Specificity of xenoreactive anti-Gal alpha 1-3Gal IgM for alpha-galactosyl ligands.
The transplantation of organs from lower animals such as pigs into humans is prevented by a severe rejection reaction initiated by complement fixing xenoreactive natural antibodies. Most anti-pig xenoreactive natural antibodies in humans are thought to recognize Gal alpha 1-3Gal beta 1-4GlcNAc and are also thought to recognize, albeit less avidly, Gal alpha 1-6Glc. Gal alpha 1-6Glc has been used as a ligand for purification of 'anti-Gal alpha 1-3Gal antibodies' and as a therapeutic or reagent to prevent the binding of these antibodies to porcine organs or cells. We tested the specificity of anti-Gal alpha 1-3Gal IgM for Gal alpha 1-6Glc and related saccharides. Based on inhibition of binding of xenoreactive anti-Gal alpha 1-3Gal IgM to porcine cells by soluble saccharides, anti-Gal alpha 1-3Gal IgM in a human serum was found to consist of a mixture of antibodies which have a similar affinity for Gal alpha 1-3Gal but varying affinities for Gal alpha 1-6Glc and other structures. Twenty to 40% of the anti-Gal alpha 1-3Gal IgM from the population tested did not recognize Gal alpha 1-6Glc. The binding of anti-Gal alpha 1-3Gal IgM to Gal alpha 1-6Glc varied widely from individual to individual, some samples lacking almost entirely anti-Gal alpha 1-3Gal IgM which bound to Gal alpha 1-6Glc.
Parker
W
W
Department of Surgery, Duke University Medical Center, Durham, NC 27710, USA.
Lateef
J
J
Everett
M L
ML
Platt
J L
JL
D000818:Animals; D000910:Antibodies, Heterophile / Q000276:immunology*; D000918:Antibody Specificity; D001011:Aorta / Q000166:cytology; D002240:Carbohydrate Sequence; D002478:Cells, Cultured; D004187:Disaccharides / Q000276:immunology*; D004730:Endothelium, Vascular / Q000276:immunology; D005697:Galactosides / Q000276:immunology*; D006801:Humans; D007075:Immunoglobulin M / Q000276:immunology*; D037102:Lectins / Q000378:metabolism; D008024:Ligands; D008969:Molecular Sequence Data; D013552:Swine
D000910:Antibodies, Heterophile; D004187:Disaccharides; D005697:Galactosides; D007075:Immunoglobulin M; D037102:Lectins; D008024:Ligands; C055075:galactosyl-(1-3)galactose