Development of a vaccine for prevention of Haemophilus influenzae otitis media

描述（由申请人提供）：中耳炎和其他由不可分型流感嗜血杆菌（NTHi）引起的疾病仍然是儿童的重要健康问题，急需预防疾病的疫苗。我们的长期目标是鉴定在保护性免疫应答中重要的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疾病具有保护性。在早期的工作中，我们确定了HMW 1/HMW 2和Hia蛋白家族作为自然感染后人类抗体应答的主要靶标。我们后来证明了这两个蛋白质家族在NTHi粘附到人真核细胞中的关键作用。几乎所有的NTHi表达HMW/HMW 2样或Hia样粘附素。我们后来证明了原型HMW 1/HMW 2蛋白在免疫研究中的疫苗潜力，其中经胃肠外免疫的龙猫被保护免受由同源菌株引起的NTHi中耳炎。我们还表明，天然获得的人抗体特异性的HMW 1/HMW 2样蛋白和多克隆抗血清提出了对这些蛋白质的调理吞噬同源和异源的HMW 1/HMW 2表达菌株。在最近的Hia蛋白的工作中，我们证明了Hia样蛋白的特异性抗体对同源和异源表达Hia的NTHi也是调理吞噬的。总之，这些数据表明，来自HMW 1/HMW 2和Hia家族的蛋白质，最有可能组合，值得认真考虑作为预防NTHi疾病的候选疫苗。本领域的许多专家认为直接粘膜免疫对于开发成功的中耳炎疫苗至关重要。在我们最近的工作中，我们构建了表达HMW 1/HMW 2或Hia蛋白的重组腺病毒载体，并在灰鼠耳炎模型中证明了这些构建体的免疫原性。在拟议的工作中，我们将建立在这些早期的研究，并确定是否HMW 1/HMW 2和Hia样蛋白可以向前作为可行的NTHi疫苗候选人。首先，我们将确定对HMW 1/HMW 2和Hia样蛋白产生的人抗体对急性NTHI中耳炎儿童恢复期血清中产生的调理吞噬活性的贡献。接下来，我们将绘制HMW 1/HMW 2-和Hia-样蛋白的区域，所述蛋白表达由能够介导针对同源和异源NTHi的调理吞噬活性的抗体识别的表位。最后，我们将评估表达HMW 1/HMW 2-或Hia-样蛋白的重组腺病毒载体在实验性中耳炎的灰鼠模型中提供针对NTHi疾病的保护的能力。我们提出的研究是创新的领域，无论是在有前途的疫苗抗原的研究和新的粘膜免疫策略正在调查。由此产生的信息将进一步推动我们朝着我们的最终目标，即开发有效的疫苗，以预防NTHi中耳炎和其他疾病的幼儿。

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.