Evaluation of Anti-endotoxin Vaccine for Human Use

描述(申请人提供)：由革兰氏阴性菌引起的感染可并发败血症、多器官衰竭和死亡。由于死亡率在过去十年中没有变化，因此需要新的策略来补充传统的抗生素治疗和支持性护理。我们研制了一种由E.cell OL11：B4，Rc(JS)化学型与B组脑膜炎球菌外膜蛋白络合的解毒脂多糖(LPS)组成的疫苗。该疫苗诱导针对细菌内毒素高度保守区域的抗体，在脓毒症动物模型中具有主动和被动保护作用。在上一次拨款期间，我们给24名受试者接种了这种疫苗。疫苗是安全的，耐受性良好，但抗体反应低于在兔子和啮齿动物身上测得的结果。因此，在这项建议中，我们希望评估这种疫苗与佐剂MF-59和寡核苷酸(CpG)一起接种时的安全性、免疫原性和功能活性，这两种佐剂都已安全地用于人类。早些时候，我们发现疫苗诱导的抗体与异种内毒素结合，增强了细菌和内毒素从大鼠循环中的清除，并中和了内毒素在体外诱导细胞因子和启动人中性粒细胞产生超氧化物的能力。我们现在将疫苗/佐剂免疫后的抗体水平与体内(清除研究和保护活性)和体外(脂多糖结合和脂多糖中和研究)的功能活性联系起来。这些活性可作为疫苗效力的替代标记物(特定目标I)。然后，我们将在人类受试者中进行疫苗和佐剂的第一阶段研究(特定目标II)。J5内毒素抑制疫苗诱导的抗体与异种内毒素的结合。因此，我们将通过比较35个内毒素的完整结构和亚单位结构与其他核心内毒素物种的抑制活性来确定是否存在一个特定的J5内毒素表位，并将与疫苗一起开发针对该表位的克隆抗体(特定目标III)。将确定补体、巨噬细胞和中性粒细胞在抗J5 DLPS抗体功能活性中的作用，以及免疫对动物和人类细胞的脂多糖表面受体(Toll样受体4和CD14)的影响(特定目标IV)。如果成功，这些研究将导致脓毒症预防和治疗的第二阶段和第二阶段研究。

DESCRIPTION (provided by applicant): Infections caused by gram negative bacteria may be complicated by sepsis, multi-organ failure, and death. Since the mortality has not changed during the last decade, new strategies to supplement conventional antibiotic therapy and supportive care are required. We developed a vaccine composed of detoxified lipopolysaccharide (LPS) from E. cell Ol11:B4, Rc (JS) chemotype complexed to the outer membrane protein of group B meningococcus 05 dLPS/OMP vaccine). This vaccine induces antibodies to a highly conserved region of bacteria LPS that are protective both actively and passively in animal models of sepsis. In the last grant period we administered this vaccine to 24 human subjects. The vaccine was safe and well-tolerated, but the antibody response was lower than that measured in rabbits and rodents. Consequently, in this proposal we wish to evaluate the safety, immuno-genicity and functional activity of this vaccine when given with the adjuvants, MF-59 and oligonucleotide (CpG), each of which has been safely administered to humans. Earlier, we found that vaccine-induced antibody bound heterologous LPS, enhanced the clearance of bacteria and endotoxin from the circulation of rats and neutralized the ability of LPS to induce cytokines ex vivo and to prime superoxide formation by human neutrophils. We now will correlate antibody levels following vaccine/adjuvant immunization with functional activity in vivo (clearance studies and protective activity) and in vitro (LPS binding and LPS neutralization studies). These activities may serve as surrogate markers for vaccine efficacy (Specific Aim I). We then will do a phase I study of vaccine and adjuvants in human subjects (Specific Aim II). J5 LPS inhibits the binding of vaccine-induced antibody to heterologous LPS. We therefore will determine if there is a specific J5 LPS epitope by comparing the inhibitory activity of complete and subunit structures of 35 LPS with other core LPS species, and will develop monoclonal antibodies to this epitope with the vaccine (Specific Aim III). The role of complement, macrophages and neutrophils in the functional activity of anti-J5 dLPS antibodies will be defined as well as the effect of immunization on LPS surface receptors (toll-like receptor 4 and CD14) of cells from both animals and humans (Specific Aim IV). If successful, these studies will lead to phase II and Ill studies for the prevention and treatment of sepsis.