Major carbohydrate epitopes in tissues of domestic and African wild animals of potential interest for xenotransplantation research

Abstract

We investigated the main glycotopes expressed on the tissues of 44 animal species, including primates, nonprimate mammals, marsupials, birds, and a reptile. Paraffin-embedded tissue sections of kidney, heart, liver, pancreas, lung, brain and intestine of 24 domestic animal species were stained with seven fluorescent-labeled lectins. Testis sections of 20 African wild animal species were tested with the same lectins. Overall, three main immunofluorescence patterns were found in the vascular compartment. First, humans and Old World monkeys express genetically polymorphic ABH antigens and do not express alphaGal. Second, New World monkeys, other mammals, and marsupials do not express ABH antigens, but have large amounts of a genetically monomorphic alphaGal. Third, birds and reptiles do not express either ABH or alphaGal, but have monomorphic betaGal, probably different from the lactosamine precursor of ABH and alphaGal. Epithelial cells producing exocrine secretions also expressed carbohydrate epitopes. The fluorescence patterns of the cells of the exocrine compartment are similar, but not identical, to those expressed in the vascular compartment. All the animals tested have some ABH and betaGal in exocrine tissues, but New World monkeys and lower mammals are the only ones expressing alphaGal in exocrine tissues.

An integrative evolution theory of histo-blood group ABO and related genes

“…Additionally, species-specific O alleles, which possibly resulted from independent silencing mutations, are known to exist in non-human primates404142. In non-primate animal species unigenic AO polymorphism has been reported of pig, dog, rat, cow, and rabbit43. The molecular mechanism of the porcine AO polymorphism was previously elucidated4445.…”

“…This is an interesting hypothesis because it may easily explain the absence of separate evolution of A and B genes. However, it seems to be less likely because all the other species than primates, which are known to have unigenic polymorphism, exhibit AO, and not AB, polymorphism43.…”

Expression of ABO or related antigenic carbohydrates on viral envelopes leads to neutralization in the presence of serum containing specific natural antibodies and complement

“…In contrast to erythrocytes, one tissue that appears to have a largely conserved expression of ABO and Gal␣1-3Gal antigens in a number of species examined is epithelial structures, in particular exocrine epithelia. 39,40 This is interesting and intriguing since such tissues are involved in the spread of many viruses from one individual to another.…”

Evolution of the human ABO polymorphism by two complementary selective pressures

“…These surfaces are coated with a layer of highly glycosylated proteins. The terminal saccharide profile of such proteins is, in part, determined by histo-blood group glycosyltransferases encoded by several different loci, including the wellknown ABO/H, Se, Lewis and Galα1,3Gal structures (Henry et al 1995;Oriol et al 1999;Ravn & Dabelsteen 2000;Henry 2001). These genetic systems are all polymorphic across a range of mammalian species; for example, ABO/H in humans, primates, pigs, dogs and rabbits (Zweibaum & Bouhou 1973;Zweibaum et al 1974;Mourant et al 1976;Balanzino et al 1994;Blancher & Socha 1997).…”