title: A unique natural human IgG antibody with anti-alpha-galactosyl specificity.
abstract: A new natural anti-alpha-galactosyl IgG antibody (anti-Gal) was found to be present in high titer in the serum of every normal individual studied. The antibody was isolated by affinity chromatography on a melibiose-Sepharose column. The reactivity of the antibody was assessed by its interaction with alpha-galactosyl residues on rabbit erythrocytes (RabRBC). The specificity was determined by inhibition experiments with various carbohydrates. The anti-Gal interacts with alpha-galactosyl residues, possibly on glycolipids of human RBC (HuRBC), after removal of membrane proteins by treatment with pronase. In addition, the anti-Gal bind specifically to normal and pathologically senescent HuRBC, suggesting a physiological role for this natural antibody in the aging of RBC. The ubiquitous presence of anti-Gal in high titers throughout life implies a constant antigenic stimulation. In addition to the theoretical interest in the antibody, the study of the anti-Gal reactivity seems to bear immunodiagnostic significance. Decrease in the antibody titer was found to reflect humoral immunodeficiency disorders.
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging; D000818:Animals; D000918:Antibody Specificity; D001666:Binding Sites, Antibody; D001782:Blood Donors; D002648:Child; D002675:Child, Preschool; D002846:Chromatography, Affinity; D004912:Erythrocytes / Q000378:metabolism / Q000648:ultrastructure; D005690:Galactose / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology / Q000302:isolation & purification / Q000502:physiology*; D007153:Immunologic Deficiency Syndromes / Q000276:immunology; D007223:Infant; D007231:Infant, Newborn; D011817:Rabbits
chemical_list: D007074:Immunoglobulin G; D005690:Galactose