Inhibition of Candida Virulence and Biofilm Formation by a Bacterial Peptide

项目总结 口咽部念珠菌病(OPC)是口腔疾病的主要病源。 包括免疫抑制者(癌症和艾滋病患者)和服用广谱抗生素的人。我们 最近发现了一种由粪肠球菌产生的抑制菌丝形态发生和 OPC的主要病原体白色念珠菌的生物被膜形成。这项研究中提出的 应用程序试图了解这种多肽的成熟形式ENTV是如何产生的，它是如何针对C的。 白念珠菌菌丝形态发生及其对OPC的保护程度，从而填补了 我们的知识，并为治疗学的发展提供了新的途径。这样做的长期目标是 研究旨在开发治疗和预防口咽部念珠菌病的新策略。的目标是 这一应用是为了确定ENTV的产生、作用方式和治疗潜力。中环 假说认为分泌和加工的ENTV作用于控制菌丝发育的信号通路(S)。 保护白念珠菌免受念珠菌病侵袭。这项研究的基本原理是确定 ENTV抑制白念珠菌侵袭性形成的机制将带来新的治疗方法 战略。通过追求三个目标，就可以达到这一应用的目的。目标1将阐明如何 生成主动形式的ENTV。使用遗传和生物化学方法，我们将检验这一假设 蛋白酶GelE和/或SprE是进行切割所必需的，DsbA催化形成二硫键 同源同源。在目标2中，粪肠球菌靶向抑制菌丝生长的白色念珠菌的基因/途径 形态发生将使用细胞生物学和遗传学方法来确定。根据初步数据， 工作假说是ENTV与C上几个已知的离散亚域中的一个直接相互作用。 白念珠菌细胞表面破坏细胞-细胞和细胞-底物黏附，这两者都是生物被膜所必需的 队形。ENTV和相关多肽对白念珠菌感染的保护作用将在 目的#3.组织培养细胞(巨噬细胞和口腔上皮细胞)和OPC和OPC小鼠模型 将利用胃肠道定植。我们推测ENTV将预防白色念珠菌感染和 纳摩尔范围内的念珠菌病。这一贡献的意义将在于了解细菌是如何 多肽抑制白色念珠菌的菌丝形态发生，可能为治疗设计开辟新的途径。 将菌丝形态发生作为可能开发新疗法的一个领域是创新的，因为 目前的抗真菌药物是针对细胞膜的完整性或生长的。这项服务的其他好处 研究包括细菌肽生成、真菌形态类型转换和 跨王国的微生物相互作用。

PROJECT SUMMARY The medical condition oropharyngeal candidiasis (OPC) is a major source of oral morbidity in patient groups including the immunosuppressed (cancer and AIDS patients) and those taking broad-spectrum antibiotics. We recently identified a peptide produced by Enterococcus faecalis that inhibits the hyphal morphogenesis and biofilm formation of the primary causative agent of OPC, Candida albicans. The research proposed in this application seeks to understand how the mature form of this peptide, EntV, is generated, how it targets C. albicans hyphal morphogenesis, and the extent to which it protects against OPC, thereby filling a critical gap in our knowledge and providing new avenues for the development of therapeutics. The long-term goal of this research is to develop novel strategies for treating and preventing oropharyngeal candidiasis. The objective of this application is to determine the generation, mode of action and therapeutic potential of EntV. The central hypothesis is that secreted and processed EntV acts on signaling pathway(s) that controls hyphal development in C. albicans resulting in protection from candidiasis. The rationale for this research is that identification of the mechanism by which EntV inhibits the formation of the invasive form of C. albicans will lead to new treatment strategies. By pursing three aims, the objective of this application will be attained. Aim #1 will elucidate how the active form of EntV is generated. Using both genetic and biochemical approaches, we will test the hypothesis that the proteases GelE and/or SprE are required for cleavage, and disulfide bond formation is catalyzed by a DsbA homolog. In Aim #2, the genes/pathways of C. albicans that are targeted by E. faecalis to inhibit hyphal morphogenesis will be determined using cell biological and genetic approaches. Based on preliminary data, the working hypothesis is that EntV interacts directly with one of several known discrete subdomains on the C. albicans cell surface to disrupt cell-cell and cell-substrate adherence, both of which are essential for biofilm formation. The efficacy of EntV and related peptides in protecting against C. albicans infection will be tested in Aim #3. Tissue culture cells (macrophages and oral epithelial cells) and mouse models of OPC and gastrointestinal colonization will be utilized. We postulate that EntV will protect against C. albicans infection and candidiasis in the nanomolar range. The significance of this contribution will be the knowledge of how a bacterial peptide inhibits C. albicans hyphal morphogenesis, potentially opening new avenues for therapeutic design. Targeting hyphal morphogenesis as an area for the possible development of novel therapeutics is innovative, as current antifungals are directed against the integrity or growth of the cell envelope. Additional benefits of this research include new knowledge in the fields of bacterial peptide generation, fungal morphotype switching, and inter-kingdom microbial interactions.