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T-cell modulation of the antibody response to bacterial polysaccharide antigens.

Pretreatment of mice with subimmunogenic doses of meningococcal polysaccharide (MP), Pseudomonas aeruginosa lipopolysaccharide (PA), or Streptococcus mutans polysaccharide (SM) resulted in suppression of antibody response. The transfer of putative suppressor T cells (Ts cells) from donor mice primed with a subimmunogenic dose of MP to naive recipients at the time of immunization with MP substantially reduced the magnitude of the antibody response. Also, the infusion of B cells taken from animals immunized with either MP or PA suppressed the antibody response of naive recipients to MP or PA, respectively, relative to controls, suggesting that Ts cells respond to determinants on immune B cells. We observed that the injection of concanavalin A or phytohemagglutinin (two lectins known to augment the activity of amplifier T cells [Ta cells]) 2 days postimmunization enhanced the antibody response to MP and SM. In addition, Ta-cell activity was transferred to naive animals by using spleen cells. Although the administration of phytohemagglutinin at the time of immunization with MP also resulted in increased antibody response, the injection of concanavalin A simultaneous with immunization resulted in a suppression of the antibody response to MP. Although Ts cells generated in response to pneumococcal polysaccharide type III were found to respond to monoclonal antibody Ly-m22, Ta cells responded to monoclonal antibodies L3T4 and Ia but not to Ly-m22. These studies suggest that Ta and Ts cells can modulate the antibody response to MP, SM, and PA in a positive and negative manner, respectively.

Animals↗

An avidin-biotin based ELISA for quantitation of antibody to bacterial polysaccharides.

A solid phase immunoassay utilizing avidin-biotin binding has been developed for measuring anticapsular polysaccharide antibodies. Capsular polysaccharides of Escherichia coli K1, Haemophilus influenzae type b, Staphylococcus aureus types 5 and 8, and levan from Aerobacter levanicum have been biotinylated through -OH or COOH groups with retention of antigenicity. Polysaccharides were immobilized on avidin-coated microtiter wells for use in an enzyme-linked immunosorbent assay (ELISA) to detect antibody. Two preparations of biotinylated S. aureus type 8 polysaccharide were equivalent as antigens in ELISA. Specificity was demonstrated by absorption of antisera, by competitive inhibition with purified antigens, and by reaction with specific monoclonal or myeloma antibodies. Reproducibility of the assay for H. influenzae type b and S. aureus type 8 antibody was demonstrated by replicate titrations of high and low level antisera.

Antibodies, Bacterial↗

The presence of sialic acid on two related bacterial polysaccharides determines the site of the primary immune response and the effect of complement depletion on the response in mice.

We have examined the antibody responses in mice to two structurally similar antigens: the capsular polysaccharide of type 3 group B streptococci (sssGBS 3) and the capsular polysaccharide of type 14 pneumococci (sssPn 14), which differ only in the presence of a terminal sialic acid on the side chain of the former. The cells that produce antibody to the nonsialated antigen (sssPn 14) reside in the spleen, whereas the cells that produce antibody to the sialated antigen (sssGBS 3) do not. Cobra venom factor treatment of the mice before immunization abrogates the antibody response to the nonsialated antigen, but does not affect the response to the sialated antigen.

Animals↗

Influence of multiple genes on the magnitude of the antibody response to bacterial polysaccharide antigens.

Studies conducted with F1 and F2 progeny of crosses between strains of inbred mice that differ greatly in their capacity to make an antibody response to type III pneumococcal polysaccharide, dextran B-1355, and lipopolysaccharide from Escherichia coli 0113 have shown that multiple genes influence the magnitude of the antibody response to these antigens. Other studies with hybrids derived from crosses between C3H/HeJ, CBA/N, and RIIIS/J mice have indicated that the genetic defects characteristic of these strains of mice are dissimilar and unlinked and that autosomal, as well as X-linked, genes control serum immunoglobulin M in unimmunized mice.

Animals↗

Evaluating children with respiratory tract infections: the role of immunization with bacterial polysaccharide vaccine.

Antibody deficiency syndromes are an important cause of recurrent infections in children. Today it is possible to perform a complete evaluation of antibody-mediated immunity leading to a definitive diagnosis of either normal or abnormal immunity in most patients. However, the interpretation of the results of IgG subclass determinations and specific antibody responses is still being defined. At this time our recommendation is that patients who meet the criteria for an evaluation of antibody-mediated immunity be referred to subspecialists trained in this evaluation until better criteria for normal have been developed. The possibility that protective amounts of antibodies against pneumococcal serotypes may develop only transiently must be considered in patients with recurrent infections after initial improvement after immunization, especially if IgG2 subclass deficiency is also present. In the future it may be possible to use a faster and more economical approach to evaluate patients with recurrent infections by immunization with pneumococcal vaccine and then measuring IgM, IgG and IgA along with postimmunization specific antipneumococcal antibody titers 4 to 6 weeks later. For this approach to become feasible, further studies comparing the information obtained from the evaluation of pre- and postimmunization antibody concentrations with that obtained from the evaluation of postimmunization concentrations alone are needed.

Antibody Formation↗

Bacterial polysaccharide capsule synthesis, export and evolution of structural diversity.

Elaboration of a capsule composed of one of a range of acidic polysaccharides is a common feature of many bacteria, particularly those capable of causing serious infections in humans. Biochemical and genetical analyses of capsule biogenesis in Escherichia coli are beginning to reveal new aspects of polysaccharide biosynthesis. Genes have been identified which are thought to encode products responsible for the translocation of these high molecular-weight polysaccharides across the cytoplasmic and outer membranes, and the organization of exported polysaccharide into a capsule. Their further analysis should provide new insights into membrane biology, particularly since the genes in question are absent from the often used laboratory strains of E. coli. Genetic analysis of capsule diversity is beginning to suggest possible mechanisms for the generation of the structural diversity of polysaccharides.

Antigens, Bacterial↗

Antibody production in vitamin A-depleted rats is impaired after immunization with bacterial polysaccharide or protein antigens.

Vitamin A nutritional status has been implicated as important in maintaining the integrity of immune functions. We have determined the effect of vitamin A (retinol) depletion on the ability of young animals to produce antibodies after challenge with various bacterial antigens. Male Lewis rats raised on vitamin A-free or adequate diets were immunized either near 40 days of age, before signs of vitamin A deficiency were apparent, or near 47 days of age when symptoms of deficiency were beginning to be manifest. For rats immunized with polysaccharide antigens from Streptococcus pneumoniae or Neisseria meningitidis, antibody production did not exceed 0-19% of the response of control rats. Vitamin A depletion also severely compromised the response to two T cell-dependent antigens, tetanus toxoid and sheep red blood cells. In striking contrast, retinol-depleted rats immunized with lipopolysaccharides from Pseudomonas aeruginosa and Serratia marcesens produced an antibody response indistinguishable from retinol-sufficient animals. These lipopolysaccharides could elicit antibodies in rat pups, whereas the capsular polysaccharide antigens could not. This is consistent with the characteristics of type 1 and type 2 antigens, respectively. These studies indicate that retinol status is an important determinant of the humoral immune response to certain types of antigen and suggest that antibody production to capsular polysaccharides and T cell-dependent antigens is particularly dependent on adequate retinol status.

Aging↗

[Molecular mimicry of bacterial polysaccharides and their role in etiology of infectious and autoimmune diseases].

Molecular mimicry is one of the most important pathogenic factor of microorganism and is defined as a structural similarity of microbial molecules to host tissue contributing to the pathogenicity. Mimicry can be observed at the molecular, serological and functional level. In the review the infectious diseases have been discussed where the mimicry phenomenon may occur, and also autoimmune disease where due to the molecular mimicry bacterial structures are potent to induce adverse immune reactions. The cross-reacting molecules mimicking the host structures comprise colominic acid, sialic acid containing capsular polysaccharides of Streptococcus group B, phosphocholine containing antigen, lipopolysaccharides of Campylobacter jejuni contributing in induction of Guillain-Barré syndrome or Lewis antigen containing lipopolysaccharides of Helicobacter pylori inducing gut carcinoma. Knowledge on the phenomenon of molecular mimicry is important when new conjugate vaccine has to be constructed, because great care should be paid not to induce autoantibodies with synthetic immunogen. Investigation of microbial factors reveal that many autoimmune diseases are of infection etiology.

Autoimmune Diseases↗

[Antigenic bacterial polysaccharides. 24. The structure of the O-specific polysaccharide chain of Salmonella arizonae 063 (Arizona 08) lipopolysaccharide].

The O-specific polysaccharide chain of the Salmonella arizonae O63 lipopolysaccharide is composed of D-glucose, D-galactose, N-acetyl-D-galactosamine, and 3-acetamido-3,6-dideoxy-D-galactose (Fuc3NAc) residues in the ratio 1:1:2:1. On the basis of methylation analysis and calculations of 13C-NMR-spectra of the polysaccharide and of the product of its selective cleavage with anhydrous hydrogen fluoride, the linear polymer lacking 3-acetamido-3,6-dideoxygalactose, it was concluded that the polysaccharide has the following structure: (Formula: see text).

Antigens, Bacterial↗

[Antigenic bacterial polysaccharides. 36. A study of the structure of the O-specific polysaccharide chain of the lipopolysaccharide of Pseudomonas fluorescens IMV 2763 (biostrain G)].

Chemical and serological characterization of the Pseudomonas fluorescens IMV 2763 (biovar G) lipopolysaccharide was carried out. The O-specific polysaccharide chain of the lipopolysaccharide is composed of D-mannose, 6-deoxy-L-talose, N-acetyl-D-galactosamine and O-acetyl groups in the ratio of approximately 2:1:1:1. The polysaccharide is branched and a half of residues of 6-deoxytalose and monosubstituted mannose carry O-acetyl groups. On the basis of methylation, partial acid hydrolysis and 13C NMR analysis it was concluded that the repeating unit of the polysaccharide has the following structure: (formula; see text)

Antigens, Bacterial↗

[Antigenic bacterial polysaccharides. 28. The structure of the O-specific lipopolysaccharide chain of Pseudomonas syringae pv. atrofaciens K-1025 and Pseudomonas holci 90a (serogroup II)].

Lipopolysaccharides of serologically related strains of Pseudomonas syringae pv. atrofaciens K-1025 and Pseudomonas holci 90a possess the identical O-specific polysaccharide chains, representing a homopolymer of D-rhamnose. On the basis of methylation, partial and complete Smith degradation, and analysis by 1H- and 13C-NMR-spectroscopy, it was concluded that the repeating unit of the polysaccharide is a branched pentasaccharide of the following structure: (formula; see text)

Antigens, Bacterial↗

[Antigenic bacterial polysaccharides. 29. The structure of the polysaccharide chain of Pseudomonas holci 8300 (serogroup I) lipopolysaccharide].

The Pseudomonas holci 8300 lipopolysaccharide has an O-specific polysaccharide chain, containing L-rhamnose and 3-acetamido-3-deoxy-D-fucose residues in the ratio 4:1. On the basis of methylation, Smith degradation, and 1H- and 13C-NMR spectroscopy data, it was concluded that the polysaccharide is built up of pentasaccharide units of A and B types in the ratio approximately 2.5:1. In some stretches of the polysaccharide, minor B units form rather long chains, and in the others they alternate with predominant A units. (formula; see text)

Antigens, Bacterial↗

[Antigenic bacterial polysaccharides. 13. The structure of the O-specific polysaccharide chain of the lipopolysaccharide from Pseudomonas cepacia strain IMV 4137].

On mild acid degradation of a lipopolysaccharide from Pseudomonas cepacia strain IMV 4137, a serologically active O-specific polysaccharide was obtained and shown to contain L-rhamnose and D-galactose. According to 1H- and 13C-NMR data as well as methylation analysis, the polysaccharide is made up of disaccharide repeating units of the following structure:----2)-alpha-L-Rhap-(1----4)-alpha-D-Galp-(1----.

Antigens, Bacterial↗

[Antigenic bacterial polysaccharides. 14. Structure of the O-specific polysaccharide chain of a lipopolysaccharide from Pseudomonas aeruginosa (Lányi)].

The lipopolysaccharide from Pseudomonas aeruginosa O12 (Lányi classification) gave on mild acid hydrolysis an O-specific polysaccharide built of D-ribose and N-acetyl-D-galactosamine. The disaccharide structure----4)-alpha-GalNAcp-(1----2)-beta-Ribf-(1----for the repeating unit of the polysaccharide was established by nondestructive way involving full interpretation of its 1H- and 13C-NMR-spectra, using homonuclear and selective heteronuclear 13C[1H] double resonances.

Antigens, Bacterial↗

[Antigenic bacterial polysaccharides. 23. The structure of the O-specific polysaccharide chain of Salmonella arizonae 059 lipopolysaccharide].

The O-specific polysaccharide of Salmonella arizonae O59 (Arizona 19) is composed of D-galactose, N-acetyl-D-glucosamine, and N-acetyl-L-fucosamine (FucNAc, 2-acetamido-2,6-dideoxy-L-galactose) in the ratio 1:1:1. The computerized calculation of the 13C NMR spectrum of the polysaccharide, based on the monosaccharide composition, spectra of the free monosaccharides and glycosydation effects, together with the chemical analysis (methylation and Smith degradation) showed that the polysaccharide is built up of trisaccharide repeating units of the following structure: ----3)-alpha-L-FucNAcp(1----3)-beta-D-GlcNAcp-(1----2)-beta- D-Galp-1(----. The molecular basis of serological interrelations between S. arizonae O59 and Pseudomonas aeruginosa O7 (Lányi) is discussed.

Antigens, Bacterial↗

[Antigenic bacterial polysaccharides. 30. The structure of the polysaccharide chain of lipopolysaccharide of Pseudomonas syringae pv. syringae 281 (serogroup I)].

Anomeric methyl 3-O-(D-mannopyranosyl- and L-rhamnopyranosyl)-beta-D-talopyranosides were synthesised by the stereoselective 1,2-cis- and 1,2-trans manno- and rhamnosylation of methyl 2,4,6-tri-O-acetyl-beta-D-talopyranoside, which has been prepared from methyl beta-D-galactopyranoside by a synthetic scheme including conversion of the C2 configuration. From 13C-NMR spectra of the disaccharides obtained the spectral alpha- and beta-effects of O3-glycosylation of talopyranose were determined.

Antigens, Bacterial↗

Influence of Divalent Cations and pH on Adsorption of a Bacterial Polysaccharide Adhesin.

Hyphomonas MHS-3 (MHS-3) elaborates a diffuse capsular material, primarily composed of polysaccharide, which has been implicated to serve as the holdfast of this prosthecate marine bacterium. A purified polysaccharide (fr2ps) from this capsular material exhibits a relatively large affinity for (Ge), or more precisely for the Ge oxide surface film. In its natural habitat MHS-3 attaches to marine sediments. This suggests that molecular properties of fr2ps have evolved to render it adhesive toward mineral oxides. In order to characterize these molecular interactions, the effect of divalent cations and pH on the adsorption of fr2ps to Ge has been measured using attenuated total internal reflection Fourier transform infrared (ATR/FT-IR) spectroscopy. The effect of adsorption of fr2ps on the Ge oxide film has been investigated using X-ray photoelectron spectroscopy (XPS). The results indicate that divalent cations participate in binding of fr2ps to Ge oxide and that atomic size of the cation is important. Evidence for significant participation of hydrogen bonding to the oxide surface is lacking. Copyright 1998 Academic Press.

Journal Article↗