Protective Activity of a Multi-Functional Immunogen

描述（由申请人提供）：需要现有人佐剂的替代品。我们的研究表明，在没有佐剂的情况下，将抗原（Ag）靶向抗原呈递细胞上的人Fc γ受体I型（hFc γ RI）增强了体外T细胞活化和体内Ag特异性抗体（Ab）和细胞因子的产生。然而，还没有人创造出重组免疫原，其允许在感染性疾病模型中检查hFc γ RI靶向方法，或对所涉及的机制进行仔细研究。肺炎链球菌是一种呼吸道病原体，其保护性抗原（PspA）已被确定。PspA是一种细菌表面蛋白，当与佐剂一起用作免疫原时，其产生针对S.肺炎感染小鼠。我们假设：1）保护S。可以通过用抗hFc γ RI-PspA融合蛋白免疫来增强肺炎链球菌感染（在没有佐剂的情况下）。2)增强机制将涉及Ag定位于淋巴组织的改变以及Ag加工的改变。为了测试后者，我们将产生抗hFc γ RI-HEL融合蛋白。HEL是一种蛋白质Ag，通常用于进行体外和体内Ag加工和呈递的机制研究。A）将已经产生的抗hFc γ RI-PspA和抗hFc γ RI-HEL融合蛋白去人源化。B）检查融合蛋白在体外和体内增强T和B细胞应答的能力。C）在体内确定hFc γ RI靶向Ag是否部分地通过增强Ag对淋巴组织的定位而起作用。A）测试抗-hFc γ RI-PspA融合蛋白保护免受沙门氏菌攻击的能力。肺炎。B）利用生物化学、免疫学和超微结构技术研究hFc γ RI靶向对Ag加工和呈递的影响。所提出的研究将为在小鼠和人类中使用各种传染病因子的进一步hFc γ RI靶向研究奠定基础，消除对传统佐剂的需要，大幅减少接种个体所需的Ag量（降低成本和潜在毒性），并提供疫苗递送系统，其同时增强体液和细胞免疫应答。因此，这些研究和疫苗策略将适用于针对成人、儿童和免疫功能低下人群中多种病原体的疫苗。

DESCRIPTION (provided by applicant): Alternatives to current human adjuvants are needed. Our studies demonstrate that in the absence of adjuvant, targeting antigen (Ag) to human Fcgamma receptor type I (hFcgammaRI) on Ag presenting cells enhances T cell activation in vitro and Ag-specific antibody (Ab) and cytokine production in vivo. However, no one has created recombinant immunogens, which permit examination of the hFcgammaRI targeting approach in an infectious disease model, or the deliberate study of the mechanism(s) involved. Strepto- coccus pneumoniae is a respiratory pathogen for which a protective Ag (PspA) has been identified. PspA is a bacterial surface protein, which, when used as an immunogen with adjuvant, generates protection against S. pneumoniae infection in mice. We hypothesize: 1) That protection against S. pneumoniae infection can be enhanced (in the absence of adjuvant) by immunizing with an anti-hFcgammaRI-PspA fusion protein. 2) That the mechanism(s) of enhancement will involve alterations in Ag localization to lymphoid tissues, as well as alterations in Ag processing. To test the latter, we will generate an anti-hFcgammaRI-HEL fusion protein. HEL is a protein Ag commonly used to conduct mechanistic studies of Ag processing and presentation, in vitro and in vivo. In Speific Aim 1 we will: A) Dehumanize anti-hFcgammaRI-PspA and anti-hFcgammaRI- HEL fusion proteins already generated. B) Examine the ability of the fusion proteins to enhance T and B cell responses in vitro and in vivo. C) Determine, in vivo, if hFcgammaRI targeting of Ag works, in part, through enhanced localization of Ag to lymphoid tissues. In Specific Aim 2 we will: A) Test the ability of the anti- hFcgammaRI-PspA fusion protein to protect against challenge with S. pneumoniae. B) Study the influence of hFcgammaRI targeting on Ag processing and presentation utilizing biochemical, immunological and ultrastructural techniques. The proposed studies will lay the ground-work for further hFcgammaRI targeting studies using a variety of infectious disease agents in mouse and human, eliminate the need for traditional adjuvant, substantially reduce the amount of Ag required to vaccinate an individual (reducing cost and potential toxicity), and provide a vaccine delivery system, which simultaneously enhances humoral and cellular immune responses. Thus, these studies and this vaccine strategy will be applicable to vaccines against a wide variety of pathogens in adult, pediatric, and immunocompromised populations.