A Novel Scrambled Antigen DNA Vaccine (SAVINE) Strategy

描述（由申请人提供）：经过20年对艾滋病毒疫苗开发的深入研究，最近几种商业上可行的候选疫苗的成功现在带来了希望。这两种DNA和痘病毒增强的DNA都诱导了强大的T细胞反应，并赋予猕猴部分保护。然而，与必须克服的障碍相比，这些成就是有限的，以保护不同的人群免受比这些研究中使用的病毒高得多的艾滋病毒分离株的影响。由Ian Ramshaw和Scott Thompson开发的一种新型疫苗SAVINE（打乱抗原疫苗）解决了这一问题。SAVINE疫苗由来自所有病毒结构和调控基因的随机重排重叠肽片段（30个氨基酸重叠15个氨基酸）组成，使用系统和合成方法，其中T细胞表位的大小和加工机制是确定抗原如何被破坏的主要标准。重要的是，没有努力使设计偏向于已知的T细胞表位。因此，不需要知道高危人群的特定病毒表位和主要HLA单倍型。在这项应用中，我们建议使用SIV猴艾滋病模型来评估SAVINE方法的免疫原性和有效性。SAVINE组合物将通过比较原型HIV SAVINE的序列和免疫原性与标准B支疫苗中的序列和免疫原性来优化（目的1和3）。利用这些信息，SIV SAVINEs将由SAVINE疫苗方法的创始人dr。斯科特·汤普森和伊恩·拉姆肖（目标2）。一旦SIV SAVINE疫苗在小鼠中被证实具有免疫原性（目标2），将对其在猕猴中诱导粘膜和全身免疫反应以及赋予粘膜保护的能力进行评估（目标4）。SAVINE DNA和SAVINE鸟痘单独或联合诱导粘膜和全身免疫反应的能力将被确定。DNA疫苗将通过共同递送大肠杆菌肠毒素基因进一步增强，我们最近在猕猴中发现，这种组合显著增强了全基因免疫诱导的T细胞反应。将评估外周和肠道相关组织（空肠固有层、肠系膜淋巴结）中T细胞反应的广度和强度，以便确定诱导粘膜反应的最佳策略，以及这些反应与保护的关系。粉状疫苗将评估小鼠和猴子的免疫反应，以便这些反应可以直接相互比较，也可以与其他DNA疫苗的历史数据进行比较。尽管其他研究表明，DNA：鸟痘组合策略诱导的全身免疫反应比单独使用任何一种疫苗都要好，但首次将DNA：鸟痘组合策略诱导粘膜免疫反应的能力与单独使用任何一种方法进行直接比较。由于全身反应往往不能很好地预测粘膜反应，这些研究应该为HIV疫苗的开发提供重要的新信息。总之，这些实验将为将这些研究转化为人体试验提供必要的数据。

DESCRIPTION (provided by applicant): After two decades of intense research in HIV vaccine development, recent successes with several commercially viable vaccine candidates now offer hope. Both DNA, and DNA boosted with poxvirus, have induced robust T cell responses and conferred partial protection macaques. These achievements are modest, however, when compared to the obstacles that must be overcome to protect diverse human populations from HIV isolates that are considerably more hypervariable than the viruses used in these studies. SAVINE (scrambled antigen vaccine), a novel vaccine developed by Ian Ramshaw and Scott Thompson, addresses this concern. SAVINE vaccines are composed of randomly rearranged overlapping peptide fragments (30 amino acids overlapping by 15 amino acids) from all viral structural and regulatory genes using a systematic and synthetic approach in which the size and processing mechanisms of T cell epitopes are the primary criteria for determining how antigens might be disrupted. Importantly, no effort is made to bias the design towards known T cell epitopes. Thus, specific viral epitopes, and the predominant HLA haplotype of the population at risk need not be known. In this application, we propose to evaluate the immunogenicity and efficacy of the SAVINE approach using the SIV macaque model for AIDS. SAVINE composition will be optimized by comparing the sequence and immunogenicity of a prototypic HIV SAVINE to those present in a standard clade B vaccine (aims 1 and 3). Using this information, SIV SAVINEs will be constructed by the founders of the SAVINE vaccine approach, Drs. Scott Thompson and Ian Ramshaw (aim 2). Once SIV SAVINE vaccines are proven immunogenic in mice (aim 2), they will be evaluated for their ability to induce both mucosal and systemic immune responses, and to confer mucosal protection, in macaques (aim 4). The ability of SAVINE DNA and SAVINE avipox, both alone and in combination, to induce mucosal, as well as systemic, immune responses will be determined. DNA vaccines will be further potentiated by co-delivery of the gene for E. coli enterotoxin, a combination that we have recently shown to significantly augment T cell responses induced by whole gene immunization in macaques. The breadth and magnitude of T cell responses will be evaluated in both periphery and gut associated tissues (jejunal lamina propria, mesenteric lymph nodes) so that the optimum strategy for inducing mucosal responses, and the relationship of these responses to protection, can be determined. Immune responses in both mice and monkeys will be evaluated by Powderject Vaccines so that these responses can be directly compared with each other, as well as to historical data with other DNA vaccines. Although other studies have shown that a combined DNA:avipox strategy induces better systemic immune responses than either vaccine alone, for the first time, the ability of the combined DNA: avipox strategy to induce mucosal immune responses will be directly compared to either approach alone. Because systemic responses are often poor predictors of mucosal responses, these studies should provide important new information in HIV vaccine development. Together, these experiments will provide data essential to the translation of these studies to human trials.