High level expression of functional human IgMs in human PER.C6 cells

Area of Science:

• Biotechnology
• Immunology
• Oncology

Background:

• Natural IgM antibodies are vital for immune defense against cancer.
• Recombinant IgM production is challenging due to size, glycosylation, and potential immunogenicity.
• Existing production methods are insufficient for clinical applications.

Purpose of the Study:

• To establish a human cell-based system for efficient recombinant IgM antibody production.
• To overcome challenges associated with recombinant IgM expression and glycosylation.
• To demonstrate the therapeutic potential of human recombinant IgM.

Main Methods:

• Utilized PER.C6 human cell line for suspension culture in protein-free medium.
• Generated stable cell lines for monoclonal IgM expression, including J chain incorporation.
• Employed fed-batch production strategies to optimize yield.

Main Results:

• Successfully produced three distinct human recombinant monoclonal IgMs, including pentameric and hexameric forms.
• Achieved high cell-specific productivities (>20 pg/cell/day) and yields (0.5–2 g/L).
• Confirmed biological activity of expressed IgMs through binding and cytotoxicity assays.

Conclusions:

• PER.C6 cells provide an effective platform for high-level production of functional recombinant IgM antibodies.
• This system addresses the need for human-derived recombinant IgMs for cancer therapy and diagnostics.
• Demonstrated potential for producing other complex polymeric molecules using this method.