Novel H1N1 influenza protection via cross-reactive immunity

描述（由申请人提供）：2009年春天，一种新型H1N1流感的爆发让流行病学家、免疫学家和疫苗学家大吃一惊，并在全世界范围内掀起了大规模的努力，生产了数百万剂疫苗来预防这种单一的流感毒株。大流行与年龄相关的w型易感性曲线有关，这在1918年大流行期间也观察到。由于新型H1N1流感的独特流行病学特征，我们假设，在缺乏交叉反应性体液免疫的老年人中，对交叉保守T细胞表位的反应可能导致流感样疾病的报告减少，并证实新型H1N1感染。我们最初的计算机分析在2009年3月发表的A/California/04/2009 （H1N1）序列中确定了超过16个交叉保守的表位，现在我们希望通过本研究计划中描述的检测进一步开展这项研究。因此，我们建议进行研究，评估来自循环、季节性H1N1毒株和传统三价流感疫苗（TIV）的高度保守的HA和NA T细胞表位在人类和小鼠模型中引发强大和持久免疫反应的能力。该项目的目的是：(1)以现有的流感序列为出发点，合成并验证“免疫原性共识序列”交叉保守的流感II类表位；(2)在HLA竞争结合试验中验证ICS表位与相关HLA分子结合的能力，并利用来自甲型h1n1流感、季节性流感暴露和新型h1n1暴露的人类受试者的外周血白细胞评估表位的抗原性。最后，(3)与Richard Webby博士合作，在HLA转基因小鼠模型中，评估它们在加/不加流感疫苗的情况下对新型H1N1的免疫原性和保护效果的影响。我们期望发现，与未引物的小鼠相比，用交叉反应性表位引物的小鼠抗体滴度更高，流感表现减弱。我们希望这些研究的结果能够证明，保守的流感序列对病毒适应性很重要，也可能具有免疫学价值，因为它们可能有助于预防发病率和通用流感疫苗设计，从而导致重新评估“启动”流感免疫反应的替代方法，减轻疾病并为下一次大流行做好准备。

DESCRIPTION (provided by applicant): The outbreak of a novel H1N1 influenza in the spring of 2009 took epidemiologists, immunologists and vaccinologists by surprise and galvanized a massive worldwide effort to produce millions of vaccine doses to protect against this single influenza strain. The pandemic has been associated with a w-shaped age-related susceptibility curve, which was also observed during the 1918 pandemic. Because of the unique epidemiology of novel H1N1 influenza, we hypothesize that response to cross-conserved T cell epitopes might have contributed to diminished reports of influenza-like illnesses and confirmed novel H1N1 infection among older adults in the absence of cross-reactive humoral immunity. Our initial in silico analysis identified more than sixteen cross-conserved epitopes in the A/California/04/2009 (H1N1) sequence published in March 2009 and now we wish to take that study further with the assays described in this research plan. We therefore propose studies that evaluate the ability of highly conserved HA and NA T cell epitopes from circulating, seasonal H1N1 strains and the conventional trivalent influenza vaccine (TIV) to elicit robust and durable immune responses in humans and in a murine model. The aims for this project are to: (1) Synthesize and validate "immunogenic consensus sequence" cross-conserved influenza class II epitopes, using available influenza sequences as our point of departure, (2) Validate the ICS epitopes for their ability to bind relevant HLA molecules in HLA competition binding assays and evaluate the epitopes' antigenicity using peripheral blood leukocytes from TIV, seasonal influenza-exposed and novel H1N1-exposed human subjects. Finally, (3) evaluate their effect on immunogenicity and protective efficacy against novel H1N1 in the HLA transgenic mouse model when used to prime with/without flu vaccine, in collaboration with Dr. Richard Webby. We expect to find that antibody titers are higher and manifestations of influenza are attenuated in mice primed with the cross-reactive epitopes, compared to mice not primed. We expect the results of these studies to demonstrate that conserved influenza sequences, which are important to viral fitness, may also be of immunological value in that they may contribute to protection against morbidity and to universal influenza vaccine design, leading to re-evaluation of alternative approaches to "priming" influenza immune responses, attenuating illness and preparing for the next pandemic. PUBLIC HEALTH RELEVANCE: The unexpected emergence of swine-origin influenza virus in 2009 prompted vaccine developers to produce a vaccine specific for the novel strain. We will explore the potential for cross-strain immunogens to induce immune responses that may give rise to development of a universal influenza vaccine.