Cell Line Development:
The process of Cell Line Development the cellular machinery to create therapeutic biologics or other proteins of interest is known as cell line development. Cell line development can be done using a variety of expression systems, including bacterial, plant-based, yeast, and mammalian. Chinese hamster ovary (CHO) cells, grown in suspension cultures for ultimate use in bioreactors at the manufacturing stage, are the most widely utilized for the production of the complex protein. In recent years, molecular tools like as zinc finger nucleases (ZFN), transcription activator-like effector nucleases (TALENs), and, most recently, the CRISPR/Cas9 system have enhanced gene editing. When it comes to designing cell lines for optimal biotherapeutic output, these strategies have resulted in significant increases in accuracy and ease-of-use.
Furthermore, the increased creation of biosimilars as a result of the patent expiration of branded therapeutics and recombinant proteins is expected to stimulate demand. During the projection period, rising chronic disease prevalence demands better treatment solutions, increasing demand for biosimilars, vaccines, therapeutic proteins, and new pharmaceuticals. Human cell lines used in vaccine manufacture include the WI-38 cell line created in the United States and the MRC-5 cell line developed in the United Kingdom. Polio, rotavirus, smallpox, and Japanese encephalitis are all treated with vaccines made utilizing animal cells. Hepatitis A, rubella, varicella, zoster, adenovirus type 4 and 7 oral, and rabies vaccinations are among the vaccines manufactured.
Cell line development process:
Transfection is the process of introducing a foreign DNA (encoding the recombinant protein of interest) into a host cell. A small population of cells with the foreign DNA integrated into their genome that maintain their ability to express recombinant protein for long periods of time are referred to as stably transfected cells.
- Antibodies screening/titer ranking – Discovery and selection of high-value clones from a transfected pool of cells. To screen large populations by quantifying cell surface expression of protein-of-interest or secreting antibodies (titer ranking) will increase the probability of finding rare high-affinity binder or high producer.
- Single-cell isolution and cell viability – Single, viable cells must be isolated and cloned in order to ensure that the cell population is genetically identical, significantly reducing the heterogeneity of expression
- Monoclonality assurance – When developing cell lines for biotherapeutics, it is crucial from a quality and regulatory perspective to ensure that the cell line originates from a single progenitor and is therefore monoclonal. Documentation of monoclonality (a regulatory metric for therapeutic cell lines) is typically image-based, whereby an image of a single cell is recorded and included in regulatory filings.
Clone productivity screening and titer – This is a test that detects the amount of recombinant protein or antibodies produced from the clonally-derived cell line.
How are cell lines developed?
Cell line development requires the discovery of single cell-derived clones that produce high and consistent levels of the target therapeutic protein. The first step in the process is the isolation of single, viable cells. Limiting dilution is a technique that relies on statistical probability but is time consuming.
It has been observed that since the year 2006, there has been a rise in the number of recombinant protein therapeutics approved by the FDA. The National Institute of Health has stated that there were more than 15 novels recombinant protein therapeutics approved by the US Food and Drug Administration (FDA) each year. In addition, the expiration of the branded drugs has given rise to the emergence of biosimilars. As a result, there has been a growing demand for cell line development. Most of the biopharmaceutical companies that develop mammalian cell lines are based on either the methotrexate (MTX) amplification technology or the glutamine synthetase (GS) system.
With the utilization of mammalian cell lines, the cell clones obtained are highly heterogeneous and large numbers of cell clones have to be screened to identify rare stable high producer cell clones. To make the screening process easier, there have been several advances done in the mammalian cell line development, which has been making it the more preferred source for cell line development. Therefore, with the advancements being done in mammalian cell lines, the segment is expected to witness healthy growth during the future.
Cell line development plays a major role in therapeutic mAb and novel antibody-based therapies. It has wide application areas including development of immunotherapy for cancer treatment. Lots of pharmaceutical and biotechnological companies are focusing on developing novel therapies such as immunotherapy due to its specificity and efficiency. CLD helps in reducing the timeline of the drug discovery process and optimizing clinical trials with high yielding mAbs, which will lead to further growth of the cell line development market.