Novel role and function of Paneth cell PYY in anti-fungal innate immunity

 描述（由申请人提供）：肽酪氨酸酪氨酸（PYY）是脊椎动物生物体中高度保守的分子，具有多种调节作用，包括饱腹感、昼夜节律和肠道生理学。以前认为PYY仅存在于肠内分泌细胞（EECs）、脑干和表皮树突状细胞中。我们现在发现PYY似乎在小肠潘氏细胞中表达，这提高了PYY作为抗菌肽具有额外作用的可能性。这种可能性进一步得到了PYY与其他抗微生物化合物在蛋白质结构和电荷分布方面的相似性的支持。此外，在用微生物产品刺激时，来自常规饲养（CONV）小鼠的离体回肠组织将PYY释放到培养物中，而来自无菌（GF）动物的组织则不释放，这类似于受微生物聚集调节并参与微生物聚集的其他抗微生物肽。然而，我们发现PYY（0- 25 μ M）似乎不具有抗菌作用，而是在抑制白色念珠菌（一种重要的人类真菌成员和肠道微生物群的潜在病原体）中的菌丝形成中的选择性作用。不表达菌丝的真菌或酵母不受PYY的影响。基于这些观察结果，我们假设PYY是一种重要的选择性抗菌化合物，可调节肠道微生物组真核微生物的毒力。为了验证这一假设，我们提出以下目标：（1）表征潘氏细胞PYY表达和释放对刺激的响应的调节以及PYY在肠粘膜和肠腔室中的定位和浓度，以及（2）研究PYY对C.白色念珠菌菌丝形成（GFP标记）、基因表达和对人Caco-2细胞培养物的致病性。我们相信，这项工作有可能在显示肠道肽（如PYY）在宿主肠道调节中的替代作用方面发生范式转变。 真菌有机体这些研究还将在新的研究领域提供进一步的培训和机会，这将继续申请人在学术生物医学研究方面的职业发展。

 DESCRIPTION (provided by applicant): Peptide tyrosine tyrosine (PYY) is a highly conserved molecule in vertebrate organisms with diverse regulatory roles, including satiety, circadian rhythmicity, and intestinal physiology. It was previously thought that PYY was exclusively found in intestinal enteroendocrine cells (EECs), the brain stem, and epidermal dendritic cells. We now find that PYY appears to be expressed in small intestinal Paneth cells, raising the possibility that PYY has an additional role as an antimicrobial peptide. This possibility is furthe supported by similarities in the protein structure and charge distribution of PYY to other antimicrobial compounds. Additionally, upon stimulation with microbial products, ex vivo ileal tissues from conventionally raised (CONV) mice release PYY into culture, while tissues from germ-free (GF) animals does not, analogous to other antimicrobial peptides that are regulated by and involved in microbial assemblage. However, we find that PYY (0-25uM) does not appear to have anti-bacterial effects, but rather a selective action in inhibiting hyphae formation in Candida albicans, an important human fungal member and potential pathogen of the gut microbiota. Non-hyphae expressing fungi, or yeast, were unaffected by PYY. Based on these observations, we hypothesize that PYY is an important and selective antimicrobial compound that modulates the virulence of eukaryotic microorganisms of the intestinal microbiome. To test this hypothesis, we propose the following aims: (1) to characterize the regulation of Paneth cell PYY expression and release in response to stimulus and the localization and concentrations of PYY within the intestinal mucous and luminal compartments, and (2) to investigate the effect of PYY upon C. albicans hyphae formation (GFP-tagged), gene expression, and pathogenicity against human Caco-2 cell culture. We believe this work has the potential to be paradigm shifting in showing alternative roles for gut peptides such as PYY in host regulation of intestinal fungal organisms. These studies will also provide further training and opportunities in new research areas that will continue the applicant's career development in academic biomedical research.