Cellular Immune Responses Induced by SIVdelta-vif plus IL-15 DNA Vaccine

描述（由申请人提供）：迫切需要开发一种有效和安全的人类免疫缺陷病毒（HIV）疫苗，其主要目标是阻止艾滋病流行病的传播。通过阐明疫苗诱导保护的免疫相关性，将有助于设计这种有效的疫苗。我们已经在恒河猴中进行了疫苗接种研究，以评估含有VIF缺失的SIVmac 239前病毒（SIVvif前病毒）的质粒DNA作为前病毒DNA疫苗。此外，我们研究了恒河猴白细胞介素（IL）-15表达质粒的佐剂活性时，共接种SIV？vif前病毒DNA。来自这些研究的发现表明，与IL-15质粒表达载体的共免疫对SIV vif缺失的前病毒DNA疫苗提供了显著的佐剂作用，并且增强了对病原性SIVmac 251的阴道攻击的保护。此外，检查SIV特异性细胞免疫反应的干扰素？ELISpot和T细胞增殖试验显示，干扰素-？通过包含IL-15作为前病毒DNA疫苗的佐剂的ELISpot应答。这些由NIH资助的疫苗研究现已结束。我们建议使用10色多参数流式细胞术分析，进一步检查来自这些相同疫苗研究的冻存PBMC样本库的病毒特异性细胞免疫应答。该试验将评价SIV诱导的T细胞细胞内细胞因子（包括干扰素-β）的表达，肿瘤坏死因子（TNF）-α和白介素-2，并且还测试细胞毒性T细胞脱粒（CD 107 α）、CD 8 T细胞记忆发育（CD 127或IL-7受体α）和阴性免疫调节蛋白（程序性死亡1/PD-1）的特异性细胞表面标志物的表达。这种类型的免疫反应评估没有描述在最初的NIH提案，资助这些SIV？vif DNA疫苗研究。然而，这项调查现在是很好的理由，从这些研究的观察和最近的报告显示，这些功能配置文件的效用，以阐明免疫相关的疫苗设计是至关重要的。假设是，实施新的工具，全面的免疫反应分析猕猴接种SIV？有或没有IL-15表达质粒的vif前病毒DNA将阐明IL-15佐剂活性和疫苗诱导的病毒载量控制的免疫相关性。此外，IL-15被认为是HAART患者的潜在免疫增强剂。因此，仔细阐明与潜在有效的细胞因子佐剂如IL-15相关的细胞免疫应答可能会影响未来HIV-1疫苗和治疗剂的设计。公共卫生相关性：最近在猴动物模型中的研究结果表明，包括淋巴细胞生长因子指定白细胞介素（IL）-15，作为高度减毒SIV的一部分？vif DNA疫苗，提高了该疫苗的有效性。然而，疫苗诱导的免疫应答的标准测试没有确定IL-15改善疫苗的特定原因或机制。我们建议使用过去十年开发的新技术进一步研究病毒特异性细胞免疫反应，以确定IL-15改善这种DNA疫苗的机制。这些研究的结果可以用于未来设计更有效的HIV-1疫苗，以及设计HIV-1感染的免疫治疗药物。

DESCRIPTION (provided by applicant): The need is pressing to develop an effective and safe vaccine against the human immunodeficiency virus (HIV) with the primary objective of arresting the spread of the AIDS epidemic. Design of such efficacious vaccines will be facilitated by the elucidation of immune correlates of vaccine-induced protection. We have conducted vaccination studies in rhesus macaques to evaluate a plasmid DNA containing a vif-deleted SIVmac239 provirus (SIVvif provirus) as a proviral DNA vaccine. Furthermore we investigated the adjuvant activity of a rhesus macaque interleukin (IL)-15 expression plasmid when co-inoculated with the SIV?vif proviral DNA. Findings from these studies indicated that co-immunization with an IL-15 plasmid expression vector affords a significant adjuvant effect to the SIV vif-deleted proviral DNA vaccine and enhanced protection against vaginal challenge with pathogenic SIVmac251. Furthermore, examination of SIV-specific cellular immune responses by interferon-? ELISpot and T cell proliferation assays revealed a significant enhancement of interferon-? ELISpot responses by inclusion of IL-15 as an adjuvant for the proviral DNA vaccine. These NIH-funded vaccine studies have now been concluded. We propose to further examine virus-specific cellular immune responses from cryopreserved PBMC samples banked from these same vaccine studies, using a 10 color multi-parameter flow cytometric assay. This assay will evaluate SIV-induced T cell intracellular expression of cytokines including interferon-?, tumor necrosis factor (TNF)-a, and interleukin-2 and also test for expression of specific cell surface markers for cytotoxic T cell degranulation (CD107a), CD8 T cell memory development (CD127 or IL-7 receptor a) and a negative immunoregulatory protein (program death 1/PD-1). This type of immune response assessment was not described in the original NIH proposal that funded these SIV?vif DNA vaccine studies. However, this investigation is now well justified by observations from these studies and by recent reports showing the utility of these functional profiles to elucidate immune correlates that are critical for vaccine design. The hypothesis is that implementation of novel tools for comprehensive immune response analysis in macaques vaccinated with SIV?vif proviral DNA with or without IL-15 expression plasmid, will elucidate an immune correlate(s) for IL-15 adjuvant activity and vaccine-induced control of virus load. Furthermore, Il-15 has been considered as a potential immunotherapeutic for patients on HAART. Accordingly, careful elucidation of cellular immune responses associated with a potentially effective cytokine adjuvant such as IL-15 may impact design of future HIV-1 vaccines and therapeutics. PUBLIC HEALTH RELEVANCE: Findings from recent studies in monkey animal models, suggested that including a lymphocyte growth factor designated interleukin (IL)-15, as part of the highly attenuated SIV?vif DNA vaccine, improved the effectiveness of this vaccine. However standard tests for vaccine-induced immune responses did not identify a specific cause or mechanism by which IL-15 improved the vaccine. We propose to further examine virus-specific cellular immune responses using new technologies developed over the past decade, to identify mechanisms by which IL-15 improved this DNA vaccine. Findings from these studies may then be used for future design for more effective HIV-1 vaccines, as well as design for immunotherapeutics for HIV-1 infection.