bluuebunny/crossref_metadata_2025 huggingface dataset:
Adhesion of Corynebacterium renale, Corynebacterium pilosum, and Corynebacterium cystitidis to bovine urinary bladder epithelial cells of various ages and levels of differentiation
Authors: Sato H , Yanagawa R , Fukuyama H
Published: January 2020

The adhesion of Corynebacterium renale, Corynebacterium pilosum, and Corynebacterium cystitidis to various epithelial cell layers of bovine urinary bladders was examined. Adhesion was most efficient to the urinary sediment epithelial cells and the superficial cells immediately before shedding, followed by the remaining superficial cells and intermediate cells in this order, and least efficient to the deeper intermediate and basal cells. Incubation of the intermediate cells for 6 h increased the number of bacteria that adhered to these cells.
Position on Mouse Chromosome 1 of a Gene that Controls Resistance to
Salmonella typhimurium
Authors: Taylor Benjamin A. , O'Brien Alison D.
Published: January 2020

Ity
is a gene which regulates the magnitude of
Salmonella typhimurium
growth in murine tissues and, hence, the innate salmonella resistance of mice. The results of a five-point backcross clearly showed that the correct gene order on chromosome 1 is
fz-Idh-1-Ity-ln-Pep-3.
Comparison of the induction of immunoglobulin M and G antibodies in mice with purified pneumococcal type 3 and meningococcal group C polysaccharides and their protein conjugates
Authors: Beuvery E C , van Rossum F , Nagel J
Published: January 2020

The nature and kinetics of the serum antibody response to pneumococcal type 3 and meningococcal group C polysaccharides and their protein conjugates were studied in mice. Bovine serum albumin and diphtheria and tetanus toxoids were used as carrier proteins. The purified polysaccharides induced only immunoglobulin M (IgM) antibodies in thymus-bearing as well as congenic athymic (nude) mice. The polysaccharides covalently conjugated to proteins produced IgM and IgG antibodies in normal mice, but only IgM antibodies in nude mice. A second dose of the polysaccharide-protein conjugates resulted in a booster effect in the IgG response to the polysaccharides. Moreover, memory B-cells, generated after a primary injection with the polysaccharide-protein conjugates, could be triggered to the production of IgG antibodies after a second injection with the pure polysaccharides alone. These data indicate that the antibody response to the pure polysaccharides is thymus independent and that this response can be changed into a thymus-dependent response by covalent conjugation of the polysaccharide to a thymus-dependent protein.
Monoclonal antibodies against Pseudomonas aeruginosa outer membrane antigens: isolation and characterization
Authors: Hancock R E , Wieczorek A A , Mutharia L M , Poole K
Published: January 2020

Hybridomas secreting monoclonal antibodies specific for Pseudomonas aeruginosa outer membrane antigens were isolated. One of the antibodies was highly specific for the O antigen of the lipopolysaccharide of International Antigen Typing Scheme serotype 5 strains, reacting only weakly with a serotype 17 strain and failing to react with the outer membranes of strains representing 15 other serotypes. This monoclonal antibody was able to agglutinate heat-killed bacterial cells as well as lipopolysaccharide-coated sheep erythrocytes. Two other monoclonal antibodies were able to interact with the outer membranes of strains representing all 17 serotypes, although they were unable to agglutinate heat-killed bacterial cells. One of these was shown to be specific for the major outer membrane lipoprotein H2. The antigenic site against which this monoclonal antibody reacted was present in the outer membranes of two Pseudomonas fluorescens strains, two Pseudomonas putida strains, a Pseudomonas anguilliseptica strain, and an Azotobacter vinelandii strain, but not in the outer membranes of five other bacterial species.
Effects of reduced temperature on the components of human lymphocyte transformation responses to antigens
Authors: Lettau L A , Sohnle P G
Published: January 2020

The present studies were designed to determine the site at which reduced temperature, such as that found at the skin surface, affects the lymphocyte transformation response to an antigenic stimulus. Extracts of Candida albicans and Pityrosporum orbiculare were used as antigens since most normal subjects demonstrate positive lymphocyte responses to both. Total lymphocyte transformation responses to both antigens were reduced and delayed at 34.5 as compared with 37 degrees C. The former temperature did not significantly affect the numbers of antigen-responsive cells, as estimated by limiting dilution analysis. However, the response of first-generation lymphocytes to both antigens was significantly reduced at the lower temperature. There did not seem to be any significant differences between the two antigens with respect to the effects of the reduced temperature on the resulting lymphocyte transformation response or its components. Therefore, the present data suggest that reduced temperature suppresses antigen-stimulated lymphocyte transformation by affecting the later stages of this response.
Effect of in vitro preincubation of polymorphonuclear leukocytes on formylmethionyl-leucyl-phenylalanine-induced chemiluminescence
Authors: Dahlgren C , Stendahl O
Published: January 2020

When polymorphonuclear leukocytes (PMNL) and soluble or particulate matter interact, the cells produce chemiluminescence. The chemotactic peptide formylmethionyl-leucyl-phenylalanine induced a two-peak chemiluminescence response in PMNL. The response was modified, both in magnitude and in the time course of the response, when PMNL were incubated at 22 degrees C for 15 to 120 min before the addition of stimulus. The cellular response to formylmethionyl-leucyl-phenylalanine was also changed by the addition of cell-free supernatants from stored PMNL suspensions to freshly prepared PMNL before the addition of formylmethionyl-leucyl-phenylalanine. This indicated that PMNL during storage released substances that changed the chemiluminescence response. A similar change could be obtained by addition of purified myeloperoxidase to freshly prepared PMNL before the addition of stimulus, indicating that the myeloperoxidase-hydrogen peroxide system can function as a modulator of the cellular response to chemotactic factors.
Gamma interferon production in allogeneic stimulation: antigenicity that is sufficient to cause interferon production
Authors: Ito Y , Shimokata K , Maeno K
Published: January 2020

Spleen cells obtained from allogeneic cell-primed mice produced immune interferon when cocultivated with the antigenic cells. The purpose of this study was to clarify the antigenic determinants for immune interferon production in this allogeneic stimulation system. An incompatibility at the K end alone or at the D end alone of the H-2 complex was sufficient for immune interferon induction. No interferon production was observed in the combinations between strains of mice that differ for the non-H-2 regions, including the M locus. Immune interferon-producing cells (IIPC), induced by difference of the H-2K or H-2D regions, recognized the specificities controlled by the H-2K or H-2D regions, respectively; namely, there was no cross-reaction between the two regions. The difference between H-2d and H-2b did not cause interferon production in the combinations of which non-H-2 regions were very similar to each other. IIPC were not induced in the combination, but when IIPC were properly induced in B6 spleen cells, the IIPC could recognize the specificities controlled by the H-2d region (B10D2) and produced immune interferon.
Defective interfering particles of respiratory syncytial virus
Authors: Treuhaft M W , Beem M O
Published: January 2020

A multiplicity-dependent interference was observed in respiratory syncytial virus preparations (Randall strain) grown in HEp-2 cells, and the factor mediating this interference was characterized. Cloned virus did not demonstrate this multiplicity-dependent interference, but its replication was shown to be inhibited by the interfering factor by assays of reduction of infectious yield assay, the interferon factor was found to be particulate, to be inactivated by UV irradiation, and not to interfere with the replication of a heterologous virus, vesicular stomatitis virus. These characteristics are compatible with the physical properties and biological behavior of defective interfering particles. Defective interfering particles were generated by four undiluted passages of cloned virus but were not apparent after eight passages at a multiplicity of infection of 0.1.
O:K:H:F serotypes of fimbriated Escherichia coli strains isolated from infants with diarrhea
Authors: Czirók E , Orskov I , Orskov F
Published: January 2020

Bacterial agglutination and crossed immunoelectrophoresis were compared as techniques for the subdivision of mannose-resistant hemagglutinating Escherichia coli fimbrial antigens. A total of 22 fimbrial strains, 15 of which had earlier been grouped into two fimbrial agglutination groups, were examined for the presence of fimbrial antigens F7 go F12 by crossed immunoelectrophoresis. Most of the strains were isolated from infants with diarrhea; they were neither enteropathogenic nor enterotoxigenic serotypes. Of the 10 strains in agglutination group 1, 4 had fimbrial antigens F7 and 1C, 4 had antigens F8 and 1C, and in 1 strain, only antigen 1C was demonstrated. The tenth strain did not, by the crossed immunoelectrophoresis test, fit into agglutination group 1. Agglutination group 2 comprised five strains. Four of these had antigens in common with the still unnumbered fimbrial antigens of an O4:K12:H5 strain. In the fifth strain, no known F antigens were demonstrated. The previously found correlation between some O:K:H serotypes and fimbrial antigens in strains from urinary tract infections was confirmed in this study in strains from diarrhea cases. We concluded that, although the agglutination test can indicate the presence of certain fimbriae, it cannot be used presently for an exact demonstration of these antigens because each strain often produces several different fimbriae.
Alteration of cell-mediated immunity to Listeria monocytogenes in protein-malnourished mice treated with thymosin fraction V
Authors: Petro T M , Chien G , Watson R R
Published: January 2020

Cell-mediated immune reactivity, measured by lymphocyte responsiveness to phytohemagglutinin, was higher in both young or aged mice fed a 4% casein diet compared with age-matched controls. Treatment in vivo with bovine thymosin fraction V decreased the responsiveness to phytohemagglutinin of lymphocytes from mice fed either the control or moderately protein-deficient diets when compared with mice treated in vivo with saline. Resistance against Listeria monocytogenes, known to be a cell-mediated immune function, was impaired in young and aged mice which were fed the low-protein diet. Treatment with thymosin was able to significantly improve the cell-mediated immune resistance to L. monocytogenes of moderately protein-malnourished mice. Thymosin treatment impaired the resistance to L. monocytogenes of young or aged mice fed the control diet. The splenic natural killer cell cytotoxicity of protein-malnourished mice was impaired compared with that of mice fed the control diet. Treatment with thymosin did not restore the natural killer cell cytotoxic activity in protein-malnourished mice, but did enhance that activity in control mice.
Cell-mediated cytotoxicity against rat fibroblasts induced by Actinomyces viscosus
Authors: Gaegauf-Zollinger R , Burckhardt J J , Gmür R , Guggenheim B
Published: January 2020

Cell-mediated cytotoxicity against syngeneic fetal rat fibroblasts that require in vitro exposure of effector cells to Actinomyces viscosus Ny1 fractions was investigated by measuring the uptake of radioactivity by fibroblasts during a 2-h pulse with [14C]aminoisobutyric acid after 1 to 3 days of coculture with splenic effector cells. By using splenocytes from inbred RIC-Sprague-Dawley rats as effector cells and syngeneic embryonic rat fibroblasts as target cells, strong cell-mediated cytotoxicity dependent on the in vitro exposure to an A. viscosus Ny1 fraction was observed, but only within a small range of effector-to-target cell ratios (3:1 to 10:1). Concanavalin A and lipopolysaccharide from Escherichia coli induced a comparable cytotoxicity, indicating that the effect might be connected with the mitogenic activity of the A. viscosus NY1 fraction. Splenocytes from rats immunized with A. viscosus Ny1 and from control rats induced similar levels of cytotoxicity in 72-h cytotoxicity assays. In shorter assays (24 h), however, splenocytes from immune animals induced low cytotoxicity, which was, however, significantly higher than that induced by splenocytes from control animals. We conclude that both antigen- and mitogen-dependent cell mediated effector mechanisms are operative in this system and that the two normally overlapping effects can be experimentally separated. This new system describes a fibroblast impairment in the presence of splenocytes and bacterial components and may provide a useful model for studying pathogenic mechanisms operative in periodontal disease.
Salmonella typhimurium infection in calves: specific immune reactivity against O-antigenic polysaccharide detectable in in vitro assays
Authors: Robertsson J A , Fossum C , Svenson S B , Lindberg A A
Published: January 2020

Peripheral blood lymphocytes collected from calves infected experimentally with Salmonella typhimurium (O antigens 4,5,12) or Salmonella sp. serotype dublin (O 9,12) were stimulated with various bacterial cell envelope components, and their [3H]thymidine incorporation was measured. It was found that peripheral blood lymphocytes from infected calves incorporated significantly more [3H]thymidine than peripheral blood lymphocytes from uninfected controls (P values ranged from less than 0.05 to less than 0.0005). The responder cell type was found in a B-cell-depleted and T-cell-enriched population. The Salmonella infections elicited T-cell responses against at least two cell envelope components: (i) a specific response against the O-antigenic polysaccharide chain of the lipopolysaccharide (This was evident in that a polysaccharide from S. enteritidis [O 9,12] which shares a trisaccharide structure [O antigen 12 determinant] with S. typhimurium stimulated [3H]thymidine uptake, which, although lower than in the homologous system, was significantly higher than that seen after incubation with unrelated Salmonella sp serotype thompson polysaccharide.) and (ii) a response against outer membrane proteins (porins), which are present in both S. typhimurium and Salmonella sp. serotype dublin. The experiments with peripheral blood lymphocytes from Salmonella sp. serotype dublin-infected calves gave results in excellent agreement with those obtained in S. typhimurium-infected calves.
Chemiluminescence response of peritoneal macrophages to parasitized erythrocytes and lysed erythrocytes from Plasmodium berghei-infected mice
Authors: Makimura S , Brinkmann V , Mossmann H , Fischer H
Published: January 2020

The chemiluminescence response of normal mouse peritoneal macrophages to parasitized erythrocytes isolated from mice 3 weeks after infection with Plasmodium berghei was examined. Only 4 of 12 animals showed positive responses, whereas 8 showed negative responses. Photomicrographs revealed that only in chemiluminescence-positive animals were parasitized erythrocytes attached to or phagocytized by macrophages. When lysed parasitized-erythrocyte cell suspensions were added to the peritoneal macrophages, chemiluminescence could be induced in all cases. The response was enhanced remarkably by the addition of very small amounts of immune serum. Normal macrophages activated in vitro by supernatant from antigen-stimulated spleen cells from immune mice showed much higher parasite-induced chemiluminescence responses than did nonactivated macrophages, especially in the presence of immune serum.
Effect of steroid hormones on virus-induced diabetes mellitus
Authors: Giron D J , Patterson R R
Published: January 2020

Female ICR Swiss mice, generally resistant to the diabetogenic effects of the D variant of encephalomyocarditis virus, develop diabetes to the same extent as males if they are pretreated with testosterone. The data suggest that testosterone is one of the factors involved in the development of diabetes in certain strains of mice.
Neutralization of lymphocyte immortalization by different strains of Epstein-Barr virus with a murine monoclonal antibody
Authors: Miller G , Heston L , Hoffman G
Published: January 2020

A murine monoclonal antibody was raised against the B95-8 strain of Epstein-Barr virus (EBV), which was isolated from a case of mononucleosis after blood transfusion (Hoffman et al. Proc. Natl. Acad. Sci. U.S.A. 77:2979, 1980). We provide evidence that neutralization of immortalization by this monoclonal antibody is virus specific, since its potency was inversely related to the dose of challenge virus. Furthermore, the monoclonal antibody recognized antigens on viruses grown in human as well as in marmoset cells. We show that this monoclonal antibody neutralized three other transforming strains of EBV originating, respectively, from American patients with mononucleosis and fatal polyclonal lymphoma and from an African child with Burkitt lymphoma. However the antibody did not neutralize or detect antigens by immunofluorescence in the W91 strain of EBV. The hybridoma antibody did neutralize other EBV strains derived from the same Burkitt lymphoma cell line (Nyevu), as was the case with the W91 strain. This monoclonal antibody provides clear evidence of antigenic differences on the surface of EBVs and will ultimately prove useful in defining the antigenic site on EBV which elicits neutralizing antibody.
Attachment of Cell Walls of
Chlamydia psittaci
to Mouse Fibroblasts (L Cells)
Authors: Levy Nancy J. , Moulder James W.
Published: January 2020

14
C-labeled cell walls of the 6BC strain of
Chlamydia psittaci
, prepared from intrinsically labeled chlamydial cells by digestion with deoxycholate and trypsin, associated with mouse fibroblasts (L cells) in a manner comparable to that of intact
C. psittaci.
Almost half of the host cell-associated cell walls were not dissociated by trypsin, suggesting that they had been attached and then ingested. The attachment of cell walls to L cells was inhibited by a number of treatments known to block association of intact
C. psittaci
with L cells: heating the cell walls for 3 min or reacting them with antiserum against intact
C. psittaci
, or pretreating the L cells with trypsin or wheat germ agglutinin. Unlike intact cells of
C. psittaci
, cell walls were not immediately toxic for L cells, and they did not measurably adsorb neutralizing antibody. As revealed by making cell walls from intact
C. psittaci
labeled with
125
I by lactoperoxidase-catalyzed iodination, cell walls contained a much smaller number of surface-labeled proteins than did whole chlamydial cells. The most abundant surface-labeled protein was one with an apparent molecular weight of 43,000. In the final step of cell wall preparation, tryptic digestion of deoxycholate-extracted cells, this major surface protein was partially cleaved to a 40,000-dalton product. When the major surface protein (both the 43,000- and 40,000-dalton moieties) was electrophoretically separated from the other cell wall proteins and used to immunize a rabbit, antibodies that neutralized the infectivity of intact
C. psittaci
were elicited. It was concluded that cell walls retain the ability to associate with L cells in much the same way as do intact cells of
C. psittaci
, but, despite the simpler structure of cell walls, the element that binds
C. psittaci
to host cells cannot yet be identified.
Arousal of mucosal secretory immunoglobulin A antitoxin in rats immunized with Escherichia coli heat-labile enterotoxin
Authors: Klipstein F A , Engert R F , Clements J D
Published: January 2020

Specific serum and mucosal antitoxin levels were determined by enzyme-linked immunosorbent assays in rats immunized with Escherichia coli heat-labile enterotoxin (LT). Immunization by means of a parenteral prime followed by peroral boosts was the only approach that aroused titers of both serum immunoglobulin G (IgG) antitoxin and mucosal secretory IgA antitoxin that were increased fourfold or more over control values. Primary parenteral immunization was effective when given either intraperitoneally or subcutaneously with either Freund complete adjuvant or alum as the adjuvant. The magnitude of the nucosal secretory IgA antitoxin response and the degree of protection against challenge with either LT or viable LT-producing organisms were related to the number and dosage of peroral boosts. LT antigenicity, as determined by enzyme-linked immunosorbent assay, was progressively reduced by toxoiding it with increasing amounts of glutaraldehyde or a carbodiimide; when LT antigenicity was reduced by greater than 50%, the effectiveness of the toxoid in stimulating mucosal antitoxin and providing protection was compromised. Strong protection extended for more than 6 weeks only in rats immunized with a sufficient peroral dosage of LT to arouse mucosal secretory IgA antitoxin titers at least fourfold greater than those of controls. These observations indicate that the ability of LT to stimulate a mucosal secretory IgA antitoxin response is dependent on the antigenicity, route, and dosage of this immunogen; they suggest that the duration of protection in animals immunized by the peroral route is related to the extent of arousal of mucosal secretory IgA antitoxin.
Serotyping of
Chlamydia psittaci
by the Micro-Immunofluorescence Test: Isolates of Ovine Origin
Authors: Eb François , Orfila Jeanne
Published: January 2020

The micro-immunofluorescence test was successfully applied to seven ovine isolates which could be separated into two distinct immunotypes. The pattern of reactivity was similar to that elucidated by the plaque reduction test and confirmed by growth characteristics and biotyping.
Monoclonal antibodies to the structural glycoprotein of tick-borne encephalitis virus
Authors: Heinz F X , Berger R , Majdic O , Knapp W , Kunz C
Published: January 2020

Hybridomas secreting antibodies to the structural glycoprotein of tick-borne encephalitis (TBE) virus were prepared by fusion of X63-Ag8/653 mouse myeloma cells with spleen cells from mice immunized with purified glycoprotein complexes of TBE virus. These antibodies were tested against 10 different TBE virus strains isolated in different European countries over a period of 26 years from different hosts. Quantitative evaluation of enzyme immunoassay results did not reveal any differences in reactivity among these strains, pointing further to the homogeneity of European TBE virus isolates, which has previously been inferred from results obtained by peptide mapping and competitive radioimmunoassay. Hybridomas defining three different antibody-combining sites (epitopes) on the glycoprotein of TBE virus were selected on the basis of cross-reactivity with another flavivirus. West Nile virus, as well as the ability to inhibit hemagglutination. Two epitopes were type specific, and the third was indistinguishably also present on West Nile virus. Hemagglutination was inhibited by monoclonal antibodies reacting with one of the type-specific epitopes as well as the cross-reactive determinant, which is apparently responsible for the broad cross-reactivity among different flaviviruses observed in hemagglutination inhibition tests with polyvalent immune sera.
Biochemical characterization of extracellular proteases from Vibrio cholerae
Authors: Young D B , Broadbent D A
Published: January 2020

Isoelectric focusing of culture supernatants from Vibrio cholerae El Tor 1621 and high protease-producing mutant strain 1621 hip revealed the presence of three different types of extracellular protease. Type I protease was the major activity in the wild-type strain and was inhibited by phenylmethylsulfonyl fluoride and by the lima bean trypsin inhibitor. Type II protease was present in the wild type and was the major activity in the high protease-producing mutant. It was resistant to inhibitors of metalloproteases and serine proteases. Two peaks of type II protease differed by 1.2 pI units in isoelectric point and by 1,500 in molecular weight. Type II protease had broad specificity, acted as a mucinase, and caused degradation of some other V. cholerae extracellular proteins, including DNase and cholera toxin. Type III protease was EDTA inhibitable and was detected only in the high protease producer. Possible roles of extracellular proteases as virulence factors in cholera pathogenesis are discussed.
Visceral Leishmania tropica infection of BALB/c mice: cellular analysis of in vitro unresponsiveness to sheep erythrocytes
Authors: Leclerc C , Modabber F , Deriaud E , Djoko-Tamnou J , Chedid L
Published: January 2020

In mice, infection with Leishmania tropica initially produced a nonspecific enhancement of the immune response to sheep erythrocytes as measured both in vitro and in vivo. Subsequently, the spleen cell responses of susceptible mice (BALB/c) to sheep erythrocytes and T- and B-cell mitogens in vitro decreased dramatically, whereas those of the resistant strain (C57BL/6) returned to normal. Analysis of the spleen cells of infected animals revealed that macrophages (the target cells of Leishmania) were not defective. However, both T- and B-cell-depleted splenocyte populations of infected animals lacked the ability to respond in the presence of their corresponding B- and T-cell-depleted populations of normal spleen cells. It was also observed that the addition of various numbers of Leishmania organisms did not alter the response of normal spleen cells in vitro. The results of cocultures of various ratios of cells from the spleen of infected and normal animals ruled out the possibility of a strong active immunosuppression. The decrease of in vitro response is attributed to the depletion of immunocompetent cells in the spleen of infected mice, which is heavily populated by null cells.
Differential sensitivity in vivo of lethal and nonlethal malarial parasites to endotoxin-induced serum factor
Authors: Taverne J , Depledge P , Playfair J H
Published: January 2020

Sera from mice infected with Plasmodium yoelii or Plasmodium berghei and given endotoxin contained nonspecific mediators which killed both species of parasite and tumor cells in vitro. The sera resembled tumor necrosis sera obtained from mice given macrophage-activating agents such as Propionibacterium acnes (formerly designated Corynebacterium acnes) or Mycobacterium bovis BCG and then endotoxin. Cytotoxicity developed parallel to parasite killing activity and indicated that macrophages were activated. Activation occurred sooner with P. berghei, which is lethal, and serum activity remained on a plateau until the mice died. In nonlethal P. yoelii infections, activation was related to the course of parasitemia. Endotoxin given to mice infected with P. yoelii caused an immediate decrease in parasitemia, presumably through the release of parasite killing factors. The extent of the decrease depended upon the time of administration. No immediate drop in the parasitemia caused by P. berghei was observed at any time. Early administration of endotoxin prolonged survival; late administration accelerated death. Passive transfer of rabbit tumor necrosis serum to infected mice decreased the parasitemia caused by P. yoelii but not that caused by P. berghei. Other components of the immune response appeared to act together with these soluble mediators to eliminate P. yoelii; they may be absent or suppressed in infections with P. berghei.
Production of a fecal mutagen by Bacteroides spp
Authors: Van Tassel R L , MacDonald D K , Wilkins T D
Published: January 2020

Forty species of anaerobes were screened for the ability to produce an ether-extractable mutagen which is present in the feces of 15 to 20% of individuals in populations at high risk for colon cancer. This mutagen can be produced in vitro by incubating the feces of these individuals anaerobically or by supplementing anaerobic broths with methanol extracts of the feces and incubating them with a dilute fecal inoculum. Of the anaerobes screened, strains of five species of Bacteroides (B. thetaiotaomicron, B. fragilis, B. ovatus, B. uniformis, and Bacteroides group 3452A) were capable of producing five- to eightfold increases in the concentration of mutagen. For in vitro production in broth, all producers required bile and the methanol extract for feces from a person who excretes the mutagen. Mutagen production appeared to be constitutive and occurred during the stationary phase of growth. Cell-free extracts were active and produced mutagen considerably faster than did whole cells. Our observations indicate that the excretion of this mutagen by certain people is dependent on the presence of some precursor of unknown origin. The mutagen-producing species of bacteria are among the most common of the intestinal microflora and were present in mutagen excreters and nonexcreters as well.
Oxygen dependence of human alveolar macrophage-mediated antibody-dependent cytotoxicity
Authors: Conkling P , Papermaster-Bender G , Whitcomb M , Sagone A L
Published: January 2020

We studied the metabolic characteristics of the human alveolar macrophage-mediated antibody-dependent cytotoxicity (ADCC) reaction, using an anti-D sensitized human erythrocyte target system. Metabolic experiments demonstrated a high resting rate of glucose metabolism in macrophages, but no oxidative metabolic burst was found to accompany the ADCC reaction. These findings were confirmed by oxygen consumption studies, showing a high resting rate of oxygen consumption by macrophages, but no change in the rate of oxygen consumption upon the addition of antibody-sensitized target cells. An anaerobic mechanism for ADCC was anticipated and investigated. Surprisingly, the macrophage-mediated ADCC reaction was found to be highly oxygen dependent. The macrophages of one chronic granulomatous disease patient were also studied and found to have a very low rate of oxidative metabolism in response to phagocytic stimuli. With oxygen present, these macrophages failed to produce significant ADCC, suggesting again that some oxidative mechanism was necessary in the macrophage-mediated ADCC reaction. Various oxygen radical scavengers were also studied. Glutathione inhibited ADCC significantly, and benzoic acid inhibited ADCC only slightly. All other scavengers had no significant inhibitory effect. Then, a known antioxidant and inhibitor of mixed-function oxidases, diethyldithiocarbamate, was found to produce a significant inhibition of the ADCC reaction. We believe this compound may be scavenging or inhibiting the production of some oxygen-dependent species important in the ADCC reaction.
Isolation of hybridoma cell lines and characterization of monoclonal antibodies against cholera enterotoxin and its subunits
Authors: Robb M , Nichols J C , Whoriskey S K , Murphy J R
Published: January 2020

Hybridoma cell lines which produced monoclonal antibodies against cholera toxin were isolated. These cell lines were detected with an enzyme-linked immunosorbent assay screening procedure with purified cholera toxin or subunit A of cholera toxin. Seven cell lines were characterized with respect to their reactivity with cholera toxin subunits by Western blot analysis. Five clones produced antibodies which were directed against subunit A, and two clones produced antibodies which reacted with subunit B. These antibodies were also characterized by Western blot analysis for reactivity with the heat-labile enterotoxin produced by porcine and human enterotoxinogenic strains of Escherichia coli. Monoclonal antibodies which reacted with subunit A of cholera toxin also reacted with subunit A of both porcine and human heat-labile enterotoxins. In contrast, monoclonal antibodies to subunit B of cholera toxin did not react with subunit B of the heat-labile enterotoxin. Antibodies directed against subunit B neutralized the biological activity of cholera toxin in vitro in the S49 mouse lymphosarcoma assay. In contrast to polyclonal anti-subunit A antisera, monoclonal anti-subunit A from four of five clones had small but measurable neutralizing capacities in vitro.
Physicochemical characterization of cytostatic factors released from human monocytes
Authors: Nissen-Meyer J , Hammerstrøm J
Published: January 2020

Cultured human monocytes released cytostatic activity upon in vitro activation with lymphokines and lipopolysaccharide. This activity was mainly due to the presence of two different cytostatic factors, termed CstF I and II, which were separated by ion-exchange chromatography. At neutral pH, CstF I bound to the weak anion exchanger DEAE-Sephacel but not to the weak cation exchanger CM-Sepharose, whereas CstF II bound to CM-Sepharose but not to DEAE-Sephacel. The molecular weights of CstF I and II as determined by gel filtration were 55,000 and 40,000, respectively. Upon chromatofocusing, CstF I behaved as if it had an isoelectric point of 5.3. Neither CstF I nor CstF II bound specifically to concanavalin A-Sepharose, indicating the absence of carbohydrate residues containing alpha-D-mannopyranosyl, alpha-D-glucopyranosyl, or sterically related components. Both factors were susceptible to inactivation by proteinase K, demonstrating their protein nature. CstF II was purified more than 3,000-fold upon chromatography on CM-Sepharose and Sephacryl S-200. Ion-exchange chromatography and chromatofocusing of CstF I removed 97% of the proteins in the monocyte supernatant, but only 15% of the activity was recovered, resulting in a fivefold purification of CstF I.
Synergism between immunosuppressive agents and uremia?
Authors: Miller T E , Ormrod D J , Wilson D M
Published: January 2020

The susceptibility of uremic patients to infectious disease has been widely reported, but the host immune factors associated with the increased incidence of infection have not been clearly defined. In this study, the possibility of synergism between biologically active components that accumulate in uremia and immunosuppressive drugs used in the course of management was investigated. An animal model of chronic stable uremia was used in these experiments to assess the effect of cyclophosphamide, methotrexate, and azathioprine on antibody response in the uremic host. Chronic uremia did not affect the immunosuppressive activity of cyclophosphamide, methotrexate, or azathioprine, and synergism between these agents and uremic components is unlikely to complicate further the immune status of the host in renal failure.
Virulence for mice of Klebsiella strains belonging to the O1 group: relationship to their capsular (K) types
Authors: Mizuta K , Ohta M , Mori M , Hasegawa T , Nakashima I , Kato N
Published: January 2020

Eighty-two Klebsiella O1 strains belonging to various K types were tested for virulence for mice by intraperitoneal inoculation. They comprised 49 strains newly isolated from various clinical specimens, 31 reference strains, and 2 laboratory strains. Of 9 Klebsiella O1:K2 strains, 7 were highly virulent inasmuch as their 50% lethal doses per mouse were less than 10 CFU, whereas the other 2 strains were avirulent even when encapsulated just like the virulent strains as revealed by the quellung test. Klebsiella K2 reference strain B5055 and strain Chedid, which were maintained in vitro for a long time, were highly virulent. Of 8 Klebsiella O1:K1 strains, 2 showed moderate virulence, and the other 6 strains had relatively low or no virulence. We found no definite correlation between the virulence of Klebsiella K1 and K2 strains for mice and the kind of clinical specimens in which they originated. All of the Klebsiella O1 strains tested belonging to K types other than K1 and K2 showed very low or no virulence for mice.
Isolation and characterization of F12 adhesive fimbrial antigen from uropathogenic Escherichia coli strains
Authors: Klemm P , Orskov I , Orskov F
Published: January 2020

The adhesive fimbrial antigen F12 from a strain of uropathogenic Escherichia coli has been isolated and characterized. The antigen was purified by ammonium sulfate precipitation and gel chromatography. The protein subunit of the F12 fimbria has a molecular weight of 18,200; the N-terminal amino acid sequence of the subunit shows close resemblance to that of the subunits of other F fimbriae and the type 1 fimbriae. We identified in these proteins a pattern of alternating conserved and variable amino acid residues which could indicate a special structural and functional feature.
Prevalence, distribution of serotypes, and cariogenic potential in hamsters of mutans streptococci from elderly individuals
Authors: Fitzgerald D B , Fitzgerald R J , Adams B O , Morhart R E
Published: January 2020

The prevalence of mutans streptococci (Streptococcus mutans, Streptococcus cricetus, Streptococcus sobrinus, and Streptococcus rattus) was determined in the salivas of 169 elderly individuals ranging in age from 60 to 87 years. Approximately 40% of these individuals were edentulous and wore full upper and lower dentures. With the exception of a higher proportion of saliva counts below 1,000 CFU/ml in the full-denture wearers, the prevalence and the serotype and species distributions of the mutans streptococci were similar in the denture wearers and individuals with natural teeth only. The species and serotype distributions of mutans streptococci in this elderly population were also consistent with reported observations of other workers on younger, more caries-prone populations. A total of 87 representative isolates of the mutans streptococci were tested for cariogenic potential in a hamster model system. A considerable degree of variation in virulence between different strains was observed. However, these differences were not relatable to individual species or serotypes or to whether the organisms were isolated from denture wearers or naturally dentate subjects. The results of our studies indicate that elderly individuals with either natural or artificial dentitions may be a hitherto unrecognized reservoir of mutans streptococci having varying degrees of potential cariogenicity. Hence, in close family situations they could serve, along with parents and siblings, as vectors in the initial transmission of cariogenic microorganisms to young children.
Neuraminidase activity and syncytial formation in variants of parainfluenza 3 virus
Authors: Shibuta H , Nozawa A , Shioda T , Kanda T
Published: January 2020

By a sensitive fluorometric assay method, we could definitely demonstrate neuraminidase activity for two variants of parainfluenza 3 virus, M and SC, which were previously shown to have no detectable neuraminidase activity. The enzyme activities of these viruses were very similar to each other, showing a much lower catalytic rate, a much higher Km value, and a more acidic pH optimum than those of the virus variants of high neuraminidase activity, 910N, LT, and MR. M and SC viruses eluted from guinea pig erythrocytes very poorly, whereas 910N and LT viruses eluted readily. M virus required the aid of a bacterial neuraminidase for effective growth and plaque formation in MDBK cells, but the virus grew well and formed plaques in R66 and Vero cells without the enzyme. SC virus required no exogenous neuraminidase for growth in all of these cell types. Depending on cell type, SC virus induced slight to extensive syncytial formation which was greatly inhibited by exogenous neuraminidase. In contrast, M virus induced extensive syncytial formation in all these cells regardless of the presence or absence of exogenous neuraminidase, although development and disintegration of the syncytia were more or less retarded by the enzyme, especially in MDBK cells. These results indicate that M virus possesses highly potent inducibility of syncytial formation which is further fortified by being low in viral neuraminidase activity.
Susceptibility of blood-derived monocytes and macrophages to caprine arthritis-encephalitis virus
Authors: Anderson L W , Klevjer-Anderson P , Liggitt H D
Published: January 2020

Permissiveness of blood-derived caprine monocytes to infection by caprine arthritis-encephalitis virus increased during in vitro cultivation and differentiation into macrophages, as evidenced by immunofluorescence and release of extracellular infectious virus. The degree of cell susceptibility to virus infection varied among individual goats, independent of age or breed. Caprine arthritis-encephalitis virus infection of macrophages in vitro resulted in no alteration of five characteristic functional activities.
Structural preferences of beta-galactoside-reactive lectins on Actinomyces viscosus T14V and Actinomyces naeslundii WVU45
Authors: McIntire F C , Crosby L K , Barlow J J , Matta K L
Published: January 2020

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.
Antigenic specificity and heterogeneity of lipopolysaccharides from pyocin-sensitive and -resistant strains of Neisseria gonorrhoeae
Authors: Connelly M C , Allen P Z
Published: January 2020

Homologous antisera were raised against lipopolysaccharides (LPSs) isolated from pyocin 103-sensitive JW31 strain Neisseria gonorrhoeae and its isogenic, pyocin-resistant variant, JW31R. Changes in immunochemical reactivity of LPS antigen associated with pyocin-resistance were examined by enzyme-linked immunosorbent assay, employing homologous and heterologous anti-LPS immune sera. The acquisition of pyocin 103 resistance is accompanied by a loss in LPS antigen reactivity with homologous anti-LPS. The variant LPS of pyocin 103-resistant mutants is immunogenic and displays a new, distinct antigenic specificity shared with other pyocin 103-resistant variant gonococcal strains. The acquisition of pyocin 103 resistance by JW31 strain gonococci is also accompanied by a striking loss of LPS cross-reactivity with antistreptococcal polysaccharide reagents having an antibody combining site specificity directed against the chemically defined lactose polymer from Streptococcus faecalis cell wall and pneumococcal type 14 capsular polysaccharide. When examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and sodium dodecyl sulfate-urea-polyacrylamide gel electrophoresis, JW31 and JW31R LPSs show banding patterns characteristic of microheterogeneous, rough-type LPS devoid of O-side chains. Immunoblot transfer analysis of gel-separated gonococcal LPS antigens shows a difference in the pattern of antibody binding by homologous versus cross-reactive anti-LPS, which suggests a heterogeneity in the distribution of cross-reactive determinants among LPS molecules.
Levamisole exacerbates coxsackievirus B3-induced murine myocarditis
Authors: Gudvangen R J , Duffey P S , Paque R E , Gauntt C J
Published: January 2020

Levamisole administration to several strains of adolescent mice at the time of or up to 4 days post-inoculation (p.i.) with a myocarditic variant of coxsackievirus B3 (CVB3m) increased the number of myocarditic lesions above that found in CVB3m-inoculated mice. Virus replication in heart tissues in vivo was not affected by levamisole administration to the mice, nor was production of neutralizing antibody to CVB3m. Lymphocytes from nodes of virus-inoculated mice treated with levamisole at 2 days p.i. exhibited an increased reactivity to phytohemagglutinin on days 6 and 8 p.i., compared with respective responses by nodal T lymphocytes from CVB3m-inoculated mice. Levamisole treatment of CVB3m-inoculated mice also increased the reactivity of splenic and peripheral blood T lymphocytes to phytohemagglutinin on day 8 p.i., but not day 6 p.i., compared with the respective responses by lymphocytes from CVB3m-inoculated mice. The proportion of theta antigen-bearing lymphocytes in the total lymphocyte population in peripheral blood of CVB3m-inoculated mice was not altered by levamisole treatment. However, CVB3m-induced reduction in this subpopulation of lymphocytes in the nodes was restored to control levels by levamisole treatment. Reactivities of cytotoxic T lymphocytes from CVB3m-inoculated mice were increased against both normal and CVB3m-inoculated target cells after levamisole treatment of these mice. The results suggest that levamisole may contribute to CVB3m induction of myocarditis by several mechanisms, such as increasing the blastogenic activity of the phytohemagglutinin-responding subset of T lymphocytes, by possibly altering T-lymphocyte distribution in the body and by nonspecifically increasing reactivities of cytotoxic T lymphocytes.
Growth of Trypanosoma cruzi in a cloned macrophage cell line and in a variant defective in oxygen metabolism
Authors: Tanaka Y , Tanowitz H , Bloom B R
Published: January 2020

A continuous cloned murine macrophage-like cell line, clone 16 derived from J774, has been found upon appropriate stimulation to be capable of oxidizing glucose by the hexose monophosphate shunt and producing O2- and H2O2. A variant in oxidative metabolism, clone C3C, was selected from this cell line which under similar conditions is unable to produce significant amounts of O2- and H2O2. When cells of the parental clone 16 were infected with epimastigotes of Trypanosoma cruzi, there was significant killing or growth inhibition of the parasites at 3 to 4 days after infection. In contrast, the parasites grew in the oxidative variant, clone C3C. Trypomastigote forms of T. cruzi were found to be only partially killed in the parental clone 16 but grew abundantly in the oxidative variant. Infection of the parental clone, but not the variant, was sufficient to stimulate oxygen metabolism as demonstrated by the increased reduction of nitro blue tetrazolium. Studies on the killing of T. cruzi epimastigotes in cell-free suspension by xanthine-xanthine oxidase indicated that 90% of the killing was catalase sensitive and due to H2O2, with at most 7 to 8% killing which could be inhibited by scavengers of . OH and singlet oxygen (1O2). In the in vitro experiment with H2O2 produced by glucose and glucose oxidase, the 50% lethal doses of epimastigotes and trypomastigotes were 6.0 and 8.7 nmol of H2O2 per min per ml, respectively, indicating that trypomastigotes were more resistant to killing by H2O2 than epimastigotes were. A reconstitution experiment of trypanocidal activity in clone C3C by ingestion of zymosan particles coupled with glucose oxidase showed that H2O2 was essential for this cytocidal process in the macrophage cell line. These results provide clear evidence for killing of an intracellular parasite by a continuous macrophage-like cell line and suggest the importance of the oxidative cytocidal mechanism in this process.