Secretor Research Articles

Blood group antigen expression is involved in C. albicans 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 77N-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.

Variation of Human Salivary O-Glycome.

The study of saliva O-glycosylation is receiving increasing attention due to the potential of glycans for disease biomarkers, but also due to easy access and non-invasive collection of saliva as biological fluid. Saliva is rich in glycoproteins which are secreted from the bloodstream or produced by salivary glands. Mucins, which are highly O-glycosylated proteins, are particularly abundant in human saliva. Their glycosylation is associated with blood group and secretor status, and represents a reservoir of potential disease biomarkers. This study aims to analyse and compare O-glycans released from whole human mouth saliva collected 3 times a day from a healthy individual over a 5 days period. O-linked glycans were released by hydrazinolysis, labelled with procainamide and analysed by ultra-high performance liquid chromatography with fluorescence detection (UHPLC-FLR) coupled to electrospray ionization mass spectrometry (ESI-MS/MS). The sample preparation method showed excellent reproducibility and can therefore be used for biomarker discovery. Our data demonstrates that the O-glycosylation in human saliva changes significantly during the day. These changes may be related to changes in the salivary concentrations of specific proteins.

The prevalence of secretor status and co-expression of lewis antigen in voluntary blood donors

Background: Blood group substances are present in soluble form in a majority of individuals in secretion such as saliva and body fl uids. Secretor status refers to the presence (SeSe and Sese) or absence (sese) of secretor gene which secrete ABH soluble substances. Secretor status can be used to resolve ABO discrepancies of people whose blood group cannot be identified by routine blood grouping and it can also help in identifying patients who may be a high risk group for getting certain diseases. Aims and Objectives:Our aim and objectives of the study is to fi nd out the Prevalence of Secretor Status and Co-expression of Lewis Antigens among the Voluntary Blood Donors.Materials and Methods:This study was conducted in sixty volunteers and the method used to determine the secretor status was hemagglutination inhibition method. Their blood was used to detect the type of Lewis (Le) antigen since the type of Lewis antigen correlated with the secretor status of the individual.Results:Among the sixty subjects tested, forty fi ve of them were found to be secretors and fifteen of them were Non-secretors. The number of Lewis (a+b-) individuals were twelve, Lewis (a-b+) were thirty nine and Lewis (a-b-) were nine.Conclusion:The prevalence of secretors was 75% and non-secretors were 25% respectively. We found 65 % of the volunteers were found to be Le (a-b+) positive, 20% were Le (a+b-) and the remaining 15% were Le (a-b-) which correlated with the ABH antigen secretor status.Asian Journal of Medical Sciences Vol.7(5) 2016 93-96

Functional and Structural Characterization of P[19] Rotavirus VP8* Interaction with Histo-blood Group Antigens.

Human P[19] is a rare P genotype of porcine origin. Based on phylogenetic analysis of VP8* sequences, P[19] was classified in the P[II] genogroup, together with P[4], P[6], and P[8], which have been reported to interact with HBGAs in a genotype-dependent manner. In this study, we explored the functional and structural characteristics of P[19] VP8* interaction with HBGAs. P[19] VP8* showed binding to A-, B-, and O-type saliva samples, as well as saliva of nonsecretors. This implies that P[19] has the potential to spread among humans with a broad binding range. Careful attention should be paid to the evolution and prevalence of P[19] RVs. Furthermore, we solved the structure of P[19] VP8*. Structure superimposition indicated that P[19] may bind to other oligosaccharides or ligands using potential binding sites, suggesting that further investigation of the specific cell attachment factors is warranted.

Role of human milk oligosaccharides in Group B Streptococcus colonisation.

Group B Streptococcus (GBS) infection is a major cause of morbidity and mortality in infants. The major risk factor for GBS disease is maternal and subsequent infant colonisation. It is unknown whether human milk oligosaccharides (HMOs) protect against GBS colonisation. HMO production is genetically determined and linked to the Lewis antigen system. We aimed to investigate the association between HMOs and infant GBS colonisation between birth and postnatal day 90. Rectovaginal swabs were collected at delivery, as well as colostrum/breast milk, infant nasopharyngeal and rectal swabs at birth, 6 days and days 60–89 postpartum from 183 Gambian mother/infant pairs. GBS colonisation and serotypes were determined using culture and PCR. 1H nuclear magnetic resonance spectroscopy was used to characterise the mother's Lewis status and HMO profile in breast milk. Mothers who were Lewis-positive were significantly less likely to be colonised by GBS (X2=12.50, P<0.001). Infants of Lewis-positive mothers were less likely GBS colonised at birth (X2=4.88 P=0.03) and more likely to clear colonisation between birth and days 60–89 than infants born to Lewis-negative women (P=0.05). There was no association between Secretor status and GBS colonisation. In vitro work revealed that lacto-N-difucohexaose I (LNDFHI) correlated with a reduction in the growth of GBS. Our results suggest that HMO such as LNDFHI may be a useful adjunct in reducing maternal and infant colonisation and hence invasive GBS disease. Secretor status offers utility as a stratification variable in GBS clinical trials.

ABO Blood Group in Patients with Peptic Ulcer Disease: Association with Secretor Status

Aims and objective of the study is to find ABO blood group association with secretor status in peptic ulcer disease patients. ABO blood grouping by direct agglutination test and secretor status by agglutination inhibition test. 50 controls and 50 endoscopically diagnosed PUD patients were selected. Blood group O is associated with duodenal ulcer but no association with secretor status was found.

ABO and Rh Blood Groups in Patients with hypertension: Association with Secretor Status

Aims and objective of the study is to find ABO and Rh blood groups association with secretor status in patients with hypertension. ABO and Rh blood grouping was done by direct agglutination test and secretor status by agglutination inhibition test. 50 controls and 50 hypertensive patients were selected. No association of ABO and Rh blood group with secretor status was found in patients with hypertension.

Norovirus Gastroenteritis in a Birth Cohort in Southern India.

BackgroundNoroviruses are an important cause of gastroenteritis but little is known about disease and re-infection rates in community settings in Asia.MethodsDisease, re-infection rates, strain prevalence and genetic susceptibility to noroviruses were investigated in a birth cohort of 373 Indian children followed up for three years. Stool samples from 1856 diarrheal episodes and 147 vomiting only episodes were screened for norovirus by RT-PCR. Norovirus positivity was correlated with clinical data, secretor status and ABO blood group.ResultsOf 1856 diarrheal episodes, 207 (11.2%) were associated with norovirus, of which 49(2.6%) were norovirus GI, 150(8.1%) norovirus GII, and 8 (0.4%) were mixed infections with both norovirus GI and GII. Of the 147 vomiting only episodes, 30 (20.4%) were positive for norovirus in stool, of which 7 (4.8%) were norovirus GI and 23 (15.6%) GII. At least a third of the children developed norovirus associated diarrhea, with the first episode at a median age of 5 and 8 months for norovirus GI and GII, respectively. Norovirus GI.3 and GII.4 were the predominant genotypes (40.3% and 53.0%) with strain diversity and change in the predominant sub-cluster over time observed among GII viruses. A second episode of norovirus gastroenteritis was documented in 44/174 (25.3%) ever-infected children. Children with the G428A homozygous mutation for inactivation of the FUT2 enzyme (se428se428) were at a significantly lower risk (48/190) of infection with norovirus (p = 0.01).ConclusionsThis is the first report of norovirus documenting disease, re-infection and genetic susceptibility in an Asian birth cohort. The high incidence and apparent lack of genogroupII specific immunity indicate the need for careful studies on further characterization of strains, asymptomatic infection and shedding and immune response to further our understanding of norovirus infection and disease.

Associations of ABO, D, and Lewis blood groups and HLA Class I and Class II alleles with West Nile virus Lineage 2 disease outcome in Greece, 2010 to 2013.

West Nile virus (WNV) infection, commonly asymptomatic, may cause mild West Nile fever (WNF) or potentially fatal neuroinvasive disease (WNND). An outbreak of 262 cases of the new Lineage 2 strain in Greece in 2010 continued with high mortality (17%) in WNND. The objective was to investigate ABO, D, and Lewis blood groups, as well as HLA Class I and Class II alleles, in relation to WNV Lineage 2 disease morbidity. A cohort of 132 Greek WNV cases in 2010 to 2013 (65% male; mean age 64 years; 41% WNF, 59% WNND) was compared to 51,339 healthy WNV-negative blood donors and 246 healthy subjects. Blood group A was more common in WNV cases (51%) than blood donors (39%) and group O less common (32% vs. 42%). D negativity within group A was higher in WNV than in blood donors (18% vs. 10%, p = 0.044). The frequency of secretors (Lewis(a-b+)) was 60% in WNV and 68% in donors (p = 0.16). HLA alleles C*08, DRB1*O4:O5, and DQB1*O2 occurred significantly less frequently in WNV than controls (p < 0.05 unadjusted for multiple testing) and DRB1*10:O1 more frequently (p = 0.039). This first study of symptomatic WNV Lineage 2 suggests A/D negativity as a new risk factor associated with WNV infection and level of morbidity. Further studies are required of the possibility that HLA C*08, DRB1*O4:O5, and DQB1*O2 are protective alleles and DRB1*10:O1 a "susceptible" allele to WNV infection and the role of secretor status in relation to WNV infection.

Relationship of secretor status in patients with oral cancers

Present study was designed to find the association of secretor status with oral cancers. In this study 50 diagnosed cases of oral cancers and 50 healthy controls were selected. Secretor status on saliva sample was performed in all these subjects. 39 (78%) subjects were secretors and 11 (22%) were non secretors in control group. 28 (56%) patients with oral cancers were secretors and 22 (44%) were non secretors. Conclusions: Oral cancer was found to be associated with non-secretor status.

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].

Salivary agglutinin is the major component in human saliva that modulates the lectin pathway of the complement system.

Saliva interacts with blood after mucosal damage or leakage of gingival crevicular fluid. Surface-adsorbed salivary agglutinin (SAG) activates the lectin pathway (LP) of the complement system via mannose-binding lectin, while SAG in solution inhibits complement activation. In the present study we investigated if, next to SAG, whole and glandular saliva itself and other salivary glycoproteins activate or inhibit the LP. Complement activation was measured by detecting C4 deposition on microtiter plates coated with saliva or purified proteins. Complement inhibition was measured after incubating serum with saliva or proteins in microtiter plates coated with mannan, an LP activator. Adsorbed whole, sublingual and submandibular saliva showed LP-dependent complement activation. Blood group secretors, but not non-secretors, activated the LP. Saliva of both secretors and non-secretors inhibited C4 deposition on mannan. After depletion of SAG, saliva no longer inhibited the LP. Other salivary proteins, including amylase, MUC5B and histatin 2, did not activate or inhibit the LP. Surface-adsorbed whole saliva and glandular saliva samples activate the LP of complement, depending on the presence of SAG and the secretor status of the donor. In solution, saliva inhibits the LP, depending on the presence of SAG, but independent of the secretor status.

Characterisation of a household norovirus outbreak occurred in Valencia (Spain).

BackgroundHuman noroviruses (NoVs) are the main cause of non-bacterial gastroenteritis worldwide. Several studies have linked human susceptibility to NoVs with the expression of histo-blood group antigens (HBGAs). In January 2012, a NoV gastroenteritis outbreak affected a household in Valencia, Spain, and the personal susceptibility to NoV was investigated.MethodsTo reach this aim 8 members of the affected household were recruited for this study and their secretor status, ABO and Lewis antigens were determined. NoV-specific saliva IgA and serum IgG antibody titers were analyzed. Their capacity to block viral binding to saliva receptors was analyzed, using virus-like particles (VLPs) of the NoV GII.4 genotype, 2006b variant, and saliva from a secretor O blood type donor.ResultsThe most relevant finding was that an asymptomatic non-secretor individual shed NoVs in his stools. Interestingly, anti-NoV IgA antibody titers in saliva from secretor and non-secretor individuals showed no differences. On the contrary, high titers of NoV-specific IgG antibody were found in both convalescent sera and in sera collected 1 year post-infection, but only from secretor individuals. NoV GII.4-2006b VLP binding to receptors present in the saliva was efficiently blocked only by sera from secretor positive individuals.ConclusionsDespite the small number of individuals involved in this outbreak, this study reinforces the idea that susceptibility to human NoV is both dependent on the HBGA profile of the individuals as well as on the viral genotype and variant. We also show that the immunity to NoV lasts for at least 1 year after infection, demonstrating that symptomatic infections strongly stimulate immune responses.

Secretor Status and Phenylthiocarbamide (PTC) Taste Perception are Risk Factors for Pulmonary Tuberculosis

Secretor Status and Phenylthiocarbamide (PTC) Taste Perception are Risk Factors for Pulmonary Tuberculosis

Evaluation of the Secretor Status of ABO Blood Group Antigens in Saliva among Southern Rajasthan Population Using Absorption Inhibition Method.

The ABO blood group system was the significant element for forensic serological examination of blood and body fluids in the past before the wide adaptation of DNA typing. A significant proportion of individuals (80%) are secretors, meaning that antigens present in the blood are also found in other body fluids such as saliva. Absorption inhibition is one such method that works by reducing strength of an antiserum based on type and amount of antigen present in the stains. To check the efficacy of identifying the blood group antigens in saliva and to know the secretor status using absorption inhibition method among southern Rajasthan population. Blood and saliva samples were collected from 80 individuals comprising 20 individuals in each blood group. The absorption inhibition method was used to determine the blood group antigens in the saliva and then the results were correlated with the blood group of the collected blood sample. The compiled data was statistically analysed using chi-square test. Blood groups A & O revealed 100% secretor status for both males and females. While blood groups B and AB revealed 95% secretor status. Secretor status evaluation of the ABO blood group antigen in saliva using absorption inhibition method can be a useful tool in forensic examination.

Evaluation of Secretory State in Patients with Oral Lichen Planus: A Case-Control Study.

Non-secretor individuals lack ABO blood group antigens in their secretions like saliva; these carbohydrate structures play an important role in protection of the oral cavity from exogenous pathogens; therefore these individuals are more susceptible to mucous membrane damages. The aim was to assess the secretory state of patients with oral lichen planus (OLP) in comparison with healthy controls. Fifty patients and 100 age-gender matched control subjects were recruited to the study. Patients were visited in the outpatient clinic of dermatology at Shohada-e-Tajrish Hospital, Shahid Beheshti University of Medical Sciences from 2012 - 2014. Two-milliliter (mL) blood was collected from each subject to detect Lewis phenotypes. According to Lewis phenotype of each subject, secretory state was determined except in subjects with Le (a-b-) phenotype, in whom saliva was collected to determine the secretor status. Non-secretor status in patients with OLP was more frequent compared with healthy controls (37 out of 50 patients (74%) vs. 24 out of 100 healthy controls (24%), (P < 0.001)). There was no association between secretory state, and type of OLP and disease duration (P > 0.05). This study supported the possible role of cell surface histo-blood group antigens in protection of mucosal surface from exogenous pathogens. Therefore, it appears that non-secretor individuals are more prone to oral lichen planus.

Expression of the Gene Encoding Secretor Type Galactoside 2 &amp;lt;i&amp;gt;α&amp;lt;/i&amp;gt; Fucosyltransferase (&amp;lt;i&amp;gt;FUT&amp;lt;/i&amp;gt;2) and CD44 Marker in Urogenital Tumors

The aim of this work was to investigate the FUT2 gene, the secretor status and the expression of CD44 protein in epithelial cells obtain from saliva and urine samples from patients with urogenital tumours. We studied 104 subjects. Half of them had urogenital tumours, while the other half was the healthy control group. We determined the secretor status in saliva with the haemagglutination inhibition technique. We analyzed the FUT2 polymorphism by allele specific oligonucleotide–polymerase chain reaction (ASO-PCR) with specific primers for the G428 allele and the wild type allele of FUT2 gene. We found higher intensity of urogenital disease in the non-secretor group (OR = 3.44). In contrast with the healthy population, 51.6% of the patients with potential malignant urogenital lesions and cancerous lesions were non-secretors. We also investigate by confocal microscopy, the expression of CD44 protein in epithelial cells obtained from urine samples from these patients. The results obtained also showed fluorescence corresponding to the presence of CD44 protein in samples from patients diagnosed with cancer. Our study suggests that the lack of wild type FUT2 gene and a nonsecretor status appear to be an associated risk marker for the development of urogenital tumors. Several mechanisms, based on the properties of CD44 as the major hyaluronan CD44 in cell carcinomas receptor, have been proposed to explain the role of elevated CD44 expression during tumour development and progression. CD44 might be a good candidate as a predictor of prognosis in this group of cancers.

The H blood group system

The H blood group system, ISBT symbol H (018), consists of a single antigen (H) defined by a terminal fucose residue found on red blood cells and in secretions formed by the action of α-1,2-fucosyltransferases 1 (α2FucT1) and 2 (α2FucT2), respectively. Mutant alleles of the corresponding FUT1 and FUT2 genes result in either a H– phenotype (Bombay phenotype, Oh) or a weak H phenotype (para-Bombay, H+w). In addition, the FUT2 gene is the molecular basis of the secretor (Se) status, and homozygosity or compound heterozygosity for null alleles is associated with the nonsecretor (se) status. H– individuals have natural anti-H (mostly IgM), which can cause severe hemolytic transfusion reactions with intravascular hemolysis.

Determination of serological markers (blood group markers) of biological fluid (urine) obtained from crime scene for individualization of the donor(s).

Urine samples collected from 20 donors with unknown blood group and secretor status had been determined from saliva. ABO typing on the concentrated samples was successfully performed after 1 month of storage. Urine stained clothing samples are often submitted to forensic science laboratories for ABH blood group antigen determination. The serogenetic markers of urine stains submitted can be used to determine the origin of any of these samples. ABH blood group substances have previously been identified from urine. ABH blood group substance is low in urine in comparison with other body fluids.

Complex Relationship of Blood Group H, ABO Glycans, and Von Willebrand Factor Levels

BackgroundABO(H) is a carbohydrate blood group system expressed in multiple tissues including red blood cells, blood vessels, and mucosal surfaces. ABO is the largest known genetic modifier of plasma VWF level (VWF:Ag). It has been hypothesized that the effect of ABO on VWF is mediated by H glycan density. FUT2, the gene underlying Secretor phenotype, encodes a glycosyltransferase synthesizing H antigen in mucosal tissues, and variation in the gene has also previously been associated with VWF:Ag, but past studies have been conflicting. To clarify these relationships, we studied the relationship between VWF:Ag, ABH glycans, and FUT2 genotype. MethodsThe primary study group was a representative cohort of US blood donors from the Retrovirus Epidemiology Donor Study (REDS, N=499). A validation cohort of unrelated individuals was created from the Genes and Blood Clotting Study (GABC), healthy siblings between ages 14 and 35 years from University of Michigan, Ann Arbor, by choosing a random individual from each family (N=488). VWFAg was determined by ELISA in platelet poor plasma. Forensic techniques were adapted to detect ABH glycans in whole blood (REDS) or RBC-rich, frozen buffy coat (GABC). A and B glycans were detected using anti-A or anti-B (Immucor). A biotinylated Ulex europaeus agglutinin (UEA lectin, Vector Labs) was used to detect H. Relative A, B, and H antigen density was quantified on dot blots with ImageQuant (GE). In REDS, functional FUT2 alleles (Secretor) were determined by Sanger sequencing of FUT2 exon 2. FUT2 copy-number was assayed with real-time quantitative PCR. In GABC, FUT2 genotypes were determined through SNP genotyping (Illumina).In REDS, genotype data was phased (BEAGLE) to identify functional haplotypes. In GABC, functional alleles were inferred from the genotypes of two SNPs (rs601338, rs1047781) that determined secretor status in nearly all samples in REDS (see below). Multivariate regression was applied to VWF:Ag as a function H antigen density and O vs. non-O blood group, both separately and within the same model. All models were adjusted for age, gender, and self-reported ethnicity. ResultsABO blood group frequencies in both cohorts were similar to that of the US population. VWF:Ag differed significantly between ABO blood groups with lower values in blood group O versus non-O (REDS: ratio = 0.75, 95% CI [0.71, 0.80], p<2.2e-16, log-linear regression). H glycan density also differed between ABO blood group (p<2.2e-16, Kruskal-Wallis; O vs. non-O, ratio = 2.03, 95% CI [1.88, 2.19], p<2.2e-16). A significant fraction of H glycan density variation was attributable to ABO (REDS r2 =0.45; GABC r2 =0.34), but a wide range of H glycan density was observed in all blood groups, including within blood group O. In multivariate regression, both H glycan density and O versus non-O blood group, considered separately or in the same model, were significantly associated with VWF:Ag (REDS combined model: p = 2.9e-5 and 2.7e-4 for H glycan and blood group, respectively). In GABC but not in REDS, regression was also significant for an interaction between H glycan density and blood group (p = 0.031). Both cohorts estimated a stronger association of VWF:Ag with H in non-O blood groups.FUT2 sequencing in the REDS cohort identified 22 distinct FUT2 haplotypes. 99.5% (497/499) of individuals could be accurately assigned FUT2 genotypes based on the common W154* (rs601338) polymorphism alone. In GABC, this decreased to 94% (476/488) due to higher frequency of a hypomorphic allele (rs1047781) more commonly found in Asian individuals. In REDS, quantitative PCR did not identify copy-number variation at FUT2. There was no significant association between FUT2 genotype-predicted function and VWF:Ag or H glycan density in either cohort. ConclusionH glycan density correlated with VWF:Ag in both cohorts. H glycan density could mediate the association between ABO blood group and VWF:Ag. If so, this suggests a non-linear, complex relationship between H and VWF and a separate ABO mechanism cannot be excluded. In both cohorts, there was no association of FUT2 (Secretor) genotype with VWF. Our data suggest prior focused approaches to FUT2 genotyping are at risk to undercall non-functional alleles, particularly in cohorts with non-European ancestries. Taken together, these indicate blood group H may be a significant modifier of VWF:Ag, and that this effect is not due to the influence of Secretor phenotype. DisclosuresJohnsen:Octapharma: Other: Speaker; Biogen: Research Funding; CSL Behring: Other: Speaker.