What is the best cell type for producing proteins for medical use?

• A. Bacterial cells
• B. Insect cells
• C. Fungal cells
• D. Mammalian cells

Answer: (D)

Mammalian cells are often considered the best cell type for producing proteins for medical use due to their ability to carry out post-translational modifications that are essential for the functionality of many therapeutic proteins. These modifications include glycosylation, phosphorylation, and proper folding, which are critical for the protein's stability, activity, and overall effectiveness when administered to humans.

Mammalian systems, such as CHO (Chinese Hamster Ovary) cells, are widely utilized in the production of biologics, including monoclonal antibodies and recombinant proteins. The proteins produced in mammalian cells more closely resemble those produced in the human body, ensuring that they are more likely to be accepted and function appropriately during therapeutic use.

Other cell types, such as bacterial, insect, and fungal cells, can be used for protein production as well; however, they often lack the complex machinery required for the same level of post-translational modifications found in mammalian cells. While bacterial cells are simpler and can quickly produce large quantities of proteins, they usually do not perform glycosylation, which is crucial for many therapeutic proteins. Insect cells can perform some modifications but may not be as effective or consistent as mammalian cells. Fungal cells, while useful for