identify and clone antigens that protective T-cells recognize in vitro from expressed products of a B. dermatitidis cDNA library, and in T-cell immunoblots of a crude, protective cell-wall membrane antigen, and demonstrate that the cloned recombinant antigens confer protective immunity in vivo to B. dermatitidis. Understanding mechanisms of immune failure and resistance to fungi will assist in planning vaccine and treatment strategies in healthy people, and in patients with impairments of host defense such as AIDS.