Selective antimicrobial peptides from milk for bacterial vaginosis

项目摘要 目前使用的几种抗生素引起了两个主要问题：耐药性和非选择性。的 快速出现的多重耐药性对全球健康构成威胁， 经济负担。由于传统抗生素在很大程度上是非选择性的， 这是由于天然宿主微生物组被改变，从而失去了体内平衡。到非常需要 创新的、有效的、天然存在的和特异性选择性的治疗方法促使我们 探索牛奶中的生物活性分子。两亿年进化压力的结果， 哺乳动物的哺乳指导婴儿的发育，并提供保护，使其免受各种各样的 感染。在从人乳中分离出数千种天然存在的肽后， 发现他们的抗菌活性，我们集中在功能和作用机制， 来自人乳的新型抗微生物肽。一种这样的肽，HBCA 2，内部12聚体 人B-酪蛋白序列快速消除革兰氏阳性和革兰氏阴性 细菌，包括但不限于1类优先病原体。我们已经观察到了 阴道加德纳菌是一种主要的细菌性阴道病（BV）相关病原体， HBCA 2，而与健康阴道微生物组相关的关键乳酸杆菌的活力仍然存在 没有改变BV仍然是一个未满足的需求，治疗选择很少，复发率高 导致对育龄妇女的若干公共卫生问题。与其相关联 结果，包括但不限于早产，性传播感染和艾滋病毒传播，以及其他生殖 挑战我们提出HBCA 2，一种乳源性抗菌肽，具有独特的选择性特征 作为局部应用的主要候选分子， BV-a疗法的治疗，这反过来可以减少BV结果的负担。 在第一阶段SBIR赠款中，我们将评估更大范围的G。其他细菌性阴道炎 阴道病相关细菌以及大量的阴道和益生菌乳酸杆菌， 对HBCA 2的应答和HBCA 2变体的合成以增强功效。此外，我们将 确定HBCA 2的作用机制，检查其功效和/或与传统的 抗微生物剂，表征耐药突变（如有），分析HBCA 2对 哺乳动物宿主细胞，并确定功能对感染和炎症的影响， 女性生殖道的临床感染模型。这项工作将有助于第二阶段的准备工作， 我们将在体内有效性和早期安全性PK研究中测试HBCA 2，并确定宫颈阴道 组织影响和免疫反应。最终，这一提议将使我们能够进一步描述 HBCA 2单独或与另外的此类肽组合作为有效的抗菌治疗剂， 来源于牛奶，可通过局部应用用于治疗复发性BV。

Project Abstract Several currently administered antibiotics raise two main concerns: resistance and non-selectivity. The rapid rate of emerging multi-drug resistance poses a global health threat and dramatically increases economic burden. With traditional antibiotics being largely non-selective, there are serious side effects due to the natural host microbiome being modified, and thus a loss in homeostasis. The strong need for innovative, potent, naturally occurring and specifically selective therapeutics have prompted us to explore for such bioactive molecules in milk. The result of 200 million years of evolutionary pressure, mammalian lactation guides the development of the infant and provides protection from a wide-variety of infections. Upon fractionating thousands of naturally occurring peptides from human milk, and discovering their antibacterial activity, we have focused on the function and mechanism of action of novel antimicrobial peptides from human milk. One such peptide, HBCA2, an internal 12-mer sequence of human b-casein rapidly eliminates the viability of gram-positive and gram-negative bacteria, including but not limited to Category 1 priority pathogens. We have made the key observation that Gardnerella vaginalis, a major bacterial vaginosis (BV)-associated pathogen, is susceptible to HBCA2, whereas the viability of key lactobacilli linked to a healthy vaginal microbiome remains unaltered. BV remains an unmet need, with few treatment options and high rates of recurrence resulting in several public health concerns for women of reproductive age. It is associated with outcomes including to not limited to pre-term labor, STI and HIV transmissions, and other reproductive challenges. We propose HBCA2, a milk-borne, antimicrobial peptide, with its unique selectivity feature of inertness towards commensal bacteria, as a lead candidate molecule in topical applications for the treatment of BV—a therapy that could in turn reduce the burden of BV outcomes. In this phase I SBIR grant, we will evaluate a larger range of G. vaginalis strains other bacterial vaginosis associated bacteria as well as a larger number of vaginal and probiotic lactobacilli for their response to HBCA2 and variants of HBCA2 synthesized to enhance efficacy. Additionally, we will determine the HBCA2 mechanism of action, examine its efficacy and/or synergy to traditional antimicrobials, characterize resistance mutations (if any), analyze the direct effect of HBCA2 on mammalian host cells and determine the impact of function on infection and inflammation in pre- clinical infection models of the female reproductive tract. This work will aid the preparation for Phase II, where we will test HBCA2 in in vivo efficacy and early safety PK studies, and determine cervicovaginal tissue impact and immune response. Ultimately, this proposal will allow us to further characterize HBCA2 alone or in combination with additional such peptides as potent antibacterial therapeutic, derived from milk, which can be employed for treatment of recurrent BV via topical applications.