Review: phenotyping for Lewis and secretor histo-blood group antigens

Emergent variant modeling of the serological repertoire to norovirus in young children

“… 56 Although the secretor status of these children is unknown, ∼20% of northern European populations do not have a functional FUT 2 gene and would likely be resistant to GII.4 infection. 57 In addition to genetic susceptibility, antibody titers waning to below the limit of detection or targeting other GII.4 variants not detected by surveillance as well as lack of exposure to norovirus in some children are likely to account for a percentage of the non-responders. To minimize the confounding influence of genetic resistance on the study outcomes, only sera with an nAb titer above the limit of detection to at least one GII.4 variant were included in further analyses.…”

Human microbiota, blood group antigens, and disease

“…Sialylation or sulfuration occurs when N-acetylneuraminic (sialic) acid is attached in α2-3 linkage to a β-D-galactose residue of an existing chain (Daniels, 2013). Fucosyltransferase enzymes expressed by Le genes (FUT3) synthesize and release Lewis antigens from exocrine epithelial cells; those with Le/Le or Le/le alleles express Lewis antigens, while those with le/le do not (Ewald & Sumner, 2016;Henry, 1996;Henry, Oriol, & Samuelsson, 1995). These antigens can be glycolipids or glycoproteins, found as membrane-bound antigens on the surface of cells and tissues or as oligosaccharides that freely circulate in blood and body fluids, and can be taken up by RBCs, platelets, and lymphocytes (Ewald & Sumner, 2016;Henry, 1996;Henry et al, 1995).…”

“…The fucosyltransferase enzymes expressed by Se genes (FUT2) primarily interact with Type 1 precursor chains; about 80% of Caucasians are "secretors" with Se/Se or Se/se alleles, while those known as "nonsecretors" have two nonfunctional copies (se/se) and the ABO antigens are not found in their saliva or other body fluids (Ewald & Sumner, 2016;Henry, 1996;Henry et al, 1995). By adulthood, the distal colon and rectum only express Le a and Le x antigens, regardless of secretor status, but the cells and secretions of the esophagus, stomach, and small intestine continue to strongly express the same HBGAs found in the fetal GI tract, with levels of HBGAs 10 to 12 times higher in the GI tract of secretors than in nonsecretors (Lloyd, 1987).…”