Relationship between the secretor status and the expression of ABH blood group antigenic determinants in human intestinal brush-border membrane hydrolases

At least six hydrolases of the human intestinal brush-border membrane bear ABH blood group antigenic determinants related to the erythrocyte phenotype: the intestinal glycoproteins of blood group A and B subjects express A or B determinants, respectively, while blood group O subjects express the H determinant identified with Ulex europaeus lectin I. These expressions are under the control of the secretor gene: ABH antigens were not detected in the hydrolases of non-secretor subjects.     

Blood group A glycosphingolipid accumulation in the hair of patients with alpha-N-acetylgalactosaminidase deficiency

In the hair of individuals with blood group AB, the level of blood group A glycosphingolipids is much lower than that of blood group B. We hypothesized that in hair, blood group A determinants are converted by alpha-N-acetylgalactosaminidase (alpha-NAGA, E.C.3.2.1.49) to H determinants. To address our hypothesis, the relative amount of ABH glycosphingolipids in hairs and nails of normal subjects, patients with Kanzaki disease, and heterozygous carriers of alpha-NAGA deficiency were analyzed by dot-blotting and enzyme-linked immunosorbent assay. In hair from normal subjects with blood group B, ABH glycosphingolipids consisted of 88% blood group B- and 12% blood group H glycosphingolipids. In blood group A subjects, 14% were group A- and 86% were group H glycosphingolipids. In Kanzaki patients, 81% were blood group A- and 19% were blood group H glycosphingolipids. In 2 alpha-NAGA deficiency carriers, the ABH glycosphingolipids consisted of 67% blood group A- and 33% blood group H glycosphingolipids. These results indicate that blood group A glycosphingolipids are catabolized to H glycosphingolipids by alpha-NAGA, resulting in lower levels of blood group A glycosphingolipids in the hair of normal subjects, and alpha-NAGA deficiency causes accumulation of blood group A glycosphingolipids in the hair of Kanzaki patients. This finding is of clinical relevance because it suggests that hair may be used to diagnose and assess the alpha-NAGA status of individuals.     

Interaction of cholera toxin and Escherichia coli heat-labile enterotoxin with glycoconjugates from rabbit intestinal brush border membranes: Relationship with ABH blood group determinants

The capacity of cholera toxin (CT) and type I heat-labile enterotoxin produced by Escherichia coli isolated from human intestine (LTh) to interact with glycoconjugates bearing ABH blood group determinants from rabbit intestinal brush border membranes (BBM) was studied. On the basis of the type of intestinal compounds related to the human ABH blood group antigens, rabbits were classified as AB or H. Toxin binding to the intestinal glycolipids and glycoproteins depends on the blood group determinant borne by the glycoconjugate and on the analyzed toxin. LTh was capable of interacting preferentially with several blood group A- and B-active BBM glycolipids compared to those isolated from animals lacking these antigens (H rabbits). Also, LTh preferably bound to several BBM glycoproteins from AB rabbit intestines compared to those from H ones. One of these glycoproteins, the sucrase-isomaltase complex (EC 3.2.1.48-10) isolated from AB and H rabbits showed the same differential LTh binding. Conversely, CT practically did not recognize either blood group A-, B-, or H-active glycolipids and glycoproteins. These results may be relevant for carrying out in vivo experiments in rabbits in order to disclose the role of ABH active-glycoconjugates in the secretory response induced by LTh in rabbit intestine.     

Histochemical reactivity of the Geodia cydonium agglutinin (GCA) in human tissues

We applied a peroxidase-antiperoxidase technique to study the distribution pattern and binding characteristics of the lectin from the marine sponge Geodia cydonium (Geodia cydonium agglutinin; GCA) in various human tissues. This lectin has been shown to possess a broad reactivity, but there was a distinct distribution of binding sites within the different organs. In the histochemical system GCA displayed no blood group specificity and labeled red blood cells, the vascular endothelium, and epithelial cells showing blood group antigen expression independent of the ABH blood group status. However, inhibition of GCA reactivity by simple sugars and complex carbohydrates demonstrated tissue-specific differences of lectin binding related to the ABH blood group status of the tissue and revealed information on the structural requirements of the histological lectin binding site. Tissues that totally lacked blood group antigens or that expressed only the H-antigen disclosed a GCA reactivity which was completely inhibited by lactose. In contrast, tissues that expressed blood group A- or blood group B-antigen exhibited a lactose-resistant lectin binding which was inhibited only by water-soluble blood group substance A from peptone A and by bovine glycophorin but not by other complex carbohydrates, including human glycophorin and human asialoglycophorin. Competitive inhibition studies in situ revealed that GCA binding was not inhibited by blood group type I/II carbohydrate sequence-specific lectins or by lectins with other sugar specificities. Inhibition by lactose of GCA binding to some histological sites indicates that the binding site consists of a beta-linked galactose-containing disaccharide. However, periodate oxidation of tissue sections had no effect on lectin binding, pointing to a subterminal location of the relevant sequence. The results obtained from inhibition studies with simple saccharides and complex carbohydrates in relation to the expression of ABH blood group antigens suggest a complex lectin combining site(s) in histological specimens. The lectin may possess either one binding site with a range of affinities for different carbohydrates (besides beta-linked disaccharides the GCA binding site accommodates to carbohydrate determinants carrying the blood group A or blood group B determinant), or may possess two different binding sites. Besides an acceptor site for beta-linked disaccharides, an additional binding site may exist accommodating to extended carbohydrate sequences related to A or B blood group structures. In conclusion, GCA represents a blood group-nonspecific lectin whose binding affinities are determined by the ABH blood group status of the tissue.     

Secretor genotype (FUT2 gene) is strongly associated with the composition of Bifidobacteria in the human intestine

Intestinal microbiota plays an important role in human health, and its composition is determined by several factors, such as diet and host genotype. However, thus far it has remained unknown which host genes are determinants for the microbiota composition. We studied the diversity and abundance of dominant bacteria and bifidobacteria from the faecal samples of 71 healthy individuals. In this cohort, 14 were non-secretor individuals and the remainders were secretors. The secretor status is defined by the expression of the ABH and Lewis histo-blood group antigens in the intestinal mucus and other secretions. It is determined by fucosyltransferase 2 enzyme, encoded by the FUT2 gene. Non-functional enzyme resulting from a nonsense mutation in the FUT2 gene leads to the non-secretor phenotype. PCR-DGGE and qPCR methods were applied for the intestinal microbiota analysis. Principal component analysis of bifidobacterial DGGE profiles showed that the samples of non-secretor individuals formed a separate cluster within the secretor samples. Moreover, bifidobacterial diversity (p<0.0001), richness (p<0.0003), and abundance (p<0.05) were significantly reduced in the samples from the non-secretor individuals as compared with those from the secretor individuals. The non-secretor individuals lacked, or were rarely colonized by, several genotypes related to B. bifidum, B. adolescentis and B. catenulatum/pseudocatenulatum. In contrast to bifidobacteria, several bacterial genotypes were more common and the richness (p<0.04) of dominant bacteria as detected by PCR-DGGE was higher in the non-secretor individuals than in the secretor individuals. We showed that the diversity and composition of the human bifidobacterial population is strongly associated with the histo-blood group ABH secretor/non-secretor status, which consequently appears to be one of the host genetic determinants for the composition of the intestinal microbiota. This association can be explained by the difference between the secretor and non-secretor individuals in their expression of ABH and Lewis glycan epitopes in the mucosa.     

ABH blood group antigens in O-glycans of human glycophorin A

The major O-linked oligosaccharide structures attached to human glycophorin A (GPA) have been extensively characterized previously. Our own recent findings, obtained by immunochemical methods, suggested the presence of blood group A and B determinants in O-glycans of human glycophorin originating from blood group A or B erythrocytes, respectively. Here, we elucidate the structure of O-glycans, isolated from GPA of blood group A, B, and O individuals by reductive beta-elimination, carrying A, B or H blood group epitopes, respectively. Structural studies based on nanoflow electrospray-ionization tandem mass spectrometry and earlier reported data on the carbohydrate moiety of GPA and ABH antigens allowed us to conclude that these blood group epitopes are elongations of the beta-GlcNAc branch attached to C-6 of the reducing GalNAc. The galactose linked to C-3 of the reducing GalNAc carries NeuAcalpha2-3 linked residue. Identified here O-glycans were found in low amounts, their content estimated at about one percent of all GPA O-glycans. These O-glycans with type-2 core, carrying the blood group A, B or H determinants, have not been identified in GPA so far. Our results demonstrate the efficacy of nanoESI MS/MS in detecting minor oligosaccharide components present in a mixture with much more abundant structures.     

Lewis phenotypes and secretor character in the "Castilla la Nueva"-region (Spain). ABH and Lewis antigen levels in salivary secretion

In 1980 blood and saliva samples were taken from Spanish students of the University of Madrid. Red cells were analysed for A1B2BO and Lewis blood groups. Saliva samples were tested to detect the specific group substances ABH, Lea and Leb. A slightly higher frequency of the "le" gene (0.419) was found in our sample as compared to other Spanish samples. The phenotype frequencies of ABH secretors (77.2%) and non-secretors (22.8%) are in the range of other European populations. The levels of A and B antigens of individuals belonging to these blood groups were similar, whereas the average titration of the H substance showed the relation O greater than A2 greater than A1 greater than A1B greater than B. Analysis of variance proved this heterogeneity to be statistically significant. The amount of Lea substance in non-secretors was higher than in secretors. This shows again that the ABH secretor status has some influence on the quantity of this antigen. The average titration of the Leb substance in secretors was higher than that of Lea in individuals belonging to O, A and AB blood groups, but not in those with blood group B.     

Relationship between lectin binding properties and the expression of blood group ABH antigens in vascular endothelia and red blood cells from 18 primate species

Summary The reactivity was examined of horseradish peroxidase labelledUlex europaeus agglutinin-I (UEA-I) andGriffonia simplicifolia agglutinin I-B₄ (GSAI-B₄) with red blood cells and vascular endothelium in formalin-fixed, paraffin embedded tissues from 18 primate species. The expression of blood group ABH antigens in these cells as well as secretions from other tissues was also examined by the indirect immunoperoxidase method using monoclonal anti-ABH antibodies as primary antibodies. In Prosimians and New World monkeys which lack ABH antigens on both red blood cells and endothelial cells, but produce these antigens in other tissue secretions, GSAI-B₄ always reacted with both red blood cells and endothelial cells. In Old World monkeys, which express blood group antigens on endothelial cells but not on red blood cells, neither GSAI-B₄ nor UEA-I reactivity were observed, except the endothelial cells from blood group B or O individuals occasionally reacted with GSAI-B₄ or UEA-I, respectively. Although UEA-I reactivity was not observed in the endothelial cells of gibbon, it reacted with these cells from chimpanzees. In these two anthropoid apes, both endothelial cells and red blood cells expressed ABH antigens as in humans. These results suggest the close evolutionary relationship between the expression of blood group ABH antigens and lectin binding properties of red blood cells and endothelial cells in primate species.     

Murine monoclonal antibodies directed to the human histo-blood group A transferase (UDP-GalNAc:Fuc alpha 1----2Gal alpha 1----3-N-acetylgalactosaminyltransferase) and the presence therein of N-linked histo-blood group A determinant

Mouse MAbs (WKH-1 through -3) to the human histo-blood group A glycosyltransferase (Fuc alpha 1----2Gal alpha 1----3 galactosaminyltransferase) were established by immunization with the purified native A transferase protein. Hybridomas were selected on the basis of solid-phase reactivity with the purified native A transferase, cell immunofluorescence and immunoprecipitation of transferase activity, and absence of reactivity with blood group ABH carbohydrate determinants. Three MAbs, thus selected, were found most likely to react with the protein epitopes unrelated to carbohydrate epitopes of purified A transferase. The MAbs reacted with cells having high A transferase activity and immunoprecipitated the A transferase activity as well as the 40,000 MW iodinated transferase protein. The antibodies were shown, however, to immunoprecipitate and partially inhibit not only A1 and A2 but also B transferase activity from plasma and A transferase from human lung, and to react with B cells expressing B transferase, thus indicating a cross-reactivity with B transferase. In contrast, they showed no reactivity with various cells having the O phenotype and did not immunoprecipitate the A transferase from porcine submaxillary glands or the alpha 1----2fucosyltransferase from Colo205 cells. The purified A glycosyltransferase was found to carry blood group A carbohydrate determinants by immunochemical detection with a panel of anti-carbohydrate MAbs. These determinants are believed to be N-linked, since treatment of the purified A transferase with N-glycanase removed activity. Immunohistological studies of three epithelial tissues showed that the antibodies stained the Golgi area of cells in epithelia from A and B, but not O, individuals.     

Identification of blood group A/A‐Leb/y and B/B‐Leb/y active glycotopes co‐expressed on the O‐glycans isolated from two distinct human ovarian cyst fluids

Although the individual human blood group A and B determinants are well defined, their co‐expression pattern on a particular glycan carrier in individuals of blood group AB status has not been delineated. To address this issue, complex O‐glycans were isolated from two distinct sources of human ovarian cyst glycoproteins (HOC 89 and Cyst 19) and profiled by advanced MS analyses, in conjunction with defining their binding characteristics against a panel of lectins and monoclonal antibodies. The major O‐glycans of HOC 89 were found to correspond to sialyl Tn, mono‐ and di‐sialyl T structures, whereas those of Cyst 19 were apparently more heterogeneous and extended to larger sizes. A minimal structure that carries both A and B determinants on the same molecule was identified, in which the A epitope is attached directly to the core GalNAc, whereas the B epitope is preferentially located on the six arms of a core 2 structure. Both arms can be further extended with internal fucosylation that appears to be restricted to those non‐sialylated chains already carrying the terminal ABH determinants, thus giving rise to rather prominent A/B‐Le^b/y glycotopes on larger O‐glycans.     

The sugar chain structures of ABO blood group active glycoproteins obtained from human erythrocyte membrane

The glycoproteins of human erythrocyte membrane have two groups of sugar chains with blood type ABH determinants, which are quite distinct in their molecular sizes. A neutral sugar chain and an acidic sugar chain, which belong to the small size group, were isolated from the glycoproteins obtained from the erythrocyte of blood type O individuals, and their structures were elucidated as Fucalpha1 leads to 2Galbeta1 leads to 3N-acetylgalactosaminitol and Fucalpha1 leads to 2Galbeta1 leads to 3(AcNeualpha2 leads to 6)N-acetylgalactosaminitol, respectively. The molecular weight of the large sugar chains with ABH determinants were estimated to be more than 4000. Both large and small neutral sugar chains of membrane glycoproteins obtained from blood type O erythrocyte could serve as acceptors of alpha-N-acetylgalactosaminyltransferases purified from milk of blood type A1 and A2 individuals, producing the same radioactive sugar chain distribution patterns. However, the acidic sugar chain with the H determinant could not serve as an acceptor of these enzymes.     

ABO blood groups in the primate species of Cebidae from the Amazon region

The ABO blood groups were determined in blood and saliva collected from 40 Aotus infulatus, 74 Saimiri sciureus, and 96 Cebus apella from the Amazonian region along the Tocantins river. Saliva samples were tested for human ABH antigens by a standard hemagglutination inhibition test. Aotus infulatus showed monomorphism, exhibiting only the B blood group. Saimiri sciureus exhibited the A (67) and AB (7) phenotypes. All four phenotypes have been found in C. apella: O (8), A (52), B (19) and AB (17). The observed distribution was as expected assuming Hardy-Weinberg equilibrium. The titers of ABH substances varied among the species and phenotypes. The B-like agglutinogen, common to all New World monkey species tested, was detected in the red blood cells. Sera were used to detect naturally occurring antibodies and the results showed discrepancies between serum and saliva phenotypes in all species studied.     

Intestinal-type glycosphingolipids in urine from patients with enterocutaneous urinary diversions

Ureteroenterocutaneous stoma is a surgical procedure for urinary diversion by which an intestinal segment is used as a conduit or reservoir for the urine. The intestinal mucosa continues to produce a mucous gel containing desquamated epithelial cells. This mucous gel is easily obtainable from the urine. Glycosphingolipids were isolated from such gels and analyzed with immunological methods using a thin-layer chromatography overlay assay and mass spectrometry. The glycosphingolipids obtained mainly belong to the lacto-type I series comprising ABH, Lea, and Leb determinants. These observations support the intestinal origin of the glycosphingolipids. A regional distribution of the ABH and Lewis antigens, which is in accordance with previous immunohistochemical findings, was observed.     

Subcellular localization of blood group substances ABH in human salivary glands

We investigated the subcellular localization of ABH antigens in human submandibular, sublingual, and buccal glands by applying a post-embedding immunogold method using monoclonal antibodies specific for A, B, and H antigens. In most glands the immunoreactivity was usually restricted to mucous cells, in which only secretory granules and sometimes Golgi cisternae were specifically labeled. A and B antigens were demonstrated only in the glands of type A, B, and AB subjects, while H antigen was visualized in glands from individuals of all blood types. Moreover, differences were observed in the relative distribution of ABH antigens, depending on the type of gland.     

Blood group antigen expression is involved in <Emphasis Type="Italic">C. albicans</Emphasis> interaction with buccal epithelial cells

Human blood group polymorphisms are known to be determined by the expression of A, B or H antigens and the Lewis antigens. Protection against microbial infections has been associated with inheritance of polymorphisms in genes encoding and regulating the expression of ABH and Lewis antigens in bodily secretions and epithelial tissue surfaces, subsequently resulting in the presentation of different glycosylated terminal antigens on the cell surface. We investigated the role of blood group antigens in diversifying the glycosylation of buccal epithelial cells (BEC) that line the oral cavity. Specifically, we characterized and statistically evaluated the expression of histo-blood group (A, B, O) antigens on N-and O-linked glycans from BEC membrane proteins of various individuals that represented different blood group type and secretor status using a porous graphitic carbon liquid chromatography electrospray ionization mass spectrometry (PGC-LC-ESI-MS) based glycomics approach. From these BEC membrane proteins a total of 77 N-glycan and 96 O-glycan structures were structurally characterized from 19 individuals and relatively quantitated. The N-glycans from the secretor individuals did not express any A/B blood group determinants, but contained several terminal H-antigens. Apart from the non-secretors, the N-glycan profiles of BEC from all blood groups displayed similar glycan types, while varying in their relative intensities between individuals. However, multivariate analysis of the O-glycans from individuals displayed segregation patterns clearly associated with their blood group type and secretor status. In adhesion assays the oral pathogen Candida albicans showed a significantly higher interaction to blood group O type BECs relative to other blood groups.     

Genetic and nongenetic influences on the ABH and Lea antigen levels of saliva and milk.

The saliva and milk of 250 parturient women were studied in relation to ABH antigen levels; part of the sample was also investigated for the Lewis (Lea) substance. The levels of A and B are higher in saliva, and those of H and Lea higher in milk. The H average salivary titers presented the relationship O greater than A2 greater than A1 greater than B greater than AB, but these differences were not present in milk. In addition, the salivary levels of A and B are similar in individuals of these groups but B greater than A in AB persons, and A1 greater than A2; while in milk A greater than B in A, B and AB subjects, and A1 approximately equal to A2. The amount of Lea substance depends of the ABH secretor status in both secretions; but independently of this difference, the average titers were always higher in milk. Correlation coefficients between the levels observed in the two secretions are statistically significant for the A substance in A persons (0.46), H in B (0.58) and Lea in all subjects tested (0.47). A stepwise multiple regression analysis performed to verify the influence of four genetic and six nongenetic variables in the ABH levels of both fluids indicated only one consistent modifying factor: ABO type.     

Semiquantitative immunohistochemical studies of blood group antigen A,B,H, Lea, Leb structures and Ii backbone chains in the normal human cervix and in cervical adenocarcinoma

Summary Epithelia frequently express blood group antigens and these are often perturbed in neoplasia. This study has characterized the range of expression of ABH and Lewis terminal structures and the Ii backbone chains in the normal human cervix by semiquantitative immunohistochemistry. Effects of the secretor gene were defined by determination of salivary secretor status. Modifications of blood group antigen expression in cervical adenocarcinoma were also addressed.Normal cervical squamous and glandular epithelia showed a range of expression of the antigens studied. Lewis-gene-negative cases showed no expression of Lewis antigens. Secretor status had no effect on ABH expression in squamous epithelium, but it did have a marked effect on ABH expression in glands and on Le^b expression in both squamous and glandular epithelia. Patterns of expression of i chains in squamous epithelium suggest that these may be the carriers of ABH and Lewis antigens in a proportion of cases. Distinct patterns of expression were seen in glandular tubal metaplasia and in endothelium.Adenocarcinomas showed topographical rather than quantitative changes in blood group antigen expression with more extensive luminal expression of ABH, Lewis and Ii structures than that seen in normal glands. This change is distinct from those usually associated with malignancy.     

Norwalk virus-like particles bind specifically to A,H and difucosylated Lewis but not to B histo-blood group active glycosphingolipids

Noroviruses and norovirus virus-like particles (VLPs) exhibit strain specific patterns in their binding to ABH and Lewis histo-blood group antigens. In this study we demonstrate for the first time specific binding of Norwalk virus VLPs to type 1 and type 2 chain glycosphingolipids (GSLs) carrying ABH and Lewis antigens. N-succinimidyl-3-tributylstannyl benzoate (ATE) was precursor labeled with ¹²⁵I and then conjugated to VLPs. The ¹²⁵I-VLPs were used in GSL thin-layer chromatogram binding assays and displayed binding to H type 1, Lewis b, A type 1, A Lewis b GSLs but no binding to B type 1 or B Lewis b GSLs. For the type 2 chain GSLs the Norwalk VLPs bound to H type 2, Lewis y, A type 2 and A Lewis y. In addition, the VLPs bound to several complex GSLs from blood group O and A, but not from blood group B red blood cells.     

Aberrant expression of histo-blood group A type 3 antigens in vascular endothelial cells in inflammatory sites.

Histo-blood group ABH antigens are widely distributed in human tissues. The epitopes of ABH antigens are carried by at least four different peripheral core isotypes of internal carbohydrate backbones (type 1-4). Each type of ABH antigen is expressed tissue specifically, and aberrant expression of ABH antigens is often observed during oncogenesis. We immunohistochemically examined the expression of A type 3 antigens in wounded and diseased skin tissues (A and AB blood groups). In uninjured skin, the expression of A type 3 antigens was restricted to the eccrine sweat gland. In addition to the sweat glands, A type 3 antigens were found in vascular endothelial cells of the wound sites. The extent of A type 3 antigens expression related to postinfliction intervals. A significantly higher expression rate of A type 3 antigens in endothelial cells was also observed in diseased skin, suggesting that inflammation might induce A type 3 antigen expression in endothelial cells. Double-color immunofluorescence staining of the specimens showed that von Willebrand factor (vWF) was a core-protein of A type 3 determinants aberrantly expressed in endothelial cells in inflamed tissues, suggesting that aberrant expression of A type 3 antigens is involved in stabilization of vWF in inflammation.     

Reexpression of blood group ABH antigens on the surface of human thyroid cells in culture

Using indirect immunofluorescence (IFL) on viable human thyroid cultures, it has been shown that, although adult follicular cells do not express blood group ABH antigens in vivo, they invariably reexpress the corresponding antigens on the cell surface when cultured in monolayers, even for very short periods. The absence of blood group antigens on noncultured thyroid cells was confirmed by negative IFL on cell suspensions obtained after enzymatic digestion of the glands, whereas these antigens were readily demonstrable on cell suspensions obtained by trypsinization of established monolayers. The quantitative expression of ABH antigens on individual thyroid cells was variable and the cell-surface IFL pattern due to binding of blood group isoantibodies was different from that given by organ-specific thyroid autoantibodies on viable cultures. Reexpression of blood group antigens by cultured thyroid cells could not be related to the secretor status of the donors, the presence of a particular source of serum in the culture medium or cell division in vitro. After 2-3 wk in culture, thyroid cells became morphologically dedifferentiated and no longer displayed blood group antigens, though they still expressed cell- surface beta 2-microglobulin. Fibroblasts present in the primary thyroid cultures were invariably negative for ABH antigens. These results demonstrate that the surface antigenic repertoire of cultured human cells is not necessarily identical to that present on the same cells in vivo. Furthermore, the possibility that blood group natural isoantibodies bind to the cell surface must be taken into account in experiments in which cultured thyroid cells are exposed to human sera.