Geiger Jeremy, Wessels Deborah, Lockhart Shawn R, Soll David R
W. M. Keck Dynamic Image Analysis Facility, Department of Biological Sciences, The University of Iowa, Iowa City, IA 52242, USA.
Infect Immun. 2004 Feb;72(2):667-77. doi: 10.1128/IAI.72.2.667-677.2004.
Previous studies employing transmembrane assays suggested that Candida albicans and related species, as well as Saccharomyces cerevisiae, release chemoattractants for human polymorphonuclear leukocytes (PMNs). Because transmembrane assays do not definitively distinguish between chemokinesis and chemotaxis, single-cell chemotaxis assays were used to confirm these findings and test whether mating-type or white-opaque switching affects the release of attractant. Our results demonstrate that C. albicans, C. dubliniensis, C. tropicalis, C. parapsilosis, and C. glabrata release bona fide chemoattractants for PMNs. S. cerevisiae, however, releases a chemokinetic factor but not a chemoattractant. Characterization of the C. albicans chemoattractant revealed that it is a peptide of approximately 1 kDa. Whereas the mating type of C. albicans did not affect the release of chemoattractant, switching did. White-phase cells released chemoattractant, but opaque-phase cells did not. Since the opaque phase of C. albicans represents the mating-competent phenotype, it may be that opaque-phase cells selectively suppress the release of chemoattractant to facilitate mating.
以往采用跨膜分析的研究表明，白色念珠菌及相关菌种，以及酿酒酵母，会释放吸引人类多形核白细胞（PMN）的趋化因子。由于跨膜分析无法明确区分化学增活作用和趋化作用，因此采用单细胞趋化分析来证实这些发现，并测试交配型或白色-不透明转换是否会影响趋化因子的释放。我们的结果表明，白色念珠菌、都柏林念珠菌、热带念珠菌、近平滑念珠菌和光滑念珠菌会释放真正吸引PMN的趋化因子。然而，酿酒酵母释放的是一种化学增活因子，而非趋化因子。对白色念珠菌趋化因子的表征显示，它是一种约1 kDa的肽。白色念珠菌的交配型并不影响趋化因子的释放，但转换会有影响。白色相细胞会释放趋化因子，而不透明相细胞则不会。由于白色念珠菌的不透明相代表有交配能力的表型，可能是不透明相细胞选择性地抑制趋化因子的释放以促进交配。
