Development of a vaccine for prevention of Haemophilus influenzae otitis media

描述(由申请人提供)：由非分型流感嗜血杆菌(NTHi)引起的中耳炎和其他疾病仍然是儿童的重大健康问题，迫切需要预防疾病的疫苗。我们的长期目标是确定在保护性免疫反应中重要的NTHi表面暴露抗原，并最终确定由这些抗原组成的疫苗是否对NTHi疾病具有保护作用。在早期的工作中，我们发现HMW1/HMW2和Hia家族的蛋白质是自然感染后人类抗体反应的主要靶点。我们后来证明了这两个蛋白家族在NTHi与人类真核细胞的黏附中发挥了关键作用。几乎所有NTHi都表达类HMW/HMW2或类Hia的粘附素。后来，我们在免疫研究中证明了原型HMW1/HMW2蛋白的疫苗潜力，在该研究中，肠外免疫的龙舌兰对由同源菌株引起的NTHi中耳炎具有保护作用。我们还证明，针对HMW1/HMW2样蛋白的自然获得的人抗体和针对这些蛋白的多克隆抗血清对同源和异源表达HMW1/HMW2的菌株都是吞噬细胞。在最近对Hia蛋白的研究中，我们证明了针对Hia样蛋白的抗体对同源和异源表达Hia的NTHi也是吞噬细胞。综上所述，这些数据表明，来自HMW1/HMW2和HIA家族的蛋白质最有可能组合在一起，值得认真考虑作为预防NTHi疾病的疫苗候选。许多该领域的专家认为，直接粘膜免疫是研制成功的中耳炎疫苗的关键。在我们最近的工作中，我们构建了表达HMW1/HMW2或Hia蛋白的重组腺病毒载体，并在栗鼠中耳炎模型中证明了这些构建物的免疫原性。在拟议的工作中，我们将在这些早期研究的基础上，确定HMW1/HMW2和Hia样蛋白是否可以作为可行的NTHi疫苗候选。首先，我们将确定针对HMW1/HMW2-和类Hia蛋白产生的人类抗体对急性NTHI中耳炎儿童恢复期血清中产生的吞噬细胞活性的贡献。接下来，我们将绘制HMW1/HMW2-和类Hia蛋白的区域，这些蛋白表达由抗体识别的表位，这些抗体能够介导对同源和异种NTHi的吞噬细胞活性。最后，我们将评估表达HMW1/HMW2或Hia样蛋白的重组腺病毒载体在实验性中耳炎灰鼠模型中提供保护NTHi疾病的能力。我们建议的研究在该领域是创新的，无论是在研究中的有希望的疫苗抗原方面，还是在正在研究的新的粘膜免疫策略方面。由此产生的信息将进一步推动我们实现开发有效疫苗以预防NTHi中耳炎和其他幼儿疾病的最终目标。 公共卫生相关性：由非分型流感嗜血杆菌引起的耳朵感染是世界各地儿童的主要问题。我们工作的目标是开发一种疫苗来预防这些嗜血杆菌耳部感染。我们之前确定了两种相关的细菌蛋白质，它们是非常有希望的候选疫苗，我们将在这项拨款中提议的研究中进一步评估它们的疫苗潜力。

DESCRIPTION (provided by applicant): Otitis media and other illnesses caused by nontypeable Haemophilus influenzae (NTHi) remain significant health problems for children and a vaccine for prevention of disease is much needed. Our long-term objectives are to identify surface-exposed antigens of NTHi that are important in a protective immune response, and ultimately, to determine whether a vaccine composed of such antigens would be protective against NTHi disease. In early work, we identified the HMW1/HMW2 and Hia families of proteins as major targets of the human antibody response following natural infection. We later demonstrated a critical role for both protein families in adhesion of NTHi to human eukaryotic cells. Virtually all NTHi express either HMW/HMW2-like or Hia-like adhesins. We later demonstrated the vaccine potential of prototype HMW1/HMW2 proteins in immunization studies in which chinchillas immunized parenterally were protected against NTHi otitis media caused by the homologous strain. We also demonstrated that naturally-acquired human antibodies specific for the HMW1/HMW2-like proteins and polyclonal antisera raised against these proteins are opsonophagocytic for both homologous and heterologous HMW1/HMW2-expressing strains. In more recent work on the Hia proteins, we demonstrated that antibodies specific for the Hia-like proteins are also opsonophagocytic for homologous and heterologous Hia-expressing NTHi. Taken together, these data suggest that proteins from both the HMW1/HMW2 and Hia families, most likely in combination, deserve serious consideration as vaccine candidates for prevention of NTHi disease. Direct mucosal immunization is thought by many experts in the field to be critical to development of a successful otitis media vaccine. In our very recent work, we constructed recombinant adenovirus vectors expressing either HMW1/HMW2 or Hia proteins and demonstrated the immunogenicity of these constructs in the chinchilla otitis model. In the proposed work, we will build upon these earlier studies and determine whether the HMW1/HMW2- and Hia-like proteins can move forward as viable NTHi vaccine candidates. First, we will define the contribution of human antibodies produced against the HMW1/HMW2- and Hia-like proteins to the opsonophagocytic activity that develops in convalescent sera of children with acute NTHI otitis media. Next, we will map the regions of the HMW1/HMW2- and Hia-like proteins that express epitopes recognized by antibodies capable of mediating opsonophagocytic activity against both homologous and heterologous NTHi. Finally, we will assess the ability of recombinant adenovirus vectors expressing the HMW1/HMW2- or Hia-like proteins to provide protection against NTHi disease in the chinchilla model of experimental otitis media. Our proposed studies are innovative for the field both in terms of the promising vaccine antigens under study and in terms of the novel mucosal immunization strategy being investigated. The resulting information will move us further towards our ultimate goal of developing effective vaccines for prevention of NTHi otitis media and other diseases in young children. PUBLIC HEALTH RELEVANCE: Ear infections caused by nontypeable Haemophilus influenzae bacteria are a major problem for children everywhere. The objective of our work is to develop a vaccine for prevention of these Haemophilus ear infections. We previously identified two related bacterial proteins that are very promising vaccine candidates and we will further assess their vaccine potential in the studies proposed in this grant.