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。为可能遇到的所有可能的生物制剂开发有效的疫苗或治疗方法是不可行的。此外，袭击中使用的生物恐怖毒剂(S)的身份可能无法及时获知，无法实施特定的治疗。因此，开发广谱的非特异性治疗方法来预防多种病原体是非常必要的。从理论上讲，预先激活适当的先天防御系统应该会降低发病率和死亡率，并改善对支持性治疗的反应。数亿年的进化赋予了人类对病毒、细菌、真菌和寄生虫一系列非凡的先天免疫防御能力。这种与生俱来的免疫力被认为在很大程度上依赖于一种名为Toll like Receptor(TLRs)的分子家族，该家族结合了存在于微生物中但不存在于正常宿主组织中的分子。最近的研究表明，TLR9的配体，称为CpG基序，在激活广谱的天然免疫防御方面特别有效，可以保护动物免受广泛的病原体的侵害。临床前研究表明，用合成的CpG寡核苷酸(ODN)预处理小鼠可以保护小鼠免受各种病毒、细菌和细胞内寄生虫的侵袭，包括A类病原体炭疽病、图拉热症和埃博拉病毒。为了防止吸入病原体，CpG ODN的最佳给药途径似乎也是吸入的。CpG-A、CpG-B和CpG-C已被鉴定为CpG-A、CpG-B和CpG-C三种类型的ODN，它们在体外和小鼠体内与人细胞具有不同的免疫特性。在300多名服用CpG-B ODN的受试者中进行的I/II期人体临床试验表明，CpG-B ODN可显著增强免疫反应，并具有极好的安全性。这项提议的总体目标是确定一种在动物挑战模型中提供针对病原体的广谱防御的CpG ODN，并开发这种CpG以保护平民免受生物恐怖制剂的伤害。在对三个类别的3000多个ODN进行研究的基础上，本项目从每个类别中选择一个优化的ODN进行比较：CPG-A 10108、CPG-B 10105和CPG-C 10107。我们的建议是基于这样一个假设，即通过CpG ODN预防性激活特定的先天性免疫防御系统将防止随后暴露于一种或多种生物恐怖制剂。预计CpG的预治疗将减少生物恐怖的发病率和死亡率，并延长可实施支持性治疗和特定对策的“黄金时段”。如果成功，拟议的研究将为人类安全临床试验和最终提交的NDA提供支持性数据。 这一目标将通过以下具体目标实现： 具体目的1.测定不同CpG等级对小鼠吸入A类病原体的保护作用。 具体目的2.确定不同CpG等级对其他吸入病原体的保护效果。 具体目的3.测定吸入CpG对呼吸道免疫功能的影响。 具体目标4.识别吸入CpG ODN的外周生物标记物(小鼠、猪、羊、灵长类)。 具体目的5.表征吸入CpG ODN的毒性。 具体目的6.表征吸入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.