Prolonged Skin Graft Survival and Histocompatibility in Highly Inbred Miniature Swine

Area of Science:

• Xenotransplantation research
• Immunology
• Genetics

Background:

• Pigs are potential organ donors for humans.
• Xenotransplantation requires genetically identical cells from different animals.
• A highly inbred line of miniature swine was developed for xenotransplantation.

Purpose of the Study:

• To test histocompatibility in a new subline of highly inbred miniature swine.
• To assess the potential for xenotransplantation using genetically identical swine cells.

Main Methods:

• Two generations of pigs with coefficients of inbreeding (COI) of 92% and 94% received split-thickness skin grafts (STSGs).
• Pigs received autografts and allografts from the same generation.
• Skin graft survival was monitored for up to 386 days.

Main Results:

• Pigs with 92% COI showed prolonged STSG survival but eventual rejection due to minor histocompatibility antigens.
• Most pigs with 94% COI accepted reciprocal skin grafts long-term (>386 days) without immunosuppression.
• This indicates homozygosity for histocompatibility loci in the 94% COI group.

Conclusions:

• The new highly inbred swine line (94% COI) shows promise for xenotransplantation.
• Long-term acceptance of skin grafts suggests potential for indefinite organ transplant acceptance without immunosuppression.
• This facilitates research requiring genetically identical cells from different animals.