Development of a multimeric CD40 ligand vaccine adjuvant

描述（由申请人提供）：CD 40配体（CD 40 L或CD 154）被广泛认为是免疫系统最重要的内源性激活剂之一。特别地，CD 40 L刺激树突状细胞（DC）以启动强的CD 8 + T细胞应答。然而，尽管进行了几次尝试，但没有任何形式的CD 40 L被许可用于临床使用。为了解决这个问题，该项目将推进开发一种高活性、可溶性形式的CD 40 L。这种新型蛋白质是通过融合Acrp 30（一种天然血清蛋白）与CD 40 L的胞外结构域而制成的。最终的蛋白质Acrp 30-CD 40 L或“MegaCD 40 L”已被验证为疫苗诱导的CD 8 + T细胞应答的高效佐剂。在该SBIR第1阶段项目中，MegaCD 40 L将通过开发产生人和小鼠MegaCD 40 L的cGMP CHO细胞的研究细胞库而推向临床。所得蛋白质将使用可扩大到工业生产的方法纯化至均一。为了证明这种新佐剂的效用，MegaCD 40 L将在由该项目顾问John Harty博士（爱荷华州大学）开发的称为“交叉初免-短间隔加强”的小鼠疫苗接种系统中进行测试。在该疫苗接种方案中，首先用抗原包被的PLGA微球接种小鼠，7天后用抗原加MegaCD 40 L加poly（I：C）加强。预计这将产生真正巨大的抗原特异性CD 8 + T细胞反应，这对预防流感，疟疾和生物防御剂引起的感染的疫苗非常重要。在该项目结束时，MegaCD 40 L将准备用于BLA-enabled cGMP蛋白质制造和正式的毒性测试，作为使用这种令人兴奋的新疫苗佐剂进行人体试验的下一步。

DESCRIPTION (provided by applicant): CD40 ligand (CD40L or CD154) is widely recognized as one of the most important endogenous activators of the immune system. In particular, CD40L stimulates dendritic cells (DCs) to initiate strong CD8+ T cell responses. However, despite several attempts, no form of CD40L has been licensed for clinical use. To solve this problem, this project will advance the development of a highly active, soluble form of CD40L. This novel protein is made by fusing the body of Acrp30 (a natural serum protein) with the extracellular domain of CD40L. The final protein, Acrp30-CD40L or "MegaCD40L," has been validated as a highly effective adjuvant for vaccine-induced CD8+ T cell responses. In this SBIR Phase 1 project, MegaCD40L will be advanced toward the clinic by developing research cell banks of cGMP CHO cells that produce human and murine MegaCD40L. The resulting proteins will be purified to homogeneity using methods that can be scaled up to industrial production. To prove the utility of this new adjuvant, MegaCD40L will be tested in a mouse vaccination system called "cross-prime-short interval boost" as developed by Dr. John Harty (University of Iowa), a Consultant to the project. In this vaccination protocol, mice are first vaccinated with PLGA microspheres coated with antigen followed 7 days later by boosting with antigen plus MegaCD40L plus poly(I:C). This is anticipated to generate a truly enormous antigen-specific CD8+ T cell response that would be important for vaccines against influenza, malaria, and infections caused by biodefense agents. At the conclusion of this project, MegaCD40L will be ready for BLA-enabling cGMP protein manufacturing and formal toxicity testing as the next steps toward a human trial with this exciting new vaccine adjuvant.