Trans-species "A-like" and human blood group A-phenotype-specific GalNAc-glycosylations as they relate to the formation of natural anti-A isoagglutinin and cross-reactive anti-Tn

Peter Arend
2016 Figshare  
%0A%0AThe%0Amultiple trans-species, genetically as-yet-undefined functions of "A-like" O-GalNAc-Ser/Thr%0Aglycosylations1-3, which dominate the early carbohydrate metabolism%0Aof vertebrates, are different from the species-intrinsic and human%0Aphenotype-determining A-allelic enzyme proteins and/or functions being%0Aexpressed only after formation of the zygote. The volatilely expressed "A-like"%0AO-GalNAc glycans are structurally related to and likely imply metabolic%0Arelationships with the
more » ... onships with the mucin-type monosaccharide GalNAcα1-O-Ser/Thr,%0Aalso referred to as the Tn antigen, whose accumulation in non-developmental%0Atissues is a marker of malignancy, and which is thus called an "aberrant"%0Aglycosylated molecule. Historically, the "A-like" Tn antigen or "T nouvelle"%0Awas named upon its discovery reported in 19574 to emphasize its distinction%0Afrom the functionally similar T (Thomsen-Friedenreich) antigen, reported in%0A19305. Early O-glycan expressions, which may be observed during germ cell%0Adevelopment6-8 and embryonic stem cell%0Adifferentiations, are characterized by extremely short half-lives9,10, and their enzyme%0Adepletions most likely cause the release of characteristic O-glycan-depleted,%0Acomplementary proteins, such as secretory IgM that is not restricted to B cells%0Abut also arises from epithelial cells11,12, and might reveal the%0Astructure of the volatilely expressed, "lost" O-glycans through%0Agermline-specific serine/theonine residues. This non-immune anti A-reactive IgM%0Ais disctinct from the innate anti-B; it has not undergone clonal selection and must%0Abe differentiated from innumerable, adaptive anti-A/B cross-specificities. Indeed,%0Athe cryptic "A-like" and/or aberrant structures may be detected by "natural"%0Aanti A and/or anti-T antibodies that are among the anti-glycan moieties p [...]
doi:10.6084/m9.figshare.4068177.v14 fatcat:imr3wi7yh5avdiksw3cabjob4q