Name: Host Cell Proteins (HCPs) Enrichment in Monoclonal Antibody (mAb) Drug Product
Uploaded: 2024-01-19T12:50:00
Description: Watch this Scientific Journal Video about Host Cell Proteins HCPs Enrichment in Monoclonal Antibody mAb Drug Product at JoVE.com

host cell proteins (hcps) enrichment in monoclonal antibody (mab) drug product

Enrichment of Host Cell Proteins in Monoclonal Antibody Drug Products

Host cell proteins (HCPs) are impurities that are released from the cell culture of the host organism and co-purified with monoclonal antibody (mAb)1,2,3,4. Trace levels of HCPs can negatively impact the quality of the drug product5,6,7,8,9,10,11,12,13,14,15, and therefore, a sensitive HCP analysis method is desired to detect HCPs in sub-ppm to ppm levels.
Orthogonal methods can be applied to detect HCPs in low abundance. Enzyme-linked immunosorbent assay (ELISA) is generally used to quantitate overall HCPs, and it can also detect and quantitate individual HCPs if the corresponding antibodies are available16. However, the production of HCP-specific antibodies is time-consuming and labor-intensive. In contrast, liquid chromatography coupled with mass spectrometry (LC-MS) can provide comprehensive information about individual HCPs in mAb drug products and is widely applied for HCP identification4,7,9,10,12,13,14,15,17,18,19,20,21,22,23,24,25,26,27.
Several methods have been developed to detect HCPs with LC-MS/MS, including limited digestion20, filtration17, Protein A deletion21, immunoprecipitation (IP), and ProteoMiner enrichment (PM)18. Most methods aim to reduce the amount of mAb and enrich HCPs prior to LC-MS/MS analysis, thereby decreasing the dynamic range between mAb peptides and HCP peptides. This protocol presents a proteomic sample enrichment method that combines ProteoMiner technology and limited digestion (PMLD)28. The ProteoMiner enrichment principle involves using commercially available proteome enrichment beads containing a diverse library of combinatorial peptide ligands. These ligands specifically bind to proteins on antibody-drug products, allowing for the removal of excess molecules while concentrating low-abundance host cell proteins (HCPs) on their respective affinity ligands. On the other hand, the principle of limited digestion involves using a low concentration of trypsin. This concentration is sufficient to digest low-abundance HCPs but not enough to digest all antibody drug products. This approach enables the recovery and enrichment of digested HCP peptides from the solution.
Compared to filtration methods, the PMLD technique is not limited by the size of the detected HCPs17. Protein A deletion methods are specific to detecting HCPs associated with antibodies21, while immunoprecipitation is restricted to predefined HCPs from a particular cell line (such as the Chinese Hamster Ovary (CHO) cell line), where an anti-HCP antibody was generated4. In contrast, PMLD can be applied to detect HCPs from any drug modules and host cell proteins co-purified with drug products from various cell lines. Additionally, PMLD exhibits better sensitivity compared to the mentioned methods17,18,20,21,24.
This approach can enrich the HCP concentration by 7000-fold and lower the detection limit to 0.002 ppm28. The experimental setup is illustrated in Figure 1.

Author Spotlight: Detecting Low-Abundant Host Cell Proteins in Drug Products Using Enrichment Beads and Limited Digestion 

Host Cell Protein Analysis using Enrichment Beads Coupled with Limited Digestion

We have developed a highly sensitive method to detect those low-abundant host cell protein from the drug product using the proteome enrichment beads. This approach help us to find the root cause and the risk associated with the drug product. There are multiple ways to improve the detection limit of HCP analysis, the untargeted method including but not limited to protein A depletion, the limited digestion, the molecular weight cutoff, the immunoprecipitation.The targeted way to detect the host cell protein, including liquid chromatography, multiple reaction monitoring, and the non-liquid chromatography parallel reaction monitoring. The major challenge associate with these HCP analysis is the significant dynamic range between antibody drug and host cell proteins. So most method aim to reduce the amount of antibody and the enrich HCP before LCMS analysis to decrease the dynamic range between antibody peptides and HCP peptides.So ProteoMiner technology and the limited digestion protocol significantly improve the detection limit of HCP analysis compared to other methods. It's non-biased compared to immunoprecipitation and can be applied to different drug module compared to protein A depletion method. This protocol is also simple and straightforward.So ProteoMiner technology and limited digestion protocol help us to identify several HCPs that degrade polysorbate and the fragment antibody drug. In combination with the nano LCMPRM method, the enrichment method can also provide quantitative results to find the biological relevant concentration of problematic host cell proteins.

Watch this Scientific Journal Video about Host Cell Proteins HCPs Enrichment in Monoclonal Antibody mAb Drug Product at JoVE.com