Division of Hygiene and Medical Microbiology, Innsbruck Medical University, Innsbruck, Austria.
Mycoses. 2013 Jul;56(4):403-13. doi: 10.1111/myc.12052. Epub 2013 Feb 14.
Aspergillus is a saprophytic fungus, which mainly becomes pathogenic in immunosuppressed hosts. A failure of host defences results in a diverse set of illnesses, ranging from chronic colonisation, aspergilloma, invasive disease and hypersensitivity. A key concept in immune responses to Aspergillus species is that host susceptibility determines the morphological form, antigenic structure and physical location of the fungus. Traditionally, innate immunity has been considered as a first line of defence and activates adaptive immune mechanisms by the provision of specific signals; innate and adaptive immune responses are intimately linked. The T-helper cell (TH 1) response is associated with increased production of inflammatory cytokines IFN-γ, IL-2 and IL-12 and stimulation of antifungal effector cells. Alternatively, TH 2-type responses are associated with suppression of antifungal effector cell activity, decreased production of IFN-γ and increased concentrations of IL-4 and IL-10, which promote humoral responses to Aspergillus. The host's defensive capacity is defined by the sum of resistance and tolerance. Resistance displays the ability to limit fungal burden and elimination of the pathogen, and tolerance means the ability to limit host damage caused by immune response.
曲霉是一种腐生真菌，主要在免疫抑制宿主中致病。宿主防御功能的失败会导致一系列不同的疾病，从慢性定植、曲霉肿、侵袭性疾病和过敏反应。宿主对曲霉属物种的免疫反应的一个关键概念是，宿主易感性决定了真菌的形态、抗原结构和物理位置。传统上，先天免疫被认为是第一道防线，并通过提供特定信号来激活适应性免疫机制；先天免疫和适应性免疫反应密切相关。辅助性 T 细胞（TH1）反应与炎症细胞因子 IFN-γ、IL-2 和 IL-12 的产生增加以及抗真菌效应细胞的刺激有关。相反，TH2 型反应与抗真菌效应细胞活性的抑制、IFN-γ产生的减少以及 IL-4 和 IL-10 的浓度增加有关，这些反应促进了针对曲霉的体液反应。宿主的防御能力由抵抗力和耐受性的总和来定义。抵抗力表现为限制真菌负荷和消除病原体的能力，而耐受性则意味着限制免疫反应引起的宿主损伤的能力。
