生物膜调控因子TEC1对白色念珠菌耐药滞留菌形成的影响及分子机制

Candida albicans is the most prevalent opportunistic human fungal pathogen. Candida albicans persisters constitute a small subpopulation of biofilm cells and are often described as dormant, multidrug-tolerant, non-growing and phenotypic variants of microorganisms. Evidence indicates that persisters may play a major role in recalcitrant chronic candidiasis; however, the mechanism underlying persister formation remains unclear. In our previous study, we found the expression pattern of TEC1 is consistent with persister formation during adhesion phase of biofilm development. And the expression differences of TEC1 in high-persister clinical isolate and low-persister clinical isolate, were confirmed by real-time fluorescence quantitative PCR. Therefore，we have preliminarily identified the transcription factor TEC1 which may directly result in persister cell formation in Candida albicans biofilm, although this conclusion still needs more sudy for identification. In this study, we try to verify that TEC1 is associated with persister formation via enhancing and inhibiting the expression of TEC1. Then, confirm the correlation between expression fluctuation of TEC1 and persister formation by observing dynamically the expression of TEC1 at the single cell level. And yeast two-hybrid system is used to screen the proteins interacting with transcription factors TEC1, and to identify the molecular mechanism of TEC1 in the persister formation. Our research group tries to uncover the mechanism of phenotypic tolerance and help to control chronic fungal infectious diseases.

白色念珠菌是最常见的条件致病真菌。滞留菌作为其生物膜中少数能够耐受高浓度药物、处于休眠状态的表型变异细胞，被认为是慢性感染迁延不愈的主要原因。目前白色念珠菌滞留菌形成的机制尚不明确。前期研究发现在生物膜粘附阶段TEC1的表达模式与滞留菌形成趋势一致；通过荧光定量PCR 验证了该基因在产生高、低比例滞留菌的临床菌株中的表达存在明显差异。因此，我们初步定位了生物膜调控因子—转录因子TEC1与白色念珠菌生物膜滞留菌的形成相关。本研究拟：1）通过增强、抑制表达进一步验证TEC1与滞留菌形成相关；2) 在单细胞水平上动态观察转录因子TEC1的表达波动，确认TEC1表达波动决定滞留菌的形成以及表达波动来源；3) 以TEC1为诱饵蛋白，通过酵母双杂交技术，筛选出与TEC1相关的蛋白成分，明确TEC1影响滞留菌形成的分子机制。为揭开白色念珠菌生物膜滞留菌形成的分子机制、有效控制慢性迁延性真菌感染提供依据。