Pulmonary innate immune activation for bioterror defense

描述（由申请人提供）： 美国和其他国家的平民面临着越来越大的生物恐怖主义威胁。要为可能遇到的所有生物战剂开发有效的疫苗或治疗方法是不可行的。此外，可能无法及时知道攻击中使用的生物恐怖制剂的身份，无法给予具体治疗。因此，非常需要开发广谱非特异性疗法，其可以保护免受广泛的病原体的侵害。从理论上讲，预先激活适当的先天防御应该可以降低发病率和死亡率，并改善对支持治疗的反应。数亿年的进化赋予了人类一系列非凡的先天免疫防御能力，以对抗病毒、细菌、真菌和寄生虫。这种先天免疫被认为在很大程度上取决于一个称为“Toll样受体”（TLR）的分子家族，该家族结合存在于微生物中的分子，但不结合存在于正常宿主组织中的分子。最近的研究表明，TLR 9的配体，称为CpG基序，在激活广谱先天免疫防御方面特别有效，可以保护动物免受各种病原体的侵害。临床前研究表明，用合成的CpG寡脱氧核苷酸（ODN）预处理可以保护小鼠免受各种病毒、细菌和细胞内寄生虫的侵害，包括A类病原体炭疽、兔热病和埃博拉病毒。为了防止吸入的病原体，CpG ODN的最佳给药途径似乎也是吸入。已经鉴定了三种类型的CpG ODN，CpG-A、CpG-B和CpG-C，在体外和小鼠体内对人细胞具有不同的免疫特性。在超过300名施用CpG-B ODN的受试者中进行的I/II期人类临床试验表明免疫应答的强烈增强和优异的安全性特征。该提案的总体目标是确定一种CpG ODN，其在动物攻击模型中提供对病原体的广谱防御，并开发这种CpG用于保护平民免受生物恐怖剂的侵害。基于对三个类别中超过3000种ODN的研究，已从每个类别中选择一种优化的ODN用于在该程序中进行比较：CpG-A 10108、CpG-B 10105和CpG-C 10107。我们的建议是基于这样的假设，即用CpG ODN预防性激活特定的先天免疫防御将防止随后暴露于一种或多种生物恐怖剂。预计用CpG预处理将降低生物恐怖的发病率和死亡率，并延长可以给予支持性治疗和特定对策的“黄金时间”。如果成功，拟议的研究将为人体安全性临床试验和最终的NDA提交提供支持性数据。 将通过以下具体目标实现这一目标： 具体目标1。确定不同CpG类别在保护小鼠免受吸入的A类病原体侵害方面的功效。 具体目标2。确定不同CpG类别在防止其他吸入性病原体方面的功效。 具体目标3。确定吸入CpG类对呼吸道免疫功能的影响。 具体目标4。吸入性CpG ODN的外周生物标志物的鉴定（小鼠、猪、绵羊、灵长类动物）。 具体目标5.表征吸入CpG ODN的毒性。 具体目标6.表征吸入的CpG ODN的吸收、分布、代谢和排泄。

DESCRIPTION (provided by applicant): Civilians in the US and other countries face a growing threat from bioterrorism. It is not feasible to develop effective vaccines or treatments for all possible biowarfare agents that may be encountered. Furthermore, the identity of the bioterror agent(s) employed in an attack may not be known in time to administer specific therapies. Therefore, it is highly desirable to develop broad-spectrum nonspecific therapies that can protect against a wide range of pathogens. In theory, pre-activating the appropriate innate defenses should reduce morbidity and mortality, and improve the response to supportive therapy. Hundreds of millions of years of evolution have endowed humans with an extraordinary range of innate immune defenses against viruses, bacteria, fungi, and parasites. This innate immunity is thought to depend in large part on a family of molecules called "Toll like receptors" (TLRs), which bind molecules that are present in microbes, but not in normal host tissues. Recent studies show that ligands for TLR9, called CpG motifs, are particularly effective at activating broad-spectrum innate immune defenses, and can protect animals against a wide range of pathogens. Preclinical studies show that pretreatment with a synthetic CpG oligodeoxynucleotide (ODN) protects mice against a wide variety of viruses, bacteria, and intracellular parasites, including the Category A agents anthrax, tularemia, and Ebola. For protection against an inhaled pathogen, the optimal route of administration for the CpG ODN also appears to be inhaled. Three classes of CpG ODN have been identified, CpG-A, CpG-B, and CpG-C, with distinct immune profiles with human cells in vitro and in vivo in mice. Phase I/II human clinical trials in over 300 subjects administered a CpG-B ODN suggest strong enhancement of immune responses and an excellent safety profile. The overall goal of this proposal is to identify a CpG ODN that provides broad-spectrum defense against pathogens in animal challenge models, and to develop this CpG for protection of civilians against a bioterror agent. Based on studies of over 3000 ODN in the three classes, one optimized ODN from each class has been selected for comparison in this program: CpG-A 10108, CpG-B 10105, and CpG-C 10107. Our proposal is based on the hypothesis that the prophylactic activation of particular innate immune defenses with a CpG ODN will protect against a subsequent exposure to one or more bioterror agents. It is expected that pretreatment with CpG would reduce morbidity and mortality from bioterror and prolong the "golden hour" during which supportive therapy and specific countermeasures could be administered. If successful, the proposed studies would provide supportive data for human safety clinical trials and an eventual NDA submission. This goal will be accomplished through the following specific aims: Specific Aim 1. Determine the efficacy of different CpG classes in protecting mice against inhaled Category A pathogens. Specific Aim 2. Determine the efficacy of different CpG classes in protecting against other inhaled pathogens. Specific Aim 3. Determine the effect of inhaled CpG classes on respiratory tract immune function. Specific Aim 4. Identification of peripheral biomarkers for inhaled CpG ODN (mice, swine, sheep, primates). Specific Aim 5. Characterize the toxicity of inhaled CpG ODN. Specific Aim 6. Characterize the absorption, distribution, metabolism, and excretion of inhaled CpG ODN.