Presence Of Histo-blood Group Antigens Research Articles

Histo-Blood Group Antigens, Enteropathogen Carriage and Environmental Enteropathy in Stunted Zambian Children.

Stunting, the most common form of childhood undernutrition, is associated with environmental enteropathy (EE). Enteric infections are believed to play a role in the pathophysiology of EE and stunting though the exact mechanism remains undetermined. The FUT2 (secretor) and FUT3 (Lewis) genes have been shown to be associated with some symptomatic enteric infections in both children and adults. These genes are responsible for the presence of histo-blood group antigens (HBGAs) in various secretions and epithelial surfaces.We evaluated whether the secretor and Lewis status influences asymptomatic enteric infections and thus EE severity on duodenal biopsies of stunted children. In this case-control study, we used saliva samples to determine the secretor and Lewis status of stunted children (cases, n = 113) enrolled in a nutritional rehabilitation program and from their well-nourished counterparts (controls, n = 42). Where available, saliva was also collected from the mothers. Baseline stool samples were used to detect asymptomatic enteropathogen carriage. Duodenal biopsies were collected from a subgroup of stunted children (n = 77) who had an upper gastrointestinal endoscopy done as part of the evaluation process for their non-response to nutritional therapy. The proportion of secretors was similar between the cases and the controls (82% vs 81%, P = 0.81). The stunted children had significantly higher rates of carrying multiple enteropathogens, but this was not associated with their secretor status nor that of their mothers. The secretor status was also not associated with mucosal morphometry of duodenal biopsies. This case-control analysis in Zambian children does not support the hypothesis that fucosylation status determines asymptomatic enteropathogen carriage in stunting.

Secretor Status is Associated with Susceptibility to Disease in a Large GII.6 Norovirus Foodborne Outbreak

Norovirus is commonly associated with food and waterborne outbreaks. Genetic susceptibility to norovirus is largely dependent on presence of histo-blood group antigens (HBGA), specifically ABO, secretor, and Lewis phenotypes. The aim of the study was to determine the association between HBGAs to norovirus susceptibility during a large norovirus foodborne outbreak linked to genotype GII.6 in an office-based company in Stockholm, Sweden, 2015. A two-episode outbreak with symptoms of diarrhea and vomiting occurred in 2015. An online questionnaire was sent to all 1109 employees that had worked during the first outbreak episode. Food and water samples were collected from in-house restaurant and tested for bacterial and viral pathogens. In addition, fecal samples were collected from 8 employees that had diarrhea. To investigate genetic susceptibility during the outbreak, 98 saliva samples were analyzed for ABO, secretor, and Lewis phenotypes using ELISA. A total of 542 of 1109 (49%) employees reported gastrointestinal symptoms. All 8 fecal samples tested positive for GII norovirus, which was also detected in coleslaw collected from the in-house restaurant. Eating at the in-house restaurant was significantly associated with risk of symptom development. Nucleotide sequencing was successful for 5/8 fecal samples and all belonged to the GII.6 genotype. HBGA characterization showed a strong secretor association to norovirus-related symptoms (P = 0.014). No association between norovirus disease and ABO phenotypes was observed. The result of this study shows that non-secretors were significantly less likely to report symptoms in a large foodborne outbreak linked to the emerging GII.6 norovirus strain.

Innate Resistance and Susceptibility to Norovirus Infection.

The notion that certain individuals appear more or less susceptible to infections or to specific microbes is not new, but, until recently, it was assumed that clinical outcome of an infection was mainly owing to virulence factors of the microorganism. Relatively little attention has been given to host genetic factors involved in innate or adaptive immunity or expression of pathogen receptors. A remarkable example of susceptibility dependence is the strong Mendelian trait resistance to the most common noroviruses among individuals with a nonsense mutation in chromosome 19[1]. Norovirus is recognized as the leading cause of gastroenteritis worldwide, affecting children and adults alike [2]. Noroviruses are highly contagious and genetically diverse RNA viruses, but not all individuals are susceptible to infection to the same norovirus genotypes. Presence of histo-blood group antigens (HBGAs) on gut epithelial surfaces is essential for susceptibility to many norovirus genotypes. The synthesis of these HBGAs, specifically of the ABH and Lewis families, requires the use of several fucosyl and glycosyltransferases encoded by the FUT2, FUT3, and ABH genes. Polymorphisms in these genes vary considerably depending on ethnicity, with a homozygous nonsense mutation (individuals called non-secretors) in the FUT2 gene occurring in approximately 5%–50% of different populations worldwide [3–5]. Secretor status also affects gut microbiota composition, including HBGA-expressing bacteria and bacteria inducing fucosylation in the gut. These could be intermediary factors that govern norovirus susceptibility [6–9].

Bacterial histo-blood group antigens contributing to genotype-dependent removal of human noroviruses with a microfiltration membrane

We demonstrated the genotype-dependent removal of human norovirus particles with a microfiltration (MF) membrane in the presence of bacteria bearing histo-blood group antigens (HBGAs). Three genotypes (GII.3, GII.4, and GII.6) of norovirus-like particles (NoVLPs) were mixed with three bacterial strains (Enterobacter sp. SENG-6, Escherichia coli O86:K61:B7, and Staphylococcus epidermidis), respectively, and the mixture was filtered with an MF membrane having a nominal pore size of 0.45 μm. All NoVLP genotypes were rejected by the MF membrane in the presence of Enterobacter sp. SENG-6, which excreted HBGAs as extracellular polymeric substances (EPS). This MF membrane removal of NoVLPs was not significant when EPS was removed from cells of Enterobacter sp. SENG-6. GII.6 NoVLP was not rejected with the MF membrane in the presence of E. coli O86:K61:B7, but the removal of EPS of E. coli O86:K61:B7 increased the removal efficiency due to the interaction of NoVLPs with the exposed B-antigen in lipopolysaccharide (LPS) of E. coli O86:K61:B7. No MF membrane removal of all three genotypes was observed when S. epidermidis, an HBGA-negative strain, was mixed with NoVLPs. These results demonstrate that the location of HBGAs on bacterial cells is an important factor in determining the genotype-dependent removal efficiency of norovirus particles with the MF membrane. The presence of HBGAs in mixed liquor suspended solids from a membrane bioreactor (MBR) pilot plant was confirmed by immune-transmission electron microscopy, which implies that bacterial HBGAs can contribute to the genotype-dependent removal of human noroviruses with MBR using MF membrane.

Epidemiologic, Virologic, and Host Genetic Factors of Norovirus Outbreaks in Long-term Care Facilities.

In the Unites States, long-term care facilities (LTCFs) are the most common setting for norovirus outbreaks. These outbreaks provide a unique opportunity to better characterize the viral and host characteristics of norovirus disease. We enrolled 43 LTCFs prospectively to study the epidemiology, virology, and genetic host factors of naturally occurring norovirus outbreaks. Acute and convalescent stool, serum, and saliva samples from cases, exposed and nonexposed controls were collected. Norovirus infection was confirmed using quantitative polymerase chain reaction testing of stool samples or 4-fold increase in serum antibody titers. The presence of histo-blood group antigens (secretor, ABO, and Lewis type) was determined in saliva. Sixty-two cases, 34 exposed controls, and 18 nonexposed controls from 10 norovirus outbreaks were enrolled. Forty-six percent of acute, 27% of convalescent case, and 11% of control stool samples tested norovirus positive. Outbreak genotypes were GII.4 (Den Haag, n = 3; New Orleans, n = 4; and Sydney, n = 2) and GI.1 (n = 1). Viral load in GII.4 Sydney outbreaks was significantly higher than in outbreaks caused by other genotypes; cases and controls shed similar amounts of virus. Forty-seven percent of cases shed virus for ≥ 21 days. Symptomatic infections with GII.4 Den Haag and GII.4 New Orleans were detected among nonsecretor individuals. Almost half of all symptomatic individuals shed virus for at least 21 days. Viral load was highest in GII.4 viruses that most recently emerged; these viruses also infect the nonsecretor population. These findings will help to guide development of targeted prevention and control measures in the elderly.

Norovirus Binding to Intestinal Epithelial Cells Is Independent of Histo-Blood Group Antigens

Human noroviruses (NoVs) are a major cause of non-bacterial gastroenteritis. Although histo-blood group antigens (HBGAs) have been implicated in the initial binding of NoV, the mechanism of that binding before internalization is not clear. To determine the involvement of NoVs and HBGAs in cell binding, we examined the localization of NoV virus-like particles (VLPs) and HBGAs in a human intestinal cell line and the human ileum biopsy specimens by immunofluorescence microscopy. The localizations of Ueno 7k VLPs (genogroup II.6) and each HBGA (type H1-, H2- and Leb-HBGAs) on the human intestinal cell line, Caco-2, were examined by confocal laser-scanning microscopy. To explore any interactions of NoVs and HBGAs in vivo, fresh biopsy specimens from human ileum were directly incubated with NoV VLPs and examined by immunofluorescence microscopy. We found that VLP binding depended on the state of cell differentiation, but not on the presence of HBGAs. In differentiated Caco-2 cells, we detected no type H1 HBGAs, but VLPs bound to the cells anyway. We incubated fresh biopsies of human ileum directly with VLPs, a model that better replicates the in vivo environment. VLPs mainly bound epithelial cells and goblet cells. Although the incubations were performed at 4°C to hinder internalization, VLPs were still detected inside cells. Our results suggest that VLPs utilize molecule(s) other than HBGAs during binding and internalization into cells.

Lack of Norovirus Replication and Histo-Blood Group Antigen Expression in 3-Dimensional Intestinal Epithelial Cells

Noroviruses (NoVs) are a leading cause of gastroenteritis worldwide. An in vitro model for NoV replication remains elusive, making study of the virus difficult. A previous study, which used a 3-dimensional (3-D) intestinal model derived from INT-407 cells reported NoV replication and extensive cytopathic effects (CPE). Using the same 3-D model, but with highly purified Norwalk virus (NV), we attempted to replicate this study. Our results showed no evidence of NV replication by real-time PCR of viral RNA or by immunocytochemical detection of viral structural and nonstructural proteins. Immunocytochemical analysis of the 3-D cultures also showed no detectable presence of histo-blood group antigens that participate in NV binding and host tropism. To determine the potential cause of CPE observed in the previous study, we exposed 3-D cultures to lipopolysaccharide concentrations consistent with contaminated stool samples and observed morphologic features similar to CPE. We conclude that the 3-D INT-407 model does not support NV replication.

The age-dependent expression of the F18 +E. coli receptor on porcine gut epithelial cells is positively correlated with the presence of histo-blood group antigens

F18 + Escherichia coli have the ability to colonize the gut and cause oedema disease or post-weaning diarrhoea by adhering to specific F18 receptors (F18R) on the porcine epithelium. Although it is well established that a DNA polymorphism on base pair 307 of the FUT1 gene, encoding an α(1,2)fucosyltransferase, accounts for the F18R phenotype, the F18R nature is not elucidated yet. The aim of the present study was to investigate the correlation between the presence of H-2 histo-blood group antigens (HBGAs) or its derivative A-2 HBGAs on the porcine gut epithelium and F18 + E. coli adherence. A significant positive correlation was found between expression of both the H-2 ( r = 0.586, P < 0.01) and A-2 ( r = 0.775, P < 0.01) HBGAs and F18 + E. coli adherence after examination of 74 pigs aged from 0 to 23 weeks. The majority of the genetically resistant pigs ( FUT1M307 A/ A ) showed no HBGA expression (91.7%) and no F18 + E. coli adherence (83.3%). In addition, it was found that F18R expression levels rise with increasing age during the first 3 weeks after birth and that F18R expression is maintained in older pigs (3–23 weeks old). Taken together, these data suggest that, apart from H-2 HBGAs, A-2 HBGAs might be involved in F18 + E. coli adherence.

Differential expression of ABH histo-blood group antigens and LAMPs in infantile hemangioma

Although infantile hemangioma (IH) are the most common tumors of infancy, the mechanism of their proliferation and involution remains vague. Proliferation, differentiation and death of endothelial cells are the basic processes involved in their pathobiology. Here we hypothesize that the glycoconjugates ABH histo-blood group antigens (HBGA) and lysosome-associated membrane proteins (LAMPs) might be implied in both the differentiation and death of endothelial cells during vascular remodeling in IH. Proliferating and involuting IH were examined immunohistochemically for HGBA and LAMP expression together with vWF and CD31. Proliferative and apoptotic indices were determined. LAMPs were found in immature endothelium of proliferating IH. In involution an increased number of immunopositive cells stained with higher intensity was detected. The enhanced expression might be associated with augmented autophagy required for tissue remodeling during tumor involution. HBGA presented an opposite pattern of expression--they stained intensely the endothelium of mature capillaries, while the immature ones were positive for vWF. The presence of HBGA in endothelial cells of IH may be related to the differentiation process only, as well as to endothelial adhesion and angiogenesis. Novel evidence for differential expression of HBGA and LAMPs in proliferative and involutive phases of IH is presented.

Correlation of expression of binding sites for synthetic blood group A-, B- and H- trisaccharides and for sarcolectin with survival of patients with bronchial carcinoma

Carrier-immobilised carbohydrates were used to monitor the presence of specific carbohydrate-binding sites in tissue sections. Sarcolectin, an interferon- α β antagonist and growth regulator, had been shown to bind the lymphokine macrophage migration inhibitory factor (MIF). The lectin is thus a MIF-specific probe. Biotinylated sarcolectin, neoglycoproteins with lactose or N-acetylglucosamine residues, and polyacrylamide-attached trisaccharides, that represent the ABH histo-blood group antigens, were applied to sections of 187 primary lung carcinomas. The panel of cases consisted of 57 epidermoid carcinomas, 55 adenocarcinomas, 43 large cell anaplastic carcinomas and 32 small cell anaplastic carcinomas. 47 cases with intrapulmonary metastatic tumours were also included. Expression of binding sites of both sarcolectin and trisaccharides of histo-blood group antigens A and H correlated with patient survival in lung cancer. In view of the widely performed analysis of the presence of histo-blood group antigens, concomitant profiling of binding sites for these sugar components is suggested to be of potential benefit.