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。这个 快速出现的多药耐药对全球健康构成威胁，并急剧增加 经济负担。由于传统抗生素在很大程度上是非选择性的，因此存在严重的副作用。 由于自然宿主微生物群被修改，因此失去了动态平衡。强烈的需求 因为创新的、有效的、自然发生的和特定的选择性疗法促使我们 在牛奶中寻找这样的生物活性分子。这是2亿年进化压力的结果， 哺乳动物的哺乳指导婴儿的发育，并为婴儿提供保护，使其免受各种 感染的可能性。从人奶中分离出数千种天然多肽，以及 在发现它们的抗菌活性后，我们重点研究了它们的功能和作用机制。 从人乳中提取的新型抗菌肽。其中一个这样的肽，HBCA2，一种内部的12-聚体 人类b-酪蛋白序列迅速消除革兰氏阳性和革兰氏阴性患者的生存能力 细菌，包括但不限于第1类优先病原体。我们已经做了关键的观察 阴道加德纳氏菌是一种与细菌性阴道病(BV)相关的主要病原体，对 HBCA2，而与健康阴道微生物群相关的关键乳杆菌的生存能力仍然存在 原封不动。BV仍然是一个未得到满足的需求，治疗选择很少，复发率很高。 这给育龄妇女带来了几个公共卫生问题。它与以下内容关联 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。我们提出了HBCA2，一种乳源性抗菌肽，具有独特的选择性 对共生菌的惰性，作为局部应用的主要候选分子 BV的治疗--这是一种可以反过来减轻BV结局负担的疗法。 在这一阶段的SBIR资助中，我们将评估更大范围的阴道革兰氏菌菌株和其他细菌。 阴道病相关细菌以及大量的阴道乳杆菌和益生菌 对HBCA2和HBCA2的变异体的反应，以提高疗效。此外，我们还将 确定HBCA2的作用机制，检查其疗效和/或与传统药物的协同作用 抗菌素，表征耐药突变(如果有)，分析HBCA2对 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， 我们将在体内测试HBCA2的有效性和早期安全性PK研究，并确定宫颈阴道 组织冲击和免疫反应。最终，这项提案将使我们能够进一步表征 HBCA2单独或与其他如有效抗菌治疗的多肽联合使用， 从牛奶中提取，可用于局部应用治疗复发的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.