Donor selection for xenotransplantation: detection of Galalpha1-3Gal on different porcine organs.

ABSTRACT

The expression of the major porcine xenoantigens (Galalpha1-3Gal) in different tissues varies between species. The selection of suitable donors and the interpretation of studies which attempt to prevent hyperacute rejection are dependent on donor expression of Galalpha1-3Gal. Screening of large number of animals to find potential Galalpha1-3Gal negative donors requires a robust, tissue-based and practical method of assessing Galalpha1-3Gal expression. In this study, we have assessed the expression of Galalpha1-3Gal in a variety of pig organs using anti Galalpha1-3Gal antibody. Biopsies of heart, kidney, ear and tail were obtained from 20 outbred pigs. Biopsies were fixed in formalin and stained with a human anti Galalpha1-3Gal antibody obtained from pooled human AB serum passed down a Galalpha1-3Gal immunoadsorbent column. Tissue from all 4 organs from all 20 pigs expressed Galalpha13Gal. This study shows that detection of Galalpha1-3Gal on an ear or tail biopsy is a simple but very reliable method for assessing Galalpha1-3Gal expression on the heart and kidney and facilitates donor selection for xenotransplantation.