MBL调节白假丝酵母菌相态转化的作用及机制的初步分析

Preliminary analysis of effects and mechanisms on MBL regulating dimorphic switching of Candida albicans

目的：探讨甘露聚糖结合凝集素（Mannan-binding lectin,MBL）对白假丝酵母菌（Candida albicans,C.albicans）相态转化的调节作用及机制。方法：以人MBL处理C.albicans 2、4、8 h,37℃200 r/min震荡培养,倒置相差显微镜下观察C.albicans的菌丝形成情况;FACS分析MBL与C.albicans的结合情况;RT-PCR分析C.albicans相态转化调控基因HWP1、DDR48的表达。结果：倒置相差显微镜观察发现MBL在早期（2~4 h）能够抑制C.albicans酵母相（Yeast form,Y）向菌丝相（Hyphal form,H）转化;FACS分析表明MBL能够以Ca2＋浓度依赖关系与C.albicans细胞结合;RT-PCR结果表明MBL能够减少C.albicans相态转化调控基因HWP1的表达,而其对DDR48表达的影响尚无规律可循。结论：MBL能够通过调控HWP1的表达抑制C.albicans酵母相向菌丝相转化。

Objective：To investigate the effects and mechanisms of mannan-binding lectin （MBL） regulate Candida albicans （C. albicans） dimorphic switching. Methods： C. albicans were processed 2 h,4 h,8 h by human MBL, and were shaked and cultured in 37 ℃ 200 r/min as well as control groups, then we observed the hyphae formation of C. albicans under the inverted phase contrast microscope. The binding of MBL and C. albicans were analyzed by FACS. The levels of C. albicans dimorphic switching regulatory genes HWP1, DDR48 on C. albicans were determined by RT-PCR. Results： Inverted phase contrast microscope＇s observation indicated that MBL inhibits C. albicans Yeast form transform to Hyphal form in the early （2 h,4 h）. FACS showed that Ca^2＋-dependent binding underlying interaction of MBL with C. albicans cells. RT-PCR showed that MBL down-regulate the expression of C. albicans phase transition regulatory genes HWP1, and yet there was no rules to follow its effect on DDR48 expression. Conclusion： MBL inhibits C. albicans Yeast form transform to Hyphal form through regulating the expression of HWP1.