The high prices of biopharmaceuticals or biologics used in the treatment of many diseases limit the access of patients to these novel therapies. One example is the monoclonal antibody trastuzumab, successfully used for breast cancer treatment. An economic alternative is the generation of biosimilars to these expensive biopharmaceuticals. Since antibody therapies may require large doses over a long period of time, robust platforms and strategies for cell line development are essential for the generation of recombinant cell lines with higher levels of expression. Here, we obtained trastuzumab-expressing CHO-K1 cells through a screening and selection strategy that combined the use of host cells pre-adapted to protein-free media and suspension culture and lentiviral vectors. The results demonstrated that the early screening strategy obtained recombinant CHO-K1 cell populations with higher enrichment of IgG-expressing cells. Moreover, the measurement of intracellular heavy chain polypeptide by flow cytometry was a useful metric to characterize the homogeneity of cell population, and our results suggest this could be used to predict the expression levels of monoclonal antibodies in early stages of cell line development. Additionally, we propose an approach using 25 cm² T-flasks in suspension and shaking culture conditions as a screening tool to identify high producing cell lines. Finally, trastuzumab-expressing CHO-K1 clones were generated and characterized by batch culture, and preliminary results related to HER2-recognition capacity were successful. Further optimization of elements such as gene optimization, vector selection, type of amplification/selection system, cell culture media composition, in combination with this strategy will allow obtaining high producing clones.

用于治疗许多疾病的生物药品或生物制剂的高昂价格限制了患者获得这些新颖疗法的机会。一个例子是单克隆抗体曲妥珠单抗，已成功用于乳腺癌治疗。一种经济的选择是产生与这些昂贵的生物药物类似的生物仿制药。由于抗体疗法可能需要长时间服用大剂量，因此细胞株发育的强大平台和策略对于产生具有较高表达水平的重组细胞株至关重要。在这里，我们通过筛选和选择策略获得了表达曲妥珠单抗的CHO-K1细胞，该策略结合了使用预先适应无蛋白培养基的宿主细胞以及悬浮培养和慢病毒载体的方法。结果表明，早期筛选策略获得了具有更高IgG表达细胞富集的重组CHO-K1细胞群体。此外，通过流式细胞术测量细胞内重链多肽是表征细胞群体同质性的有用指标，我们的结果表明该方法可用于预测细胞系发育早期单克隆抗体的表达水平。此外，我们建议使用25厘米的方法 我们的结果表明，这可用于预测细胞系发育早期单克隆抗体的表达水平。此外，我们建议使用25厘米的方法 我们的结果表明，这可用于预测细胞系发育早期单克隆抗体的表达水平。此外，我们建议使用25厘米的方法悬浮和摇动培养条件下的^2个T瓶，作为鉴定高产细胞系的筛选工具。最后，产生了曲妥珠单抗的CHO-K1克隆并通过分批培养进行了表征，并且成功获得了与HER2识别能力有关的初步结果。结合这种策略，进一步优化元素，例如基因优化，载体选择，扩增/选择系统的类型，细胞培养基组成，都将获得高产量的克隆。