Function of NALT in nasal immunization to heterotypic strains of influenza

描述（由申请方提供）：冷适应流感疫苗（CAV）是感染上呼吸道（包括鼻相关类扁桃体组织（NALT））的减毒活病毒。由于NALT是一种粘膜淋巴器官，推测其指导最有效保护呼吸道的B和T细胞的发育。尽管CAV流感疫苗具有潜在的益处，但由于担心当代流感病毒株与疫苗株之间的重组，使用这些疫苗来引发对人畜共患病毒（例如H5 N1禽流感）的免疫受到限制。此外，CAV流感疫苗未被批准用于儿童或老年人。因此，需要开发像CAV一样可以引发异型免疫并靶向NALT和呼吸道的疫苗。然而，NALT的实际功能知之甚少，NALT在CAV免疫应答中的作用从未被测试过。因此，本提案的总体目标是专门评价鼻内递送重组蛋白和冷适应流感病毒（CAV）引起的NALT中的免疫应答。我们将确定NALT中是否启动了对CAV或蛋白抗原的免疫反应，NALT中的启动是否赋予T细胞粘膜归巢特性，以及NALT中的T细胞是否启动回到肺组织和气道。我们还将确定对CAV的免疫应答是否引起CD 4 T细胞，这些T细胞在功能上不同于用蛋白质鼻接种引起的那些T细胞。此外，我们将确定是否与CAV或蛋白抗原鼻内接种诱发M2 e-特异性B细胞，家庭上下呼吸道。我们还将测试CAV或重组蛋白的抗原如何传递到NALT中的淋巴细胞，M细胞是否是这一过程的一部分，以及NALT中的M细胞是否与Peyer's patch NALT中的M细胞相似。最后，我们将确定用CAV或蛋白质抗原鼻内免疫是否导致对强毒株、异型流感毒株的长期免疫。与公共卫生的相关性：甲型流感病毒是人类的重要自然病原体，在美国每年平均造成35，000人死亡。此外，特别致命的流感病毒定期出现，并在一个季节内造成数百万人死亡。这些新出现的流感病毒株，例如1997年在香港出现的高毒性H5 N1变种，有可能引发另一次全球性大流行，造成毁灭性的社会和经济后果。因此，我们必须开发针对广泛的流感血清型的疫苗。该提案描述了将确定鼻内接种冷适应病毒或纯化蛋白质促进对流感免疫的机制的实验。这一信息对于开发疫苗至关重要，这些疫苗可促进对流感的持久交叉反应免疫力，流感病毒仍是一种新出现的传染病。

DESCRIPTION (provided by applicant): Cold adapted influenza vaccines (CAV) are live attenuated viruses that infect the upper respiratory tract, including the Nasal Associated Lymphoid Tissue (NALT). Since NALT is a mucosal lymphoid organ, it is presumed to direct the development of B and T cells that most effectively protect the respiratory tract. Despite the potential benefits of CAV influenza vaccines, the use of these vaccines to elicit immunity to zoonotic viruses, such as H5N1 avian influenza, is limited due to the fear of recombination between contemporary influenza strains and the vaccine strain. In addition, CAV influenza vaccines are not approved for children or the elderly. Thus, it is desirable to develop vaccines that, like CAV, can elicit heterotypic immunity and target the NALT and respiratory tract. However, the actual function of NALT is poorly understood and the role of NALT in immune responses to CAV has never been tested. Therefore, the overall goal of this proposal is to specifically evaluate immune responses in NALT elicited by intranasally delivered recombinant protein and cold-adapted influenza virus (CAV). We will determine whether immune responses to CAV or protein antigens are initiated in NALT, whether priming in NALT confers mucosal homing properties on T cells and whether T cells primed in NALT home to the lung tissue and airways. We will also determine whether immune responses to CAV elicit CD4 T cells that are functionally different than those elicited by nasal vaccination with proteins. Moreover, we will determine whether intranasal vaccination with CAV or protein antigens elicit M2e-specific B cells that home to the upper and lower respiratory tract. We will also test how antigens from CAV or recombinant proteins are delivered to lymphocytes in NALT, whether M cells are a part of this process and whether M cells in NALT are similar to those in Peyer's patches NALT. Finally, we will determine whether intranasal immunization with CAV or protein antigens results in long-lived immunity to virulent, heterotypic strains of influenza. Relevance to public health: Influenza A virus is a significant natural pathogen of man that is responsible for an average of 35,000 deaths annually in the US. In addition, particularly virulent influenza viruses periodically emerge and cause millions of deaths in a single season. These emerging strains of influenza, such as the highly virulent H5N1 variant that appeared in Hong Kong in 1997, have the potential to trigger another worldwide pandemic with devastating social and economic consequences. Thus, it is imperative that we develop vaccines that are protective against a wide array of influenza serotypes. This proposal describes experiments that will determine the mechanisms by which intranasal vaccination with cold adapted viruses or purified proteins promote immunity to influenza. This information will be essential for the development of vaccines that promote long-lasting cross-reactive immunity to influenza, a virus that continues to be an emerging infectious disease.