The ABO, Lewis and related blood group antigens; a review of structure and biosynthesis

Numerous studies have shown that the antigenic determinants of the ABO blood group system are closely related in biochemical terms to the antigenic determinants of the Hh, P, Lewis and Ii blood group systems. The blood group antigens of each of these systems are formed by the addition of specific sugars to an oligosaccharide precursor chain which may be bound through sphingosine to fatty acids (glycolipid) or through serine or threonine to a peptide chain (glycoproteins). The direct gene products of each of these blood group systems are the glycosyltransferase enzymes which catalyse the addition of the specific sugar thus conferring the specified blood group activity to the glycolipid or glycoprotein molecule. The antigenic determinants of the ABO and Lewis systems in addition to red cells also exist in the body secretions in soluble form when the relevant genes are expressed in the phenotype. The antigens expressed on both the red cells and in the secretions are determined by the interaction of Hh, Sese, ABO and Lele genes.     

The ABO, Lewis and related blood group antigens; a review of structure and biosynthesis

Abstract Numerous studies have shown that the antigenic determinants of the ABO blood group system are closely related in biochemical terms to the antigenic determinants of the Hh, P, Lewis and Ii blood group systems. The blood group antigens of each of these systems are formed by the addition of specific sugars to an oligosaccharide precursor chain which may be bound through sphingosine to fatty acids (glycolipid) or through serine or threonine to a peptide chain (glycoproteins). The direct gene products of each of these blood group systems are the glycosyltransferase enzymes which catalyse the addition of the specific sugar thus conferring the specified blood group activity to the glycolipid or glycoprotein molecule. The antigenic determinants of the ABO and Lewis systems in addition to red cells also exist in the body secretions in soluble form when the relevant genes are expressed in the phenotype. The antigens expressed on both the red cells and in the secretions are determined by the interaction of Hh, Sese, ABO and Lele genes.     

B para-Bombay phenotype in China caused by homozygous mutation for site 328 G>A of FUT1 gene: a case report

The aim of this paper is to accurately identify a case of B para-Bombay and to analyze the genetic mutation. ABO and Lewis blood groups were identified by standard serological methods, and trace antigens on RBCs were detected by adsorption-elution test, while blood group substances in the saliva were detected by agglutination inhibition test. The ABO gene exons 6-7, FUT1 gene exon 4 and FUT2 gene exon 2 were directly sequenced. Serological results showed that there were B antigens on RBCs without H antigens, anti-A and anti-HI antibodies in serum, and B and H blood group substances in the saliva. The Lewis phenotype was Le (a-b+). According to gene sequencing analysis, ABO, FUT1 and FUT2 genotypes were B101/O02, h^328G/Ah^328G/A and Se^357C/TSe^357C/T, respectively. This rare phenotype can be mislabeled as "O" if any of the detailed investigations are not performed. Therefore, in order to ensure the safety of blood transfusion, genetic and serological tests are necessary for the correct identification of difficult blood groups.     

B para-Bombay phenotype in China caused by homozygous mutation for site 328 G > A of FUT1 gene: a case report

The aim of this paper is to accurately identify a case of B para-Bombay and to analyze the genetic mutation. ABO and Lewis blood groups were identified by standard serological methods, and trace antigens on RBCs were detected by adsorption-elution test, while blood group substances in the saliva were detected by agglutination inhibition test. The ABO gene exons 6-7, FUT1 gene exon 4 and FUT2 gene exon 2 were directly sequenced. Serological results showed that there were B antigens on RBCs without H antigens, anti-A and anti-HI antibodies in serum, and B and H blood group substances in the saliva. The Lewis phenotype was Le (a-b+). According to gene sequencing analysis, ABO, FUT1 and FUT2 genotypes were B101/O02, h^328G/Ah3^28G/A and Se^357C/TSe^357C/T, respectively. This rare phenotype can be mislabeled as "O" if any of the detailed investigations are not performed. Therefore, in order to ensure the safety of blood transfusion, genetic and serological tests are necessary for the correct identification of difficult blood groups.     

Molecular analysis to FUT-1, 2, 3 and ABO genotyping may instead of serological typing to diagnose para-Bombay in Chinese

The aim of this study was to evaluate the consistency between serotyping and molecular analysis in Chinese with para-Bombay. The molecular analysis of gene fragments in FUT-1, FUT-2, FUT-3 and ABO genotyping and serotyping were used including a saliva test to examine the A, B, H substance and an absorption elution test to examine the A, B, H; and further routine tests including ABO, H and Lewis phenotype. From eleven samples with anti-H negative, 10 samples were confirmed with para-Bombay by sequencing to FUT-1, from which six samples were 547-548delAG, three samples were 880TT deletion, one sample was 35C>T and one sample was 649G>T heterozygous (h7, China) as carrier. The sequencing to FUT-2 confirmed 357C>T in 11 samples, meaning H, A and B substance was secreted in saliva except for one sample which occurred 385A>T (I129F) heterozygous, which is a weak secretor. The FUT-3 sequence result demonstrated four samples with heterozygous mutations to 59T>G (L20R) combined with 508G>A (G170S) and seven samples without mutations in FUT-3 gene fragment same as reference. The consistency between sequencing with FUT-1/FUT-2 and serotyping by anti-H reported an identical result, except for one sample, which interestingly showed the H/h7 carrier with serotyping negative to anti-H. The result of sequencing with FUT-2/FUT-3 and Lewis phenotyping also reported a complete consistency. The saliva test to A, B, H substance and absorption elution test examining the A, B, H antigens on the surface of red blood cells completely matched the ABO exon 6, 7 sequence results. The sequencing of FUT-1, FUT-2, FUT-3 and ABO exon 6, 7 may become a useful tool to confirm the para-Bombay blood type.     

Role of ABO secretor status in mucosal innate immunity and H. pylori infection

The fucosylated ABH antigens, which constitute the molecular basis for the ABO blood group system, are also expressed in salivary secretions and gastrointestinal epithelia in individuals of positive secretor status; however, the biological function of the ABO blood group system is unknown. Gastric mucosa biopsies of 41 Rhesus monkeys originating from Southern Asia were analyzed by immunohistochemistry. A majority of these animals were found to be of blood group B and weak-secretor phenotype (i.e., expressing both Lewis a and Lewis b antigens), which are also common in South Asian human populations. A selected group of ten monkeys was inoculated with Helicobacter pylori and studied for changes in gastric mucosal glycosylation during a 10-month period. We observed a loss in mucosal fucosylation and concurrent induction and time-dependent dynamics in gastric mucosal sialylation (carbohydrate marker of inflammation), which affect H. pylori adhesion targets and thus modulate host-bacterial interactions. Of particular relevance, gastric mucosal density of H. pylori, gastritis, and sialylation were all higher in secretor individuals compared to weak-secretors, the latter being apparently "protected." These results demonstrate that the secretor status plays an intrinsic role in resistance to H. pylori infection and suggest that the fucosylated secretor ABH antigens constitute interactive members of the human and primate mucosal innate immune system.     

ABH and Lewis histo-blood group antigens, a model for the meaning of oligosaccharide diversity in the face of a changing world

Antigens of the ABH and Lewis histo-blood group family have been known for a long time. Yet their biological meaning is still largely obscure. Based on the available knowledge about the genes involved in their biosynthesis and about their tissue distribution in humans and other mammals, we discuss here the selective forces that may maintain or propagate these oligosaccharide antigens. The ABO, alpha 1,2fucosyltransferase and alpha 1,3fucosyltransferase enzyme families have been generated by gene duplications. Members of these families contribute to biosynthesis of the antigens through epistatic interactions. We suggest that the highly polymorphic genes of each family provide intraspecies diversity that allows coping with diverse and rapidly evolving pathogens. In contrast, the genes of low frequency polymorphism are expected to play roles at the cellular level, although they may be dispensable at the individual level. In addition, some members of these three gene families are expected to be functionally redundant and may either provide a reservoir for additional diversity in the future or become inactivated. We also discuss the role of the ABH and Lewis histo-blood group antigens in pathologies such as cancer and cardiovascular diseases, but argue that it is merely incidental and devoid of evolutionary impact.     

Blood group antigens: molecules seeking a function?

The blood group antigens have been dismissed by some researchers as merely ‘icing on the cake’ of glycoprotein structures. The fact that there are no lethal mutations and individuals have been described lacking ABO, H and Lewis antigens seems to lend weight to the argument. This paper reviews the research which suggests that these antigens do indeed have function and argues that blood group antigens play important roles in modulation of protein activity, infection and cancer. It explores the evidence and poses questions as to the relevance and implications of the results. This revised version was published online in November 2006 with corrections to the Cover Date.     

Insights into the expression of ABH and Lewis antigens through human bone marrow transplantation.

Twelve information bone marrow transplants, with at least one difference in ABO and/or Lewis types between donor and recipient, were retrospectively studied. ABH and Lewis antigens were determined in plasma, erythrocytes, and lymphocytes. Donor lymphocytes acquired the ABH and Lewis antigens from the recipient's plasma in the same way that donor erythrocytes acquired the Lewis antigens from it. Lymphocytotoxicity detected type 1 ABH and Lewis antigens only, providing evidence for the existence of combined ABH and Lewis antigens on lymphocytes. This was in contrast with the ABH antigens on type 2 chains of red cells, which are devoid of Lewis specificities. The differences in genetic control, probable chemical structure, and cellular origin of these two types of ABH antigens are presented in a theoretical model that accounts for most of the known data.     

Lewis antigens in Helicobacter pylori: biosynthesis and phase variation

The lipopolysaccharides (LPS) of most Helicobacter pylori strains contain complex carbohydrates known as Lewis antigens that are structurally related to the human blood group antigens. Investigations on the genetic determinants involved in the biosynthesis of Lewis antigens have led to the identification of the fucosyltransferases of H. pylori, which have substrate specificities distinct from the mammalian fucosyltransferases. Compared with its human host, H. pylori utilizes a different pathway to synthesize the difucosylated Lewis antigens, Lewis y. and Lewis b. Unique features in the H. pylori fucosyltransferase genes, including homopolymeric tracts mediating slipped-strand mispairing and the elements regulating translational frameshifting, enable H. pylori to produce variable LPS epitopes on its surface. These new findings have provided us with a basis to further examine the roles of molecular mimicry and phase variation of H. pylori Lewis antigen expression in both persistent infection and pathogenesis of this important human gastric pathogen.     

Human-type ABO,MN, and Lewis blood groups,and Gm and Inv factors in several species of macaques

More than 1,000 blood samples were collected from macaques of speciesM. fuscata, M. cyclopis, M. irus, M. mulatta, M. nemestrina, andM. speciosa, and all or a part of them were tested for human-type ABO, MN, and Lewis blood groups, and Gm and Inv factors. Differences between and/or within species analogous to racial differences in man were markedly noted in the distribution of the ABO and Lewis blood groups. Saliva samples from a small number ofM. fuscata were tested quantitatively for the presence of H and Lewis substances, and it was found that almost all the animals were secretors of H, Le^a, and Le^b, independently of the Lewis blood groups of their red cells. Red cells of all macaques tested contained M or M-like, but not N^v(V), antigens, and no polymorphism of MN blood groups was present. Selected plasma samples fromM. fuscata, M. cyclopis, M. irus, andM. nemestrina were found to be negative for all Gm(1), Gm(2), Gm(4), and Inv(1) factors tested.This study was supported in part by the Japan Society for Promotion of Science Grant B-54 and by National Science Foundation Grant FJ 4.11. 1 as part of the Japan-U.S. Cooperative Science Program.     

Unravelling the biochemical basis of blood group ABO and Lewis antigenic specificity

The ABO blood-group polymorphism is still the most clinically important system in blood transfusion practice. The groups were discovered in 1900 and the genes at the ABO locus were cloned nearly a century later in 1990. To enable this goal to be reached intensive studies were carried out in the intervening years on the serology, genetics, inheritance and biochemistry of the antigens belonging to this system. This article describes biochemical genetic investigations on ABO and the related Lewis antigens starting from the time in the 1940s when serological and classical genetical studies had established the immunological basis and mode of inheritance of the antigens but practically nothing was known about their chemical structure. Essential steps were the definition of H as the product of a genetic system Hh independent of ABO, and the establishment of the precursor–product relationship of H to A and B antigens. Indirect methods gave first indications that the specificity of antigens resided in carbohydrate and revealed the immunodominant sugars in the antigenic structures. Subsequently chemical fragmentation procedures enabled the complete determinant structures to be established. Degradation experiments with glycosidases revealed how loss of one specificity by the removal of a single sugar unit exposed a new specificity and suggested that biosynthesis proceeded by a reversal of this process whereby the oligosaccharide structures were built up by the sequential addition of sugar units. Hence, the primary blood-group gene products were predicted to be glycosyltransferase enzymes that added the last sugar to complete the determinant structures. Identification of these enzymes gave new genetic markers and eventually purification of the blood-group A-gene encoded N-acetylgalactosaminyltransferase gave a probe for cloning the ABO locus. Blood-group ABO genotyping by DNA methods has now become a practical possibility.     

Immunocytochemical approach to the structure of human blood group B and H glycoconjugate antigens in the three days old rat cochlea

The possible structure of human blood-group antigens, as found in cochlear hair cells of 3-day-old rats, is suggested. Data were obtained from immunocytochemical studies using 77 antibodies against the major human blood group antigens of the ABO, H, I and Lewis genetic systems. Neither the anti-A-related nor the anti-Lewis-related antibodies showed any positive immunoreaction on hair cells. In contrast, anti-B, anti-AB and anti-H antibodies displayed specific positive immunoreactive patterns on the hair cells. The results suggest that, in immature hair cells, two main glycoconjugate structures of the lactoseries are present: H type 2 antigen, which is the precursor of the B type 2 antigen, and the B type 2 antigen itself. Similar H and B carbohydrate structures have been reported in rat olfactory receptors. The type 2 glycoconjugates carrying these H and B antigens of auditive and olfactory receptors are resistant to fixation and paraffin embedding, suggesting that they might be glycoproteins. These auditive and olfactory H and B antigens must be different from the B-related antigens that are expressed by pseudo-unipolar neurons of rat posterior root ganglia, that are built from type 4 core chains, and that are destroyed by routine paraffin embedding procedures.     

Regulation of expression of carbohydrate blood group antigens

The carbohydrate antigens associated with the human ABO and Lewis blood group systems are excellent models for the study of the genetic regulation of glycoconjugate biosynthesis because their expression on erythrocytes and in saliva has been thoroughly investigated in terms of classical genetics and the chemical structures and pathways for the formation of the antigens are now well understood. The primary protein products of the blood group genes are believed to be the glycosyltransferase enzymes that complete the biosynthesis of the determinants. The important controlling factors still to be elucidated are the genetic and environmental influences leading to the tissue specific expression of these antigens. The 3 types of regulation mechanisms discussed in this review are those arising: 1) from the specificity requirements of the glycosyltransferases encoded by the blood group genes; 2) from the competition or co-operation of glycosyltransferases encoded by genes at the same or independent loci; and 3) from the existence and tissue distribution of glycosyltransferases with related, but not identical, substrate specificities.     

The distribution of type-2 chain histo-blood group antigens in normal cycling human endometrium

Summary The blood group ABO(H) determinants are major allogenic antigens in both erythrocytes and tissue of man. These antigens and related carbohydrates are markers of cellular maturation and differentiation in many epithelial tissues and have recently attracted great interest as tumor-associated antigens. Previous studies of endometrial tissues have indicated that glycosylation in this tissue may be related to hormonal stimulation. We have investigated the immunohistochemical distribution of type-2 chain histo-blood group-related carbohydrates in specimens of normal, cycling endometria obtained from hysterectomies on women with known ABO/Lewis erythrocyte type and saliva secretor status. N-acetyllactosamine and Le^x were demonstrated to be uninfluenced by the genetic background. A and Ale^y antigens were exclusively demonstrated in endometria from blood group A individuals, while Le^y was expressed in endometria from blood group 0 individuals mainly. The precursor N-acetyllactosamine as well as the terminal H, A, and ALe^y antigens were shown in only a few cells. In contrast, N-acetyllactosamine substituted by sialic acid and/or fucose residues (Le^x, sialosyl-Le^x, Le^y) were demonstrated in epithelial cells of normal, cycling endometrium, but with both quantitative and qualitative differences in staining relating to the menstrual cycle, indicating that type-2 chain antigens are expressed under both genetic and hormonal influence in human cycling endometrium.     

Red cell H-deficient,salivary ABH secretor phenotype of Reunion island. Genetic control of the expression of H antigen in the skin

Based on the genetic model proposing thatH andSe are two structural genes, we predicted that the red cell H-deficient, salivary ABH secretor phenotype should be found on Reunion island, where a large series of H-deficient non-secretor families have been previously described. Two such Reunion individuals are now reported. POU [A_h, Le(a–b+), secretor of A, H, Le^a and Le^b in saliva] and SOU [O_h, Le(a–b+), secretor of H, Le^a and Le^b in saliva]. Both are devoid of H -2-fucosyltransferase activity in serum. In addition, the preparation of total non-acid glycosphingolipids from plasma and red cells of POU revealed the type 1ALe^b heptaglycosylceramide and small amounts of the monofucosylated type 1 A hexaglycosylceramide. Both glycolipids possess an H structure probably synthesised by the product of theSe gene. No other blood group A glycolipids, with types 2, 3 or 4 chains, normally present in the presence of the product of theH gene, were found on red cells or plasma of POU.TheH,Se andLe genetic control of the expression of ABH and related antigens in different tissue structures of the skin is described in 54 H-normal individuals of known ABO, secretor and Lewis phenotypes; in one red cell H-deficient salivary secretor (SOU); and in one H-deficient non-secretor (FRA). Sweat glands express ABH under the control of theSe gene. Sweat ducts express ABH under the control of bothH andSe genes and Lewis antigens under the control ofLe and bothH andSe genes. Epidermis, vascular endothelium and red cells express ABH under the control of theH gene. The products ofH andSe genes are usually expressed in different cells. However, the results illustrate that in some structures, like the epithelial cells of sweat ducts, both the products ofH andSe genes can contribute to the synthesis of the same Le^b structure.     

Synthesis and NMR studies on the ABO histo-blood group antigens: synthesis of type III and IV structures and NMR characterization of type I-VI antigens

The ABO histo-blood group antigens are best known for their important roles in solid organ and bone marrow transplantation as well as transfusion medicine. Here we report the synthesis of the ABO type III and IV antigens with a 7-octen-1-yl aglycone. Also described is an NMR study of the ABO type I to VI antigens, which were carried out to probe differences in overall conformation of the molecules. These NMR investigations showed very little difference in the ¹H chemical shifts, as well as ¹H–¹H coupling constants, across all compounds, suggesting that these ABO subtypes adopt nearly identical conformations in solution.     

Advances in ABO gene expression regulation

The ABO blood group system is vital to blood transfusion and organ transplantation. ABO antigens are the most important of all blood group antigens in clinical practice, and are not only present in red blood cells and platelets, but also in most secretions and epithelial tissues. ABO antigens are known to undergo drastic changes during the development, differentiation, and maturation of normal cells. Profound changes have also been documented in pathological processes such as tumorigenesis. To elucidate the molecular basis of how ABO genes are controlled in cell type specific expressions, such as normal cell differentiation or in cancer cells lacking A/B antigens, it is essential to understand the regulatory mechanisms of ABO gene expression. In this review, current knowledge concerning the regulatory mechanisms of ABO gene expression was summarized.     

不同发育时期小鼠胚泡表面Lewis寡糖抗原的表达

在胚泡表面表达的Lewis寡糖抗原 (LewisX ,LewisY)在胚胎发育以及着床过程中起重要作用 .应用免疫印迹和免疫荧光等方法对着床前小鼠胚泡表面的Lewis寡糖抗原进行分析 .结果发现 :小鼠胚泡LewisX寡糖蛋白有 2 7kD、2 9kD、6 8kD和 80kD 4种 ,LewisY寡糖蛋白有 70kD和 90kD 2种 ;2种寡糖抗原均在 8细胞时期开始表达 ,其中 ,LewisY寡糖抗原在胚泡表面的表达持续升高 ,直至胚泡着床 ;而LewisX寡糖抗原的表达则在桑椹期后逐渐降低 ,但仍在胚胎期的囊胚腔侧的顶端可见有部分表达 ;应用RT PCR的分析结果显示 ,LewisX合成的关键糖基转移酶FUT9基因在 4细胞及桑椹期高表达 ,到胚泡期虽然强度明显减弱 ,但仍有表达 ;而LewisY合成关键酶FUT1基因在 4细胞未见表达 ,在桑椹和胚泡阶段均有表达并逐渐升高 ,表达趋势与相应寡糖的表达趋势基本一致 .结果说明 ,在小鼠胚泡表面表达的Lewis寡糖抗原的表达受到相应糖基转移酶基因转录的调控