PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Polysaccharides”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1977

Non-encapsulated variant of Cryptococcus neoformans. II. Surface receptors for cryptococcal polysaccharide and their role in inhibition of phagocytosis by polysaccharide.

The binding of cryptococcal polysaccharide to a non-encapsulated strain of Cryptococcus neoformans was studied. Binding of purified polysaccharide to the yeast was determined by inhibition of phagocytosis and by indirect immunofluorescence techniques. The ability of cryptococcal polysaccharide to prevent phagocytosis of the non-encapsulated strain appears to be directly related to adherence of polysaccharide to the yeast via specific receptors on the cell surface. Addition of varying doses of cryptococcal polysaccharide to non-encapsulated yeast cells inhibited phagocytosis only at polysaccharide concentrations at which the polysaccharide could be demonstrated on the yeast surface by immunofluorescence. Macrophages treated with cryptococcal polysaccharide had no detectable amounts of cryptococcal polysaccharide adherent to their surface, and they had a normal ability to phagocytize the yeast. Kinetic studies showed that inhibition of phagocytosis is directly related to the presence of cryptococcal polysaccharide at the yeast surface rather than to some indirect effect by the polysaccharide on serum components necessary for phagocytosis. Purified polysaccharide from C. neoformans serotypes A, B, C, and D bound to the yeast, but type III pneumococcal polysaccharide did not inhibit phagocytosis of the nonencapsulated yeast. Cryptococcal polysaccharide did not bind to cells of Candida albicans, C. pseudotropicalis, Torulopsis sp., Rhodotorula sp., or Saccharomyces cerevisiae.

Ascitic Fluid↗
PubMed1976

Bacillus pumilus polysaccharide cross-reactive with meningococcal group A polysaccharide.

A polysaccharide, antigenically and structurally related to meningococcal group A polysaccharide, was isolated from Bacillus pumilus Sh-17. This enteric bacterium has been implicated as a source of natural meningococcal group A immunity (Myerowitz et al., 1973). The B. pumilus polysaccharide was composed of a homopolymer of (1-6)-N-acetyl-manosamine-1-phosphate, glycerol phosphate teichoic acid-containing N-acetylglucosamine and alkali-labile alanine esters, and a mucopeptide. The cross-reaction was due to the poly-(1-6)-N-acetyl-mannosamine-1-phosphate in the B. pumilus and the meningococcal group A polysaccharides, based on the following evidence. Both polysaccharides contained N-acetyl-mannosamine phosphate. Periodate oxidized the mannosamine phosphate residues of the polysaccharide and destroyed their precipitating activity with meningococcal group A antiserum. Mild acid treatment released phosphomonoesters and destroyed the meningococcal group A precipitating activity of both polysaccharides. N-acetyl-mannosamine-6-phosphate inhibited the precipitation reaction between strain Sh-17 and meningococcal group A antisera. Only mannosamine phosphate was detected in trichloroacetic acid extracts of Sh-17 polysaccharide and meningococcal group A antigen-antibody precipitates.

Amino Acids↗
PubMed1979

ELISA methodology for polysaccharide antigens: protein coupling of polysaccharides for adsorption to plastic tubes.

A method is described which permits the adaption of ELISA techniques for measurement of antibody against bacterial polysaccharides. First, the polysaccharides antigen is covalently bound to poly-L-lysine, using cyanuric chloride as the coupling agent. The poly-L-lysine then adsorbs to the walls of plastic tubes, thus immobilizing the polysaccharide coupled to the poly-L-lysine. The method is simple, rapid, and utilizes small amounts of polysaccharide antigen.

Adsorption↗
PubMed1978

Structure of extracellular polysaccharides of Escherichia coli strains 36M, 72M, and 29M isolated from coligranuloma of chick intestine. I. Polysaccharide from E. coli 36M.

An extracellular polysaccharide was isolated from culture broth of Escherichia coli 36M, and fractionated on a column of Sephadex G-150 into two fractions; the high molecular weight portion (85% of the total polysaccharide) contained pyruvic acid, and showed a positive immune reaction with anti-Ps-I-serum obtained from a rabbit. The low molecular weight portion (15% of the total polysaccharide) showed a negative immune reaction. The methylation, Smith's degradation, partial acid hydrolysis and methanolysis of the higher molecular weight polysaccharide revealed a repeating structure as follows: (see article).

Animals↗
PubMed1978

Immunogenicity of gonococcal Gc2 polysaccharide: comparative studies with pneumococcal type III polysaccharide and Salmonella typhosa Vi antigen.

A plaque assay technique was used to assess the immunogenicity of a gonococcal cell wall polysaccharide (Gc2 antigen) in BALB/c mice. The Gc2 antigen was shown to be immunogenic, and the kinetics of the response differed from that of a pneumococcal polysaccharide (SSS-III) and a polysaccharide antigen of Salmonella typhosa (Vi antigen). In addition, using antithymocyte sera, the T-lymphocyte dependency of these antigens was investigated. The immune response to the Gc2 antigen was demonstrated to be dependent on a population of helper T cells, whereas the response to SSS-III appears to be regulated by suppressor T cells. There appears to be marked differences in the immune response of mice to different bacterial polysaccharides.

Animals↗
PubMed1977

Multiple polysaccharide antigens of group B streptococcus, type Ia: emphasis on a sialic acid type-specific polysaccharide.

Group B streptococci, type Ia (strain 090/14/4), were subjected to sequential extraction procedures and the various extracts were fractionated by a combination of DEAE-cellulose chromatography and gel-filtration. Three major antigens were isolated: the conventional group-specific and type-specific carbohydrates and an acidic polysaccharide consisting of galactose, glucose, glucosamine, and sialic acid. Immunochemical data suggest that the acidic antigen, with the exception of the immunodominant sialic acid, is structurally similar to the conventional pH 2.0 extracted type-specific antigen. Removal of the terminal sialic acid residues from the acidic antigen by mild acid hydrolysis resulted in a residual polymer which was chemically and immunologically analogous to the type-specific carbohydrate. Precipitin analysis focused attention to the cross-reactivity between thia acidic antigen and anti-types Ib, Ic, and III sera.

Animals↗
PubMed1979

Comparative immunogenicity of group 6 pneumococcal type 6A(6) and type 6B(26) capsular polysaccharides.

The comparative immunogenicity of the two cross-reacting group 6 pneumococcal capsular polysaccharides, type 6A(6) and type 6B(26), was studied with hyperimmune rabbit typing antisera and with sera from adult volunteers injected with polyvalent pneumococcal vaccines containing either 50 mug of type 6A (U.S. designation, type 6) or 50 mug each of type 6A and type 6B (U.S. designation, type 26) polysaccharides. Both group 6 polysaccharides were linear copolymers composed of 1 mol each of d-galactose, d-glucose, l-rhamnose, and d-ribitol phosphate. They differed only in that type 6A had a rhammopyranosyl-(1 --> 3)-d-ribitol bond and the type 6B had a rhamnopyranosyl-(1 --> 4)-d-ribitol bond. Quantitative precipitation and absorption analyses with rabbit hyperimmune antisera induced by simultaneous injection with type 6A and type 6B organisms revealed extensive cross-reactions between the two group 6 polysaccharides. There was less, although still quite extensive, cross-reactivity between the two group 6 polysaccharides examined with antisera from rabbits injected with only one of the group 6 pneumococci. In a radioimmunoassay, using (14)C internally labeled type 6A or type 6B polysaccharide antigens, there was no difference in the serum antibody level to either type of volunteer injected with polyvalent pneumococcal vaccines containing type 6A or both type 6A and type 6B polysaccharides. These studies indicate that the structural similarity of the pneumococcal group 6 polysaccharides confers extensive cross-reactivity with hyperimmune typing antisera prepared with whole organisms or after injection of purified polysaccharides in adult volunteers. With our current polysaccharides, it appears that a polyvalent pneumococcal vaccine formulation that contains only type 6A will serve to induce the maximum amount of serum antibodies to both group 6 organisms.

Adult↗
PubMed1976

The role of the capsular polysaccharide in the activation of the alternative pathway by the pneumococcus.

Previous studies have shown that when pneumococci are incubated in normal, nonimmune serum, they activate the alternative pathway and opsonically active C3b is fixed to the surface of the organism. Other studies have demonstrated that C3-dependent opsonization via the alternative pathway plays a significant role in the nonimmune host's defense against the pneumococcus. The present studies concern the role of the capsular polysaccharide in initiating the activation of the alternative pathway by the pneumococcus. Some pneumococcal capsular polysaccharide types, but not all, are able to activate the alternative pathway. Soluble purified capsular polysaccharide types 1, 4 and 25 activate the alternative pathway, whereas types 2, 3, 14, and 19 do not. Since the capsular polysaccharides exist in their native form attached to the pneumococcal surface, selected capsular polysaccharides were also tested for their ability to activate the alternative pathway when attached to a particulate carrier, sheep erythrocytes. Capsular polysaccharide types 2 and 3 failed to activate the alternative pathway when attached to sheep erythrocytes, paralleling the results obtained when these capsular polysaccharides were in solution. In contrast, the type 25 capsular polysaccharide not only activated the alternative pathway when attached to sheep erythrocytes, as it had when in solution, but it also initiated alternative pathway-mediated lysis of the erythrocytes. The capsular polysaccharide is not required for the activation of the alternative pathway by the pneumococcus. Although all types of encapsulated pneumococci are able to activate the alternative pathway, not all the purified capsular polysaccharide types are able to do so. In addition, a nonencapsulated pneumococcus, derived originally from a type 2 organism, activates the alternative pathway as well as a fully encapsulated type 2 pneumococcus.

Cell Wall↗
PubMed1978

Immunochemistry of streptococcal group C polysaccharide and the nature of its crossreaction with the Forssman glycolipid.

Acid hydrolysis of streptococal Group C polysaccharide yields a disaccharide, 3-O-alpha-N-acetylgalactosaminosyl-N-acetylgalactosamine (3-O-alpha-GalNAc-GalNAc) which expresses Group C antigenic activity. This disaccharide, which exists as a side chain in the intact polysaccharide, can completely inhibit the binding between Group C polysaccharide and most Group C antibodies, indicating that this unit is the immunodominant feature of the intact polysaccharide. The alpha anomeric configuration and N-acetylation are required for the expression of the antigenic activity by the haptenic disaccharide. Also obtained from the acid hydrolysis of the Group C polysaccharide are rhamnose oligosaccharides with structural identity to the Group A-variant polysaccharide and with Group A-variant antigenic activity. It is inferred from these data that the Group A-varient polysaccharide structure is the core unit of the Group C polysaccharide. The nature of the immunologic crossreactivity between the Forssman glycolipid and Group C polysaccharide, which possess identical nonreducing terminal digalactosamine units, was investigated. Rabbit anti-Group C antibodies bound the Forssman glycolipid with approximately the same affinity as 3-O-alpha-GalNAc-GalNAc and were capable of mediating lysis of sheep red blood cells (SRBC). Antibody fractions isolated from anti-sheep hemolysin were likewise able to bind Group C polysaccharide. The heterologous reactions were in most assay systems weaker than reactions with the immunizing antigen.

Amino Sugars↗
PubMed1975

Cytochemistry and distribution of polysaccharides in an electroreceptor: the tuberous organ of Gnathonemus petersii (Mormyrids).

The polysaccharides were studied in an electroreceptor organ, the tuberous organ of Gnathonemus petersii (Mormyridae). Histochemical methods (P.A.S., alcian blue, toluidine blue and iron colloidal reactions) allowed us to demonstrate the existence of glycogen in the sensory cytoplasm, and P.A.S. positive polysaccharides in the sensory cavity. The polysaccharides were shown to be amylase proof; they display an acidity due to the existence of sulphated radicals. The histochemical study was completed by a cytochemical analysis: a treatment with thiocarbohydrazide (TCH) according to the Thiery's method. This method allowed us to estimate the glycogen concentration, its localization, and relationship with cellular organites within the sensory cytoplasm, as well as to differentiate the highly glycogenous type II cells of the platform from the other accessory cells (Derbin and Szabo, 1968). After a treatment for 20 hours with TCH, silver stained grains were visible on the polysaccharide filaments of the sensory chamber, between the microvilli and the vacuoles of the epidermal cells lining to the sensory cavity. Silver grains coated the outer surface of the microvilli. Such polysaccharides were not identical to the filamentous polysaccharides of the cavity. In order to determine the cytochemical localization of the polysaccharide acid groups, sections were stained with iron salts. The colloidal iron constitutes a deposit opaque to electrons and located both on the filamentous polysaccharides of the sensory cavity and in the vacuoles of the epidermal cells, indicating that only these filamentous polysaccharides display acid radicals.

Animals↗
PubMed1978

A novel type of endotoxin structure present in Bordetella pertussis. Isolation of two different polysaccharides bound to lipid A.

The endotoxin of Bordetella pertussis was cleaved by mild acidic hydrolysis to yield a polysaccharide (polysaccharide I, 15%), a glycolipid (63%) and lipid X (2%). Further treatment of the glycolipid with stronger acid released a second polysaccharide (polysaccharide II, 9%) and material similar to lipid A present in enterobacterial endotoxins. Both polysaccharides possess a single molecule of 3-deoxy-2-octulosonic acid as the reducing, terminal sugar. In polysaccharide II the octulosonic acid is phosphorylated in position 5 and presumably substituted in position 4; in polysaccharide I the octulosonic acid is not phosphorylated, but is substituted in position 5. Following treatment of the endotoxin with strong base, a fragment was isolated that contained bound, non-phosphorylated 3-deoxy-2-octulosonic acid, glucosamine phosphate and fatty acids. This indicated that polysaccharide I, like polysaccharide II, was bound to the lipid region of the endotoxin. The endotoxin structure thus defined is different from that proposed for the lipopolysaccharides of enterobacteria.

Bordetella pertussis↗
PubMed1975

Molecular immunological heterogeneity of the Salmonella zuerich [1, 9, 12, (46), 27] cell-wall polysaccharides.

Extraction of O specific polysaccharide from S. zuerich leads to three fractions (ZA, ZB, ZC). Polysaccharide ZB carries specificities 1, 27, and 46, present on the Salmonella cells. It exhibits a factor 27 that is very similar to that present on the S. typhi T2 1-minus 27-+ polysaccharide, a factor 1 that is close to that present on S. senftenberg polysaccharide, and a factor 46 that gives a very weak cross-reaction with anti-46 antibodies. Polysaccharides ZA and ZB are immunologically different and ZB contains two distinct fractions: ZB 1-minus devoid of Ofactor 1 and carrying the specificities 46 and 27 mostly, of not completely, on the same molecule (46, 27); and ZB1-+ carrying O factors 1, (46), 27. ZB 1-+ is composed of at least two different molecules: [1,(46)] precipitable with anti-1 antibodies but only coprecipitable with anti-46 antibodies; and (1, 27) precipitable with both anti-1 and anti-27 antibodies. Molecules [1, (46)] precipitate only part of the anti-1 antibodies precipitable by (1, 27). The smaller precipitation of anti-27 antibodies (when factor 27 is present together with factor 1 on the same molecule) and the coprecipitation, instead of precipitation, of anti-46 antibodies (when factors 46 and 1 are present on the same molecule) may be explained by a sterical hindrance between O-factors 1 and 27, and 1 and 46. The molecular, immunological heterogeneity of the polysaccharides extracted from S. zuerich would result from the presence on the cells of two kinds of O polysaccharides: one with, the other without O factor1, which is related to the presence of a side-chain of an alpha-D-glucosyl residue. A structure for S. zuerich polysaccharide is proposed.

ABO Blood-Group System↗
PubMed1976

Antigenicity of type-specific pneumococcal polysaccharides in rats.

Hemagglutinating antibody responses of Lewis-Wistar and Sprague-Dawley rats to graded doses of type-specific pneumococcal polysaccharide were measured. Rats given a small dose (0.2 to 50 mug)of type 1 or 8 polysaccharide intraperitoneally developed type-specific hemagglutinating antibody. Rats given larger doses of polysaccharide (greater than or equal to200 mug) did not develop detectable hemagglutinating antibody, and they were unresponsive to a subsequence injection of a small (and normally antigenic) dose of polysaccharide. There was prolonged antigenemia in rats injected with a large dose of polysaccharide. There was prolonged antigenemia in rats injected with a large dose of polysaccharide, and the kinetics of antigen clearance in these animals resembled that reported for mice with polysaccharide immunological paralysis. These results indicate that a phenomenon resembling immunological paralysis with type-specific pneumococcal polysaccharides can be produced in rats.

Animals↗