Induction of mucosal SIV immunity in non human primates by secreted Hsp-Gp96

通过分泌的 Hsp-Gp96 诱导非人灵长类动物粘膜 SIV 免疫

• 批准号: 7786796
• 负责人: ECKHARD R PODACK
• 金额: $ 45.9万
• 依托单位: UNIVERSITY OF MIAMI SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-03-15 至 2012-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7786796
• 关键词: Immunity; SIV; nonhuman primate

DESCRIPTION (provided by applicant): Cellular immunity and memory is required for clearance of viruses and for protection from viral infection. Cellular immunity by CD8 CTL and NK cells is initiated through activation of the innate immune response, maturation of dendritic cells (DC) and antigen cross presentation to CD8 T cells. Anti viral vaccines stimulating cellular immunity have to imitate this process. Adjuvants for the stimulation of antibody responses are used effectively however our knowledge about adjuvants for the stimulation of CTL immunity is limited. We have demonstrated that the endoplasmic reticulum resident heat shock protein gp96, a chaperone for peptides transported to be presented by MHC-I, is a natural adjuvant for the activation of DC, NK and cognate CD8 T cells. DC and macrophages have receptors for gp96-peptide complexes and become activated upon gp96-binding. Gp96 together with its associated peptides is taken up the APC, the peptide moiety is transported to the ER and used to charge MHC-I molecules. Concomitant activation of DC results in more than million fold enhanced cross priming of cognate CD8 T cells when compared to cross priming by intact protein taken up by DC. To take advantage of this unique adjuvant effect and the ability to transport relevant peptides, we have made a secretable form of gp96, gp96-lg, by replacing the KDEL ER-retention signal with the Fc portion of lgG1. We hypothesize that cell-based gp96-lg vaccines, by prolonged in vivo secretion of gp96-lg-peptide, imitate viral replication and provide immune stimuli comparable to attenuated viruses. In model systems in mice we have shown that gp96-lg transfected, antigen expressing tumor cells secrete gp96-lg in vivo and stimulate the innate DC and NK as well as adaptive, cognate cellular CD8 CTL immune response and generate specific CD8 memory independent of CD4 help and in the absence of lymph nodes. Both systemic and strong mucosal immunity in intraepithelial, lamina propria and Peyer's patch CD8 CTL is generated by gp96-lg vaccines. Because of their unique properties we now plan to evaluate the gp96- vaccines in non-human primate models for SIV for their immunogenicity for mucosal and systemic cellular immunity (R21). In addition we will examine the protective power of SIV-gp96-vaccines against subsequent viral challenge (R33). To maximize the chances of success, the team in Miami (Podack/Pahwa) has entered into a collaboration with experts (Franchini lab) at the NIH bringing together basic immunologists with experts in human and non human primate HIV/SIV pathogenesis.

描述（由申请人提供）：清除病毒和防止病毒感染需要细胞免疫和记忆。 CD8 CTL 和 NK 细胞的细胞免疫是通过先天免疫反应的激活、树突状细胞 (DC) 的成熟以及抗原交叉呈递给 CD8 T 细胞而启动的。刺激细胞免疫的抗病毒疫苗必须模仿这个过程。用于刺激抗体反应的佐剂被有效地使用，但是我们对用于刺激CTL免疫的佐剂的了解是有限的。我们已经证明，内质网驻留热休克蛋白 gp96 是由 MHC-I 转运呈递的肽的伴侣，是激活 DC、NK 和同源 CD8 T 细胞的天然佐剂。 DC 和巨噬细胞具有 gp96-肽复合物的受体，并在与 gp96 结合后被激活。 Gp96 与其相关肽一起被 APC 吸收，肽部分被转运至 ER 并用于给 MHC-I 分子充电。与 DC 摄取的完整蛋白质的交叉引发相比，DC 的同时激活导致同源 CD8 T 细胞的交叉引发增强超过百万倍。为了利用这种独特的佐剂效应和转运相关肽的能力，我们通过用 IgG1 的 Fc 部分替换 KDEL ER 保留信号，制备了 gp96 的分泌形式，即 gp96-lg。我们假设基于细胞的 gp96-lg 疫苗通过延长体内 gp96-lg 肽的分泌来模仿病毒复制并提供与减毒病毒相当的免疫刺激。在小鼠模型系统中，我们发现转染gp96-lg的抗原表达肿瘤细胞在体内分泌gp96-lg并刺激先天DC和NK以及适应性同源细胞CD8 CTL免疫反应，并在没有淋巴结的情况下产生独立于CD4帮助的特异性CD8记忆。 gp96-lg 疫苗可产生上皮内、固有层和派尔氏集结 CD8 CTL 的全身性和强粘膜免疫。由于其独特的特性，我们现在计划在非人灵长类动物 SIV 模型中评估 gp96 疫苗对粘膜和全身细胞免疫 (R21) 的免疫原性。此外，我们将检查 SIV-gp96 疫苗针对后续病毒攻击 (R33) 的保护能力。为了最大限度地提高成功机会，迈阿密团队（Podack/Pahwa）已与 NIH 的专家（Franchini 实验室）展开合作，将基础免疫学家与人类和非人类灵长类 HIV/SIV 发病机制方面的专家聚集在一起。