Developing novel adjuvants for HIV vaccination

描述(申请人提供)：接种疫苗或自然感染诱导的免疫反应不能有效预防和控制HIV感染。因此，探索替代免疫途径和新型佐剂，以产生优于天然免疫的保护性免疫应答，对抗HIV感染具有重要意义。树突状细胞(DC)等抗原提呈细胞(APC)在免疫反应的激活和维持中起着关键作用，它们受刺激信号和抑制信号的调节。最近，我们发现促炎症信号的负调控因子，如锌指泛素修饰酶A20和细胞因子信号抑制因子1(SOCS1)，在限制APC的免疫刺激活性和自身抗原的自身反应中起着关键作用。我们证明，沉默A20或SOCS1显著增强了TLR激动剂和DC疫苗诱导T细胞和抗体反应的刺激效力。在这项研究中，我们的目标是通过抑制致炎信号的关键负调控因子来开发新型和有效的佐剂，以促进HIV预防和治疗性疫苗的开发。这项研究的中心假设是，一种新型的疫苗佐剂可以被创造出来，该佐剂由TLR配体和用于触发和维持APC中TLR信号级联的促炎信号的负调节因子的抑制物组成，可以将针对HIV的细胞和体液反应的幅度和持续时间提高到更高的水平，这是目前所描述的疫苗接种方法或自然感染无法实现的，并且可能能够克服HIV的免疫逃避和抑制。本研究的具体目的是：1)。2)检测可溶性鞭毛蛋白-鱼精蛋白(P)融合蛋白/siA20复合物是否能有效刺激APC作为新型佐剂，在小鼠体内诱导更强更广的HIV特异性CTL和Th应答；3)研究Flc-P/siA20复合体和突变的HIV env与天然免疫保护性表位联合免疫是否能更有效地诱导小鼠和兔产生中和抗体；检测Flc-P/sihA20复合体在激活人DC以刺激HIV特异性T和B细胞方面是否优于TLR激动剂，用于潜在的临床应用。总之，迫切需要开发由TLR配体和A20抑制剂组成的新型佐剂，这种佐剂具有独特的刺激能力，可以将针对HIV的固有和适应性细胞和体液反应提高到目前所描述的佐剂无法达到的更高水平。在这项拟议的研究中，我们的目标是开发用于HIV疫苗接种的新型佐剂，以诱导保护性细胞和体液免疫反应。具体地说，我们将产生并测试由TLR配体和A20抑制剂组成的新型佐剂，这种佐剂具有独特的刺激能力，可以将针对艾滋病毒的固有和适应性细胞和体液反应提高到目前所描述的佐剂无法达到的更高水平。

DESCRIPTION (provided by applicant): The immune responses induced by vaccination or natural infection fail to effectively prevent and control HIV infection. Thus, it is important to explore alternative immunization approaches and novel adjuvants to generate protective immune response that is superior to the natural immunity against HIV infection. Antigen-presenting cells (APCs) such as dendritic cells (DCs) play a critical role in the activation and maintenance of immune responses, and they are regulated by stimulatory as well as inhibitory signaling. Recently, we found that the negative regulators of proinflammatory signaling, such as the zinc-finger ubiquitin-modifying enzyme A20 and suppressor of cytokine signaling 1 (SOCS1), play critical roles in limiting the immunostimulatory potency of APCs and the autoreactive response against self-antigens. We demonstrated that silencing of A20 or SOCS1 drastically enhanced the stimulatory potency of TLR agonists and DC vaccines to induce both T cell and antibody responses. In this study we aim to develop novel and potent adjuvants by inhibiting key negative regulators of proinflammatory signaling to facilitate the development of prophylactic and therapeutic vaccines against HIV. The central hypothesis of this study is that a new type of vaccine adjuvants comprised of a TLR ligand and an inhibitor of the negative regulator of proinflammatory signaling for triggering and sustaining TLR signaling cascades in APCs can be created to enhance the magnitude and duration of cellular and humoral responses against HIV to higher levels that cannot be achieved by currently described vaccination approaches or natural infection and may be capable of overcoming HIV's immune evasion and suppression. The specific aims of this study are: 1). To test whether soluble flagellin (FliC)-protamine (P) fusion protein/siA20 complexes can potently stimulate APCs as novel adjuvants to induce stronger and broader HIV-specific CTL and Th responses in mice; 2). To investigate whether immunization of FliC-P/siA20 complexes and mutated HIV Env with enhanced exposure of naturally shielded, protective epitopes more efficiently induces neutralizing antibodies against HIV in mice and rabbits; and 3). To test whether FliC-P/sihA20 complexes are superior to TLR agonists in activating human DCs to stimulate HIV-specific T and B cells for potential clinic use. In summary, there is a compelling need for the development of the novel adjuvant comprised of TLR ligands and A20 inhibitors that have a unique stimulatory ability to enhance innate and adaptive cellular and humoral responses against HIV to higher levels that cannot be achieved by currently described adjuvants. In this proposed study, we aim to develop novel adjuvants for HIV vaccination to induce protective cellular and humoral immune responses. Specifically, we will generate and test the novel adjuvant comprised of TLR ligands and A20 inhibitors that have a unique stimulatory ability to enhance innate and adaptive cellular and humoral responses against HIV to higher levels that cannot be achieved by currently described adjuvants.