Calcedo Roberto, Ramirez-Garcia Andoni, Abad Ana, Rementeria Aitor, Pontón José, Hernando Fernando Luis
Department of Immunology, Microbiology and Parasitology, Faculty of Science and Technology, University of the Basque Country, Spain.
Rev Iberoam Micol. 2012 Jul-Sep;29(3):172-4. doi: 10.1016/j.riam.2011.07.004. Epub 2011 Aug 11.
Candida albicans is an opportunistic dimorphic fungus commonly present in the human oral cavity that causes infections in immunocompromised patients. The antigen variability, influenced by growth conditions, is a pathogenicity factor.
To determine the effect of nutritional and heat stress on the antigen expression of C. albicans, and to identify major antigens recognized by human salivary secretory immunoglobulin A (sIgA).
Under various different nutritional conditions, heat shock was induced in C. albicans cells in stationary and exponential growth phases. The expression of protein determinants of C. albicans was assessed by Western blot analysis against human saliva. The antigens were purified and characterized by two-dimensional electrophoresis and identified by protein microsequencing.
Five antigens recognized by salivary IgA were characterized as mannoproteins due to their reactivity with concanavalin A. They did not show reactivity with anti-heat shock protein monoclonal antibodies. Two of them (42 and 36 kDa) were found to be regulated by heat shock and by nutritional stress and they were identified as phosphoglycerate kinase and fructose bisphosphate aldolase, respectively.
These glycolytic enzymes are major antigens of C. albicans, and their differential expression and recognition by the mucosal immune response system could be involved in protection against oral infection.
白色念珠菌是一种机会性双态真菌，常见于人类口腔，可导致免疫功能低下患者感染。受生长条件影响的抗原变异性是一种致病因素。
确定营养和热应激对白色念珠菌抗原表达的影响，并鉴定人类唾液分泌型免疫球蛋白A（sIgA）识别的主要抗原。
在各种不同的营养条件下，对处于稳定期和指数生长期的白色念珠菌细胞进行热休克诱导。通过针对人唾液的蛋白质印迹分析评估白色念珠菌蛋白质决定簇的表达。通过二维电泳纯化和表征抗原，并通过蛋白质微测序进行鉴定。
唾液IgA识别的五种抗原由于它们与伴刀豆球蛋白A的反应性而被鉴定为甘露糖蛋白。它们与抗热休克蛋白单克隆抗体没有反应性。其中两种（42和36 kDa）被发现受热休克和营养应激调节，分别被鉴定为磷酸甘油酸激酶和果糖二磷酸醛缩酶。
这些糖酵解酶是白色念珠菌的主要抗原，它们的差异表达以及被黏膜免疫反应系统识别可能参与预防口腔感染。
