Development of a stable antibody production system utilizing an Hspa5 promoter in CHO cells.

Chinese hamster ovary (CHO) cells are widely used for manufacturing antibody drugs. We attempted to clone a novel high-expression promoter for producing monoclonal antibodies (mAbs) based on transcriptome analysis to enhance the transcriptional abundance of mAb genes. The efficacy of conventional promoters such as CMV and hEF1α decrease in the latter phase of fed-batch cell culture. To overcome this, we screened genes whose expression was maintained or increased throughout the culture period. Since CHO cells have diverse genetic expression depending on the selected clone and culture medium, transcriptome analysis was performed on multiple clones and culture media anticipated to be used in mAb manufacturing. We thus acquired the Hspa5 promoter as a novel high-expression promoter, which uniquely enables mAb productivity per cell to improve late in the culture period. Productivity also improved for various IgG subclasses under Hspa5 promoter control, indicating this promoter's potential universal value for mAb production. Finally, it was suggested that mAb production with this promoter is correlated with the transcription levels of endoplasmic reticulum stress-related genes. Therefore, mAb production utilizing the Hspa5 promoter might be a new method for maintaining protein homeostasis and achieving stable expression of introduced mAb genes during fed-batch culture.

Treatment of Secondary Immune Thrombocytopenia with Non-Hodgkin Lymphoma: A Case Report and Literature Review.

Secondary immune thrombocytopenic purpura (ITP) with non-Hodgkin lymphoma (NHL) is a rare disease. Although some treatment regimens are available for primary ITP, the treatment strategy for secondary ITP remains unconfirmed. We herein report a 79-year-old man who was diagnosed with secondary ITP with mantle cell lymphoma. Although intravenous immunoglobulin (IVIG) has been considered an effective option for secondary ITP, similar to the treatment of primary ITP, our patient did not benefit from IVIG. A literature review including the current report revealed that IVIG was ineffective in all treated patients. Secondary ITP with NHL should be treated differently from primary ITP.

Sodium phenoxide-phosphine oxides as extremely active Lewis base catalysts for the Mukaiyama aldol reaction with ketones.

A highly efficient Mukaiyama aldol reaction between ketones and trimethylsilyl enolates catalyzed by sodium phenoxide-phosphine oxides as simple homogeneous Lewis base catalysts (0.5-10 mol %) was developed, which minimized competing retro-aldol reaction. For a variety of aromatic ketones and aldimines, aldol and Mannich-type products with an alpha-quaternary carbon center were obtained in good to excellent yields. Up to 100 mmol scale of benzophenone and trimethylsilyl enolate with 0.5 mol % of catalyst was established in 97% yield (34.8 g).