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J Moulds

Publications and source records attributed to J Moulds.

At least 19 recordsLinked to original sources
PubMed1998

Characterization of the gene encoding the human Kidd blood group/urea transporter protein. Evidence for splice site mutations in Jknull individuals.

The Kidd (JK) blood group is carried by an integral membrane glycoprotein which transports urea through the red cell membrane and is also present on endothelial cells of the vasa recta in the kidney. The exon-intron structure of the human blood group Kidd/urea transporter gene has been determined. It is organized into 11 exons distributed over 30 kilobase pairs. The mature protein is encoded by exons 4-11. The transcription initiation site was identified by 5'-rapid amplification of cDNA ends-polymerase chain reaction at 335 base pairs upstream of the translation start point located in exon 4. The 5'-flanking region, from nucleotide -837 to -336, contains TATA and inverted CAAT boxes as well as GATA-1/SP1 erythroid-specific cis-acting regulatory elements. Analysis of the 3'-untranslated region reveals that the two equally abundant erythroid transcripts of 4.4 and 2.0 kilobase pairs arise from usage of different alternative polyadenylation signals. No obvious abnormality of the Kidd/urea transporter gene, including the 5'- and 3'-untranslated regions, has been detected by Southern blot analysis of the blood of two unrelated Jknull individuals (B.S. and L.P.), which lacks all Jk antigens and Jk proteins on red cells, but was genotyped as homozygous for a "silent" Jkb allele. Further analysis indicated that different splice site mutations occurred in each variant. The first mutation affected the invariant G residue of the 3'-acceptor splice site of intron 5 (variant B.S.), while the second mutation affected the invariant G residue of the 5'-donor splice site of intron 7 (variant L.P.). These mutations caused the skipping of exon 6 and 7, respectively, as seen by sequence analysis of the Jk transcripts present in reticulocytes. Expression studies in Xenopus oocytes demonstrated that the truncated proteins encoded by the spliced transcripts did not mediate a facilitated urea transport compared with the wild type Kidd/urea transporter protein and were not expressed on the oocyte's plasma membrane. These findings provide a rational explanation for the lack of Kidd/urea transporter protein and defect in urea transport of Jknull cells.

Base Sequence↗
PubMed1997

Detection of blood group antigens utilising immobilised antibodies and surface plasmon resonance.

Surface plasmon resonance (SPR) detection using the BIAcore biosensing system was employed for the detection of blood group-associated antigens (BGAA) on whole erythrocytes. The quantitative detection of erythrocytes was accomplished by covalently immobilising blood group-specific antibodies (IgM) to a dextran matrix and monitoring the cell binding response. Non-specific binding of erythrocytes to the IgM coated surface was not detected. Relatively mild regeneration conditions (20 mM NaOH) were employed to elute bound erythrocytes in order to preserve the activity of the immobilised antibody and allow the surface to be used repeatedly. Regeneration of the surface was particularly difficult when a high IgM immobilisation level was used and when the number of bound cells was high. Despite these considerations, a quantitative relationship between the cell binding response and erythrocyte concentration was confirmed. Erythrocyte preparations, diluted by a factor of ten as compared to physiological concentrations, were detectable. The occurrence of non-specific false positives appears to be minimal and allows the system to be used for blood typing. As a model study, the lectin concanavalin A (ConA) was covalently immobilised onto a hydrophilic dextran matrix and successfully used to support the capture of erythrocytes from suspension.

Antibodies, Monoclonal↗
PubMed1995

dra-related X adhesins of gestational pyelonephritis-associated Escherichia coli recognize SCR-3 and SCR-4 domains of recombinant decay-accelerating factor.

Bacterial adhesins are important virulence factors that allow colonization of the human urogenital tract by Escherichia coli. Adhesins of the Dr family have been found to be more frequently expressed in strains associated with symptomatic urinary tract infections. Because of the high frequency of symptomatic urinary tract infections during pregnancy, we screened E. coli isolates from 64 gestational pyelonephritis patients for the expression of Dr and X adhesins to address their potential virulence roles in this population. Using PCR and primers for the afaB gene, we detected dra-related operons in 17 isolates (27%). On the basis of the lack of hemagglutination of Dr(a-) erythrocytes containing a point mutation in the decay-accelerating factor (DAF) short consensus repeat-3 (SCR-3) domain, 12 of these strains were categorized as classical Dr adhesins. The hemagglutination of O erythrocytes by Dr+ strains was blocked or reduced by a monoclonal antibody to the DAF SCR-3 domain. The remaining five dra-positive strains agglutinated Dr(a-) erythrocytes. Monoclonal antibody to the DAF SCR-3 domain failed to block O-erythrocyte hemagglutination. Adhesins in these strains did not fulfill criteria for Dr hemagglutinins because of the undefined receptor specificities and were categorized as X. E. coli strains bearing dra-related X adhesins bound to DAF cDNA-transfected Chinese hamster ovary cells. Three of these dra-related X-adhesin-bearing E. coli strains failed to attach to the SCR-3 delta deletion transfectant, which suggested that binding sites were located in the SCR-3 domain but outside the region blocked by the monoclonal anti-SCR-3 immunoglobulin G. The binding sites of the remaining two dra-related X adhesin strains were localized to the SCR-4 domain, as the attachment was shown to be abolished on an SCR-4 delta mutant but unaffected by an SCR-3 delta deletion. The heterogeneity in the binding sites of E. coli DAF (Dr) family adhesins from gestational pyelonephritis isolates may reflect the ability of the adhesins to evolve to recognize alternate peptide epitopes for efficient colonization.

Adhesins, Escherichia coli↗
PubMed1993

Different manifestations of the antiphospholipid antibody syndrome in a family with systemic lupus erythematosus.

OBJECTIVE: Familial associations of the antiphospholipid antibody syndrome (APS) offer the opportunity to study genetic mechanisms of autoantibody production and disease, but are unusual. We identified a family, including identical twins and their mother, in which all members had systemic lupus erythematosus (SLE) and presented with different manifestations of the APS. METHODS: Review of case histories and clinical laboratory results, antiphospholipid antibody (aPL) studies, complement C4 protein and gene analysis, and HLA typing of family members were performed. RESULTS: Each of the 3 family members presented with a different clinical association of the APS. These various clinical presentations were closely temporally related. No particular aPL activity could be separated out that would account for the different manifestations, although the twin with thrombocytopenia and livedo reticularis had a strikingly high IgM anticardiolipin antibody level. C4A or C4B deficiencies could not be implicated in the autoimmune process. However, the mother and the twins shared the HLA haplotype that included the class II antigens DR4, DRw53, and DQw7, which has previously been associated with aPL production. CONCLUSION: This family study emphasizes the different clinical associations of aPL production in SLE. In addition to genetic influences that appear to include HLA class II antigens, the clinical presentations also suggest an environmental trigger.

Adolescent↗
PubMed1990

The Dr hemagglutinin, afimbrial adhesins AFA-I and AFA-III, and F1845 fimbriae of uropathogenic and diarrhea-associated Escherichia coli belong to a family of hemagglutinins with Dr receptor recognition.

The receptor specificities of four Escherichia coli cloned hemagglutinins, AFA-I, AFA-III, F1845 fimbriae, and the Dr hemagglutinin were studied. Evidence is provided that all four hemagglutinins recognize as their receptor the Dr blood group antigen. However, results of experiments using enzyme-treated erythrocytes and monoclonal antibodies indicate that the four adhesins recognize different epitopes on the Dr antigen and thus constitute a family of Dr receptor-recognizing bacterial adhesins. Furthermore, the same results suggest that the Dr antigen itself may be divided into subcomponents on the basis of bacterial adhesins.

Adhesins, Escherichia coli↗
PubMed1988

A hemagglutinin of uropathogenic Escherichia coli recognizes the Dr blood group antigen.

A receptor moiety and blood group substance recognized by the O75X adhesin was studied. Well-defined erythrocytes representing different blood group systems and bacterial derivatives carrying plasmid pBJN406 encoding the adhesin were used in a direct hemagglutination assay. We showed that Dr blood group antigen, a component of the IFC blood group complex, is the receptor for the O75X fimbrialike adhesin (Dr hemagglutinin) of uropathogenic Escherichia coli. The molecule recognized by the Dr hemagglutinin on Dr blood group substance is a chloramphenicol-like structure. The inhibitory effect of the active compounds indicates that a tyrosine-containing molecule could be a natural receptor for the Dr hemagglutinin. Dr blood group substance was found in tubular basement membrane and Bowman's capsule of the human kidney. Specific attachment of a Dr hemagglutinin-positive bacterial strain to the kidney substructures was inhibited by chloramphenicol.

Bacterial Adhesion↗
PubMed1988

Presence of the Dr receptor in normal human tissues and its possible role in the pathogenesis of ascending urinary tract infection.

The Dr hemagglutinin of uropathogenic Escherichia coli recognizes the Dra blood group antigen, a component of the IFC or Cromer-related blood group complex. The present report used the Dr hemagglutinin to demonstrate location of the Dr receptor in selected human tissues and to evaluate the possible use of this lectin as a tissue marker recognizing sites sensitive for bacterial colonization. It was found that the Dr receptor was expressed in different parts of the digestive, urinary, genital, and respiratory tracts, and skin. Intense staining by Dr hemagglutinin was shown in colonic, bronchial, and endometrial glands, and skin eccrine sweat glands. Structures of the urinary tract showing strong fluorescence were renal tubular basement membrane, Bowmans' capsule, and transitional epithelium. The role of Dra antigen as receptor for adhesion for Dr-positive E. coli in ascending colonization of urinary tract and the possible importance of Dra in human pathology is discussed.

Antigens, Bacterial↗
PubMed1987

Hybrid glycophorins from human erythrocyte membranes. Isolation and complete structural analysis of the novel sialoglycoprotein from St(a+) red cells.

Human red cells from donor Pj carry the Sta blood group antigen and an unusual sialoglycoprotein of 24 kDa molecular mass tentatively identified as a hybrid molecule of the anti-Lepore type [Blanchard et al. (1982) Biochem. J. 203, 419-426]. This component is resistant towards proteinase treatment and was purified from trypsin-treated and chymotrypsin-treated Pj erythrocytes. The molecule is composed of 99 amino acid residues whose alignment was established following manual and automatic sequencing of cyanogen bromide, trypsin, chymotrypsin and V8 proteinase peptides. The polypeptide chain comprises residues 1-26/28 of glycophorin B and residues 59/61-131 of glycophorin A. The sugar composition resembles that of glycophorin B, indicating the absence of an N-glycosidic chain. Identical sequences were obtained from analyses of the 24-kDa component purified from unrelated St(a+) donors. These results support the hypothesis that glycoprotein Pj represents a B-A hybrid molecule which is encoded by a new gene product resulting from an unequal crossing-over between the genes coding for the polypeptide chains of the glycophorins A and B. The novel molecule carries both N and Sta blood group antigens. The N activity is clearly understandable from the sequence of the five N-terminal residues (Leu and Glu at positions 1 and 5 respectively). Inhibition studies with the untreated and chemically modified hybrid glycoprotein indicate that the Sta determinant is located within residues approximately 25-30 of the molecule, which corresponds to the newly formed sequence found neither in glycophorin A nor in glycophorin B.

Amino Acid Sequence↗
PubMed1987

Hybrid glycophorins from human erythrocyte membranes. I. Isolation and complete structural analysis of the hybrid sialoglycoprotein from Dantu-positive red cells of the N.E. variety.

The hybrid glycophorin in Dantu-positive human erythrocytes of the N.E. variety was not cleaved by treatment of intact cells with various proteases, in contrast to normal glycophorins. Therefore, it could be purified by phenol/saline extraction of membranes from trypsin-treated and chymotrypsin-treated red cells and subsequent gel filtration in the presence of Ammonyx-LO. The complete structure of the hybrid molecule, comprising 99 amino acid residues, was elucidated by sequence analyses of peptides prepared by chymotrypsin, trypsin, cyanogen bromide or V8 proteinase treatment. The N-terminal 39 residues and the glycosylation of the molecule were found to be indistinguishable from those of blood-group-s-specific glycophorin B. Conversely, the residues 39-99 were shown to be identical with the residues 71-131 of the major blood-group M-active or N-active sialoglycoprotein (glycophorin A). Hemagglutination inhibition assays revealed that the Dantu antigen represents a labile structure. The receptor might be located within the residues approximately 28-40 of the hybrid glycophorin, as judged from the effects of modifications of membranes. Our data provide an explanation for the previous findings that Dantu-positive cells (N.E. type) exhibit a protease-resistant N antigen and a qualitatively altered s antigen.

Amino Acids↗
PubMed1987

The Dantu erythrocyte phenotype of the NE variety. I. Dodecylsulfate polyacrylamide gel electrophoretic studies.

Red cell membranes from patient NE, Mr. Dantu and 16 additional Black individuals, positive for the low-frequency MNSs-system antigen Dantu, were studied by dodecylsulfate polyacrylamide gel electrophoretic techniques. The content of the major, blood group M- or N-active sialoglycoprotein (glycophorin A, GP A) was found to be decreased by about 57%. The blood group S- or s-active sialoglycoprotein (GP B) was decreased by about 51% in membranes from proven Dantu/U heterozygotes and not detectable in those from patient NE and other Dantu+U- individuals. Donor NE was shown to exhibit the genotype Dantu/u. Dantu-positive cells exhibit a proteinase-resistant GP B-GP A hybrid with an apparent molecular mass of 29 KDa whose intramembraneous and cytoplasmic domains were shown to be similar to those of GP A. The molar hybrid: GP A ratio in all cells was found to be about 2.4: 1, indicating that the NE variety of the Dantu phenotype is much more frequent than the Ph or MD types. The significance of an additional minor 'new' component (molecular mass 21 KDa) in Dantu+ membranes and the minor component J (molecular mass 22 KDa) occurring in normal and Dantu+U+ GP preparations, but not in those from Dantu+U- cells, has not been resolved. The apparent molecular mass of the anion channel protein (band 3) in all cells of the NE variety was shown to be decreased by about 3 KDa, due to a shortening of carbohydrate chains. This suggests that the hybrid, just like GP A, might form a complex with band 3.

Alleles↗
PubMed1987

Characterization of the Ss sialoglycoprotein and its antigens in Rhnull erythrocytes.

The Ss sialoglycoprotein (glycophorin B) and its antigens in Rhnull erythrocytes, which lack the Rhesus blood group antigens, due to apparently silent (amorphic type) or independent suppressor (regulator type) genes, were investigated. The quantity of the molecule in amorphic and in regulator type red cell membranes was found to be decreased by about 60%-70%, as judged from sodium-dodecylsulfate polyacrylamide gel electrophoresis. The Ss glycoprotein content in the erythrocytes from heterozygotes (regulator type) was diminished to an extent of about 30%. Confirming and extending previous studies, the S, s, Ux, Uz and 'N' antigens were slightly weakened in Rhnull erythrocytes. The U and Duclos receptors were only slightly or not depressed in amorphic Rhnull cells, but almost absent from or not detectable in those of the regulator type. This demonstrates that an additional alteration, apart from the decreased Ss glycoprotein content of the membranes, accounts for the weakness of these receptors in regulator type cells. We propose the hypothesis that (a) protein(s) encoded by the Rhesus locus form(s) a complex with the Ss glycoprotein. Thus, it (they) might facilitate the incorporation of the Ss glycoprotein into the membrane and also contribute to the complete expression of the U and Duclos antigens in normal cells.

Densitometry↗
PubMed1987

Swa: a subdivision.

For some time, anomalous serological reactions have been observed when the same anti-Swa sera are tested against red cells from different individuals reported as Sw(a+). A comparative collaborative study using the same collection of Sw(a+) cells and anti-Swa sera was undertaken by 4 reference laboratories, and it was found that Swa represents a heterogeneous group of antigens that can be subdivided into two categories. Both categories, Sw(a+) 700:41 and Sw(a+) 700:-41, were shown to be inherited.

Blood Group Antigens↗
PubMed1985

Altered membrane sialoglycoproteins in human erythrocytes lacking the Gerbich blood group antigens.

The sialoglycoproteins (glycophorins) in human red cell membranes of rare individuals lacking totally (Ge-1,-2,-3 phenotype) or partially (Ge-1,-2,3 phenotype) the Gerbich (Ge) blood group antigens and two Ge-1,-2,-3 heterozygotes were studied by dodecylsulfate polyacrylamide gel electrophoretic techniques. Two sialoglycoproteins (components D and E) were not detectable in the membranes from the homozygotes and found to be decreased by about 50% in those from the heterozygotes. Ge--1,-2,-3 and Ge-1,-2,3 cells were found to contain a 'new' component (mol. masses about 29 and 30 kDa, respectively) possibly representing a D/E hybrid molecule. This sialoglycoprotein was not detectable in membranes from the Ge-1,-2,-3 heterozygotes, suggesting that the Ge-1,-2,-3 phenotype may be caused by at least two different alleles at the Ge blood group antigen locus. Hemagglutination or hemagglutination inhibition tests involving anti-Ge 1,2,3 and -Ge 1,2 as well as native and enzyme-treated normal red cells (phenotype Ge 1,2,3) or membrane and sialoglycoprotein fractions from normal erythrocytes indicate that the receptors of these sera are located within the glycosylated domain(s) of the D and/or E sialoglycoprotein(s). Our data suggest that the Ge locus encodes the polypeptide sequences of the D and E sialoglycoproteins.

Blood Group Antigens↗
PubMed1985

High frequency antigens of human erythrocyte membrane sialoglycoproteins. I. Ena receptors in the glycosylated domain of the MN sialoglycoprotein.

The specificity of various allo- and autoantibodies, which agglutinate normal erythrocytes, but do not react with En(a-) red cells and normal erythrocytes, treated with trypsin (anti-EnaTS) or ficin (anti-EnaFS), was investigated. Various fragments and modification products of the major (MN) red cell membranes sialoglycoprotein were used in hemagglutination inhibition assays. Six anti-EnaFS sera were found to be directed against the residues approx. 46-56 of the molecule. Five of these require the carbohydrate unit, attached to Thr50, for binding. One anti-EnaTS serum was found to be directed against the residues approx. 36-42. Another antibody with anti-EnaTS specificity was shown to react with the residues 31-39 in some of the MN sialoglycoprotein molecules, namely those not glycosylated at a certain position (probably Thr33). A third anti-EnaTS serum, directed against the sequence domain around Lys30, was also found to react only with a fraction of the molecules, apparently due to the variable attachment of oligosaccharides in that region. The heterogeneity of glycosylation, detected by these two sera, appears to account for the partial tryptic and chymotryptic cleavage in this domain of the MN sialoglycoprotein, which has been described previously. Heterogeneity of the glycosylation at various positions of the molecule could be established by the isolation and analysis of peptides.

Amino Acid Sequence↗
PubMed1984

Structural analysis of the Ss sialoglycoprotein specific for Henshaw blood group from human erythrocyte membranes.

The N-terminal structures of the MN and Ss erythrocyte membrane sialoglycoproteins (glycophorins A, B) from two Henshaw (He) blood-group heterozygotes were determined by manual sequencing of tryptic glycopeptides and various secondary fragments. No structural alteration of the MN glycoprotein could be detected. The He-specific portion of the Ss glycoprotein was found to exhibit the N-terminal sequence Trp-Ser+-Thr+-Ser+-Gly-(+ = glycosylation). Thus it differs at three positions from its normal counterpart which possesses 'N' activity and exhibits the N-terminal structure Leu-Ser+-Thr+-Thr+-Glu-. Analysis of the Ss glycoprotein from 15 He-negative erythrocyte samples did not reveal any of the three He-specific structural alterations. The presence of a glycine residue at the fifth position of the blood-group-M-active MN glycoprotein as well as in the He-specific Ss glycoprotein provides an explanation for the occurrence of antisera (anti-Me) reacting with the M and He antigens.

Amino Acid Sequence↗
PubMed1982

Alloantibody-induced impaired neonatal expression of a red blood cell antigen associated with maternal alloimmunization.

Animals genetically capable of making certain gene products have been shown to have the production of such products completely or partially suppressed by exposure in utero or neonatally to antibodies specific for that gene product. This alloantibody-induced depression of expression of a specific antigenic determinant has yet to be shown to occur in man. The McCoya red blood cell antigen is reported to be well developed at birth. However, 2 children born to mothers with high-titer McCoya antibodies in their serum, phenotyped as McCoy (a-) at birth and, on retesting their red blood cells, 1 at 5 months and the 2nd at 11 months, both phenotyped as McCoy (a+). It is possible that this lack of expression of the McCoya antigen at birth represents a characteristic of an obligate heterozygote. However, on testing 50 random umbilical cord red blood cell samples with two potent McCoya antisera, only 1 was found to be negative. If the negative phenotype were a characteristic of an obligate heterozygote at birth, then the neonatal incidence of the McCoy (a-) phenotype should have been significantly (p less than 10(-4)) high in our random cord blood sample than observed (expected 11). The impaired expression of the McCoya antigen on the red blood cells of these 2 infants at birth, in conjunction with evidence of maternal alloimmunization, strongly suggests alloantibody-induced antigenic suppression of the McCoya antigen as a probable cause.

Adult↗