Institute of Microbiology, Leopold-Franzens-University Innsbruck, Innsbruck, Austria.
Mycoses. 2011 Oct;54 Suppl 3:48-55. doi: 10.1111/j.1439-0507.2011.02117.x.
Representatives of the genus Pseudallescheria (anamorph: Scedosporium) are saprobes and the aetiologic agent of invasive mycosis in humans. After dissemination, the central nervous system (CNS) is one of the most affected organs. Prerequisites for the survival of Pseudallescheria/Scedosporium in the host are the ability to acquire nutrients and to evade the immune attack. The cleavage of complement compounds via the secretion of fungal proteases might meet both challenges since proteolytic degradation of proteins can provide nutrients and destroy the complement factors, a fast and effective immune weapon in the CNS. Therefore, we studied the capacity of different Pseudallescheria/Scedosporium species to degrade key elements of the complement cascade in the cerebrospinal fluid and investigated a correlation with the phylogenetic background. The majority of the Pseudallescheria apiosperma isolates tested were demonstrated to efficiently eliminate proteins like complement factors C3 and C1q, thus affecting two main components of a functional complement cascade, presumably by proteolytic degradation, and using them as nutrient source. In contrast, the tested strains of Pseudallescheria boydii have no or only weak capacity to eliminate these complement proteins. We hypothesise that the ability of Pseudallescheria/Scedosporium strains to acquire nutrients and to undermine the complement attack is at least partly phylogenetically determined.
假丝酵母属（无性型：枝孢霉属）的代表种是腐生菌，也是人类侵袭性真菌感染的病原体。在传播后，中枢神经系统（CNS）是最易受影响的器官之一。假丝酵母/枝孢霉在宿主体内存活的前提是获取营养和逃避免疫攻击的能力。通过分泌真菌蛋白酶切割补体化合物可能同时满足这两个挑战，因为蛋白酶对蛋白质的降解可以提供营养物质并破坏补体因子，这是 CNS 中一种快速有效的免疫武器。因此，我们研究了不同假丝酵母/枝孢霉种在脑脊液中降解补体级联关键成分的能力，并调查了与系统发育背景的相关性。大多数测试的假丝酵母棘孢木霉分离株被证明能够有效地消除补体因子 C3 和 C1q 等蛋白质，从而通过蛋白水解降解作用影响功能补体级联的两个主要成分，并将其用作营养源。相比之下，测试的假丝酵母男孩株对这些补体蛋白没有或只有较弱的消除能力。我们假设，假丝酵母/枝孢霉株获取营养和破坏补体攻击的能力至少部分是由系统发育决定的。
