Express Blood Group Antigens Research Articles

Evaluation of the Bactericidal Activity of Galectins.

Over a century ago, Karl Landsteiner discovered that blood group antigens could predict the immunological outcome of red blood cell transfusion. While the discovery of ABO(H) blood group antigens revolutionized transfusion medicine, many questions remain regarding the development and regulation of naturally occurring anti-blood group antibody formation. Early studies suggested that blood group antibodies develop following stimulation by bacteria that express blood group antigens. While this may explain the development of anti-blood group antibodies in blood group-negative individuals, how blood group-positive individuals protect themselves against blood group-positive microbes remained unknown. Recent studies suggest that several members of the galectin family specifically target blood group-positive microbes, thereby providing innate immune protection against blood group antigen-positive microbes regardless of the blood group status of an individual. Importantly, subsequent studies suggest that this unique form of immunity may not be limited to blood group expressing microbes, but may reflect a more generalized form of innate immunity against molecular mimicry. As this form of antimicrobial activity represents a unique and unprecedented form of immunity, we will examine important considerations and methodological approaches that can be used when seeking to ascertain the potential antimicrobial activity of various members of the galectin family.

Blood Group Antigen Expression in Isolated Human Liver Cells in Preparation for Implementing Clinical ABO-Incompatible Hepatocyte Transplantation

ABO blood group antigens in the liver are expressed mainly on endothelial cells or biliary epithelial cellsbut not on hepatocytes. This suggests that ABO-incompatible hepatocyte transplantation (ABOi-HTx) is theoretically feasible. However, the effects of stress on ABO blood group antigen expression caused by isolation and intraportal infusion require thorough investigation before ABOi-HTx can be implemented in clinical settings. Human hepatocytes were isolated from liver tissue obtained from liver resection or deceased donor livers. The expression of blood group antigens on cryopreserved human liver tissues and isolated hepatocyte smear specimens were examined by immunofluorescent staining. The effect of proinflammatory cytokines on blood group antigen expression of hepatocytes was evaluated by flow cytometry. Instant blood-mediated inflammatory reaction after hepatocyte incubation with ABO-incompatible whole blood was examined using the tubing loop model. Blood group antigens were mainly expressed on vessels in the portal area. In hepatocyte smear specimens, isolated hepatocytes did not express blood group antigens. In contrast, a subset of cells in the smear specimens of nonparenchymal liver cells stained positive. In the flow cytometry analysis, isolated hepatocytes were negative for blood group antigens, even after 4-h incubation with cytokines. Platelet counts and complement activation were not significantly different in ABO-identical versus ABO-incompatible settings in the tubing loop model. Our study showed that blood group antigens were not expressed on hepatocytes, even after isolation procedures or subsequent incubation with cytokines. This finding is an important step toward removing the restriction of ABO matching in hepatocyte transplantation. Our results suggest that ABOi-HTx is a feasible therapeutic option, especially in patients who require urgent treatment with freshly isolated hepatocytes, such as those with acute liver failure.

Genetic Susceptibility to Human Norovirus Infection: An Update.

Noroviruses are the most common etiological agent of acute gastroenteritis worldwide. Despite their high infectivity, a subpopulation of individuals is resistant to infection and disease. This susceptibility is norovirus genotype-dependent and is largely mediated by the presence or absence of human histo-blood group antigens (HBGAs) on gut epithelial surfaces. The synthesis of these HBGAs is mediated by fucosyl- and glycosyltransferases under the genetic control of the FUT2 (secretor), FUT3 (Lewis) and ABO(H) genes. The so-called non-secretors, having an inactivated FUT2 enzyme, do not express blood group antigens and are resistant to several norovirus genotypes, including the predominant GII.4. Significant genotypic and phenotypic diversity of HBGA expression exists between different human populations. Here, we review previous in vivo studies on genetic susceptibility to norovirus infection. These are discussed in relation to population susceptibility, vaccines, norovirus epidemiology and the impact on public health.

ABO Antigens Active Tri- and Disaccharides Microarray to Evaluate C-type Lectin Receptor Binding Preferences

Understanding blood group antigen binding preferences for C-type lectin receptors holds promise for modulating immune responses, since several Gram-negative bacteria express blood group antigens as molecular mimicry to evade immune responses. Herein, we report the synthesis of ABO blood group antigen active tri and disaccharides to investigate the binding specificity with various C-type lectin receptors using glycan microarray. The results of binding preferences show that distinct glycosylation on the galactose and fucose motifs are key for C-type lectin receptor binding and that these interactions occur in a Ca2+-dependent fashion.

The Role of Liver Sinusoidal Endothelial Cells in Induction of Carbohydrate Reactive B Cells Tolerance Through the Programmed Death 1/Programmed Death Ligand 1 Pathway.

A spontaneous tolerance of B cells responding to blood group antigens frequently develops in ABO-incompatible pediatric liver transplantation (LT). Liver sinusoidal endothelial cells (LSECs), which exclusively express blood group antigens in the liver, possess a capacity to induce alloantigen-specific tolerance. In this study, we elucidated the role of LSECs in the tolerance induction of blood group antigen-reactive B cells after ABO-incompatible LT using mice that lack galactose-α(1,3)galactose (Gal) epitopes resembling blood group carbohydrate antigens. Using adoptive transfer of LSECs from wild type (WT) C57BL/6J mice to congenic α1,3-galactosyltransferase gene knockout (GalT) mice, we established orthotropic GalT → GalT LSEC chimera mice. Anti-Gal Ab (antibody) production was evaluated after immunization of GalT → GalT LSEC chimera mice with Gal rabbit RBC. Adoptive transfer of LSECs isolated from WT GalT mice via the portal vein resulted in persistent engraftment of Gal LSECs in congenic GalT mouse livers. Only when GalT mice were splenectomized before LSEC inoculation, the GalT → GalT LSEC chimera lost the ability to produce anti-Gal Abs. The administration of blocking monoclonal Abs (mAbs) against programmed death ligand 1 to the splenectomized GalT → GalT LSEC chimera resulted in the recovery of anti-Gal Ab production. These findings suggest that LSECs take a part in tolerization of immature but not mature B cells specifically for Gal. Furthermore, the programmed death 1/programmed death ligand 1 pathway likely plays a crucial role in the mechanisms underlying spontaneous tolerization of B cells responding to ABO-blood group antigens in LT.

Evaluation of the bactericidal activity of galectins.

Over a century ago, Karl Landsteiner discovered that blood group antigens could predict the immunological outcome of red blood cell transfusion. While the discovery of ABO(H) blood group antigens revolutionized transfusion medicine, many questions remain regarding the development and regulation of naturally occurring anti-blood group antibody formation. Early studies suggested that blood group antibodies develop following stimulation by bacteria that express blood group antigens. While this may explain the development of anti-blood group antibodies in blood group negative individuals, how blood group positive individuals, who cannot generate anti-blood group antibodies, protect themselves against blood group positive microbes remained unknown. Recent studies suggest that several members of the galectin family specifically target blood group positive microbes, thereby providing innate immune protection against blood group antigen positive microbes regardless of the blood group status of an individual. Importantly, subsequent studies suggest that this unique form of immunity may not be limited to blood group expressing microbes, but may reflect a more generalized form of innate immunity against molecular mimicry. As this form of antimicrobial activity represents a unique and unprecedented form of immunity, we will examine important considerations and methodological approaches that can be used when seeking to ascertain the potential antimicrobial activity of various members of the galectin family.

Red blood cell alloimmunization from an African perspective

Red blood cell (RBC) alloimmunization occurs when individuals are exposed to erythrocytes that express blood group antigens different from their own. Consequences of alloimmunization include hemolytic disease of the fetus and newborn and hemolytic transfusion reactions, with potentially serious morbidity and mortality. Patients who formed antibodies showed a four to five times increased risk for additional alloantibodies upon further transfusion exposure and may be at increased risk for transfusion reactions. In view of the main transfusion indications in Africans (e.g. malaria and pregnancy), the lifetime risk of exposure to multiple transfusion events is substantial, stressing the need for information on RBC alloimmunization in African transfusion recipients. Three cross-sectional studies on RBC alloimmunization from two African countries of Uganda and Malawi showed that 1-6% of transfused patients possessed clinically relevant RBC antibodies. Regarding RBC compatibility testing for transfusion, ABO/D typing is mandatory in African settings but complete crossmatches are not routinely performed. Despite the limited data on posttransfusion alloimmunization, a complete crossmatch for patients with past transfusions could be recommended. However, more information on blood group distribution in Africans and RBC alloimmunization rates and specificity is needed to consider immunoprophylaxis for hemolytic disease, pretransfusion testing, and preventive strategies to avoid transfusion-induced alloimmunization.

Funções biológicas dos antígenos eritrocitários

Os antigenos de grupos sanguineos eritrocitarios sao estruturas macromoleculares localizadas na superficie extracelular da membrana eritrocitaria. Com o desenvolvimento de estudos moleculares, mais de 250 antigenos sao conhecidos e estao organizados em 29 sistemas de grupos sanguineos reconhecidos pela Sociedade Internacional de Transfusao Sanguinea (ISBT). Estudos tem revelado que os antigenos de grupo sanguineo estao expressos na membrana eritrocitaria com ampla diversidade estrutural, incluindo epitopos de carboidratos em glicoproteinas e/ou glicolipidios e em proteinas inseridas na membrana via um dominio, via dominios de multipassagem ou ligados a glicosilfosfatidinositol. Alem das diversidades estruturais, muitas funcoes importantes tem sido associadas aos antigenos eritrocitarios recentemente identificadas, podendo ser esquematicamente divididas em: estruturais, transportadores, receptores e moleculas de adesao, enzimas, proteinas controladoras do complemento e outras. Esta revisao tem como foco as funcoes potenciais das moleculas que expressam os antigenos eritrocitarios.

Analysis of mucins: role in laboratory diagnosis

Mucins are high molecular weight glycoproteins with complex oligosaccharide side chains attached to the apomucin protein backbone by O-glycosidic linkage; they are found in crude mucus gels that protect epithelial...

No alloantibodies against mesenchymal stromal cells, but presence of anti-fetal calf serum antibodies, after transplantation in allogeneic hematopoietic stem cell recipients

Mesenchymal stromal cells (MSC) may be used in cellular therapy to treat graft-versus-host-disease and autoimmune disorders, and in regenerative medicine. Preliminary data suggest limited cellular allogeneic rejection, but less is known about humoral responses. The objective of this study was to investigate whether antibodies against MSC were present after hematopoietic stem cell transplantation (HSCT) including treatment with matched or mismatched allogeneic MSC. Twelve patients were evaluated using flow cytometric cross matches (FCXM) and enzyme-linked immunosorbent assays. Expression of blood group antigens, regarded as alloantigens giving rise to humoral alloimmunity, on MSC were explored using flow cytometry and immunofluorescence. Three of 12 patients exhibited late positivity in the FCXM. In absorption studies, antibodies directed against fetal calf serum (FCS), a component of the MSC culture medium, were identified. Healthy individuals expressed varying levels of anti-FCS antibodies and the same pattern was seen in immunosuppressed HSCT patients. MSC did not express blood group antigens. The patients with positive FCXM are alive and well. We have shown that immunosuppressed patients can exhibit anti-FCS antibodies, but no alloantibodies, that may bind to MSC. These antibodies seem clinically insignificant.

AB0-Blutgruppenexpression in Hornhäuten mit Transplantatversagen

ABO blood group antigens are only expressed by the epithelial cells of normal human corneas. Since AB0 blood group antigens are also known to be expressed on stromal and endothelial cells of inflamed corneas, this study aimed to investigate the extend of ABO blood group antigen expression in corneal allograft failures. Twenty-two failed corneal allografts of 22 patients were examined. In 12 cases the patients had clinically proven corneal allograft rejection. In 10 cases there was no evident history of allograft rejection and the diagnosis graft failure due to chronic endothelial cell loss was made. Immunohistochemical staining of paraffin embedded sections was performed with monoclonal mouse antibodies to human blood group antigen A or B using the streptavidin-biotin-peroxidase complex technique. Blood group antigens A or B were expressed by stromal keratocytes in 5 out of 12 and by endothelial cells in 7 out of 12 corneas with clinically proven immunologic graft rejection. Corneal transplants with chronic endothelial cell loss expressed blood group antigens A and/or B on the endothelial cells in three out of ten cases. The results of this study show that ABO blood group antigens can be up-regulated in cases of corneal allograft failure, especially in cases of immune mediated graft rejection. This phenomenon might play a role in corneal allograft rejection.

Secretor polymorphism and human immunodeficiency virus infection in Senegalese women.

The FUT2 gene encodes the enzyme alpha (1,2) fucosyltransferase, which determines expression of blood-group antigens on mucosal epithelial cell surfaces and in secretions. Homozygotes for a specific stop mutation in FUT2 (nonsecretors) cannot produce this enzyme and thus are unable to express blood group antigens. Nonsecretor status is associated with a decreased risk of several respiratory viral infections. By use of molecular genotyping, 2 populations of Senegalese women were examined for polymorphisms of the FUT2 gene. Among Senegalese commercial sex workers, absence of FUT2 (nonsecretor genotype) was associated with reduced risk of human immunodeficiency virus (HIV) type 1 infection (odds ratio [OR] adjusted for cervical and vaginal infection, 0.18; 95% confidence interval [CI], 0.04-0.90) and HIV-2 infection (adjusted OR, 0.43; 95% CI, 0.13-1.39), although the latter was not statistically significant. Modification of cell surface carbohydrates at mucosal surfaces determined by the FUT2 gene may underlie the protective association against heterosexual HIV infection.

ABO Blood Group Antigens on Human Plasma von Willebrand Factor After ABO-Mismatched Bone Marrow Transplantation

von Willebrand factor (vWF) is synthesized exclusively by endothelial cells and megakaryocytes, and stored in the intracellular granules or constitutively secreted into plasma. ABO blood group antigens are covalently associated with asparagine-linked sugar chains of plasma vWF. The effect of ABO-mismatched bone marrow transplantation (BMT) or blood stem cell transplantation (BSCT) on the expression of ABO blood group antigens on the vWF was examined to obtain information on the origin of these antigens. In ABO-mismatched (HLA-matched) groups, 8 cases of BMT and 4 cases of BSCT were examined. In all cases, the ABO blood groups on red blood cells were gradually converted to the donor's type within 80 to 90 days after the transplantation. The blood group antigens on the vWF were consistent with the recipient's blood group for the period monitored by enzyme-linked immunosorbent assay (ELISA). When vWF was isolated from normal platelets and examined for the blood group antigens using ELISA or immunoblotting, it showed few antigens. However, vWF extracted from veins expressed blood group antigens. These findings indicate that platelet (megakaryocyte)-derived vWF does not contain blood group antigens and that these antigens may be specifically associated with vWF synthesized in endothelial cells and secreted into plasma. Furthermore, it is possible that the persistence of the recipient's blood group antigens on plasma glycoproteins such as vWF, independent of the donor-derived erythrocytes, after ABO-mismatched stem cell transplantation, may influence the immunological system in the production of anti-blood group antibodies resulting in the establishment of immunological tolerance in the recipient plasma.

Expression of blood group antigens A and/or B in diseased corneas

Purpose. Only epithelial cells are thought to express blood group antigens (bga) A and/or B in normal corneas, and ABO blood group (bg) matching seems to reduce immune rejection in high risk transplantations. This study attempts for the first time to investigate to what extent the bga A and/or B are expressed in diseased corneas.Methods. Thirty-nine diseased corneal buttons of 39 patients were examined. Immunohistochemical staining of paraffin-embedded sections was performed with monoclonal mouse anti human blood groups A and B antibodies using the Streptavidin-Biotin-peroxidase complex technique (LSAB Kit, Dako).Results. The expression of blood group antigens A and/or B on the cornea was found to correlate directly with the blood group of the patients in all cases. The corneal epithelium of all 18 patients with blood groups A and/or B could be stained with antibodies to bga A and/or B. However, neither bga A nor bga B could be detected in any corneal cells of patients with the blood group O (21 patients). In addition to the epithelium, the stromal keratinocytes as well as the endothelium contained immunohistochemically detectable bga A and/or B in cases of keratitis or keratoconus, but not in stromal and/or endothelial cells of corneas with pseudophakic bullous keratopathy and Fuchs' dystrophy (all patients with the bgs A and/or B).Conclusion. These findings show that an up-regulation of bga A and/or B in corneal stromal and endothelial cells is possible in diseased corneas. This phenomenon might play an important role in graft rejection after corneal transplantation. Curr. Eye Res. 17: 650–655, 1998.

Expression of blood group antigens A and/or B in diseased corneas

Purpose. Only epithelial cells are thought to express blood group antigens (bga) A and/or B in normal corneas, and ABO blood group (bg) matching seems to reduce immune rejection in high risk transplantations. This study attempts for the first time to investigate to what extent the bga A and/or B are expressed in diseased corneas.Methods. Thirty-nine diseased corneal buttons of 39 patients were examined. Immunohistochemical staining of paraffin-embedded sections was performed with monoclonal mouse anti human blood groups A and B antibodies using the Streptavidin-Biotin-peroxidase complex technique (LSAB Kit, Dako).Results. The expression of blood group antigens A and/or B on the cornea was found to correlate directly with the blood group of the patients in all cases. The corneal epithelium of all 18 patients with blood groups A and/or B could be stained with antibodies to bga A and/or B. However, neither bga A nor bga B could be detected in any corneal cells of patients with the blood group O (21 patients). In addition to the epithelium, the stromal keratinocytes as well as the endothelium contained immunohistochemically detectable bga A and/or B in cases of keratitis or keratoconus, but not in stromal and/or endothelial cells of corneas with pseudophakic bullous keratopathy and Fuchs' dystrophy (all patients with the bgs A and/or B).Conclusion. These findings show that an up-regulation of bga A and/or B in corneal stromal and endothelial cells is possible in diseased corneas. This phenomenon might play an important role in graft rejection after corneal transplantation. Curr. Eye Res. 17: 650–655, 1998.

Acquired deficiency in C1-inhibitor associated with signet ring cell gastric adenocarcinoma: A probable connection of antitumor-associated antibodies, hemolytic anemia, and complement turnover

Background: Acquired deficiency in C1-inhibitor (C1-INH) associated with malignancy is often asymptomatic because clinical manifestations are not dependent on a critical complement threshold (in contrast to hereditary C1-INH deficiency). Increased complement consumption involving different kinds of antibodies is the postulated mechanism for this disease, but other factors must play an important role. Case report: A 76-year-old woman with unremarkable medical history experienced three episodes of angioedema over 6 months. Investigations revealed a complement profile characteristic of acquired deficiency in C1-INH, a hemolytic anemia, and a signet ring cell adenocarcinoma (linitis plastica). A gastrectomy and a splenectomy were performed. The postoperative course was characterized by a complete disappearance of the symptoms of angioedema and hemolytic anemia. A local recurrence of the tumor 5 months later could not be resected. The patient died 17 months after the initial surgery was performed. Results: Quantitative and functional analyses of the complement factors showed persistent excessive complement consumption. Markers of hemolytic anemia disappeared after tumor removal but recurred in the second part of the disease evolution. Immunohistochemical findings in tumor tissue showed loss of normal blood group antigens but expression of Le a antigen, as well as C1q deposition. Conclusion: To explain the whole clinical and laboratory picture, we hypothesize a connection between tumor immunohistochemical profile, complement consumption, and hemolytic anemia. Tumor cell surface antigens might lead to a permanent but asymptomatic complement consumption that is worsened and becomes clinically manifest by superimposed hemolytic anemia caused by cross-reactive antibodies to newly expressed blood group antigens on tumor cells. This hypothesis should be confirmed by other observations. (J A LLERGY C LIN I MMUNOL 1995;95:124-31.)

Semiquantitative immunohistochemical studies of blood group antigen A, B, H, Le(a), Le(b) structures and Ii backbone chains in the normal human cervix and in cervical adenocarcinoma.

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.

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

The reactivity was examined of horseradish peroxidase labelled Ulex europaeus agglutinin-I (UEA-I) and Griffonia 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.

Heterogeneic expression of blood group A and H isoantigens in bladder tumors: association with nuclear volume.

Intratumor heterogeneity is a major problem in immunodiagnosis and treatment of carcinomas. To elucidate the well-known heterogeneity in transitional-cell carcinomas of the ability to express blood group ABO isoantigens, a stereological estimate of the mean nuclear volume in areas expressing blood group antigens was compared to the estimate from areas of identical pathological grade at which antigen expression was deleted. Four microscopic fields were examined from antigen-positive and four from antigen-negative areas in sections from 21 blood group O and 20 blood group A individuals. The sections were stained before examination by an indirect peroxidase method using monoclonal anti-H and anti-A antibodies. The mean nuclear volume increased, as expected, with increasing pathological grade. In blood group O individuals the mean nuclear volume was 241.5 microns 3 in antigen-positive areas and 338.2 microns 3 in antigen-negative areas (2p less than 0.0005) of identical pathological grade. In group A individuals the mean nuclear volume was 217.1 microns 3 in positive areas and 351.1 microns 3 in corresponding negative areas (2p less than 0.0025). The variation in volume parameter was essentially caused by a true variation between tumors (greater than 82%). The results indicate a complex biological mechanism associated with the cellular ability to express blood group antigens.

Immunohistochemical Markers of Tonsillar Crypt Epithelium

The crypt epithelium of human palatinal tonsils is a specialized squamous epithelium characterized by the presence of intraepithelial passages which are filled by non-epithelial cells. The passages are covered by the so-called M cells. This reticulated epithelium (reticulum = network) is a highly differentiated one. In the present study immunohistochemical markers were searched for the discrimination between the superficial mucosal squamous epithelium (from which the crypts were developed) and the reticulated crypt epithelium. The reticulated epithelium is replaced by simple squamous epithelium in the course of recurrent tonsillitis. The immunohistochemical characteristics of this metaplastic epithelium were also studied. The superficial epithelium expressed blood group antigens extensively, but these antigens were almost absent from the crypt epithelium. Epithelial membrane antigen was present only in the superficial layers of the surface epithelium. Abundant positivity was characteristic for the reticulated epithelium. The metaplastic foci in the crypts were identical with the surface squamous epithelium using these markers.