Polysaccharide intercellular adhesin (PIA), an exopolysaccharide composed of poly-N-acetyl glucosamine (PNAG), is an essential component in many pathogenic biofilms. Partial deacetylation of PNAG is required for biofilm formation, but limited structural knowledge hinders therapeutic development. Employing a new monoclonal antibody (TG10) that selectively binds highly deacetylated PNAG and an antibody (F598) in clinical trials that binds highly acetylated PNAG, we demonstrate that PIA within the biofilm contains distinct regions of highly acetylated and deacetylated exopolysaccharide, contrary to the previous model invoking stochastic deacetylation throughout the biofilm. This discovery led us to hypothesize that targeting both forms of PNAG would enhance efficacy. Remarkably, TG10 and F598 synergistically increased in vitro and in vivo activity, providing 90% survival in a lethal Staphylococcus aureus challenge murine model. Our advanced model deepens the conceptual understanding of PIA architecture and maturation and reveals improved design strategies for PIA-targeting therapeutics, vaccines, and diagnostic agents.

中文翻译：

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对生物膜结构和成熟的见解有助于改进胞外多糖靶向治疗的临床策略


多糖细胞间粘附素 （PIA） 是一种由聚-N-乙酰氨基葡萄糖 （PNAG） 组成的胞外多糖，是许多致病性生物膜的重要组成部分。生物膜形成需要 PNAG 的部分脱乙酰化，但有限的结构知识阻碍了治疗的发展。在临床试验中采用选择性结合高度脱乙酰化 PNAG 的新型单克隆抗体 （TG10） 和结合高度乙酰化 PNAG 的抗体 （F598），我们证明生物膜内的 PIA 包含高度乙酰化和脱乙酰化胞外多糖的不同区域，这与之前在整个生物膜中调用随机脱乙酰化的模型相反。这一发现使我们假设靶向两种形式的 PNAG 都会提高疗效。值得注意的是，TG10 和 F598 协同提高了 体外和 体内活性，在致命的金黄色葡萄球菌攻击小鼠模型中提供了 90% 的存活率。我们的高级模型加深了对 PIA 架构和成熟的概念理解，并揭示了针对 PIA 靶向疗法、疫苗和诊断剂的改进设计策略。