SBIR Phase I: Novel Method for Class Switching IgM Secretors to IgG

该小型企业创新研究（SBIR）I期项目旨在开发一种快速可靠的方法，用于使用体外转换培养基，凝胶微滴（GMD）技术和荧光激活细胞分选（FACS）诱导，检测和回收杂交瘤细胞系中的同种型转换变体。抗体广泛用于研究和临床应用。IgM亚类的抗体通常被认为是最不有用的，因为它们的五聚体结构和缺乏对蛋白A和蛋白G的亲和力，这使得IgM抗体的纯化和修饰困难，并且用于Fab片段产生的酶消化几乎是不可能的。然而，产生的许多杂交瘤是IgM亚类的。然而，产生IgM的杂交瘤会自发地将其产生的抗体亚类转换为IgG，尽管频率很低。目前，还没有简单的方法来控制类别切换和隔离类别切换变体。已经开发了几种方案来实现产生IgM的杂交瘤的类别转换并分离类别转换变体，但是这些程序是冗长的并且非常劳动密集的，涉及多个筛选循环。通过提供一种快速分离IgG开关变体的方法，GMD方法将显著改善用于研究和治疗用途的单克隆抗体的生物加工。该项目的商业应用将用于开发用于研究、治疗、诊断和成像目的的单克隆抗体产品。

This Small Business Innovation Research (SBIR) Phase I project aims to develop a rapid and reliable method for inducing, detecting and recovering isotypic switch variants in hybridoma cell lines using in-vitro switching media, gel microdrop (GMD) technology and fluorescence activated cell sorting (FACS). Antibodies are widely used in research and clinical applications. Antibodies of the IgM subclass are generally considered the least useful due to their pentameric structure and lack of affinity for protein A and protein G which makes purification and modification of IgM antibodies difficult, and enzymatic digestion for Fab fragment production almost impossible. Many of the hybridomas produced, however, are of the IgM subclass. IgM producinghybridomas do, however, spontaneously switch the subclass of antibody they produce to IgG, although at very low frequencies. Currently there is no simple method for controlling class switching and isolating class switch variants. Several protocols have been developed to effect class switching of IgM producing hybridomas and to isolate class switch variants, but these procedures are lengthy and very labor-intensive involving multiple screening cycles. By providing a rapid method for isolating IgG switch variants, the GMD method will significantly improve bioprocessing of monoclonal antibodies for research and therapeutic use.The commercial application of this project will be in the development of monoclonal antibody products for research, therapeutic, diagnostic and imaging purposes.