Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, IL 61802, USA.
Microbiology (Reading). 2010 Dec;156(Pt 12):3645-3659. doi: 10.1099/mic.0.043851-0. Epub 2010 Aug 12.
Despite an abundance of data describing expression of genes in the Candida albicans ALS (agglutinin-like sequence) gene family, little is known about the production of Als proteins on individual cells, their spatial localization or stability. Als proteins are most commonly discussed with respect to function in adhesion of C. albicans to host and abiotic surfaces. Development of a mAb specific for Als1, one of the eight large glycoproteins encoded by the ALS family, provided the opportunity to detect Als1 during growth of yeast and hyphae, both in vitro and in vivo, and to demonstrate the utility of the mAb in blocking C. albicans adhesion to host cells. Although most C. albicans yeast cells in a saturated culture are Als1-negative by indirect immunofluorescence, Als1 is detected on the surface of nearly all cells shortly after transfer into fresh growth medium. Als1 covers the yeast cell surface, with the exception of bud scars. Daughters of the inoculum cells, and sometimes granddaughters, also have detectable Als1, but Als1 is not detectable on cells from subsequent generations. On germ tubes and hyphae, most Als1 is localized proximal to the mother yeast. Once deposited on yeasts or hyphae, Als1 persists long after the culture has reached saturation. Growth stage-dependent production of Als1, coupled with its persistence on the cell surface, results in a heterogeneous population of cells within a C. albicans culture. Anti-Als1 immunolabelling patterns vary depending on the source of the C. albicans cells, with obvious differences between cells recovered from culture and those from a murine model of disseminated candidiasis. Results from this work highlight the temporal parallels for ALS1 expression and Als1 production in yeasts and germ tubes, the specialized spatial localization and persistence of Als1 on the C. albicans cell surface, and the differences in Als1 localization that occur in vitro and in vivo.
尽管有大量数据描述了白色念珠菌 ALS（凝集素样序列）基因家族中基因的表达，但对于单个细胞中 Als 蛋白的产生、它们的空间定位或稳定性知之甚少。Als 蛋白最常被讨论的是其在白色念珠菌与宿主和非生物表面粘附中的功能。开发针对 Als1 的 mAb（一种由 ALS 家族编码的 8 个大糖蛋白之一）提供了机会，使我们能够在体外和体内检测酵母和菌丝生长过程中的 Als1，并证明该 mAb 在阻断白色念珠菌与宿主细胞粘附中的应用。尽管在饱和培养物中的大多数白色念珠菌酵母细胞通过间接免疫荧光呈 Als1 阴性，但在转移到新鲜生长培养基后不久，几乎所有细胞的表面都能检测到 Als1。Als1 覆盖酵母细胞表面，除了芽痕。接种细胞的子细胞，有时还有孙代细胞，也有可检测到的 Als1，但在随后几代的细胞中无法检测到 Als1。在发芽管和菌丝上，大多数 Als1 定位于母酵母的近端。一旦沉积在酵母或菌丝上，Als1 在培养物达到饱和后仍能长时间存在。Als1 的生长阶段依赖性产生，加上其在细胞表面的持久性，导致白色念珠菌培养物中存在异质细胞群体。抗 Als1 免疫标记模式因白色念珠菌细胞的来源而异，从培养物中回收的细胞与播散性念珠菌病的鼠模型中回收的细胞之间存在明显差异。这项工作的结果突出了 ALS1 表达和酵母和发芽管中 Als1 产生之间的时间平行性、Als1 在白色念珠菌细胞表面的特殊空间定位和持久性，以及在体外和体内发生的 Als1 定位差异。
