TLR Ligand-Based Vaccines for SIV/HIV

描述(由申请人提供)：控制全球艾滋病毒流行将需要开发一种预防性和治疗性艾滋病毒疫苗。一种有效的疫苗需要激发中和抗体和有效的CTL反应。Toll样受体(Toll-like Receptor，TLR)配体是抗原提呈细胞的有效激活剂，在成功的获得性免疫反应的发展中起关键作用。我们假设，在HIV疫苗制备中使用合成的TLR配体，如免疫刺激DNA，将改善抗HIV免疫反应。此外，抑制TLR诱导的下调免疫反应的抑制途径，如IL-10和吲哚胺2，3-双加氧酶(IDO)，应该会进一步优化免疫反应。因此，我们建议研究：1)基于TLR配体的模型抗原(卵清蛋白)和灭活SIV免疫后记忆CD8+T细胞反应的发展，效应和中枢记忆反应的特征，以及记忆细胞发育和维持对CD4+T细胞的需求；2)通过抑制IDO增强免疫反应的能力，IDO是色氨酸分解代谢中的关键酶，下调T细胞反应，和/或在体外和体内系统中中和抑制细胞因子IL-10；3)上述方法在小鼠体内诱导针对SIV的免疫反应的结果，这些免疫反应将被重建以表达TLR9的人/灵长类细胞表达谱；4)在体外和体内SIV攻击前后在SA 1-3中选择的最有前途的方法；5)基于TLR配体的疫苗在人PBMC系统中的有效性。具体地说，将评估在与TLR配体和灭活的CMV孵育后CMV+捐赠者的CD4+和CD8+T细胞对CMV的记忆反应的增强，以及CD4耗竭对HIV+/CMV+捐赠者的PBMC抗CMV反应和抗HIV反应的影响。 这些实验旨在提供一个平衡的调查，探索基础免疫学，并提供疫苗学的实际方面，将推动我们更接近于为人类开发有效的艾滋病毒疫苗。

DESCRIPTION (provided by applicant): Control of the worldwide HIV epidemic will require development of a preventive and therapeutic HIV vaccine. An effective vaccine will need to elicit neutralizing antibodies as well as an effective CTL response. Toll-like receptor (TLR) ligands are potent activators of antigen presenting cells that are central in the development of a successful adaptive immune response. We hypothesize that using synthetic TLR ligands, such as immunostimulatory DNA, in HIV vaccine preparations will improve anti-HIV immune responses. Furthermore, inhibiting TLR-induced inhibitory pathways that down-regulate immune responses, such as IL-10 and indoleamine 2,3-dioxygenase (IDO), should further optimize immune responses. Thus, we propose to investigate: 1) the development of memory CD8+ T cell responses after TLR ligand-based vaccination with a model antigen (ovalbumin) and with inactivated SIV, characterization of the effector and central memory responses, and requirement for CD4+ T cells in the development and maintenance of memory cells; 2) the ability to augment immune responses by inhibiting IDO, a critical enzyme in tryptophan catabolism that down-regulates T cell responses, and/or by neutralizing the inhibitory cytokine IL-10 in in vitro and in vivo systems; 3) the outcome of the approaches mentioned above to elicit immune responses against SIV in mice that will be reconstructed to express the human/primate cellular expression profile of TLR9; 4) the most promising approaches selected in SA 1-3 in an in vitro and in an in vivo macaque system before and after SIV challenge; 5) the efficacy of TLR ligand-based vaccines in a human PBMC system. Specifically, the augmentation of CD4+ and CD8+ T cell memory responses to CMV in CMV+ donors after incubation with TLR ligands and inactivated CMV will be assessed as well as the effect of CD4-depletion on the anti-CMV responses and anti-HIV responses by using PBMCs from HIV+/CMV+ donors. These experiments were designed to provide a balanced investigation that explores fundamental immunology and provides the practical aspects of vaccinology that will move us closer to development of an effective HIV vaccine for humans.