Novel H1N1 influenza protection via cross-reactive immunity

描述(申请人提供)：2009年春季爆发的一种新型H1N1流感让流行病学家、免疫学家和疫苗接种学家大吃一惊，并引发了全球范围内生产数百万剂疫苗以预防这种单一流感毒株的巨大努力。这场大流行与年龄相关的W型易感曲线有关，1918年大流行期间也观察到了这一点。由于新型H1N1流感的独特流行病学，我们推测，在没有交叉反应性体液免疫的情况下，对交叉保守的T细胞表位的反应可能有助于减少流感样疾病的报道，并在老年人中确认新型H1N1感染。我们最初的电子分析在2009年3月发表的A/California/04/2009(H1N1)序列中发现了16个以上的交叉保守表位，现在我们希望通过本研究计划中描述的分析进一步进行这项研究。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诱导强大和持久免疫反应的能力。本项目的目标是：(1)以已有的流感序列为出发点，合成和验证“免疫原性共识序列”交叉保守的流感II类表位；(2)验证ICS表位在人类白细胞抗原竞争结合试验中与相关的HLA分子结合的能力，并利用TIV、季节性流感暴露者和新型H1N1暴露者的外周血细胞来评估这些表位的抗原性。最后，(3)与Richard Webby博士合作，在使用/不使用流感疫苗的情况下，评估它们在人类白细胞抗原转基因小鼠模型中对新型H1N1病毒的免疫原性和保护效力的影响。我们希望发现，与未接种的小鼠相比，接种了交叉反应表位的小鼠的抗体效价更高，流感的表现也有所减轻。我们预计这些研究的结果将证明，保守的流感序列对病毒的适应性很重要，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，导致重新评估“启动”流感免疫反应、减轻疾病和为下一次大流行做准备的替代方法。 公共卫生相关性：2009年猪源流感病毒的意外出现促使疫苗开发人员生产了一种针对这种新毒株的疫苗。我们将探索跨毒株免疫原诱导免疫反应的可能性，这可能会导致通用流感疫苗的开发。

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.