Poulain D, Cailliez J C, Dubremetz J F
Unité INSERM 42, Biologie et Biochimie Parasitaires et Fongiques, Villeneuve d'Aseq/France.
Eur J Cell Biol. 1989 Oct;50(1):94-9.
A monoclonal antibody raised against the pathogenic phase of Candida albicans has been coupled to colloidal gold and used to detect the corresponding epitope in cell wall and culture medium of blastoconidia grown as germ tubes in vitro. Immunogold silver staining of Western blots of culture supernatants demonstrated release of the epitope into the culture medium. The stain revealed 3 well defined bands of 205,000, 66,000 and 30,000 Mr and a smear from the top of the gel to an Mr of 120,000. Immunoelectron microscopy of ultrathin frozen sections of the corresponding growth forms showed that epitope accumulated first in the periplasmic space, generally corresponding to plasmalemma invaginations within the cytoplasm. From these sites, it was possible to follow continuous lines of epitope distribution through the cell wall and antigenic extrusion at the cell surface. In tangential sections of intensely labeled walls, these preferential excretion ways appeared to be organized as a parallel network. Antigen emergence at the cell surface corresponded to patches of material which tended to coalesce in an easily dissociated layer, probably corresponding to the fuzzy coat. These experiments demonstrate, for the first time, preferential ways for cellular secretion through the yeast cell wall.
一种针对白色念珠菌致病阶段产生的单克隆抗体已与胶体金偶联，并用于检测体外生长为芽管的芽生孢子的细胞壁和培养基中的相应表位。对培养上清液的蛋白质免疫印迹进行免疫金银染色，结果表明该表位释放到了培养基中。染色显示出三条清晰的条带，分子量分别为205,000、66,000和30,000，以及一条从凝胶顶部到分子量120,000的拖尾条带。对相应生长形式的超薄冷冻切片进行免疫电子显微镜观察表明，表位首先在周质空间积累，通常对应于细胞质内的质膜内陷。从这些部位，可以追踪到表位在细胞壁中的连续分布线以及在细胞表面的抗原外排。在强染色壁的切向切片中，这些优先排泄途径似乎组织成一个平行网络。细胞表面的抗原出现对应于倾向于在一个易于解离的层中聚结的物质斑块，可能对应于模糊层。这些实验首次证明了酵母细胞壁细胞分泌的优先途径。
