Scaffolds mimicking antigen presenting cells

目前用于治疗应用的体外扩增T细胞的方法受到低扩增率的限制 和功能有限的T细胞产品。为了解决这些问题，我们最近描述了一种系统 模拟自然抗原提呈细胞(APC)。这些模拟APC的支架(APC-ms)由一种液体脂质组成 介孔二氧化硅微棒(MSR)支撑的双层膜。脂质双层呈现与膜结合的信号 用于预定义密度的T细胞受体刺激和共刺激，而微棒使持续 释放可溶的旁分泌信号。利用抗CD3、抗CD28和白细胞介素2的控制释放，我们有 结果表明，APC-ms促进原代小鼠和人类T细胞的多克隆扩增10倍以上 可以用来调整扩增的T细胞的表型属性 产品。APC-MS还支持CD19 CAR-T细胞的5倍以上的扩增， 在临床相关的异种移植淋巴瘤模型中提高疗效。而APC-MS是一种很有前途的T细胞 扩展系统，有几个开发活动将有助于其临床和商业 翻译。目前的MSR合成工艺还没有针对这一应用进行标准化，并且缺乏 建立标准操作规程，以生产性能一致的材料产品。目前，呈现的是表面线索 在使用生物素-链霉亲和素的APC-MS上，但使用点击化学代替链霉亲和素可以提供 多项优势。而APC-ms被设计为在T细胞培养过程中完全降解 在此期间，不需要在细胞输送之前将其移除，我们尚未彻底探讨其影响 输注的T细胞产品上是否有任何潜在的残留物。这些需求会导致以下具体情况 本项目的目标(1)建立APC-MS合成的标准操作规程。这将包括确定MSR关键 功能APC-M的质量属性(CQA)和了解关键过程参数(CPP)如何 MSR合成影响这些CQA(2)发展一种直接和选择性地共轭表面线索的过程 通过点击化学作用，使APC-MS组装和功能的简单化和模块化。(3) 表征T细胞处理过程中残留的APC-ms材料，并进行彻底的体内安全性 评估。这些目标的成功实现将立即解决与使用 APC-ms作为T细胞体外扩增平台。

Current approaches to expand T cells ex vivo for therapeutic applications are limited by low expansion rates and T-cell products of limited functionality. To address these issues, we have recently described a system that mimics natural antigen-presenting cells (APCs). These APC-mimetic scaffolds (APC-ms) consist of a fluid lipid bilayer supported by mesoporous silica micro-rods (MSRs). The lipid bilayer presents membrane-bound cues for T-cell receptor stimulation and costimulation at predefined densities, while the micro-rods enable sustained release of soluble paracrine cues. Using anti-CD3, anti-CD28 and controlled release of interleukin-2, we have shown that the APC-ms promotes ten-fold greater polyclonal expansion of primary mouse and human T cells than commercial beads (Dynabeads), and can be used to tune the phenotypic attributes of expanded T-cell products. APC-ms also support over 5-fold greater expansion of CD19 CAR-T cells than Dynabeads, with increased efficacy in a clinically-relevant xenograft lymphoma model. While APC-ms is a promising T cell expansion system, there are several development activities that would aid its clinical and commercial translation. The current MSR synthesis process has not been standardized for this application, and lacks established SOPs to yield material products with consistent properties. Currently, surface cues are presented on APC-ms using biotin-streptavidin, but the use of click chemistry in place of streptavidin could provide a number of advantages. While APC-ms is designed to completely degrade during the process of T cell culture period, obviating the need for its removal before cell delivery, we have not yet thoroughly explored the impact of any potential residual materials on the infused T cell products. These needs lead to the following specific objectives for this project (1) Establish SOPs for APC-ms synthesis. This will include identifying MSR critical quality attributes (CQAs) for functional APC-ms and understanding how critical process parameters (CPPs) in MSR synthesis affect those CQAs (2) Develop a process to directly and selectively conjugate surface cues onto lipid bilayers, via click chemistry, to simplify and modularity of APC-ms assembly and function. (3) Characterize residual APC-ms materials during T cell processing, and perform a thorough in vivo safety assessment. The successful achievement of these aims will immediately address key issues related to using APC-ms as an ex vivo T-cell expansion platform.