bluuebunny/crossref_metadata_2025 huggingface dataset:
Microbial interference and colonization of the murine gastrointestinal tract by Listeria monocytogenes
Authors: Zachar Z , Savage D C
Published: January 2020

Two strains of Listeria monocytogenes, one that formed smooth colonies on agar surfaces and a varient of it that formed rough colonies, colonized the gastrointestinal tracts of germfree mice. Within 24 h after mice were inoculated orally with about 100 bacteria, the population levels per gram (wet weight) of tissue of both strains were 10(5) to 10(7) in the stomach and ileum and 10(8) to 10(9) in the cecum and colon, respectively. As detected in Gram-stained histological sections, in such gnotobiotes, the bacteria colonized the lumen in all areas of the tract and much of the mucus layer on the epithelial surface in the proximal colon. The strain that formed smooth colonies did not colonize the tracts of specific-pathogen-free mice, but did colonize, to the same levels as in germfree mice, the stomachs and bowels of ex-germfree mice previously associated with two members of the indigenous flora (Bacteroides and Clostridium). In the latter animals, however, the listeria did not form layers on the colonic epithelium as efficiently as they did in monoassociated gnotobiotes.
Lymphoid cells in endotoxin-induced production of the amyloid-related serum amyloid A protein
Authors: Rosenstreich D L , McAdam K P
Published: January 2020

Endotoxin-treated mice exhibit a rapid rise in the level of the serum amyloid A (SAA) protein, but this effect is not observed in endotoxin-resistant C3H/HeJ mice. To evaluate the role of lymphoid cells in the production of SAA protein, C3H/HeJ mice were adoptively transfused with endotoxin-sensitive (C3H/HeN) bone marrow cells. After such adoptive transfer, endotoxin treatment of C3H/HeJ mice resulted in high serum levels of SAA protein. The ability of chimeric mice to make SAA protein correlated with the presence of endotoxin-sensitive B lymphocytes and macrophages. These findings suggest that lymphocytes and/or macrophages play an important role in initiating SAA protein synthesis after endotoxin treatment and suggest a possible mechanism by which chronic infection or inflammation leads to amyloidosis.
Enhancement of resistance to murine osteogenic sarcoma in vivo by an extract of Brucella abortus (Bru-Pel): association with activation of reticuloendothelial system macrophages
Authors: Glasgow L A , Crane J L , Schleupner C J , Kern E R , Youngner J S , Feingold D S
Published: January 2020

The administration of an aqueous-ether extracted residue of Brucella abortus (Bru-Pel) inhibits development of transplanted osteogenic sarcomas in mice as evidenced by a decrease in mortality. At least one mechanism through which Bru-Pel modulates host resistance is activation of macrophages of the reticuloendothelial system. Peritoneal macrophages harvested from mice receiving Bru-Pel were cytotoxic for osteogenic sarcoma cells in vitro, limited the replication of vaccinia virus in cell cultures, and demonstrated enhanced emittance of chemiluminescence during phagocytosis of zymosan particles of Candida albicans. The concept of reticuloendothelial system activation was further supported by the evidence that administration of Bru-Pel enhanced resistance of mice to challenge with a lethal inoculum of Listeria monocytogenes. These observation support the hypothesis that Bru-Pel shares a number of characteristics with recognized immunomodulating agents and that one mechanism by which it modulates host resistance to tumors, to virus infections, and to challenge with L. monocytogenes is through activation of macrophages.
Model Studies on Dental Plaque Formation: Deoxyhexoses in
Actinomyces viscosus
Authors: Tylenda C. A. , Charon D. , Lombardi F. P. , Gabriel O.
Published: January 2020

A careful examination of two strains of
Actinomyces viscosus
, T14V (virulent) and T14AV (avirulent), revealed no qualitative or quantitative difference in 6-deoxyhexose content of their cell surface. For a further study of the role of these sugars in cell surface-related phenomena, the stereochemical configuration of deoxyhexoses of
A. viscosus
T14 was established by two complementary approaches. (i) Examination of the biosynthetic pathway was found to lead to the formation of both 6-deoxy-
l
-talose and 6-deoxy-
l
-mannose and showed no differences in the ability of either bacterial strain,
A. viscosus
T14V or T14AV, to produce the precursors of these cell wall components. The biosynthetic pathway for 6-deoxy-
l
-talose and 6-deoxy-
l
-mannose was found to originate from deoxy-thymidine diphosphate (dTDP)-
d
-glucose, which in turn is converted to dTDP-4-keto-6-deoxy-
d
-glucose. Epimerization at carbons 3 and 5 of the hexose moiety of dTDP-4-keto-6-deoxy-
d
-glucose is followed by stereospecific reduction with reduced nicotinamide adenine dinucleotide phosphate to yield dTDP-6-deoxy-
l
-talose and dTDP-6-deoxy-
l
-mannose. In cell-free extracts of both
A. viscosus
T14 and T14AV, an identical ratio of 6-deoxy-
l
-talose to 6-deoxy-
l
-mannose of 1:8 was produced. Known precursors for the
d
-isomers of the same 6-deoxyhexoses such as guanosine diphosphate-
d
-mannose and dTDP-
d
-mannose were not converted by
A. viscosus
T14 cell-free extracts. (ii) Isolation of 6-[
U
-
14
C]deoxytalose and 6-[
U
-
14
C]deoxymannose from both strains of
A. viscosus
T14 was carried out by growing cells in a medium containing
d
-[
U
-
14
C]glucose. Again no qualitative or quantitative difference was noticeable between the two strains when 6-deoxy-hexoses were released from whole cells or purified cell walls by acid hydrolysis. Radioactive 6-[
U
-
14
C]deoxytalose isolated from the cell surface was used in an isotope dilution experiment to establish the stereochemical configuration of this 6-deoxyhexose. The radioactive sugar was mixed with unlabeled standard
d
- or
l
-6-deoxyhexose, respectively, and conversion to the corresponding 1-phenylflavazole derivative was carried out. Recrystallization to constant specific activity identified the radioactive sugar isolated from
A. viscosus
to be the
l
-isomer. A facile synthesis of the rare sugars 6-deoxy-
l
-talose and 6-deoxy-
d
-talose is reported.
Relationship between enterotoxin production and serotype in enterotoxigenic Escherichia coli
Authors: Merson M H , Orskov F , Orskov I , Sack R B , Huq I , Koster F T
Published: January 2020

We examined the relationship between serotype and enterotoxin production in 109 enterotoxigenic Escherichia coli strains isolated from 109 patients with severe cholera-like diarrhea in Dacca, Bangladesh. Of 69 strains producing both heat-labile and heat-stable toxins, 59 (86%) belonged to the one of four O serogroups, and 56 (81%) of these strains belonged to one of six O:K:H serotypes. In contrast, 34 strains producing only heat-stable toxin were distributed among 15 O serogroups, and six strains producing only heat-labile toxin were distributed among six O serogroups. Twelve strains producing heat-labile and heat-stable toxins and five strains producing heat-stable toxin were found which had the same serotype (O78:K-:H12) and biotype. It appears that at least in one geographic setting E. coli strains producing both heat-labile and heat-stable toxins are more restricted in their O groups and O:K:H serotypes than E. coli that produce only heat-stable toxin and that certain serobiotypes may commonly include strains which produce both toxin types.
Adjuvants in the induction of suppressor cells
Authors: Neta R , Salvin S B
Published: January 2020

The effect of different mycobacterial adjuvants on the parameters of delayed hypersensitivity was investigated in strain 13 guinea pigs. The composition of the tubercle bacilli and the type of vehicle in which the antigen was presented determined the presence and extent of suppressor cell activity. When antigen was introduced in complete Freund adjuvant, both adherent and nonadherent cells had suppressive properties, with the suppressive effect demonstrable in vitro from 1 to 5 weeks after sensitization. Suppressor activity was indicated in vivo by a reduction of delayed footpad hypersensitivity in animals presensitized with complete Freund adjuvant.
Volatile fatty acids and aerobic flora in the gastrointestinal tract of mice under various conditions
Authors: Byrne B M , Dankert J
Published: January 2020

Volatile fatty acids are reported to exert a repressive effect upon Enterobacteriaceae and Pseudomonas species in vitro and in vivo in young mice. The mean total volatile fatty acid concentration in the cecal samples of conventional mice fed ad libitum was 81.7 mumol/g (wet weight), which is antibacterial in vitro, and in the rectal samples it was 41.1 mumol/g (wet weight). The mean count of Enterobacteriaceae in the cecum was only 10(2)/g, whereas in the rectum it was 10(5)/g. Volatile fatty acid levels were influenced by food intake and increased to peak levels approximately 6 to 10 h after eating and then declined. In mice fasted for 17 h, the butyric acid concentration was considerably lower and the number of cecal samples positive for Enterobacteriaceae increased. When fasted for 4 days, mice had extremely low cecal and rectal volatile fatty acid concentrations and the Enterobacteriaceae and enterococci counts increased to mean of 2 x 10(6)/g and 3 x 10(6)/g, respectively, in the cecum and to means of 10(7) and 5 x 10(6)/g in the rectum. We conclude that volatile fatty acids are probably one of the many interference mechanisms which are involved with control of the levels of Enterobacteriaceae (and enterococci) in the large intestine of mice.
Effect of Bacteriocin Production by
Streptococcus mutans
on the Plaque of Gnotobiotic Rats
Authors: Rogers A. H. , van der Hoeven J. S. , Mikx F. H. M.
Published: January 2020

The effect of bacteriocins produced by strains of
Streptococcus mutans
on the microbial composition of dental plaque was studied in gnotobiotic rats. In one set of tests, using
S. mutans
strains T2 and SW31, rats were simultaneously infected with the bacteriocinogenic parent (
bac
+
) and corresponding
bac
−
mutants, and the relative proportions of each strain present in three different tooth sites were determined at various time intervals after inoculation. Some animals were monoinfected with
bac
+
and
bac
−
strains, and in vivo properties, such as plaque fermentation end products, amount of plaque formed, and cariogenicity, were measured. In another series of tests with strains T2
bac
+
and T2
bac
−
, animals were sequentially inoculated with a time interval of 1 week. On simultaneous inoculation, the
bac
−
mutant, which was sensitive in vitro to the bacteriocin produced by the parent, was totally unable to establish in a plaque consisting of the
bac
+
strain even when the challenging dose was increased 100-fold. In contrast, the
bac
+
strain was successful not only in invading an established
bac
−
plaque but also in eventually almost eliminating the mutant. In monoinfected animals, there were no significant differences in plaque-forming ability, fermentation end products, or cariogenicity between the two strains. Also, bacteriocin activity was detected in plaque harboring the
bac
+
but not the
bac
−
strain. The results not only indicate that bacteriocin activity can occur in vivo but also suggest that bacteriocinogeny might confer an ecological advantage upon a strain attempting to establish itself in an ecosystem.
Effects of cannabinoids on host resistance to Listeria monocytogenes and herpes simplex virus
Authors: Morahan P S , Klykken P C , Smith S H , Harris L S , Munson A E
Published: January 2020

Previous investigations from our laboratories have demonstrated that cannabinoids possess immunosuppressive properties. The present studies were designed to determine whether these agents decrease host resistance to infections with Listeria monocytogenes and herpes simplex virus type 2. Host resistance was measured by changes in the 50% lethal dose of the pathogen in cannabinoid-treated and control mice. The effect of cannabinoids on resistance to L. monocytogens was dose dependent. Delta-9-tetrhydrocannabinol at doses of 38, 75, and 150 mg/kg suppressed resistance to infection by 10-, 17-, and 657-fold, respectively. Marijuana extract was less active but significantly reduced resistance to L. moncytogenes at all tested doses. Resistance to systemic herpes simplex virus type 2 infection was decreased 96-fold by delta-9-tetrahydrocannabinol, although marijuana extract was inactive. The doses and regimen of treatment with cannabinoids that produced significant decreases in host resistance were similar to those which caused suppression of delayed-type hypersensitivity to sheep erythrocytes. The possible mechanisms and public health aspects of the decreased host resistance produced by marijuana extract and its cannabinoids are discussed.
Isolation, characterization, and biological properties of an endotoxin-like material from the gram-positive organism Listeria monocytogenes
Authors: Wexler H , Oppenheim J D
Published: January 2020

The bacterial component responsible for the induction of transient cold agglutinin syndrome in rabbits after intravenous injection of heat-killed Listeria monocytogenes type 4B has been purified and biologically and chemically characterized. A purified immunoglobulin M cold agglutinin was prepared from high-titer sera resulting from the immunization of rabbits with heat-killed L. monocytogenes type 4B and was subsequently used to monitor the purification of the bacterial component responsible for its induction. The bacterial component was isolated from a hot phenol-water extract of lyophilized L. monocytogenes type 4B by multiple molecular sieve chromatography. Upon chemical analysis the purified material was found to be strikingly similar in chemical composition to gram-negative lipopolysaccharide endotoxins. The material contained 15% total fatty acid (of which 50% was beta-hydroxymyristic acid), 40 to 45% neutral sugar (glucose, galactose, and rhamnose), 11.5% amino sugar, 12% uronic acid, 2.5% 2-keto-3-deoxyoctonic acid, 2% heptose, 0.87% phosphorus, and 1.6% amino acid, thereby accounting for 85 to 90% of the weight of the component. Electron micrographs of the purified material were similar to those of lipopolysaccharide preparations from gram-negative organisms. The purified material exist in aqueous solutions as large aggregates, but can be dissociated into a single smaller subunit (3.1S) by dialysis against sodium dodecyl sulfate buffer. The listerial component was toxic and pyrogenic to rabbits, producing symptoms typical of gram-negative endotoxins. Activity in the limulus lysate gelation assay and in the carbocyanine dye assay provides a further link of this material with classical gram-negative endotoxins.
Purification and antigenic properties of intracellular invertase from Streptococcus mutans
Authors: Maynard M T , Kuramitsu H K
Published: January 2020

Intracellular invertase from Streptococcus mutans GS5 was purified to near homogeneity by gel filtration and ion-exchange chromatography followed by preparative polyacrylamide gel electrophoresis. The invertase appeared to be composed of a single polypeptide chain with a molecular weight of 48,000. Extracellular invertase was identified in strain GS5 and was determined to have a molecular weight of 500,000. No antigenic relationship between these two forms of invertase was observed since antibody prepared against purified intracellular invertase neither affected extracellular invertase activity nor precipitated that enzyme on immunodiffusion. No antigenic relatedness between intracellular invertase and glucosyl- and fructosyl- transferases was detected since cross-reactivity with antibody prepared against either enzyme fraction was not observed after immunodiffusion. Using immunodiffusion and quantitative precipitin data, we examined the relationships of other S. mutans intracellular invertases to the serotype c enzyme. It appeared that the intracellular invertases from serotypes e, f, and g were structurally similar to the enzyme from serotype c, whereas the structure of invertases from serotypes a, b, and d appeared less similar to that of enzyme from serotype c.
Splenic Influence on the Development of a Local Pulmonary Immune Response
Authors: Stein-Streilein Joan , Frazier Janet L. , Gross Gary N. , Hart David A.
Published: January 2020

The role of the spleen in the development of specific antibody-forming cells (sAFC) in the pulmonary draining lymph nodes (pdLNC) of hamsters after local inoculation of sheep erythrocytes (SRBC) was evaluated. The role of the spleen was viewed from two vantage points. Panels of animals were either splenectomized with appropriate sham-operated controls before intratracheal inoculation of SRBC, or panels were immunized intravenously simultaneously with the local inoculation of antigen. The presence of an intact spleen was not necessary for the induction of a sAFC response to occur in the pdLNC. Similar numbers of immunoglobulin M (IgM) sAFC were recorded in the pdLNC on day 4 of both sham-operated and splenectomized animals. However, an enhancement of this local response occurred on day 7 if the animals were systemically immunized and therefore demonstrated active participation of the spleen in the specific immune response. The results support the hypothesis that although a local response may occur in the pdLFC in the absence of a spleen or a splenic response, the presence of a systemic or splenic response appears to be important for the enhancement of local IgM sAFC response. These observations suggest that the immune defenses involved in the lower respiratory tract may differ from those in upper respiratory tract and other mucosally lined organs in that the response of the spleen to the antigen affects the local response to that antigen.
Adjuvant Effects of Low Doses of a Nuclease-Resistant Derivative of Polyinosinic Acid · Polycytidylic Acid on Antibody Responses of Monkeys to Inactivated Venezuelan Equine Encephalomyelitis Virus Vaccine
Authors: Harrington D. G. , Crabbs C. L. , Hilmas D. E. , Brown J. R. , Higbee G. A. , Cole F. E. , Levy H. B.
Published: January 2020

Polyriboinosinic·polyribocytidylic acid [poly(I)·poly(C)] stabilized with poly-
l
-lysine and carboxymethylcellulose [poly(ICLC)] has been previously shown to be a compound with marked adjuvant activity when given in high doses with inactivated Venezuelan equine encephalomyelitis (VEE) virus vaccine. This study investigated the effects of much lower doses of poly(ICLC) on the magnitude and kinetics of the primary and secondary humoral antibody responses of rhesus monkeys to inactivated VEE virus vaccine. Monkeys given a single injection of vaccine developed very low neutralizing antibody titers, whereas those given adjuvant plus vaccine had 30- to 100-fold-higher titers which remained elevated for longer than 6 months. Low doses of poly(ICLC) given with VEE virus vaccine resulted in a profound but transient increase in priming of secondary antibody responses to the antigen. In contrast, the administration of poly-
l
-lysine and carboxymethylcellulose alone without the poly(I)·poly(C) component of the complex had no adjuvant effect on antibody responses of monkeys to VEE virus vaccine. The temporal development of antibody by class (immunoglobulin M-immunoglobulin G) in monkeys given two injections of adjuvant-vaccine was not different from that with vaccine alone. Serial hematological and clinical chemistry determinations on monkeys given single or multiple doses of poly(ICLC) with vaccine were not different from values in monkeys given vaccine alone.
Chemical, immunochemical, and structural studies of the cross-reactive antigens of Streptococcus mutans AHT and B13
Authors: Brown T A , Bleiweis A S
Published: January 2020

Two antigenic polysaccharides were extracted from cell walls of the cross-reactive strains Streptococcus mutans AHT (a) and S. mutans B13 (d). The antigens extracted from walls by the hot formamide method, were purified by affinity chromatography on columns containing the galactose-specific lectin from the castor bean and were found to be diheteroglycans consisting of galactose and glucose. Antigenic specificities of both the serotype-specific and the cross-reactive sites on each polymer were studied: the AHT (a) antigen is determined by D-galactose linked 1 leads to 6 to adjacent sugar, the B13 (d) antigen is determined by D-glucose similarly linked to o its neighbor, and the cross-reactive (a--d) site present on both polymers consists of D-galactose linked 1 leads to 6 to a subterminal sugar moiety. Methylation analysis revealed structural similarities between the purified polysaccharides that may reflect the nature of the cross-reactive sites and differences that may reflect the natures of the specific haptenic regions. Based on these studies, a partial hypothetical structural model is proposed.
Evaluation of a ribosomal vaccine against pertussis
Authors: Field L H , Parker C D , Manclark C R , Berry L J
Published: January 2020

A crude ribosomal vaccine derived from Bordetella pertussis administered to ICR and N:NIH (SW) strains of mice protected them effectively against a standardized intracranial challenge. The dose of vaccine that protected half the mice was less for N:NIH (SW) than for ICR mice and compared favorably with a killed reference vaccine. Ribosomes prepared from bacteria ground with washed sea sand were more immunogenic than those obtained by rupture with alumina or with a Braun homogenizer. The protective effect of the crude ribosomes was not an innate part of the organelle but was due to a substance or substances that could be removed from them by a 1 M NH4Cl wash. The material in the wash was highly immunogenic and retained both the histamine-sensitizing and leukocytosis-promoting properties. It lost much of the dermonecrotic activity and was poorly pyrogenic in rabbits. The most potent pyrogen was present in the washed ribosomes, which apparently, retained the endotoxic components of the cell wall. The best vaccines permitted acceptable weight gain in the immunized mice.
Superoxide production in pulmonary alveolar macrophages and killing of BCG by the superoxide-generating system with or without catalase
Authors: Ando M , Suga M , Sugimoto M , Tokuomi H
Published: January 2020

The superoxide production of BCG-infected and noninfected alveolar macrophages was measured by superoxide dismutase-inhibitable nitro blue tetrazolium reduction. The cells were incubated with or without cell-free bronchial lavage fluid (pulmonary washings). When control alveolar macrophages were infected by BCG, superoxide production was decreased markedly, probably due to bacterial cytotoxic factors. In contrast, the production of superoxide in alveolar macrophages exposed to pulmonary washings was increased and not appreciably influenced by BCG infection. Superoxide production by alveolar macrophages was dependent on time and on the protein concentration in the pulmonary washings. In controls, it was inversely proportional to the infecting dose of BCG. We observed previously that alveolar macrophages activated by pulmonary washings inhibited intracellular growth of BCG. We now present evidence that enhanced production of superoxide contributes to such inhibition, especially in the presence of catalase at acid pH. These findings are pertinent to the defense of inflamed lungs, where serum and serum immunoglobulin G transuded from blood into alveolar spaces probably induce such activation on alveolar macrophages.
Purification and Characterization of a
Serratia marcescens
Metalloprotease
Authors: Lyerly David , Kreger Arnold
Published: January 2020

An extracellular, nonelastolytic, neutral metalloprotease of
Serratia marcescens
was purified by sequential ammonium sulfate precipitation, hydroxyapatite adsorption chromatography, flat-bed isoelectric focusing, and Sephadex G-100 gel filtration. The protease preparation had a 280/260 nm absorbance ratio of 1.8, was free of detectable amounts of endotoxin, carbohydrate, phosphorus, and other known extracellular enzymes of
S. marcescens
, and was homogeneous by Ouchterlony double immunodiffusion and Grabar-Williams immunoelectrophoresis. Crossed immunoelectrophoresis, thin-layer electrofocusing in polyacrylamide gel, and polyacrylamide disc gel electrophoresis showed three to four closely migrating, Coomassie blue-staining components in the protease preparation. However, zymogram analyses of the patterns showed that protease activity was associated with each component and that the protease was, therefore, microheterogeneous. The isoelectric point and sedimentation coefficient of the protease were approximately 5.3 to 5.4 and 4.2S, respectively, and the molecular weight estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and by gel filtration was approximately 52,500 and 44,000, respectively. The pH optimum range, with azocasein as the substrate, was 5.5 to 7.5. The enzyme contained a high percentage of acidic amino acids, no cysteine, and 1 g-atom of Zn
2+
and 7 g-atoms of Ca
2+
per mol. Various heavy metal ions and chelating agents and heating at 60°C for 15 min inactivated the enzyme. Intracorneal, intratracheal, and intradermal administration of the protease into rabbits elicited rapid and extensive tissue damage. The minimum lethal intravenous dose for mice was approximately 17 mg/kg of body weight.
Capsular serotypic specificity of the protection conferred on mice by Klebsiella pneumoniae ribosomal preparations
Authors: Riottot M , Fournier J M , Pillot J
Published: January 2020

Klebsiella pneumoniae ribosomal preparations protect mice immunized by the subcutaneous route against an intraperitoneal challenge of 100 50% lethal doses. The minimal protective doses are 5 and 0.4 micrograms of proteins for preparations extracted from strains of capsular serotypes 1 and 2, respectively. This difference in protective activity is also found in bacteria killed by Formalin. The protective activity of these preparations is not diminished by their purification on sucrose gradient, which eliminates most of the membrane vesicles which are visible by electron microscopy. The use of four strains of K. pneumoniae belonging to capsular serotypes 1 and 2 allowed us to show that the immunoprotective capacity of the ribosomal preparations was specific to the capsular serotype of the origin strain. This was confirmed by experiments in which the serum of immunized mice was transferred passively. The experimental data favor the presence in the ribosomal preparation of antigens belonging to the bacterial surface and resisting elimination by ultracentrifugation on sucrose gradient. Those surface antigens (possibly capsular polysaccharide) at least play a role in the orientation of the specificity of the protection induced by the ribosomal preparations.
Suppression of tuberculin hypersensitivity during influenza infection in mice
Authors: Massanari R M
Published: January 2020

Tuberculin hypersensitivity was examined during acute influenza infection in mice. Employing the footpad test as a measure of delayed-type hypersensitivity, it was noted that tuberculin hypersensitivity was suppressed temporarily beginning on day 3 and continuing through days 10 to 16 following intranasal infection with influenza A/PR8. These changes occurred at a time when influenza virus was replicating in lung tissue. Suppression of footpad swelling was not detected when mice were administered live virus intravenously, were given Formalin-inactivated virus intranasally, or were immunized against influenza before intranasal infection. Transient reduction of total circulating lymphocytes also occurred during influenza infection but did not correlate with the duration of footpad suppression. Because this model system reproduces many of the alterations in immunological function reported to occur during influenza infection in humans, it should provide a useful tool for investigating mechanisms of influenza-induced immunosuppression.
Persistent infection of a human lymphoblastoid cell line with equine herpesvirus 1
Authors: Roumillat L F , Feorino P M , Lukert P D
Published: January 2020

Infection of a human lymphoblastoid cell line (Jijoye line derived from a Burkitt lymphoma which contains Epstein-Barr virus) with equine herpesvirus 1, maintained and observed for 53 days, was characterized by the continuous production of infectious extracellular and intracellular virus. Maximum virus production correlated with active cell multiplication. Less than 15% of the cells possessed viral capsid antigen at any one time. Five percent of the cells in the Jijoye line possess Epstein-Barr viral capsid antigen; 80% of the Epstein-Barr viral caspid-containing cells also contained equine herpesvirus 1 antigen as detected by double staining. The interaction of equine herpesvirus 1 and lymphoblastoid cells provides a useful in vitro model which may help clarify the mechanism for herpesvirus latency.
Characterization of the chemical and physical properties of a novel B-lymphocyte activator, endotoxin protein
Authors: Goodman G W , Sultzer B M
Published: January 2020

Endotoxin protein, a novel mouse B-lymphocyte mitogen, is a hydrophobic acidic compound composed of approximately 85% protein and 2.2% glucosamine, but no 2-keto-3-deoxyoctonate. Endotoxin protein also contains lipid, and analysis of the fatty acids in this material demonstrated the presence of beta-hydroxymyristate, a marker for lipid A. In addition, analysis of endotoxin protein by polyacrylamide gel electrophoresis showed that it is heterogeneous, containing four or five major polypeptides, depending upon the bacterial species from which it was isolated. The mitogenicity of endotoxin protein was diminished by alkaline hydrolysis, but not by treatment with hydrochloric or acetic acid. Furthermore, its activity was resistant to digestion with trypsin, chymotrypsin, and pronase and was only partially degraded by papain.
Adherence of
Escherichia coli
to Human Urinary Tract Epithelial Cells
Authors: Schaeffer Anthony J. , Amundsen Susan K. , Schmidt Lawrence N.
Published: January 2020

The adherence of
Escherichia coli
to human uroepithelial cells obtained from midstream urine specimens of healthy women was studied. Bacteria labeled with [
3
H]uridine were used, and unattached organisms were separated from the epithelial cells by vacuum filtration with 5-μm-pore-size Nucleopore membrane filters. These techniques allowed adherence to be measured in large numbers of epithelial cells and overcame the problem of distinguishing experimental bacteria from the indigenous organisms present on uroepithelial cells. Adherence was not appreciably affected by temperature. Adherence was maximal at pH 4 to 5 and at bacterial-to-epithelial-cell ratios of 5,000 or more. The latter observation suggested that there are a limited number of receptors on the epithelial cell surface, an idea which was supported by competition experiments. Adherence occurred within 1 min and then decreased gradually or quickly, depending on the type of bacterial growth medium, to a stationary level of adherence, approximately 50% of that observed initially. The ability of epithelial cells from a single individual to bind
E. coli
varied in a cyclical and repetitive pattern. Adherence tended to be higher during the early phase of the menstrual cycle and diminished shortly after the time of expected ovulation; adherence frequently correlated with the value obtained on the same day of the menstrual cycle during the preceding months. Adherence was markedly enhanced by bacterial incubation in broth for 72 h and inhibited by α-
d
-mannose. These results suggest that adherence is a complex phenomenon perhaps mediated in part by bacterial pili and mannose residues on uroepithelial cells.
Identification of protective cell surface proteins in ribosomal fractions from Salmonella typhimurium
Authors: Misfeldt M L , Johnson W
Published: January 2020

Cell surface antigen preparations from Salmonella typhimurium SR-11 prepared by either trichloroacetic acid extraction or boiling in sodium dodecyl sulfate were able to protect C3H/HeJ, C3H/HeDub, and A/J mice. Some of the proteins found in these preparations were shown to exist in the protective ribosomal fraction isolated from S. typhimurium SR-11. Passage of ribosomes isolated from S. typhimurium SR-11 and 6707 through a Sepharose 2B column removed the protective immunogen from 6707 ribosomes but did not completely remove it from SR-11 ribosomes. Immunity to salmonella infection in C3H/HeJ mice induced by ribosomal vaccines may be dependent on the presence of cell surface proteins in the ribosomal fraction.
Immunotherapy of guinea pig line 10 hepatoma with nonliving BCG cells in aqueous medium
Authors: Bekierkunst A , Goren M B
Published: January 2020

Killed BCG cells suspended in 1.5% carboxymethylcellulose cured guinea pigs with established line 10 tumors in a high percentage of cases. The bacterial preparation of BCG in carboxymethylcellulose displayed a stronger tumor regressive activity and the process of healing was accelerated when endotoxin from a rough (Re) strain of Salmonella typhimurium was added to the BCG bacilli.
Production of exoenzyme S during Pseudomonas aeruginosa infections of burned mice
Authors: Bjorn M J , Pavlovskis O R , Thompson M R , Iglewski B H
Published: January 2020

Antisera which distinguished between Pseudomonas aeruginosa exoenzyme S and toxin A neutralized the adenosine diphosphate ribosyl transferase activity of the homologous, but not the heterologous, enzyme. Skin extracts and sera from burned mice infected with the exoenzyme S-producing strain P. aeruginosa 388 contained adenosine diphosphate ribosyl transferase activity that was not found in skin extracts or sera from uninfected mice. On the basis of immunological reactivity and enzymatic properties, the adenosine diphosphate ribosyl transferase activity present in skin extracts and sera from P. aeruginosa 388-infected mice was identified as exoenzyme S. Active elongation factor 2 levels in tissues from strain 388-infected mice were normal at 24 h postinfection, indicating that strain 388 does not produce detectable amounts of toxin A in vivo. An unexpected finding in this investigation was the presence of exoenzyme S-inactivating activity in the sera from some nonimmunized animals.
Electron microscopic studies on the attachment of Mycoplasma pneumoniae to guinea pig erythrocytes
Authors: Brunner H , Krauss H , Schaar H , Schiefer H G
Published: January 2020

A mechanism of pathogenicity of Mycoplasma pneumoniae is its ability to attach to the surface of mammalian cells. It has previously been demonstrated by others that M. pneumoniae adheres with a specialized terminal structure, the "tip," to ciliated epithelial cells of the respiratory tract. In this report we show by electron microscopy that M. pneumoniae adsorbs with membrane sites other than the tip to guinea pig erythrocytes.
Evidence for two heat-stable enterotoxins produced by enterotoxigenic Escherichia coli
Authors: Kapitany R A , Scoot A , Forsyth G W , McKenzie S L , Worthington R W
Published: January 2020

Heat-stable enterotoxins from a bovine and porcine strain of Escherichia coli were isolated and showed significant differences in amino acid composition and heat stability.
Enhancement and suppression by actinomycin D of a Vero cell nontransmissible measles infection
Authors: Winston S H , Rustigian R
Published: January 2020

The effect of low doses of actinomycin D on Vero cell nontransmissible measles infection produced after cocultivation with a HeLa subline with persistent defective infection by Edmonston measles virus was examined by pretreatment of Vero cells with the drug and treatment at 1, 4, and 7 days after Vero cell infection. Pretreatment enhanced focal formation of viral immunofluorescent Vero cell syncytia but did not induce synthesis of detectable amounts od cocultures suppressed syncytial formation, and treatment of 4- and 7-day-old cocultures had little, if any, effect on syncytial formation. Pretreatment also eliminated a transient resistance to homologous superinfection. A possible relation of these findings to the presence of a cell-associated viral inhibitor in the persistently infected HeLa cells is discussed.
Alterations of the immune response associated with chronic experimental leishmaniasis
Authors: Arredondo B , Pérez H
Published: January 2020

BALB/c mice infected with Leishmania mexicana developed a chronic infection usually accompanied by the appearance of metastatic lesions. Throughout the 20 weeks of observation, infected mice ;howed an impairment in both in vivo delayed hypersensitivity response and in vitro lymphocyte reactivity to leishmanial antigen. Four to 8 weeks after inoculation infected mice displayed a transitory enhancement of spleen cell responses to phytohemagglutinin P, concanavalin A, and lipopolysaccharide. At the same time, immunization with sheep erythrocytes resulted in a greater number of immunoglobulin P, lipopolysaccharide, and sheep erythrocytes diminished progressively, whereas reactivity to concanavalin A was markedly augmented. When cocultivated with spleen cells from mice infected for 12 to 20 weeks, normal lymphocyte responses to phytohemagglutinin P, concanavalin A, and lipopolysaccharide were drastically reduced. These results suggest a role for suppressor cells in chronic experimental cutaneous leishmaniasis.
Antibody responses and interferon titers in the respiratory tracts of mice after aerosolized exposure to influenza virus
Authors: Zee Y C , Osebold J W , Dotson W M
Published: January 2020

We studied the temporal appearance of immunoglobulins (immunoglobulins G1, G2, M, and A) and interferon in lung lavage fluids of mice after aerosol exposure to influenza virus in six animal groups in which mortality rates ranged from 0 to 24%. Immunoglobulin levels in the lung lavage fluids were markedly higher in mouse groups with higher mortality rates (16, 20, and 24%) than in those with low mortality rates (0, 2.5, and 7.5%). Analysis of serum albumin in the respiratory secretions as an index of edema indicated that increased immunoglobulin G levels during the early phase of infection were due to increased vascular permeability. The detection of virus-neutralizing antibodies and antibodies reactive with influenza virus antigens in the lavage fluids at 6 to 8 days postinfection suggested local immunoglobulin synthesis as a result of antigenic stimulation. Both systemic and local antibody productions contributed to immunoglobulin levels in the respiratory secretions after aerosolized influenza virus infection. Peak levels of interferon in the lavage fluids were reached before detection of significant levels of virus-neutralizing antibody in the serum or the lung lavage.
Rabies virus immunity in genetically selected high- and low-responder lines of mice
Authors: Nilsson M R , Sant'anna O A , Siqueira M , Nilsson T T , Gennari M
Published: January 2020

The antibody responsiveness to and the specific vaccination effect of rabies virus infection were investigated in high- and low-responder lines of mice produced by two-way selective breedings for quantitative production of antibodies to flagellar (H/f and L/f lines) or somatic (H/s and L/s lines) antigens of salmonellae. After specific immunization, both high lines were more resistant to rabies virus infection than were the low lines, and the protector effect was related to the level of antibody produced, as demonstrated by neutralizing serum activity. The present findings confirm the nonspecific genetic modification of the general antibody responsiveness induced in high- and low-responder lines selected for quantitative antibody production.
Immunization against Schistosoma mansoni in rhesus monkeys and the requirement of activation of both cell-mediated and humoral mechanisms
Authors: Maddison S E , Kagan I G , Chandler F W , Gold D , Hillyer G V , Slemenda S B , Tsang V
Published: January 2020

When groups of rhesus monkeys were pretreated with BCG plus hyperimmune serum from monkeys with chronic schistosomiasis or with dialyzable transfer factor from uninfected monkeys plus hyperimmune serum and were challenged with 1,500 cercariae of Schistosoma mansoni, the mean worm burdens were significantly lower than that of untreated controls. Pretreatment with neither BCG alone nor Corynebacterium parvum plus a membrane antigen of adult worms of S. mansoni affected susceptibility. Neither lymphocyte proliferation in the presence of mitogens or schistosome antigen nor serological responsiveness (as measured by gel diffusion, Cercarienhüllenreaktion, circumoval precipitation, or enzyme-linked immunoabsorbent assay) correlated with the degree of resistance of the animals to S. mansoni. The pretreatment procedures used did not cause any abnormal histopathological responses and did not alter the characteristic host response to schistosome eggs in the lungs, liver, mesenteric lymph nodes, and colon.
Interaction of Mycoplasma pneumoniae with human lung fibroblasts: characterization of the in vitro model
Authors: Gabridge M G , Taylor-Robinson D , Davies H A , Dourmashkin R R
Published: January 2020

The interaction of pathogenic Mycoplasma pneumoniae and host cells was studied in cell cultures of MRC-5 human lung fibroblasts. A comparison of results obtained with fibroblasts in a monolayer format and with hamster tracheal explant cultures indicated that the former can bind significantly larger numbers of mycoplasmas. In addition, the attachment was 96% specific, that is, mediated through a neuraminidase-sensitive receptor on the host cell. Uptake of mycoplasmas was directly related to the number of mycoplasma cells present in the inoculum, and attachment was virtually complete within a 30-min period at 37 degrees C. High doses of M. pneumoniae induced a marked cytopathic effect, whereas doses of less than or equal to 10(6) colony-forming units per ml produced grossly observable cell damage that was moderate and variable. Transmission electron microscopy studies indicated that attachment of M. pneumoniae to the surface of lung fibroblasts occurred with the specialized terminal structure or binding site oriented closest to the epithelial cell surface. The filamentous mycoplasma cells were spatially arranged in several configurations and were not limited to a vertical orientation. The advantages and disadvantages of human lung fibroblast monolayer cultures, in reference to other in vitro models are discussed. A new mycoplasma agar medium (G-200 agar) with a defined tissue culture base and 10% horse serum is also described.
Cytochalasin B does not inhibit ingestion of Chlamydia psittaci by mouse fibroblasts (L cells) and mouse peritoneal macrophages
Authors: Gregory W W , Byrne G I , Gardner M , Moulder J W
Published: January 2020

Cytochalasin B did not inhibit ingestion of Chlamydia psittaci by either mouse fibroblasts (L cells) or mouse peritoneal macrophages in concentrations that produced distinctive morphological changes and inhibited phagocytosis of polystyrene latex beads and Escherichia coli K-12.
Suppressor T-cells in BCG-infected mice
Authors: Collins F M , Watson S R
Published: January 2020

Specific pathogen-free B6D2 hybrid mice were infected with high (10(8) cells, intravenous), moderate (10(6) cells, intravenous), and low 10(3) cells, aerogenic) doses of viable BCG Pasteur. The growth of the BCG in the lungs and spleens of the three groups was followed over a 90-day period and correlated with the level of tuberculin hypersensitivity. Spleen cells were harvested from the three groups of mice at increasing time intervals and filtered through nylon wool to remove adherent cells, and the level of blast transformation after exposure to phytohemagglutinin and purified protein derivative was determined. Early in the BCG infection both the high- and the intermediate-dose groups showed enhanced thymidine incorporation by the spleen cell cultures, followed by a profound depression late in the infection. At this time, both groups of mice were anergic to purified protein derivative injected into footpads. Cell mixing studies demonstrated the presence of a population of suppressor cells in the spleens of the anergic animals. The suppressive abilities of these cells would be ablated by treatment with anti-Thy-1 antiserum and complement. The aerogenically infected mice were unresponsive to purified protein derivative but showed no evidence of suppressor T-cells. The lack of tuberculin sensitivity in these mice seemed to be due to a lack of sensitized T-cells in the spleen rather than to active immunosuppression.
Development of Suppressor T-Cells in
Mycobacterium habana
-Infected Mice
Authors: Watson Susan R. , Collins Frank M.
Published: January 2020

Mice were infected intravenously with increasing numbers of
Mycobacterium habana
(simiae serotype II), and the levels of delayed-type hypersensitivity to purified protein derivative and
M. habana
cytoplasmic protein antigen were determined after 14, 30, and 90 days. A footpad delayed-type hypersensitivity response was seen in 14-day-infected mice and was followed by a persisting anergy. T-cell-enriched suspensions collected 30 and 90 days into the infection (anergic donors) showed depressed transformation indexes after phytohemagglutinin and
M. habana
cytoplasmic protein antigen treatment in vitro. The corresponding B-cell mitogen (lipopolysaccharide) responses were not affected. Mixing experiments with T-cell-enriched suspensions from day-90
M. habana
-infected donors adoptively suppressed lymphocyte transformation by normal and day-14 spleen cells. This effect could be ablated by anti-theta serum and complement treatment of the day-90 cells, indicating that the lack of in vitro responsiveness to cytoplasmic protein antigen was mediated by a population of suppressor T-cells present in the heavily infected spleens. There was no evidence that similar cells were present in the spleens of the 14-day-infected animals. Suppressor T-cells could be induced in vitro by exposure of day-14 spleen cells to concanavalin A or
M. habana
cytoplasmic protein antigen before they were mixed with normal or day-14 indicator splenic lymphocytes. The timing of the appearance of suppressor T-cells in the infected spleens corresponded to a loss of footpad hypersensitivity by the
M. habana
-infected animals.
Secretion of phospholipase C by Pseudomonas aeruginosa
Authors: Stinson M W , Hayden C
Published: January 2020

The conditions necessary for the secretion of phospholipase C (phosphatidylcholine cholinephosphohydrolase) by Pseudomonas aeruginosa were studied. Enzyme secretion by washed cell suspensions required a carbon source and ammonium, potassium, and calcium ions. The calcium requirement could be substituted by magnesium and strontium but not by copper, manganese, cobalt, or zinc. During growth in liquid medium, cells secreted phospholipase C during late logarithmic and early stationary phases. Secretion was repressed by the addition of inorganic phosphate but not by organic phosphates, glucose, or sodium succinate. Studies with tetracycline indicated that de novo protein synthesis was necessary for the secretion of phospholipase C and that the exoenzyme was not released from a preformed periplasmic pool. Similarly, extraction of actively secreting cells with 0.2 M MgCl2 at pH 8.4 solubilized large quantities of the periplasmic enzyme alkaline phosphatase but insignificant amounts of phospholipase C. Bacteria continued to secrete enzyme for nearly 45 min after the addition of inorganic phosphate or rifampin.
Exposure of guinea pigs to Rickettsia rickettsii by aerosol, nasal, conjunctival, gastric, and subcutaneous routes and protection afforded by an experimental vaccine
Authors: Kenyon R H , Kishimoto R A , Hall W C
Published: January 2020

Guinea pigs were inoculated with Rocky Mountain spotted fever by the aerosol, conjunctival, subcutaneous, intragastric, and intranasal routes. Rickettsial infection was produced by all routes except intragastric. All animals with clinical signs of disease developed agglutinating antibody, and most developed a cell-mediated immune response. Disease produced by all experimental routes (except intragastric) was indistinguishable. The tissue culture-derived inactivated vaccine produced in this laboratory protected guinea pigs against an aerosol challenge.