Scherwitz C, Martin R
Dermatologica. 1979;159(1):12-23. doi: 10.1159/000250556.
This in vitro study investigates the phagocytosis and killing rate of Candida albicans blastospores and germ tubes by polymorphonuclear leukocytes. Suspensions of C. albicans blastospores and germ tubes were incubated for 60 and 150 min with a neutrophil suspension. The rate of phagocytosis was found to be 92 +/- 3% for blastospores, but only 9.5 +/- 2.5% for germ tubes. The candidacidal activity rate was 29 +/- 6% for blastospores, but only 5.5 +/- 1.5% for germ tubes. Electronmicroscopically, cytoplasmic and plasma membrane alterations of phagocytized yeast cells lying in phagosomes were observed. Short germ tubes surrounded by a phagosomal membrane were found in neutrophils. Older, longer germ tubes were seen in an extracellular position. Usually, several neutrophils were adjacent to these long tubes. Obviously phagocytosis could not take place owing to the size of the germ tubes. The findings indicate that the transition of the yeast phase to the mycelium phase in a case of Candida infection may be a mechanism enabling the parasite to escape phagocytosis by the host.
这项体外研究调查了多形核白细胞对白色念珠菌芽生孢子和芽管的吞噬作用及杀伤率。将白色念珠菌芽生孢子和芽管的悬浮液与中性粒细胞悬浮液孵育60分钟和150分钟。发现芽生孢子的吞噬率为92±3%，而芽管的吞噬率仅为9.5±2.5%。芽生孢子的杀念珠菌活性率为29±6%，而芽管的杀念珠菌活性率仅为5.5±1.5%。在电子显微镜下，观察到位于吞噬小体中的被吞噬酵母细胞的细胞质和质膜改变。在中性粒细胞中发现了被吞噬体膜包围的短芽管。在细胞外位置可见较老、较长的芽管。通常，几个中性粒细胞与这些长芽管相邻。显然，由于芽管的大小，吞噬作用无法发生。研究结果表明，在念珠菌感染的情况下，酵母相转变为菌丝相可能是一种使寄生虫能够逃避宿主吞噬作用的机制。
