Niche-activated defense mechanisms of a commensal fungus

人类和其他动物是各种微生物的宿主。 不同的部位，如皮肤，口腔或消化系统，有不同的微生物群落。 微生物如何适应这些地方以及那里的特殊压力还没有很好的了解。 事实上，对压力的适应是决定哪些微生物在皮肤上还是口腔上的主要因素。一个惊人的发现是，人类居住的酵母菌白色念珠菌感知唾液中的无毒成分（硝酸盐，硫氰酸盐），并激活对口腔和胃中产生的有毒化学物质（亚硝酸盐和一氧化氮）的防御。 这一发现表明，微生物能够感知它们的局部环境，然后诱导反应，从而在宿主生态位中更有效地生存和生长。 为了进一步验证这一新的假设，酵母信号通路的组成部分，允许？期待？有毒的亚硝酸盐/一氧化氮压力将被确定和使用遗传学和生物化学的特点。 另一个目标是研究念珠菌用于感知和抵抗一种名为次硫氰酸盐的有毒漂白剂样化学物质的分子机制，该化学物质在口腔中自然产生。 这笔赠款还将启动研究学徒指导项目，其中来自休斯顿公立高中的少数民族学生将在每年夏天进行关于学生与主持人互动的研究，重要的是，将他们的研究结果和经验传达给同一所高中的同龄人，从其中另一名学生将被招募做研究等。这一赠款的两个重要影响是，令人兴奋的新方面强调微生物-宿主相互作用的预期和涉及对等交流的潜在变革机制-用于使代表性不足的少数民族学生参与生物学研究。

Humans and other animals are host to a variety of microbes. Different locations such as skin, mouth or digestive system have different communities of microbes. How microbes adapt to these locations and the special stresses there is not well understood. Indeed, adaptation to stress is a major factor in determining which microbes are on skin versus mouth, etc. A striking discovery is that the human-resident yeast Candida albicans senses nontoxic components of saliva (nitrate, thiocyanate) and activates defenses against toxic chemicals (nitrite and nitric oxide) generated in the mouth and stomach. This finding suggests that microbes sense their local environment and then induce responses to allow more effective survival and growth in that host niche. To further test this novel hypothesis, components of the yeast signaling pathway that allow ?anticipation? of toxic nitrite/nitric oxide stress will be identified and characterized using genetics and biochemistry. Another goal is to investigate the molecular mechanisms used by Candida to sense and resist a toxic bleach-like chemical called hypothiocyanite that is produced naturally in the mouth. This grant will also initiate the Research Apprentice Mentoring Project wherein a minority student from a Houston public high school will conduct research each summer on Candida-host interaction and, importantly, communicate their research results and experience back to peers at the same high school, from which another student will be recruited for doing research and so on. Two important impacts of this grant are thus the investigations of an exciting new aspect stress anticipation of microbe-host interaction and a potentially transformative mechanism involving peer-to-peer communication - for engaging under-represented minority students in biology research.