bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Mycobacterium leprae immunogenicity via adoptive transfer studies
Authors: Graham L , Navalkar R G
Published: January 2020

The immune response of mice to live, heat-killed, or autoclaved Mycobacterium leprae was investigated. After sensitization with 10(7) organisms in each group, recipient mice were transfused with the sensitized splenocytes 28 days later. A selected number of these mice were infected with 5 X 10(3) M. leprae, and the remaining animals were sacrificed at scheduled intervals for evidence of cell-mediated immunity to the M. leprae cell extract. Data from these and the bacteriological assays showed that all three materials induce cell-mediated immunity and also extend protection against the M. leprae challenge but not against a Listeria monocytogenes challenge. Adoptive immunity against M. leprae was expressed equally effectively in both non-irradiated animals and those sublethally (500 R) irradiated. This study reveals that, after adoptive transfer of immunity, a bacillary restriction occurs with concomitant onset of delayed hypersensitivity and that the protection observed could be specifically directed against an M. leprae challenge.
Influence of yeast mannan on release of myeloperoxidase by human neutrophils: determination of structural features of mannan required for formation of myeloperoxidase-mannan-neutrophil complexes
Authors: Wright C D , Bowie J U , Nelson R D
Published: January 2020

Structural features of mannan which participate in the formation of myeloperoxidase-mannan-neutrophil complexes have been studied by using a battery of structurally modified mannans. Mannan was isolated from Saccharomyces cerevisiae X2180 wild type and modified by strong alkaline degradation, selective (mild) alkaline degradation, and selective acetolysis. Mannose oligosaccharides bound to the peptide portion of mannan appeared to be required for binding of mannan to the neutrophil. The interaction of mannan with myeloperoxidase appeared to occur through phosphate groups of the mannan outer chain. The myeloperoxidase-mannan interaction was determined to be ionic in nature. The mannan-neutrophil interaction may involve cell membrane receptors for mannose.
Role of the phosphoenolpyruvate-dependent glucose phosphotransferase system of Streptococcus mutans GS5 in the regulation of lactose uptake
Authors: Liberman E S , Bleiweis A S
Published: January 2020

When Streptococcus mutans GS5 was grown in equimolar (5 mM) amounts of glucose and lactose, a classical diauxic growth curve was obtained. Glucose was taken up during the first growth phase, followed by a 60-min lag, and then lactose was transported. Synthesis of lactose phosphotransferase system (PTS) enzymes was repressed until the complete exhaustion of glucose, indicative of an inducer exclusion mechanism of repression. The enzyme phospho-beta-galactosidase, however, was found in small amounts even in the presence of glucose. Repression was not observed when GS5 was grown in equimolar amounts of fructose and lactose. Although fructose was taken up preferentially, synthesis of the lactose PTS occurred from the onset of growth in these sugars. It is proposed that a component of the glucose PTS may be a regulatory factor in lactose transport. Glucose PTS- mutants did not display diauxic growth in glucoselactose mixtures and, in fact, transported the disaccharide preferentially.
Polyamino acid enhancement of bacterial phagocytosis by human polymorphonuclear leukocytes and peritoneal macrophages
Authors: Peterson P K , Gekker G , Shapiro R , Freiberg M , Keane W F
Published: January 2020

Cationic polyamino acids are known to enhance a variety of cell-cell interactions by virtue of their ability to alter electrostatic forces of cell surfaces. In this study, the effect of polyamino acids on phagocytosis of 3H-labeled bacteria by human polymorphonuclear leukocytes (PMNs) and peritoneal macrophages was investigated. Negatively charged and neutral polyamino acids did not influence phagocytosis of unopsonized Staphylococcus epidermidis, whereas protamine, poly-L-arginine, and poly-L-lysine stimulated phagocytosis in a dose-dependent manner. At 50 micrograms/ml, greater than 30% uptake by PMNs was seen with each of these cationic polyamino acids. Although cationic polyamino acids promoted PMN and peritoneal macrophage phagocytosis of unopsonized S. epidermidis, Staphylococcus aureus M (encapsulated) and M variant (unencapsulated), and Escherichia coli J5, little effect was seen with the parent E. coli O111:B4 or a serotype O222:H16 strain. Pretreatment of bacteria and phagocytes separately demonstrated that the phagocytosis-promoting property of polyamino acids is manifest predominantly on the bacteria. Bacteria pretreated with cationic polyamino acids also elicited a PMN chemiluminescent response, and PMN-associated bacteria were killed, as determined by a fluorochrome microassay. Thus, cationic polyamino acids promote the phagocytosis and killing of many but not all bacterial strains, and in this respect polyamino acids function as opsonins.
Genetic variation in the ability of several strains of rats to produce interferon in response to polyriboinosinic-polyribocytodilic acid
Authors: Davis C T , Blankenhorn E P , Murasko D M
Published: January 2020

The ability of various strains of rats to produce interferon in response to polyriboinosinic-polyribocytodilic acid was investigated. ACI and DA (RT-1a), BN (RT-1n), Buffalo (RT-1b), August (RT-1c), and GH (RT-1l) strains produced low levels of interferon in response to intraperitoneal administration of polyriboinosinic-polyribocytodilic acid. However, Lewis (RT-1l) rats demonstrated a 20- to 40-fold higher response. The genetic basis of this difference in production was examined through use of F1 and backcross generations of rats. Both (ACI X Lewis) and (Lewis X ACI) F1 rats exhibited levels of interferon production intermediate to those of the parental strains. No maternal or paternal effects were observed. Results with the F1 rats and the wide variation of response also observed in the backcross generations of F1 rats to either low (ACI) or high (Lewis) responders suggested that several loci control the ability of these rats to produce interferon. Compatibility at the RT-1 locus in both low and high responders negates any significant involvement of the major histocompatibility complex in this control.
Identification of cross-reactive promastigote cell surface antigens of some leishmanial stocks by 125I labeling and immunoprecipitation
Authors: Gardiner P R , Jaffe C L , Dwyer D M
Published: January 2020

Externally oriented surface membrane constituents of promastigotes from several Leishmania species were radiolabeled with 125I. Autoradiographs of cell surface-labeled and sodium dodecyl sulfate-polyacrylamide gel electrophoresis-separated proteins of the stocks revealed distinctive patterns of bands in the molecular weight range of 6,000 to 240,000. Immunoprecipitation of detergent extracts of the labeled promastigote stocks with anti-Leishmania donovani membrane serum demonstrated that each of the stocks contained some antigenically cross-reactive determinants. The electrophoretic patterns of these determinants serve both to distinguish the parasite stocks (by unique, species-specific patterns) and to indicate antigenic similarities in stocks thought to be different by other biochemical criteria. At least 12 cross-reactive cell surface antigens in two New World leishmanias are recognized by polyvalent anti-L. donovani serum, suggesting that these common leishmanial antigens may account for the documented serological cross-reactivities among various Leishmania species. In all stocks tested, an iodinated protein was identified which had a relative molecular weight of 65,000 under reducing conditions but which demonstrated an increase in relative mobility in sodium dodecyl sulfate-polyacrylamide gels under nonreducing conditions. Distinctive patterns of the antigens common to the several stocks were also demonstrated with the use of monoclonal antibodies.
Neuraminidase production by Vibrio cholerae O1 and other diarrheagenic bacteria
Authors: Kabir S , Ahmad N , Ali S
Published: January 2020

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.
In vitro effect of the slime of Pseudomonas aeruginosa on the function of human polymorphonuclear neutrophils
Authors: Laharrague P F , Corberand J X , Fillola G , Gleizes B J , Fontanilles A M , Gyrard E
Published: January 2020

The slime of Pseudomonas aeruginosa markedly impaired the in vitro motility, endocytosis, and phagosome formation of normal human polymorphonuclear neutrophils. This profound impairment of neutrophils, although without alteration of their viability, may contribute to the virulence of this microorganism.
Bacteriological study of periodontal lesions in two sisters with juvenile periodontitis and their mother
Authors: Okuda K , Naito Y , Ohta K , Fukumoto Y , Kimura Y , Ishikawa I , Kinoshita S , Takazoe I
Published: January 2020

A total of five bacteriological samples from the periodontal pockets of two sisters with localized juvenile periodontitis and their mother with advanced periodontitis was studied. Gram-negative anaerobic rods were predominant in the samples. Bacteroides intermedius and Bacteroides loescheii were the most predominant species. The antigenicity and bacteriocinogenicity of these isolates were quite similar. Serum immunoglobulin G antibody levels of the subjects to gram-negative periodontopathic bacteria were measured by using the micro-enzyme-linked immunosorbent assay. The levels of antibodies to saccharolytic black-pigmented Bacteroides species were significantly higher than the levels in healthy young females.
Purification and antibacterial activity of antimicrobial peptides of rabbit granulocytes
Authors: Selsted M E , Szklarek D , Lehrer R I
Published: January 2020

Six antimicrobial peptides, corresponding to the family of "lysosomal cationic proteins" described previously by Zeya and Spitznagel (H. I. Zeya and J. K. Spitznagel, J. Bacteriol. 91:750-754, 1966; H. I. Zeya and J. K. Spitznagel, J. Bacteriol. 91:755-762, 1966), were purified from rabbit peritoneal granulocytes by preparative acrylamide gel electrophoresis and reversed-phase high-pressure liquid chromatography. Each of the peptides was of low molecular weight (ca. 4,000) as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The two most cationic peptides, NP-1 and NP-2, were active against a broad spectrum of gram-positive and gram-negative bacteria. The remaining four peptides, NP-3A, NP-3B, NP-4, and NP-5, had more selective antibacterial activity. None of the peptides was active against Bordetella bronchiseptica, a common pathogen of domestic rabbits. Antibacterial activity was best expressed at near neutral pH under conditions of low ionic strength.
Suppression of fibroblast proliferation by oral spirochetes
Authors: Boehringer H , Taichman N S , Shenker B J
Published: January 2020

Soluble sonic extracts of several strains of Treponema denticola and Treponema vincentii were examined for their abilities to alter proliferation of both murine and human fibroblasts. We found that sonic extracts of all tested strains of T. denticola caused a dose-dependent inhibition of murine and human fibroblast proliferation when assessed by both DNA synthesis ([3H]thymidine incorporation) and direct cell counts. T. vincentii had only a minimal inhibitory effect at comparable doses. No inhibition was observed when sonic extracts were added simultaneously with [3H]thymidine, indicating that suppression was not due to the presence of excessive amounts of cold thymidine in the extract, nonspecific effects on thymidine utilization by the cells (transport and incorporation), or degradation of label. RNA ([3H]uridine incorporation) and protein ([3H]leucine incorporation) synthesis were similarly altered after exposure to the T. denticola sonic extracts. There was no effect on cell viability as measured by trypan blue exclusion. Inhibition could be reversed by extensive washing of the cells within the first few hours of exposure to sonic extracts. Preliminary characterization and purification indicated that the inhibitory factor(s) is not endotoxin since it is heat labile, and elutes in a single, well-defined peak on a Sephadex G-150 chromatography column corresponding to a molecular weight of approximately 50,000. Since oral spirochetes have been implicated in the pathogenesis of periodontal disorders, it is possible that they contribute to the disease process by inhibition of fibroblast growth and therefore may, at least in part, account for the loss of collagen seen in diseased tissue.
Interaction of group A streptococcal peptidoglycan polysaccharide with human polymorphonuclear leukocytes: implications for pathogenesis of chronic inflammation
Authors: Leong P A , Schwab J H , Cohen M S
Published: January 2020

Injection of sterile aqueous preparations of the peptidoglycan polysaccharide of group A streptococci produces chronic inflammation in several animal models. Accordingly, the effect of peptidoglycan and group A-specific polysaccharide (PG-APS) polymers on human polymorphonuclear neutrophil oxidative metabolism was studied with the supposition that this interaction may contribute to the inflammation observed. PG-APS in concentrations of 1.0 to 100 micrograms/ml stimulated oxygen consumption and hexose monophosphate shunt activity in the presence of 10% normal serum in a dose-related manner. Stimulation did not occur in serum-free media and was reduced in media with heat-treated serum. The stimulation of hexose monophosphate shunt activity by PG-APS opsonized with normal serum (bound complement components) and the activated supernatant from which PG-APS had been removed by centrifugation (presumably containing the soluble complement component, C5a) demonstrated 79 and 75%, respectively, of the stimulation with PG-APS in the presence of 10% normal serum. PG-APS triggered release of O2- (3.4 +/- 2.0 nmol by 10(6) human polymorphonuclear neutrophils over 30 min), which was significantly enhanced (9.6 +/- 2.9 nmol O2-) by treatment of cells with cytochalasin B. These results show that PG-APS interacts with serum in such a fashion as to activate human polymorphonuclear neutrophil metabolism and increase secretion of O2-.
Effects of an immunomodulating agent on peripheral blood lymphocytes and subgingival microflora in ligature-induced periodontitis
Authors: Manti F , Kornman K , Goldschneider I
Published: January 2020

The peripheral blood lymphocyte populations and the subgingival levels of black-pigmented Bacteroides species were monitored during the conversion of chronic gingivitis to progressing periodontitis in cynomolgus monkeys. In addition, the effects of an immunomodulating agent, the pentapeptide of thymopoietin (TP5), were determined. After the induction of active periodontitis, proportions of helper T-cells (OKT-4 positive) decreased from 31.5 to 26.4%, and proportions of B-cells (surface immunoglobulin positive) increased from 44.5 to 51.8%. Proportions of suppressor T-cells (OKT-8 positive) remained unchanged, but the numbers of OKT-8-positive cells increased. During this same time period the total cultivable subgingival flora increased from 1.5 X 10(6) to 3.5 X 10(6) per sample, with Bacteroides gingivalis increasing from 5.3 to 16.6% of the total cultivable subgingival flora. After 10 weeks of active periodontitis, animals were treated with either TP5 or placebo. Treatment with TP5 produced an increase in helper T-cells but had no effect on B-cells. The OKT-4/OKT-8 cell ratio, which decreased from 1.3 to 0.8 with disease induction, was increased to 1.1 after TP5 treatment but remained at 0.9 in placebo-treated animals. TP5 had no effect on the total cultivable subgingival flora but significantly decreased the subgingival proportions of B. gingivalis and other black-pigmented Bacteroides species. In this model system, active periodontitis was associated with an increase in B. gingivalis, a decreased helper/suppressor T-cell ratio, and increased levels of B-cells. Treatment with TP5 increased the helper/suppressor T-cell ratio and decreased B. gingivalis levels, suggesting that lymphocyte subsets have the potential to influence subgingival levels of potential periodontal pathogens.
Preparation and characterization of a nontoxic polysaccharide-protein conjugate that induces active immunity and passively protective antibody against Pseudomonas aeruginosa immunotype 1 in mice
Authors: Tsay G C , Collins M S
Published: January 2020

Acid treatment of Pseudomonas aeruginosa immunotype 1 lipopolysaccharide generated a low-molecular-weight polysaccharide fraction that was detectable in agar gel immunodiffusion but did not induce antibodies or resistance to infection in mice. The polysaccharide was treated with periodate to generate additional aldehyde groups. Oxidized polysaccharide was covalently coupled by reductive amination to 1,4-diaminobutyl-derivatized bovine serum albumin. Physical properties of the conjugate were characterized by gel filtration and high-pressure liquid chromatography. The gelation activity of the conjugate in the Limulus amoebocyte lysate assay was 4,000-fold less than native lipopolysaccharide by weight. Mice immunized with the conjugate resisted challenge with P. aeruginosa immunotype 1 that killed 90% of mice immunized with saline. Immunization with the conjugate vaccine induced humoral immunoglobulin G that passively protected normal and burned mice. These results indicate that conjugation of nonimmunogenic polysaccharide antigen of P. aeruginosa restores immunogenicity similar to that of native lipopolysaccharide without restoring endotoxicity inherent in lipopolysaccharide.
Persistence of plasmids, cholera toxin genes, and prophage DNA in classical Vibrio cholerae O1
Authors: Cook W L , Wachsmuth K , Johnson S R , Birkness K A , Samadi A R
Published: January 2020

Plasmid profiles, the location of cholera toxin subunit A genes, and the presence of the defective VcA1 prophage genome in classical Vibrio cholerae isolated from patients in Bangladesh in 1982 were compared with those in older classical strains isolated during the sixth pandemic and with those in selected eltor and nontoxigenic O1 isolates. Classical strains typically had two plasmids (21 and 3 megadaltons), eltor strains typically had no plasmids, and nontoxigenic O1 strains had zero to three plasmids. The old and new isolates of classical V. cholerae had two HindIII chromosomal digest fragments containing cholera toxin subunit A genes, whereas the eltor strains from Eastern countries had one fragment. The eltor strains from areas surrounding the Gulf of Mexico also had two subunit A gene fragments, which were smaller and easily distinguished from the classical pattern. All classical strains had 8 to 10 HindIII fragments containing the defective VcA1 prophage genome; none of the Eastern eltor strains had these genes, and the Gulf Coast eltor strains contained a different array of weakly hybridizing genes. These data suggest that the recent isolates of classical cholera in Bangladesh are closely related to the bacterial strain(s) which caused classical cholera during the sixth pandemic. These data do not support hypotheses that either the eltor or the nontoxigenic O1 strains are precursors of the new classical strains.
Molecular homogeneity of heat-stable enterotoxins produced by bovine enterotoxigenic Escherichia coli
Authors: Saeed A M , Magnuson N S , Sriranganathan N , Burger D , Cosand W
Published: January 2020

Heat-stable enterotoxins (STs) from four strains of bovine enterotoxigenic Escherichia coli representing four serogroups were purified to homogeneity by utilizing previously published purification schemata. Biochemical characterization of the purified STs showed that they met the basic criteria for the heat-stable enterotoxins of E. coli. Amino acid analysis of the purified STs revealed that they were peptides of identical amino acid composition. This composition consisted of 18 residues of 10 different amino acids, 6 of which were cysteine. The amino acid composition of the four ST peptides was identical to that reported for the STs of human and porcine E. coli. In addition, complete sequence analysis of two of the ST peptides and partial sequencing of several others revealed strong homology to the sequences of STs from human and porcine E. coli and to the sequence predicted from the last 18 codons of the transposon Tn1681. There was also substantial homology to the sequence predicted from the ST-coding genetic element of human E. coli, which may indicate the existence of identical bioactive configuration among ST peptides of E. coli strains of various host origins. These data support the hypothesis that STs produced by human, bovine, and porcine E. coli are coded by a closely related genetic element which may have originated from a single, widely disseminated transposon.
Function of anti-Streptococcus mutans antibodies: anti-ribosomal antibodies inhibit acid production, growth, and glucose phosphotransferase activity
Authors: Gregory R L , Michalek S M , Shechmeister I L , McGhee J R
Published: January 2020

Antibodies induced in sera and saliva of rats and rabbits immunized with ribosomal preparations from Streptococcus mutans 6715 inhibited transport of glucose by the phosphotransferase system by greater than 60%, acid production from sucrose by greater than 95%, and growth of the homologous S. mutans by greater than 59%. Inhibition of growth and acid production by immune sera and saliva were abrogated by prior adsorption with S. mutans 6715 whole cells, glucosyltransferase, lipoteichoic acid, or alpha 1-6 or alpha 1-3 dextran. These results indicate that antibodies induced to an S. mutans ribosomal preparation react with cell surface determinants and suggest that the antibodies inhibit sucrose-induced acid formation and growth of virulent S. mutans by neutralizing the glucose-phosphotransferase system.
Mechanism of lipopolysaccharide-induced immunosuppression: immunological activity of B cell subsets responding to T-dependent or T-independent antigens in lipopolysaccharide-preinjected mice
Authors: Uchiyama T , Kamagata Y , Yoshioka M
Published: January 2020

Spleen cells from mice preinjected with high doses of bacterial lipopolysaccharide did not generate anti-trinitrophenyl (TNP) plaque-forming cells in vitro to the T-dependent antigen, TNP-sheep erythrocytes, but did generate fully plaque-forming cells to the T-independent antigens, TNP-Ficoll and TNP-Brucella abortus. The immunological activity of B cells from such lipopolysaccharide-preinjected mice was analyzed in the present study. T cell-depleted spleen cells from mice injected with 30 micrograms of lipopolysaccharide 3 days previously did not respond to combined stimulation with TNP-sheep erythrocytes and concanavalin A-induced T cell-replacing factor and had no suppressive activity on normal T cell-depleted spleen cells. Splenic B cells, which were separated from T cells and macrophages from mice injected with 30 micrograms of lipopolysaccharide 3 days previously, responded only partially (about 25% of the control response) to combined stimulation with TNP-sheep erythrocytes and concanavalin A-induced cell-replacing factor in the presence of normal macrophages, but responded fully to TNP-B. abortus, regardless of the presence of normal macrophages. These results indicate that B cells responding to the T-dependent antigens are rendered unresponsive to antigenic stimulation in mice preinjected with lipopolysaccharide, whereas B cells responding to the T-independent antigens are kept intact.
Characterization of Neisseria gonorrhoeae protein II phase variation by use of monoclonal antibodies
Authors: Black W J , Schwalbe R S , Nachamkin I , Cannon J G
Published: January 2020

The protein II (P.II) outer membrane proteins of Neisseria gonorrhoeae, which have been implicated in gonococcal pathogenesis, have been previously shown to undergo a type of phase variation in which expression of any of several different forms of the proteins may be switched on or off. We identified six electrophoretically distinct forms of P.II proteins (designated P.IIa through P.IIf) within strain FA1090, and we isolated colonial variants of FA1090 that expressed only one of the six different P.II protein forms. Two monoclonal antibodies that bound specifically and differentially to P.II proteins were produced. One antibody bound to proteins P.IIb and P.IId and was bactericidal for all colonial variants expressing P.IIb. The second antibody bound to P.IIa and was bactericidal for colonial variants expressing P.IIa. P.II protein profiles of survivors of antibody killing indicated that multiple P.II protein species may be expressed on a single bacterium and that P.II protein switching in the gonococcus is nonrandom.
Serological characterization of Streptococcus mutans serotype polysaccharide g and its different molecular weight forms
Authors: Takada K , Wyszomirska J , Shiota T
Published: January 2020

The serotype polysaccharide g from Streptococcus mutans 6715 was found to cross-react with serotype polysaccharide a from S. mutans HS6 and serotype polysaccharide d from S. mutans B13. Double immunodiffusion experiments indicated that the serotype polysaccharide g consisted of the following: (i) the type-specific g site; (ii) a cross-reactive site g-a that was in common with polysaccharide a; (iii) a cross-reactive site g-d that was in common with polysaccharide d; and (iv) a cross-reactive site g-(a-d) that was in common with both polysaccharides a and d. Moreover, by a procedure involving several column chromatography steps, six polysaccharide-containing fractions showing reactivity with anti-g serum were found. By gel filtration, the molecular weight estimates of fractions LI, LII, LIII, SI, SII, and SIII were 2 X 10(6), 5 X 10(5), 6 X 10(4), 3 X 10(4), 1.4 X 10(4), and 1 X 10(4), respectively. Double immunodiffusion analysis indicated that LI, LII, and LIII contained the four antigenic sites of the putative polysaccharide g. LII also contained another additional immunodominant region, designated site x. The analysis also suggested that fraction SI lacked the type-specific site g, fraction SII lacked sites g and g-a, and fraction SIII lacked sites g, g-a, and g-d.
Preparation of procoligenoids from Escherichia coli heat-labile enterotoxins
Authors: Finkelstein R A , Sciortino C V , Rieke L C , Burks M F , Boesman-Finkelstein M
Published: January 2020

Heat-labile enterotoxins from Escherichia coli strains of porcine and human origin polymerize on heating to form high-molecular-weight aggregates, "procoligenoids," analogous to procholeragenoid derived from the cholera enterotoxin. This aggregation is accompanied by loss of biological activity (toxicity). Further heating results in the release of B-subunit oligomers, coligenoids, analogous to choleragenoid. Further studies are needed to determine whether, like procholeragenoid, the procoligenoids are superior antigens in stimulating gut immunity after parenteral administration.
Effect of Pseudomonas aeruginosa cytotoxin on thymidine incorporation by murine splenocytes
Authors: Obrig T G , Baltch A L , Moran T P , Mudzinski S P , Smith R P , Lutz F
Published: January 2020

The interaction of highly purified Pseudomonas aeruginosa cytotoxin (PAC) with murine splenocytes was examined. Added at culture initiation, PAC (0.1 to 0.5 microgram/ml) inhibited subsequent [3H]deoxythymidine incorporation measured between 42 to 48 h. Incorporation of [3H]deoxythymidine was inhibited 50% in lipopolysaccharide-, phytohemagglutinin-, and concanavalin A-stimulated cultures by 0.20, 0.32, and 0.39 microgram of PAC per ml, respectively. It is concluded that PAC exhibits a narrow inhibitory concentration response range of 0.1 to 0.5 microgram/ml which, secondarily, is affected by the presence of mitogens. Antitoxin added at splenocyte culture initiation, directly after PAC, yielded greater than or equal to 86% protection against PAC inhibition of [3H]deoxythymidine incorporation. Addition of antitoxin to cultures at different times after PAC demonstrated a time-dependent loss of antitoxin protective effect over a 12-h period, indicating that PAC became cell associated and refractory to antitoxin within this time period. PAC preincubated with splenocytes at 4 degrees C for less than or equal to 1 h could not be removed by washing of cells and was fully inhibitory to [3H]deoxythymidine incorporation when these cells were cultured at 37 degrees C. This finding was confirmed by demonstrating that 125I-labeled PAC bound immediately to cells. It is concluded that PAC action on splenocytes is dose- and time-dependent and consists of a two-phase process: (i) a very rapid binding of PAC to the cell surface available to antitoxin, and (ii) a slower toxicity development phase of ca. 12 h, during which PAC becomes refractory to antitoxin.
Effects of zinc on stationary-phase phenotype and macromolecular synthesis accompanying outgrowth of Candida albicans
Authors: Anderson J M , Soll D R
Published: January 2020

When cultures of Candida albicans which had entered stationary phase due to the depletion of zinc (zinc-limiting conditions) were compared with cultures which had entered stationary phase due to the depletion of another growth-limiting component (zinc-excess conditions), at least two cellular characteristics were found to differ: (i) zinc-limited cells appeared more homogeneous and larger on the average than zinc-excess cells, and (ii) zinc-limited cells evaginated on the average of 40 min later than zinc-excess cells. In the present study, it is demonstrated that the distribution of volumes for a stationary-phase culture of zinc-excess cells is skewed towards very small volumes, but even the smallest cells contain nuclei; in contrast, the volumes of zinc-limited cells are evenly distributed around a much larger mean value; the evagination kinetics of zinc-excess cells released into fresh medium are far less synchronous than are those of zinc-limited cells, and the smaller cells in the population take much longer to evaginate than do the larger cells; the onset of net RNA accumulation and achievement of a maximum rate of [3H]uridine incorporation occur significantly earlier in zinc-excess cells than in zinc-limited cells released into fresh medium; and the onset of net protein accumulation and [3H]leucine incorporation occur significantly earlier in zinc-excess cells than in zinc-limited cells released into fresh medium. These results indicate that although zinc-excess cells are extremely heterogeneous in volume, they may still be homogeneously blocked in the nuclear division cycle, and that the later average evagination time of released zinc-limited cells may be due to a delay in the onset of protein synthesis, which in turn may be due to the time necessary to reaccumulate zinc to levels sufficient for the reinitiation of RNA synthesis.
Cell surface proteins of oral streptococci
Authors: Appelbaum B , Rosan B
Published: January 2020

Whole cells of representative strains of oral streptococci (Streptococcus sanguis, S. mitis, and S. salivarius) were radiolabeled by the lactoperoxidase method of radioiodination. The labeled polypeptides obtained by extraction of whole cells with boiling sodium dodecyl sulfate were analyzed by polyacrylamide gel electrophoresis and autoradiography. Of the total radioactivity, ca. 70% was released by treating whole cells with trypsin, suggesting that the labeling was confined to proteins located on the cell surface. Most S. sanguis strains studied gave a characteristic banding pattern consisting of a high-molecular-weight (120,000 [120K] to 63K) group of six proteins. Three low-molecular-weight (12K, 16K, and 18K) proteins were also detected in many strains.
Adoptive transfer of immune enhancement of experimental ulcerative colitis
Authors: Onderdonk A B , Steeves R M , Cisneros R L , Bronson R T
Published: January 2020

Previous experiments with the carrageenan model for ulcerative colitis have shown that the inflammatory response in guinea pigs can be enhanced by immunization with and subsequent feeding of Bacteroides vulgatus to experimental animals. The present studies showed that only certain strains of B. vulgatus are capable of provoking immune enhancement of ulcerative colitis. Animals were fed carrageenan and various strains of viable B. vulgatus after immunization with a strain of B. vulgatus isolated from a guinea pig with experimentally induced colitis. Histological comparison of immune and nonimmune groups revealed that immune animals which received B. vulgatus from a patient with inflammatory bowel disease had a significantly (P less than 0.025) greater number of histopathological lesions at 21 days than did nonimmune animals. Immune animals receiving B. vulgatus isolated from a clinically normal source did not show any significant difference in disease status when compared to nonimmune animals. Additional experiments showed that adoptive transfer of spleen cells from animals immunized with B. vulgatus to nonimmune recipient animals is effective in transferring the immune enhancement demonstrated in actively immunized animals. Animals which received immune spleen cells with concurrent feeding of B. vulgatus showed a significant (P less than 0.005) increase in inflammation over control groups, in the absence of high titers of circulating antibody. These experiments indicate that B. vulgatus strain-specific factors are important to immune enhancement of experimental disease and also suggest an involvement of the cell-mediated immune system in this model.
Purification and characterization of Serratia marcescens US5 pili
Authors: Kohno K , Yamamoto T , Kuroiwa A , Amako K
Published: January 2020

The pili of Serratia marcescens US5 isolated from a patient with urinary tract infection were purified and characterized. During the aeration culture, the pili were detached from the bacteria and were precipitated by the addition of ammonium sulfate. The purification of the pili was carried out by ion-exchange chromatography and gel filtration on Sepharose 4B. In electron microscopy, the purified pilus showed a filament of 3 nm in diameter and 0.3 micron in average length. The molecular weight of the protein subunit of the purified pili was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Two protein bands appeared. One has a molecular size of 19,000 daltons, and the other has a molecular size of 39,000 daltons. The isoelectric point was 3.7. The content of hydrophobic amino acids in purified pili subunits was 42% of the total amino acid content. Further purification of pili by isopycnic centrifugation failed to remove the large protein band. No identical protein bands to pili proteins were detected in the electrophoresis pattern of the outer membrane proteins extracted from S. marcescens US5 in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. These two proteins might be a dimer of a small molecule. A survey of clinically isolated strains of S. marcescens revealed that more than 60% of the strains had this type of pili. These results suggest that these pili are widely distributed among strains of S. marcescens.
Serological confirmation of Brucella abortus and Yersinia enterocolitica O:9 O-antigens by monoclonal antibodies
Authors: Bundle D R , Gidney M A , Perry M B , Duncan J R , Cherwonogrodzky J W
Published: January 2020

Murine monoclonal antibodies that bind the O-antigens of Yersinia enterocolitica serotype O:9 and Brucella abortus 1119-3 were generated after immunization of BALB/c mice with killed, whole cells. Highly purified lipopolysaccharide preparations from each organism were used to screen for antigen-specific antibodies. Immunization with B. abortus cells induced 56 antigen-specific hybrids, and 10 of the highest antibody-producing clones were selected for further study. Seven of these clones secreted immunoglobulin G, and three secreted immunoglobulin M antibodies. Immunization with Y. enterocolitica cells resulted after fusion in 76 antigen-specific hybrid cell lines; from these, seven immunoglobulin G-secreting clones were selected for study. The serological cross-reactivity of the B. abortus and Y. enterocolitica O-antigens was established by enzyme-linked immunosorbent assay, immunoprecipitation, and agglutination tests with the monoclonal antibodies induced by each bacterium. This serological cross-reactivity is consistent with the structural identity of the two O-antigens established by chemical analysis.
Development of a Neisseria meningitidis group B serotype 2b protein vaccine and evaluation in a mouse model
Authors: Wang L Y , Frasch C E
Published: January 2020

Although serotype 2 remains the predominant cause of group B Neisseria meningitidis disease in many parts of the world, most cases of this disease are now due to serotype 2b rather than 2a. For this reason, we adapted the serotype 2a vaccine method of C. E. Frasch and M. S. Peppler (Infect. Immun. 37:271-280, 1982) to the production of a serotype 2b protein vaccine. A spontaneously occurring nonencapsulated mutant of the group B serotype 2b strain 3006 was obtained by selection on group B antiserum agar. Serotype 2b outer membrane protein vaccines were prepared with less than 1% lipoplysaccharide contamination. The immunogenicity of these vaccines was evaluated in mice in the presence and absence of meningococcal group B and group C capsular polysaccharides. The group B and group C polysaccharides equally potentiated the antibody response to the serotype 2b protein. Addition of aluminum hydroxide or aluminum phosphate markedly improved the antibody response to the serotype 2b protein, but aluminum hydroxide-adjuvanted vaccines consistently elicited higher antibody levels. Aluminum hydroxide-adsorbed serotype 2a and 2b protein vaccines were evaluated for induction of cross-protective bactericidal antibodies. The 2a vaccines were 2a specific, whereas the 2b vaccines elicited antibodies strongly bactericidal for both 2a and 2b meningococcal strains and protected against bacteremia in a mouse model. It may therefore be possible to provide protection against both 2a and 2b disease by using an aluminum hydroxide-adsorbed protein vaccine containing a single serotype 2 protein component.
Bordetella pertussis infection in mice: correlation of specific antibodies against two antigens, pertussis toxin, and filamentous hemagglutinin with mouse protectivity in an intracerebral or aerosol challenge system
Authors: Sato H , Sato Y
Published: January 2020

The correlation of titers of specific serum immunoglobulin G antibodies against two antigens, pertussis toxin (PT), and filamentous hemagglutinin (FHA), which are the main components of pertussis vaccine in Japan, with mouse protectivity was examined by both intracerebral and aerosol challenge systems with virulent Bordetella pertussis cells. Titer of the antibodies was calculated from the enzyme-linked immunosorbent assay (ELISA) unit given arbitrarily to reference antibodies. PT antibody titer which protected 50% of mice was indistinguishable in both active immunization followed by intracerebral challenge and passive immunization followed by aerosol challenge. The 50% effective dose was 23 ELISA U/ml in the former mice and 24 ELISA U/mouse in the latter. In the intracerebral challenge system, FHA did not elicit a protective response but was very helpful for PT as an immunizing antigen. When anti-FHA immunoglobulin G coexisted with anti-PT immunoglobulin G in mice, the 50% effective dose of PT antibody was 4.4 or 10 ELISA U/mouse in intracerebral or aerosol challenge systems, respectively. In this active immunization system, pertussis toxoid of 1 micrograms or 0.1 microgram/mouse produced PT antibody of ca. 20 or 5 ELISA U/ml, respectively. It was concluded that pertussis toxoid or its antibody was much more potent than Formalin-treated FHA or its antibody; Formalin-treated FHA or its antibody was helpful when it was administered with pertussis toxoid toxoid or its antibody, however.
Lectin-dependent attachment of Actinomyces naeslundii to receptors on epithelial cells
Authors: Brennan M J , Cisar J O , Vatter A E , Sandberg A L
Published: January 2020

The adherence of Actinomyces naeslundii WVU45 to monolayer cultures of human epithelial cell lines was mediated by the lactose-sensitive fimbriae (type 2) of strain WVU45. The attachment of Actinomyces viscosus T14V, which has both types 1 and 2 fimbriae, was approximately half that of A. naeslundii, and only minimal attachment of A. naeslundii and A. viscosus mutants lacking type 2 fimbriae was detected. The adherence of strain WVU45 was enhanced two- to threefold by neuraminidase treatment of the epithelial cells. The Fab fragments of antibodies which recognize the type 2 fimbriae inhibited the adherence of A. naeslundii WVU45 to the epithelial cells. The bacterial interaction with epithelial cells was inhibited by lactose, methyl-beta-D-galactoside, and N-acetyl-D-galactosamine, but not by methyl-alpha-D-galactoside, cellobiose, N-acetyl-D-glucosamine, L-fucose, or D-mannose. To further characterize the epithelial cell receptors for the bacterial lectin, we utilized several plant and invertebrate lectins as potential inhibitors of bacterial adherence. Lectins from Bauhinia purpurea and Arachis hypogaea which recognize N-acetyl-D-galactosamine, D-galactose, and D-galactose-beta-(1----3)-N-acetyl-D-galactosamine inhibited bacterial attachment, and binding of these lectins to epithelial cells was enhanced by the addition of neuraminidase. Lectins reacting with alpha-linked D-galactose, alpha-linked N-acetyl-D-galactosamine, D-mannose, or sialic acid were not inhibitory. Under similar assay conditions, adherence of a mannose-sensitive strain of Escherichia coli was inhibited by concanavalin A but not by the lectin from Bauhinia purpurea. These results indicate that certain plant lectins have specificities similar to that of the actinomyces fimbrial lectin and are, therefore, useful probes for identifying receptors on epithelial cells for certain bacteria.
Agglutination of Streptococcus mutans by low-molecular-weight salivary components: effect of beta 2-microglobulin
Authors: Ericson D
Published: January 2020

Radiolabeled monomeric human beta 2-microglobulin (beta 2m) was tested for binding to Streptococcus mutans strains in buffers containing 1 mM calcium (Ca2+). Binding was seen to strains with a previously established binding capacity of aggregated beta 2m. Monomeric beta 2m agglutinated beta 2m-binding strains when Ca2+ was present. At Ca2+ concentrations of 1.4 mM, 0.032 micrograms of monomeric beta 2m per ml caused bacterial agglutination. Parotid saliva was gel filtered on a Sephadex G-75 column, and low-molecular-weight fractions containing beta 2m could agglutinate S. mutans cells. Five of six strains that could bind beta 2m were agglutinated by these fractions, but only one of five nonbinding strains was. All strains tested were agglutinated by void volume fractions. A new method for the measurement of turbidity in bacterial agglutination inhibition experiments with parotid saliva was used. Suspensions containing parotid saliva, bacteria, and control serum were directly compared in a spectrophotometer with test suspensions containing goat anti-human beta 2m, bacteria, and saliva. Thus, the spectrophotometer directly read the difference in agglutination of the two suspensions, and the result was presented as one curve by the recorder. Agglutination of five beta 2m-binding strains of S. mutans was inhibited or decreased by the addition of goat anti-human beta 2m as compared with control serum. The agglutination of two beta 2m-nonbinding strains and one with variable binding was not inhibited. Thus, salivary beta 2m may contribute to agglutination of S. mutans cells in parotid saliva.
Activation of complement system by porins extracted from Salmonella typhimurium
Authors: Galdiero F , Tufano M A , Sommese L , Folgore A , Tedesco F
Published: January 2020

The effect of porins purified from Salmonella typhimurium on the complement system was investigated both in vitro and in vivo. Incubation of porins with either human or guinea pig serum resulted in the consumption of the total complement activity when an amount of porins ranging from 8 to 10 micrograms per 100 microliters of serum was used. The activation of the complement system was temperature dependent, suggesting an active process rather than passive adsorption of the complement components by porins. In addition, the activation had a fast kinetic and proceeded mainly through the classical pathway. This conclusion is supported by the consumption of C1s and C4 in normal human serum treated with porins and also by the depletion of C3 activity in the C1s-deficient serum which was marked only when purified C1s was added to the serum before incubation with porins. Injection of 100 micrograms of porins into guinea pigs induced profound complement consumption at 6 h postinjection that persisted up to 12 h. We conclude from this study that porins can effectively contribute to complement activation and to subsequent biological events induced by gram-negative bacteria.
Effect of peroral immunization of humans with Streptococcus mutans on induction of salivary and serum antibodies and inhibition of experimental infection
Authors: Cole M F , Emilson C G , Hsu S D , Li S H , Bowen W H
Published: January 2020

Naturally occurring antibodies reactive with Streptococcus mutans whole cells were assayed in whole saliva, parotid saliva, and blood samples collected from eight human volunteers. The levels and serotypes of indigenous S. mutans in plaque and whole saliva samples were also determined. After baseline sampling the teeth were cleaned and the subjects were inoculated with streptomycin-resistant S. mutans strains Ingbritt (serotype c) and OMZ65 (serotype g). The level of implantation and duration of colonization were determined in plaque and saliva, and antibodies reactive with these strains were monitored in saliva and serum. After the implanted bacteria were shed, the subjects wee immunized by the daily ingestion of an enteric-coated capsule containing 25 mg of Formalin-killed, freeze-dried OMZ65 cells for 3 days and inoculation was repeated. The levels of antibodies and of implantation and the duration of colonization were monitored as before. One month after the bacteria could no longer be detected, the immunization and inoculation cycle was repeated except that the subjects were immunized for 7 days. Five of the eight subjects were successfully colonized by strains Ingbritt and OMZ65. The remaining three did not become colonized with either strain. Strain OMZ65 implanted at a higher level than did strain Ingbritt. Oral immunization did not result in a detectable antibody response in saliva or serum to whole bacterial cells. However, after both the first and second immunizations there were marked reductions in the peak levels of infection and the duration of colonization of both OMZ65 and Ingbritt.
Staphylococcus aureus peptidoglycan induces histamine release from basophil human leukocytes in vitro
Authors: Espersen F , Jarløv J O , Jensen C , Skov P S , Norn S
Published: January 2020

Whole killed cells, cell walls, and peptidoglycans of Staphylococcus aureus were found to release histamine from human leukocytes and isolated rat mast cells in vitro. The histamine-releasing capability increased in the order of whole bacteria, cell walls, and peptidoglycans. Peptidoglycan was found to release histamine by a nonimmunological mechanism, as demonstrated by release in cells deprived of surface immunoglobulins, whereas whole bacteria and cell walls seemed to operate both by immunological and nonimmunological mechanisms. Histamine release was not a specific property of S. aureus; a wide range of whole bacterial species had this activity. We suggest that peptidoglycan may be a common factor responsible for histamine release by different bacteria.