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S Kabir

Publications and source records attributed to S Kabir.

At least 37 records · Page 2Linked to original sources
PubMed1989

Antigenic analysis of Vibrio cholerate O1 by crossed immunoelectrophoresis.

Antigens from Vibrio cholerae O1 were analyzed by crossed immunoelectrophoresis (CIE) using sera from immunized rabbits. Thirty different anode-migrating antigens were detected in sonicated antigen preparations of V. cholerae. These antigens were numbered in order to establish a reference precipitation pattern. Antigen no. 30 was identified as the lipopolysaccharide (LPS) antigen, because it reacted with (i) periodic acid-Schiff (PAS) reagent and (ii) the affinity-purified anti-LPS antibodies. Treatment with proteinase K demonstrated that most of the precipitation lines were due to proteins, a part of which were localised at the cell surface. The major outer membrane protein was found to be closely associated with the precipitation line due to the LPS (antigen no. 30). The antigenicity and immunogenicity of V. cholerae cells killed by different methods (merthiolate, heat, phenol, formalin) were examined. As determined by CIE, killing with merthiolate preserved most of the major components of V. cholerae. Heat, phenol and formalin altered the antigenic mosaic of V. cholerae. These results suggested that CIE can be used to analyze several aspects of V. cholerae antigens.

Animals↗
PubMed1989

A novel urinary sialoglycoprotein as the inhibitor of interleukin-1.

An inhibitor of interleukin-1 (IL-1) was purified to homogeneity from febrile human urine by using a sequence of ammonium sulphate fractionation, DEAE-cellulose chromatography and gel filtration on a column of ACA 54. The inhibitor was a sialoglycoprotein and its molecular weight, examined by SDS-PAGE, was found to be 30 kD. It was acidic in nature and its isoelectric point, determined by electrofocusing on thin-layer polyacrylamide gels, was found to be 3.5-3.6. The inhibitor was sensitive to the action of sialidase from Vibrio cholerae as the enzyme treated material was electrofocused at a higher pH range (4.5-5.2). The inhibitor contained 10% sialic acid as estimated by the Thiobarbituric acid assay. It interacted with the lectins jacalin and concanavalin A, suggesting the presence of carbohydrate moieties such as galactose and mannose. The inhibitor did not block the specific binding of IL-1 to cells, nor did it directly bind IL-1. Early rejection urine from a kidney transplant patient was also found to contain the 30 kD IL-1 inhibitor protein. This was visualised by immunoblotting using specific antibody raised against the 30 kD IL-1 inhibitor isolated from the urine of febrile patients.

Electrophoresis, Polyacrylamide Gel↗
PubMed1987

Preparation and immunogenicity of a bivalent cell-surface protein-polysaccharide conjugate of Vibrio cholerae.

Alkali-treated lipopolysaccharides (LPS) from Ogawa and Inaba serotypes of Vibrio cholerae were chemically coupled to cell-surface proteins of V. cholerae. The reaction product was eluted in the void volume when fractionated on a column of Sephacryl S-300. The material did not enter the gel when subjected to polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate (SDS-PAGE). The bivalent protein-polysaccharide conjugate was nonpyrogenic, as determined by the Limulus lysate assay. It was immunogenic and elicited, in rabbits, antibodies against both intact LPS and cell surface proteins, as determined by enzyme linked immunosorbent assay. LPS from Ogawa serotype was resolved into two major bands by SDS-PAGE and that from the Inaba serotype into one major band. Immunoblotting studies indicated that antisera to the protein-polysaccharide conjugate contained antibodies to the major LPS fractions from both serotypes. Antisera to the protein-polysaccharide conjugate tested by crossed-immunoelectrophoresis produced immunoprecipitation with whole-cell sonicates of both biotypes and serotypes of V. cholerae. Such antisera also possessed agglutinating and complement-mediated bactericidal activities towards V. cholerae strains of both biotypes and serotypes. These results suggest that a bivalent cell-surface protein-polysaccharide conjugate of V. cholerae could be developed as a nonpyrogenic vaccine against cholera.

Agglutination Tests↗
PubMed1987

Immunological responses of rabbits to various somatic and secreted antigens of Vibrio cholerae after intra-duodenal inoculation.

The immunological responses of rabbits after intra-duodenal immunisation with live Vibrio cholerae organisms were studied in various body fluids. Serum, bile and intestinal samples were collected from rabbits at different times (1-8 weeks) after immunisation. Three different extracts from the small intestine were prepared. At first the small intestine was washed with saline (method A). Later, ultrasonic lysates were prepared from epithelial cells separated with citrate (method B) and of mucosal tissue above the muscularis layer (method C). All had agglutinating activities against V. cholerae strains belonging to both biotypes (classical and el tor) and both serotypes (Ogawa and Inaba). Levels in intestinal extracts, sera and bile of antibodies to somatic (lipopolysaccharide and cell-surface proteins) and secreted (cholera toxin and neuraminidase) antigens of V. cholerae were determined by an enzyme-linked immunosorbent assay. All contained antibodies to these antigens; although both IgA and IgG were present, IgA predominated. Serum and bile samples contained mainly IgG and IgA respectively. Immunoblotting studies demonstrated that the antisera contained antibodies to most cell-surface proteins and to cholera toxin. Cell-surface proteins appeared to be the major cross-reacting somatic antigens of V. cholerae.

Agglutination Tests↗
PubMed1986

Composition and immunochemical properties of the cell surface proteins of Vibrio cholerae.

The composition and immunochemical properties of cell surface proteins of Vibrio cholerae belonging to both the biotypes (classical and El Tor) and the serotypes (Ogawa and Inaba) were investigated. Proteins were isolated by extraction with EDTA/NaCl. When the extract was further treated with sodium deoxycholate, a product significantly enriched with the major protein was obtained. The surface localization of these proteins was confirmed by immunoelectron microscopy using protein A-colloidal gold particles as probes. Antisera to these proteins possessed complement-mediated bactericidal activities towards V. cholerae strains belonging to both the biotypes and the serotypes, and upon crossed immunoelectrophoresis produced several immunoprecipitation reactions towards whole-cell sonicates belonging to all types of V. cholerae. These proteins were immunogenic in the rabbit intestine, as antibodies of two classes (IgG and IgA) were detected in the intestinal fluids. The intestinal immune response was greatly enhanced when cell surface proteins were administered with liposomes. These results suggest that cell surface proteins represent common antigens of V. cholerae and can be explored as vaccine candidates against cholera.

Animals↗
PubMed1984

Neuraminidase production by Vibrio cholerae O1 and other diarrheagenic bacteria.

Vibrio cholerae O1 strains belonging to both biotypes (classical and El Tor) and both serotypes (Ogawa and Inaba) produced neuraminidase which was released rather than cell bound. Classical strains made more neuraminidase than did El Tor strains. About one-third of V. cholerae non-O1 strains and one-fourth of Aeromonas hydrophila strains were neuraminidase positive. Strains of enterotoxigenic Escherichia coli, Vibrio parahaemolyticus, and Shigella spp. did not produce detectable neuraminidase.

Diarrhea↗
PubMed1983

The serological properties of the cell surface proteins of Vibrio cholerae.

The serological properties of cell surface proteins of Vibrio cholerae belonging to both the biotypes (classical and El Tor) and the serotypes (Ogawa and Inaba) were investigated. Proteins were isolated by extracting V. cholerae with EDTA in the presence of sodium chloride. The surface localization of these proteins was confirmed with (a) radioiodinated protein A as an immunoprobe and (b) antiserum absorption studies with whole bacteria. There were similarities among the polypeptides of cell surface proteins isolated from various V. cholerae types. Antisera to these proteins agglutinated several V. cholerae strains, irrespective of biotype, serotype and antibiotic sensitivity. The antisera did not agglutinate pathogenic enteric bacteria such as enterotoxigenic Escherichia coli, Salmonella typhi, Shigella spp., Aeromonas hydrophila and Yersinia enterocolitica. The cell surface proteins of V. cholerae were immunogenic in rabbits as high titres of anti-protein specific antibodies were detected by the ELISA technique in the immune sera. These results suggest that the cell surface proteins are common antigens of V. cholerae and can be developed as a potential vaccine candidate against cholera.

Agglutination Tests↗
PubMed1983

Immunochemical properties of the major outer membrane protein of Vibrio cholerae.

Antisera to the major outer membrane protein of Vibrio cholerae (molecular weight, 48,000) raised in rabbits (i) agglutinated several strains of V. cholerae and (ii) immunoprecipitated outer membrane proteins prepared from both the biotypes and serotypes of V. cholerae. Antibodies of all isotypes to the major outer membrane protein were detected in immune human sera by enzyme-linked immunosorbent assay. These results suggest that the major outer membrane protein was the common outer membrane antigen of V. cholerae which was immunogenic in humans.

Agglutination↗
PubMed1983

Characterization of surface properties of Vibrio cholerae.

A number of isolates of Vibrio cholerae were examined with respect to their (i) surface hydrophobicity as measured by hydrophobic interaction chromatography, (ii) capacity to agglutinate erythrocytes, and (iii) ability to bind to an ion-exchange matrix. V. cholerae isolates, cultured under a variety of growth conditions, were conspicuously hydrophobic. The hydrophobicity was accentuated when these strains were (i) cultivated in a chemically defined synthetic medium, (ii) harvested at the exponential phase of growth, and (iii) cultured at a lower temperature. Rough strains were more hydrophobic than smooth strains. Of the various surface components examined, the outer membrane proteins were conspicuously hydrophobic. The cell-bound hemagglutinating activity of V. cholerae strains was increased when these strains were cultured in synthetic medium and harvested at the stationary phase of growth. This property was unaffected by the growth temperature. Only D-mannose, at a high concentration, inhibited hemagglutination of 80% of the isolates examined. L-Fucose did not inhibit the hemagglutinating activity. V. cholerae strains adhered strongly to the anion-exchange matrix DEAE-cellulose. The surface charge density was accentuated when these strains were grown in synthetic medium. These results suggest that the V. cholerae surface contains both specific (hemagglutinating) and nonspecific (hydrophobic and ionic) factors which may influence its eventual adherence to the host cell surface.

Adhesiveness↗
PubMed1982

Characterization of the lipopolysaccharide from Vibrio cholerae 395 (Ogawa).

The chemical structure and biological properties of the lipopolysaccharide (LPS) from Vibrio cholerae 395 (Ogawa), isolated by the phenol-water procedure, were studied. Upon acid hydrolysis, the LPS was split into its polysaccharide and lipid A moieties. The polysaccharide contained both neutral (glucose, heptose, fructose) and amino (glucosamine, quinovosamine) sugars. The LPS contained the acid-labile amino sugar, 4-amino-arabinose, which was absent in the Inaba serotype of V. cholerae. The LPS differed from the LPSs of Enterobacteriaceae by the absence of 2-keto-3-deoxyoctonate and the presence of fructose. Analysis of the methylated polysaccharide by gas-liquid chromatography and mass spectrometry showed that it had a branched structure with glucose and heptose residues primarily appearing at the nonreducing-end groups. Interactions with lectins, concanavalin A. and wheat germ agglutinin suggested that terminal glucose residues were alpha linked, whereas terminal glucosamine residues were connected by alpha-1,3 linkages. The major fatty acids of the LPS were C14:0, C16:0, C12h:0, and C14h:0 compounds, of which only the C14h:0 were amide linked, the remainder being ester linked to the backbone. Biological studies showed that the LPS possessed endotoxic properties such as lethality, pyrogenicity, limulus lysate gelation, and ability to induce non-specific resistance to infection. Thus, the LPS from V. cholerae 395 (Ogawa) possessed both common and distinct features as compared with the LPSs from the Enterobacteriaceae.

Animals↗
PubMed1980

Immunological properties of the cell envelope components of Vibrio cholerae.

Several immunobiological properties of cell envelope components of Vibrio cholerae such as mitogenicity, antigenicity, adjuvanticity and toxicity were tested in mice. Killed whole bacteria, spheroplasts, lipopolysaccharide and outer membrane proteins possessed mitogenic activity as determined by [3H]thymidine uptake in spleen cell cultures. All these components predominantly stimulated murine bone-marrow derived (B) lymphocytes. The mitogenicity induced by V. cholerae lipopolysaccharide was similar in magnitude to that observed with Salmonella typhimurium lipopolysaccharide. Vibrio cholerae lipopolysaccharide was mitogenic for gut-associated lymphocytes such as those obtained from Peyer's patches and small intestine. Antibody formation at the cellular level was detected by the haemolytic plaque assay. Plaque-forming cells to V. cholerae lipopolysaccharide were only detected when mice were immunized intraperitoneally with intact cells or with spheroplasts. Among the various cell envelope components, lipopolysaccharide alone possessed adjuvant properties as it increased the number of plaque-forming cells to sheep erythrocytes fourfold in mouse spleens. Also, lipopolysaccharide was the only component found to be toxic for the mouse (LD50 0 . 5 mg). Neither spheroplasts nor outer membrane of V. cholerae showed adjuvanticity or toxicity in mice.

Adjuvants, Immunologic↗
PubMed1980

Composition and immunochemical properties of outer membrane proteins of Vibrio cholerae.

The protein compositions of the outer membranes of various Vibrio cholerae strains, belonging to both biotypes (El Tor and classical) and both serotypes (Ogawa and Inaba), were analyzed by electrophoresis on polyacrylamide slab gels in the presence of sodium dodecyl sulfate. All these strains contained a major protein band of molecular weight 48,000. But they differed in the composition and proportions of minor proteins. The outer membrane protein profile was influenced by the growth medium. A protein band of molecular weight 15,000 was observed in the outer membrane when V. cholerae Ogawa 395 (classical) was grown in peptone-water, whereas a protein of molecular weight 68,000 appeared when it was grown in the synthetic medium. Under anaerobic growth conditions the proportion of the 13,000-molecular-weight protein was greatly enhanced. The outer membrane contained heat-modifiable proteins, as the protein bands with molecular weights 41,000 and 37,000 disappeared when membrane proteins were disaggregated in sodium dodecyl sulfate at or above 60 degrees C. The antisera to the outer membrane proteins of V. cholerae Ogawa 395 (classical) produced immunoprecipitation to the outer membrane proteins of both biotypes and both serotypes. Also, the antisera agglutinated bacteria of both biotypes and both serotypes, suggesting the presence of a common protein antigen in the outer membrane of V. cholerae.

Amino Acids↗
PubMed1978

The isolation and characterization of plasma membranes from calf thymocytes.

A simple method is described for the isolation and characterization of plasma membranes from calf thymocytes. The procedure involves extraction of thymocytes in a hypotonic medium containing borate and EDTA. Membrane ghosts, obtained by centrifugation of the cell lysate, are purified by passage through a column containing glass beads. The purity of plasma membranes was checked by chemical analysis, by assay of marker enzymes and also by electron microscopy. Polyacrylamide gel electrophoresis of the calf thymocyte plasma membrane produced a number of protein bands as well as a major band which stained for carbohydrate. The method is rapid and could be applied to isolate plasma membranes from nucleated cells of various types in large quantities.

Animals↗
PubMed1977

Binding of bacterial endotoxin to murine spleen lymphocytes.

The early events in lipopolysaccharide (LPS)-induced B-cell activation were investigated by studying the binding of 14C-labeled LPS to murine lymphocytes in vitro. In these studies we utilized intrinsically labeled 14C-labeled LPS from Salmonella minnesota or the 14C-labeled glycolipid derived from the Re mutant of S. minnesota (R595). Bone marrow-derived (B) lymphocytes bound more LPS than did thymus-derived (T) lymphocytes. Binding of LPS to murine spleen lymphocytes from strain C3H/HeN was compared with the binding to spleen lymphocytes from strain C3H/HeJ, a strain resistant to certain biological activities of LPS including mitogenesis. Spleen cells from both strains bound LPS equally well, suggesting that unresponsiveness of C3H/HeJ mice to LPS is due to factors other than a defect in binding of LPS. LPS binding to cells appeared to be due to a nonspecific interaction between the lipid moiety of LPS and the lipid components of the cell membrane. Thus, the highly lipophilic, polysaccharide-deficient glycolipid from R595 bound at least 20 times better than did LPS. Furthermore, partial removal of cell surface proteins with trypsin or sialic acids with neuraminidase enhanced glycolipid binding, suggesting that binding is not through a protein- or sialic acid-containing receptor. The binding of glycolipid to lymphocytes was only partially specific since unlabeled glycolipid R595, lipid A, and LPS did not completely inhibit the uptake of 14C-labeled glycolipid R595. In addition, binding could be inhibited by a nonmitogenic phospholipid (phosphatidyl ethanolamine), which also is consistent with a nonspecific lipid-lipid interaction. Experiments were performed to determine the relationship of LPS binding to lymphocyte activation in the lymphocytes. The process of activation of lymphocytes by LPS was a slow one, since LPS was required to be present in culture for at least 24 h in order to obtain significant lymphocyte activation, suggesting that the amounts of LPS bound earlier are either quantitatively or qualitatively insufficient to irreversibly activate the cell.

Animals↗
PubMed1977

Investigations on the outer membrane proteins of Salmonella typhimurium.

The number, nature and organization of the outer membrane proteins of Salmonella typhimurium have not yet been resolved. Therefore these proteins were isolated using a concentrated solution of guanidine hydrochloride and studied using different analytical techniques. Upon chromatography on Sephadex G-200 four fractions were obtained. Only the fraction containing a protein of molecular weight 13,000 produced immunoprecipitation reactions with the antisera raised against the whole bacteria. On polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate, 7 major proteins were found, with molecular weights between 13,000 and 43,000. Isoelectric focusing on 4.6% polyacrylamide gels resolved the outer membrane proteins into 10 bands with apparent isoelectric points between 5.0 and 8.4. Finally these proteins could be further resolved into as many as 50 spots where a two-dimensional electrophoresis was carried out with isoelectric focusing in the first dimension, and polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate in the second dimension. These results demonstrated that the outer membrane proteins of S. typhimurium are extremely heterogeneous. To investigate the mode of organization of lipopolysaccharides in the outer membrane, the membrane proteins were separated by the liquid isoelectric focusing technique. Lipopolysaccharides were primarily found to be associated with a protein of isoelectric point 7.8.

Bacterial Proteins↗
PubMed1975

Cell surface protein of Salmonella typhimurium.

Lactoperoxidase-catalyzed radioiodination with Na125I was performed both on intact Salmonella typhimurium 1195 and on ghost membrane isolated from the same bacterial strain. Ghost membrane was also prepared from radioiodinated whole bacteria. The labelled proteins from both these ghost membrane preparations were compared by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate to identify the cell surface proteinmfrom the results obtained it was concluded that one major protein with an apparent molecular weight of 1200-1300 was exposed on the exterior surface of the ghost membrane.

Bacterial Proteins↗