Project 2: Defining the Protective vs. Susceptible Immune Proteome of S. aureus Osteomyelitis

摘要 假体关节感染(PJI)是择期全关节置换术(TJR)的祸害。 其中绝大多数是由葡萄球菌引起的。众所周知，PJI的1-5%的发病率是 在很大程度上由患者特定因素决定的非随机事件。此外，约13%的患者 感染金黄色葡萄球菌的人会变成败血症，死于多器官衰竭，而其他人几乎不会康复 干预。除了已确定的宿主易感因素外，还有两种主要的理论可以 解释一下这个。第一种是“免疫蛋白质组”假说，该假说认为一系列特定的 宿主对金黄色葡萄球菌产生的抗体决定了其对感染的敏感性和保护性。这个 第二种是金黄色葡萄球菌传播的“特洛伊木马”模型，在这种模型中，白细胞在 手术部位，并将细胞内细菌输送到血流和内脏，最终达到 易感宿主感染性死亡。目前，没有直接的实验或临床证据表明 支持这些理论。然而，我们最近有了几个潜在的突破性发现， 证实这些模型。第一个是针对自溶素(Atl)蛋白的抗体有效。 诱导金黄色葡萄球菌巨噬细胞形成、吞噬和保护/存活 小鼠和人类的骨髓炎。其次是铁敏感决定簇B(ISDB)是最多的 小鼠和人免疫优势金黄色葡萄球菌抗原，抗ISDB抗体是 与脓毒症、多器官衰竭和手术部位感染后死亡有关。 建议：1)阐明抗ISDB介导脓毒症死亡的分子机制；2)验证抗ISDB介导的脓毒症死亡 PJI患者中“易感”的抗ISD抗体与“保护性”的抗ATL免疫蛋白质组，以及3)延长这一范围 骨免疫学以阐明表皮葡萄球菌和鹿顿葡萄球菌的免疫蛋白质组。我们的 实现这些目标的方法体现在三个具体目标上。在目标1中，我们将阐明 抗ISDB及相关的抗ISDA和抗ISDH抗体介导的脓毒症的机制。 金黄色骨髓炎。我们还将完成一项临床初步研究，以证明骨髓炎 死于金黄色葡萄球菌败血症死亡的患者具有高抗ISD效价和特洛伊木马 血液和内脏中的巨噬细胞。在目标2中，我们将检验免疫蛋白质组假说 通过将抗ISD和抗ATL效价与300名接受2-JI治疗的PJI患者的临床结果相关联， 使用我们的多重Luminex分析进行分期翻修手术，并定义易感人群：保护性指数 这些免疫蛋白质组。在目标3中，我们将扩展我们对哺乳动物宿主的了解 表皮葡萄球菌和葡萄球菌多重放免试验对葡萄球菌的反应 并使用它们来筛选小鼠和PJI患者的血清，就像我们对金黄色葡萄球菌所做的那样。 好了！

Abstract Prosthetic joint infection (PJI) is the bane of elective total joint replacement (TJR) surgery, of which the vast majority is caused by Staphylococcal species. The 1-5% incidence of PJI is known to be a nonrandom event that is largely determined by patient specific factors. Moreover, ~13% of patients infected with S. aureus become septic and die from multiorgan failure, while others recover with little intervention. In addition to the established host susceptibility factors, there are two leading theories to explain this. The first is the “immune proteome” hypothesis, which posits that the array of specific antibodies a host develops against S. aureus dictates its susceptibility vs. protection to infection. The second is the “Trojan horse” model of S. aureus dissemination, in which leukocytes get infected at the surgical site, and transport intracellular bacteria to the blood stream and internal organs, culminating in septic death of susceptible hosts. Currently, there is no direct experimental or clinical evidence to support these theories. However, we recently made several potential breakthrough discoveries that substantiate these models. The first is that antibodies against the autolysin (Atl) proteins efficiently induce megacluster formation, opsonophagocytosis, and protection/survival following S. aureus osteomyelitis in mice and humans. The second is that iron sensing determinant B (IsdB) is the most immuno-dominant S. aureus antigen in mouse and man, and that antibodies against IsdB are associated with sepsis, multiorgan failure and death following surgical site infection.8,13 Here we propose to: 1) elucidate the molecular mechanism of anti-IsdB mediated septic death, 2) validate the “susceptible” anti-Isd vs. “protective” anti-Atl immune proteome in PJI patients, and 3) extend this osteoimmunology to elucidate the immune proteomes of S. epidermidis and S. lugdunensis. Our approaches to achieve these goals are embodied by three Specific Aims. In Aim 1 we will elucidate the mechanism of anti-IsdB and related anti-IsdA and anti-IsdH antibody mediated sepsis following S. aureus osteomyelitis. We will also complete a clinical pilot study to demonstrate that osteomyelitis patients who succumb to S. aureus septic death have high anti-Isd titers and Trojan horse macrophages in their blood and internal organs. In Aim 2 we will test the immune proteome hypothesis by correlating anti-Isd and anti-Atl titers with the clinical outcomes of 300 PJI patients that undergo 2- stage revision surgery using our multiplex-Luminex assay, and define the susceptible:protective index of these immune proteomes. And in Aim 3 we will extend our knowledge of the mammalian host response to Staphylococcus species by generate multiplex-Luminex assays for S. epidermidis and S. lugdunensis, and uses them to screen sera from mice and PJI patients as we have done for S. aureus. !