Development of Serum-Free Culture Systems for an Immortalized Porcine Kidney-Derived Macrophage Cell Line

Area of Science:

• Veterinary Virology
• Cell Biology
• Animal Biotechnology

Background:

• Immortalized porcine kidney-derived macrophage (IPKM) cells are crucial for African swine fever virus (ASFV) research.
• Standard cell culture methods often rely on serum-containing media, which can be costly and variable.
• Optimizing IPKM cell culture is vital for consistent ASFV production and study.

Purpose of the Study:

• To develop a serum-free medium for long-term subculture of IPKM cells.
• To identify essential growth factors for IPKM cell proliferation.
• To establish stable suspension culture methods for IPKM cells.

Main Methods:

• Utilized KnockOut serum replacement in a modified medium.
• Supplemented medium with porcine colony stimulating factor 1 (pCSF1) and pCSF2.
• Added polyvinylpyrrolidone K90 to enhance cell adhesion for long-term culture.
• Investigated spinner flask suspension culture without microcarriers.
• Assessed cell viability, chromosomal stability, and macrophage marker expression (CD172a, CD203a, Iba1).

Main Results:

• Successfully established long-term subculture of IPKM cells in a serum-free medium.
• pCSF1 and pCSF2 were identified as essential for IPKM cell proliferation.
• Polyvinylpyrrolidone K90 improved cell adhesion and enabled stable suspension culture.
• IPKM cells maintained normal chromosome numbers and expressed macrophage-specific markers in both adherent and suspension cultures.
• A modified serum- and calcium-free medium supported extended IPKM cell culture.

Conclusions:

• A robust serum-free culture system for IPKM cells was developed, facilitating long-term propagation.
• The findings enable consistent and scalable production of IPKM cells for ASFV research.
• IPKM cells retain their characteristic macrophage properties under the optimized culture conditions.