Biomedical subjects

F C McIntire

Publications and source records attributed to F C McIntire.

At least 19 recordsLinked to original sources

PubMed1988

A polysaccharide from Streptococcus sanguis 34 that inhibits coaggregation of S. sanguis 34 with Actinomyces viscosus T14V.

Coaggregation between Actinomyces viscosus T14V and Streptococcus sanguis 34 depends on interaction of a lectin on A. viscosus T14V with a cell surface carbohydrate on S. sanguis 34. This carbohydrate was isolated, and its chemical makeup was established. The carbohydrate remained attached to S. sanguis 34 cells through extraction with Triton X-100 and treatment with pronase. It was cleaved from the cell residue by autoclaving and purified by differential centrifugation and column chromatography on DEAE-Sephacel and Sephadex G-75. The polysaccharide contained phosphate which was neither inorganic nor monoester. Treatment with NaOH-NaBH4, followed by Escherichia coli alkaline phosphatase, or with 48% HF at 4 degrees C, followed by NaBH4, yielded inorganic phosphate and oligosaccharide alditols. Therefore, the polysaccharide is composed of oligosaccharide units joined together by phosphodiester bridges. The structure and stereochemistry of the main oligosaccharide alditol was established previously (F. C. McIntire, C. A. Bush, S.-S. Wu, S.-C. Li, Y.-T. Li, M. McNeil, S. Tjoa, and P. V. Fennessey, Carbohydr. Res. 166:133-143). Permethylation analysis, 1H and 31P nuclear magnetic resonance studies on the whole polysaccharide revealed the position of the phosphodiester linkages. The polysaccharide is mainly a polymer of (6) GalNAc(alpha 1-3)Rha(beta 1-4)Glc(beta 1-6)Galf(beta 1-6)GalNAc(beta 1- 3)Gal(alpha 1)-OPO3. It reacted as a single antigen with antiserum to S. sanguis 34 cells and was a potent inhibitor of coaggregation between A. viscosus T14V and S. sanguis 34. Quantitative inhibition of precipitation assays with oligosaccharides, O-allyl N-acetylgalactosaminides, and simple sugars indicated that specific antibodies were directed to the GalNAc end of the hexasaccharide unit. In contrast, coaggregation was inhibited much more effectively by saccharides containing betaGalNAc. Thus, the specificity of the A. viscosus T14V lectin is strikingly different from that of antibodies directed against the S. sanguis 34 polysaccharide.

Actinomyces↗

PubMed1987

Structure of a new hexasaccharide from the coaggregation polysaccharide of Streptococcus sanguis 34.

The major constituent of a coaggregation polysaccharide from Streptococcus sanguis 34 is a hexasaccharide, isolated as the alditol. The proposed structure is alpha-D-GalpNAc-(1----3)-beta-L-Rhap-(1----4)-beta-D-Glcp-(1----6) -beta-D-Galf- (1----6)-beta-D-GalpNAc-(1----3)-D-Galol, based upon g.l.c.-m.s. of alditol acetates and partially methylated alditol acetates, f.a.b.-m.s., 1H-n.m.r. spectroscopy, g.l.c.-m.s. of trimethylsilylated (+)- and (-)-2-butyl glycosides, and cleavage by alpha-N-acetylgalactosaminidase. The structural deduction was facilitated by cleavage of the hexasaccharide at the furanoside linkage by 48% hydrogen fluoride, and reduction of the product, to yield alpha-D-GalpNAc-(1----3)-beta-L-Rhap-(1----4)-beta-D-Glcp-(1----6) -D-Galol.

Carbohydrate Conformation↗

PubMed1983

A factor from Actinomyces viscosus T14V that specifically aggregates Streptococcus sanguis H1.

A highly specific aggregation factor for Streptococcus sanguis H1 (AFH1) was obtained by lysozyme treatment of Actinomyces viscosus T14V. At 1 micrograms/ml, AFH1 aggregated a suspension of S. sanguis H1, with which A. viscosus T14V coaggregates by a mechanism not inhibited by lactose: even at much higher levels AFH1 caused little or no aggregation of streptococci from other coaggregation groups (J. O. Cisar et al., Infect. Immun. 24:742-752, 1979). The most active fraction of AFH1 obtained by gel chromatography (near the void volume of Bio-Gel A1.5 m) reacted as a single antigen with anti-A. viscosus T14V serum and was unrelated to the fimbrial antigens of A. viscosus T14V. Smaller molecular fractions, at high levels, inhibited aggregation of S. sanguis H1 by high-molecular-weight AFH1 as well as coaggregation of S. sanguis H1 with A. viscosus T14V. The AFH1 fraction with high aggregating activity was composed of approximately 53% cell wall components (alanine, glutamine, lysine, N-acetylglucosamine, and N-acetylmuramic acid). 40% polysaccharide (N-acetylgalactosamine, rhamnose, and 6-deoxytalose), and 7% protein; teichoic acid was not detected. The fraction which inhibited aggregation and coaggregation contained much less of the cell wall constituents and more of the polysaccharide than the fraction with potent aggregating activity. Aggregation was completely prevented either by treating AFH1 with 0.01 M periodate at 25 degrees C for 4 h or by treating S. sanguis H1 with heat or pronase. A role for electrostatic forces in the aggregation was indicated by: (i) NaCl inhibition of aggregation, and (ii) a great decrease in aggregation potency as a result of chemical modification of either cationic or anionic groups of AFH1. On the other hand, NaCl reversed the aggregation only very weakly. The overall data suggest that a carbohydrate-protein interaction may be dominant in the aggregation of S. sanguis H1 by AFH1 and in the coaggregation of S. sanguis H1 with A. viscosus T14V.

Acetylgalactosamine↗

PubMed1983

Structural preferences of beta-galactoside-reactive lectins on Actinomyces viscosus T14V and Actinomyces naeslundii WVU45.

Specificities of lectins on Actinomyces viscosus T14V and Actinomyces naeslundii WVU45 were compared by measuring the abilities of D-galactose, N-acetyl-D-galactosamine, 14 beta-D-galacto-oligosaccharides, and 2 beta-D-fuco-oligosaccharides to inhibit coaggregation between Streptococcus sanguis 34 and each actinomycete. Inhibition profiles were similar, but WVU45 was significantly more sensitive to several inhibitors. D-Galactose-beta(1 leads to 3)-N-acetyl-D-galactosamine glycosides were most potent.

Actinomyces↗

PubMed1982

Inhibitors of coaggregation between Actinomyces viscosus T14V and Streptococcus sanguis 34: beta-galactosides, related sugars, and anionic amphipathic compounds.

Coaggregation between Actinomyces viscosus T14V (T14V) and Streptococcus sanguis 34 (Ss34) depends upon specific reaction between lectin on T14V and carbohydrate on Ss34. Studies on coaggregation inhibition by sugars related to D-galactose, beta-galactosides, and amphipathic molecules revealed: (i) D-fucose, D-talose approximately equal to D-galactose, which was 0.2 potency of lactose. No other hexoses or pentoses inhibited at 0.1 M. (ii) Gal beta (1 leads to 3)GalNAc alpha OCH2C6H5 was the most potent beta-galactoside inhibitor; it had 20 times the potency of lactose. (iii) Anionic nonaromatic amphipathic compounds were good inhibitors; sodium deoxycholate (I) was equal to lactose; sodium dodecyl sulfate (II) had 15 times the potency of lactose; there was 90 to 100% irreversible inhibition when T14V was treated with 0.005 M (II). Treatment of Ss34 with II had no effect. (iv) Synergism of inhibition was observed between lactose and I or lactose and II, e.g., inhibition by 0.01 M lactose = 5%; inhibition by 0.01 M I = 9%; inhibition by 0.01 M lactose + 0.01 M I = 87%. (v) The irreversible inhibition by II was prevented when 0.25 M lactose or 0.25 M I was present during treatment of T14V with 0.005 M II. (vi) Synergism and prevention by lactose or by I of irreversible inhibition by II suggest that all three react at the same site on T14V lectin. We hypothesize that the T14V lectin combining site for Ss34 carbohydrate has specific affinity for beta-galactosides and for anionic nonaromatic amphipathic molecules. This site can be saturated by either kind of reagent to exclude the other reagent or to inhibit coaggregation.

Actinomyces↗

PubMed1979

Specificity of coaggregation reactions between human oral streptococci and strains of Actinomyces viscosus or Actinomyces naeslundii.

Coaggregation reactions between actinomycete and streptococcal cells occurred frequently when human strains of Actinomyces viscosus or A. naeslundii were mixed with human isolates of Streptococcus sanguis or S. mitis, but were infrequent with other oral actinomycetes and streptococci. Two groups of actinomycetes and four groups of streptococci were defined by the patterns of their coaggregation reactions and by the ability of beta-linked galactosides (i.e., lactose) to reverse these reactions. Coaggregations occurred by one of the following three kinds to cell-cell interactions: (i) coaggregation that was blocked by heating the streptococcus but not the actinomycete and was not reversed by lactose; (ii) coaggregation that was blocked by heating the actinomycete but not the streptococcus and was reversed by lactose; and (iii) coaggregation that was blocked only by heating both cell types. The latter reaction was a combination of the first two since lactose reversed coaggregation between heated streptococci and unheated actinomycetes but did not reverse coaggregations between unheated streptococci and heated actinomycetes. Cells that could be heat inactivated also were inactivated by amino group acetylation or protease digestion, whereas cells that were unaffected by heat were not inactivated by these treatments. Coaggregation reactions of each kind were Ca2+ dependent and insensitive to dextranase treatment. These findings are consistent with the hypothesis that human strains of A. viscosus and A. naeslundii coaggregate with strains of S. sanguis and S. mitis by a system of specific cell surface interactions between protein or glycoprotein receptors on one cell type and carbohydrates on the other type.

Acetylation↗

PubMed1978

Fimbriae of Actinomyces viscosus t14v: their relationship to the virulence-associated antigen and to coaggregation with Streptococcus sanguis 34.

1) Fimbriae from A. viscosus T14V may be similar to those found on other bacteria. 2) The antigenic difference between virulent and avirulent A. viscosus T14 appears to be of a quantitative rather than a qualitative nature and is related to fimbriae and not to the cell wall polysaccharide. 3) Coaggregation between A. viscosus T14V and S. sanguis 34 is mediated by fimbriae on the former which have specificity for beta-linked galactosyl residues.

Actinomyces↗

PubMed1978

Identification of the virulence-associated antigen on the surface fibrils of Actinomyces viscosus T14.

Actinomyces viscosus T14V is virulent (V) for monoinfected rats, causing periodontal disease and bone loss, whereas, A. viscosus T14AV, a mutant strain, is avirulent (AV). Surface antigens from the T14V and T14AV strains were prepared by lysozyme digestion of cell walls and were compared by immunodiffusion against antisera to T14V and T14AV whole cells. The V-associated antigen (V-antigen) was detected readily in the T14V, but not readily in the T14AV cell wall extract. Antiserum specific for the V-antigen was prepared by absorbing anti-A. viscosus T14V serum with cell walls from the T14AV strain. This antiserum was used in the indirect peroxidase-labeled antibody technique to localize the V-antigen on the bacterial cell surface at the ultrastructural level. With whole bacterial cells, the V-antigen was found on fine fibrils and was detected in both the T14V and T14AV strains. The presence of V-antigen on the AV strain was supported by the demonstration of antibodies against the V-antigen in anti-A. viscosus T14AV serum. Examination of isolated bacterial cell walls revealed a greater amount of fibrils and V-antigen on the T14V cell wall than on the T14AV cell wall. The data suggest that the presence of V-antigen represents a quantitative rather than a qualitative difference between the V and the AV strains of A. viscosus T14. Samples of human plaque were examined, and the V-antigen was found to be a specific marker for the fibril-containing layer of certain plaque bacteria, which are probably strains of A. viscosus or A. naeslundii.

Actinomyces↗

PubMed1978

Mechanism of coaggregation between Actinomyces viscosus T14V and Streptococcus sanguis 34.

Actinomyces viscosus T14V and Streptococcus sanguis 34 coaggregate by a mechanism which is not inhibited by 1 M NaCl, is dextran independent, requires calcium, is pH dependent with an optimum at pH 8.0 to 8.5, and appears to require the interaction of a protein or glycoprotein on A. viscosus with a carbohydrate on S. sanguis. The coaggregation is inhibited more than 80% by 0.01 M lactose, 0.02 M beta-methyl-D-galactoside, or 0.05 M D-galactose; inhibition of coaggregation was less than 10% in 0.1 M alpha-methyl-D-galactoside, melibiose, maltose, cellobiose, sucrose, and a number of monosaccharides. At very high concentrations of enzyme, protease from S. griseus destroyed the reactive site on A. viscosus but not on S. sanguis. Both were totally resistant to dextranase. Periodate (0.01 M; pH 4) inactivated both bacteria. The ability of S. sanguis to coaggregate with A. viscosus was not destroyed by phenol-water extraction at 65 degrees C for 15 min. When the bacteria were cultured under specified conditions, the coaggregation was highly reproducible. Under the same conditions, T14AV, the avirulent mutant of A. viscosus T14V, did not coaggregate with S. sanguis 34. Electron microscopic studies of coaggregates, labeled immunochemically with antibody to A. viscosus, indicated that fibrils on A. viscosus may be involved in the coaggregation.

Actinomyces↗

PubMed1976

Biologic properties of nontoxic derivatives of a lipopolysaccharide from Escherichia coli K235.

Lipopolysaccharide (LPS)2 from Escherichia coli K235 was treated with o-phthalic anhydride to obtain a high degree of esterification of available hydroxyl groups, leaving a free carboxyl for each hydroxyl esterified (SPLPS). Although there was no demonstrable loss of fatty acids, this conversion of LPS to a polyanionic molecule altered dramatically the spectrum of biologic properties, most of which are normally attributed to the lipid A (LA) moiety. Mitogenicity for mouse B cells was decreased several hundred-fold; reaction with antibodies to LPS was abolished; pyrogenicity and toxicity were decreased by factors of 10(5) and 10(4); the ability to induce the Shwartzman reaction in rabbits was decreased 500-fold, and the ability to stimulate production of interferon in mice was decreased by more than 2 x 10(3). However, despite the loss of these properties, SPLPS retained the ability to act as an immunologic adjuvant. The nature of the anionic group is important, e.g., sodium succinyl-LPS (SuLPS) is 10-fold more pyrogenic and toxic than sodium phthalyl-LPS (SPLPS). Data on another LPS derivative, from which ester-linked fatty acid residues were removed before phthalylation, suggest that the ester-linked fatty acid groups in the lipid A moeity of SPLPS may not be necessary for its immunologic adjuvant effect.

Adjuvants, Immunologic↗

PubMed1975