bluuebunny/crossref_metadata_2025 huggingface dataset:
Inflammation triggers hypoferremia and de novo synthesis of serum transferrin and ceruloplasmin in mice
Authors: Beaumier D L , Caldwell M A , Holbein B E
Published: January 2020

Oil of turpentine was used to induce an artificial inflammation so that we could study its effect on iron metabolism and on synthesis of serum transferrin and ceruloplasmin in mice. It was found that turpentine-induced inflammation triggered the establishment of a hypoferremic state characterized by low levels of serum iron, followed by recovery and a gradual return to normal plasma iron levels. This turpentine-induced hypoferremia and its subsequent recovery paralleled the hypoferremia obtained during meningococcal infection. Moreover, serum transferrin and ceruloplasmin activity levels increased drastically during the recovery from hypoferremia. [14C]leucine incorporation studies revealed a de novo synthesis of both transferrin and ceruloplasmin. Turpentine-induced hypoferremia was also found to provide a protective effect against meningococcal infection which could be partially reversed by exogenous iron. The results of this study suggest that transferrin and ceruloplasmin may be synthesized partly in response to the altered iron metabolism observed during hypoferremia.
Effects of Escherichia coli heat-stable enterotoxin STb on intestines of mice, rats, rabbits, and piglets
Authors: Kennedy D J , Greenberg R N , Dunn J A , Abernathy R , Ryerse J S , Guerrant R L
Published: January 2020

There are at least two classes of Escherichia coli heat-stable enterotoxins, STa and STb. Unlike STa, which is active in suckling mice and piglets, STb is inactive in suckling mice but active in piglets and older, weaned pigs. This study examined the activity of STb in several animals and its effect on intestinal histology and cyclic GMP levels in intestinal mucosal cells. STb did not cause fluid secretion in suckling mice up to 12 days old or in rat or rabbit intestinal-loop preparations. STb-induced fluid secretion in weaned-pig intestinal loops occurred by 30 min and became maximal by 3 to 6 h. STb did not disrupt intestinal histology and did not alter cyclic GMP levels in intestinal mucosal cells from piglet intestinal loops after 0.5- and 6-h incubations. Our studies support the concept that STb is a second heat-stable E. coli enterotoxin with properties and a mechanism of action unlike those of STa.
Resistance of Actinobacillus actinomycetemcomitans and differential susceptibility of oral Haemophilus species to the bactericidal effects of hydrogen peroxide
Authors: Miyasaki K T , Wilson M E , Reynolds H S , Genco R J
Published: January 2020

We compared the sensitivities of oral and nonoral isolates of Actinobacillus actinomycetemcomitans, Haemophilus segnis, H. aphrophilus, and H. paraphrophilus to the bactericidal action of reagent hydrogen peroxide (H2O2). Susceptibility to a range of H2O2 concentrations (10(-6) to 10(-3) M) was assessed by incubating bacterial suspensions for 1 h at 37 degrees C in the presence of H2O2 and plating on chocolate agar to determine the concentration of H2O2 that would produce a 50% reduction in CFU (50% lethal dose). As a group, A. actinomycetemcomitans was more resistant to H2O2 than the oral haemophili, and H. aphrophilus was much more sensitive than all other organisms tested. The range of 50% lethal dose values for A. actinomycetemcomitans was between 8.5 X 10(-5) and 10(-3) M H2O2 or above. In contrast, H. aphrophilus exhibited 50% lethal dose values from below 1 X 10(-6) to 3.4 X 10(-4) M H2O2. The resistance of A. actinomycetemcomitans to H2O2 may be sufficient to protect these organisms from direct H2O2-mediated killing by host phagocytes.
Role of superoxide dismutase and catalase as determinants of pathogenicity of Nocardia asteroides: importance in resistance to microbicidal activities of human polymorphonuclear neutrophils
Authors: Beaman B L , Black C M , Doughty F , Beaman L
Published: January 2020

The roles of nocardial superoxide dismutase (SOD) and catalase in the resistance of Nocardia asteroides to the microbicidal properties of human polymorphonuclear leukocytes were determined in vitro. The neutrophils killed ca. 80% of the cells of the less virulent N. asteroides 10905 and ca. 50% of the log phase of the more virulent N. asteroides GUH-2 after 180 min of incubation. These phagocytes were not able to kill early-stationary-phase cells of strain GUH-2 that contained 10 times more intracytoplasmic catalase than log-phase cells of the same culture. However, the polymorphonuclear leukocytes were able to kill more than 50% of the cells of early-stationary-phase strain GUH-2 after treatment with purified antibody specific for surface-associated SOD. No killing was observed when the bacteria were treated with normal rabbit immunoglobulin G or with serum obtained from rabbits immunized against whole nocardial cells (containing little or no activity against SOD). These phagocytes killed more than 99% of Listeria monocytogenes used as a control. Chlorpromazine-treated polymorphonuclear leukocytes killed L. monocytogenes (70%) but they were not able to kill antibody-treated cells of N. asteroides GUH-2. Exogenously added SOD partially protected strain 10905, which lacked surface-associated enzyme, but it had no effect on the killing of strain GUH-2, which already possessed significant amounts of surface-bound SOD. In contrast, catalase added to the nocardiae provided almost complete protection to the log-phase cells of strain GUH-2, but strain 10905 was only partially protected. SOD combined with catalase had additive activity which completely protected the cells of strain 10905. A mutant of N. asteroides GUH-2 (SCII-C) is more virulent during the log phase than is the parental strain. This mutant contained at least 7 times more catalase at this stage of growth than did the parent. No other differences between these two strains were observed during the log phase. In sharp contrast to those of the parent, log-phase cells of this high-catalase mutant were not killed by polymorphonuclear phagocytes. These data indicate a role for both SOD and catalase in the resistance of Nocardia spp. to human neutrophils, and they represent at least two factors associated with virulence.
Pulmonary macrophage function during experimental cytomegalovirus interstitial pneumonia
Authors: Miller S A , Bia F J , Coleman D L , Lucia H L , Young K R , Root R K
Published: January 2020

Since cytomegalovirus (CMV) infections may alter host defense against a variety of pathogens, phagocytosis, oxygen uptake, and H2O2 release by pulmonary macrophages obtained from guinea pigs with acute CMV interstitial pneumonia were evaluated. Experimental animals were inoculated subcutaneously on day zero with 10(7.5) 50% tissue culture infective doses of virulent guinea pig CMV. Control animals received an uninfected salivary gland suspension. The animals were sacrificed on day 7; the tissues were cocultivated for virus isolation, and the lungs were lavaged to obtain pulmonary macrophages. CMV was isolated from buffy coat cells (96%), bone marrow cells (71%), whole lungs (77%), pulmonary macrophages (60%), and pulmonary granulocytes (49%). There was no significant difference between groups at sacrifice in the total number of macrophages obtained by pulmonary lavage or in the phagocytic activity of the macrophages in vitro. However, in CMV-infected animals, the maximum rates of O2 consumption in response to the soluble stimulus, phorbol myristate acetate, and the particulate stimulus, Staphylococcus aureus, were 47 and 55%, respectively, of the rates in uninfected controls. Total macrophage O2 consumption in CMV-infected animals was 32 and 37%, respectively, of control values in response to the same stimuli. In CMV-infected animals, the maximum rates of H2O2 release were 22% of those in simultaneous controls for both stimuli, and total H2O2 release was 30 and 25%, respectively, of that in controls in response to these stimuli. Such alterations in macrophage oxidative function may contribute to superinfection during CMV pneumonia.
Genetic resistance to murine cryptococcosis: increased susceptibility in the CBA/N XID mutant strain of mice
Authors: Marquis G , Montplaisir S , Pelletier M , Mousseau S , Auger P
Published: January 2020

In a survey of 301 normocomplementemic inbred mice (belonging to nine different strains: BALB/cN nu/nu and nu/+, CBA/N, C57BL/KsJ, C57BR/cdJ, CBA/CaJ, BRVR, DW/+, and C57BL/6J) for natural resistance to Cryptococcus neoformans, cumulative survival values were found to range from 12 to 22 days. When the average organ weights of infected animals were compared with reference values obtained in uninfected mice of the same age and genetic lineage, the following changes were documented. In the CBA/N strain, the mean spleen and brain weights increased 313 and 13.5%, respectively, whereas the mean liver weight remained unchanged. In the CBA/Ca strain, cerebral cryptococcosis was the dominant clinical feature, and a 54% increase in mean brain weight was recorded at the time of death. The averaged liver weight was drastically lower, whereas spleen weight values evinced a biphasic pattern of transient splenomegaly followed by involution. At the median time of death, CBA/N mice had significantly more cryptococci in the liver and spleen than corresponding CBA/Ca mice. In the (CBA/N X CBA/Ca)F1 mice, susceptibility to C. neoformans segregated according to the sex-linked inheritance of the X-linked immunodeficiency (xid) gene. It is concluded that (i) susceptibility to cryptococcosis is under multigenic control, (ii) the xid locus on the X chromosome influences susceptibility to cryptococcosis, and (iii) xid mice behave differently than CBA/Ca mice in their organ response during the course of the infection.
Shiga-like cytotoxin production by enteropathogenic Escherichia coli serogroups
Authors: Cleary T G , Mathewson J J , Faris E , Pickering L K
Published: January 2020

The mechanism by which enteropathogenic Escherichia coli (EPEC) cause disease remains to be defined. We studied EPEC and non-EPEC strains of E. coli from stool specimens obtained from infants and adults for production of Shiga-like cytotoxin. Although it was common for healthy infants and adults to have cytotoxin-producing E. coli as part of the fecal flora, Shiga-like cytotoxin was detected more commonly and in greater amounts among EPEC than among other fecal E. coli. These results suggest a role for Shiga-like cytotoxin in the pathogenesis of EPEC-related gastroenteritis.
Competitive exclusion of uropathogens from human uroepithelial cells by Lactobacillus whole cells and cell wall fragments
Authors: Chan R C , Reid G , Irvin R T , Bruce A W , Costerton J W
Published: January 2020

Previous studies have shown that indigenous bacteria isolated from cervical, vaginal, and urethral surfaces of healthy women are able to adhere to human uroepithelial cells in vitro. Furthermore, these organisms were found to block the adherence of uropathogenic bacteria to uroepithelial cells from women with and without a history of urinary tract infections. In the present study, complete or partial inhibition of the adherence of gram-negative uropathogens was achieved by preincubating the uroepithelial cells with bacterial cell wall fragments isolated from a Lactobacillus strain. Competitive exclusion was most effective with whole viable cells and less effective with cell wall fragments obtained by sonication, extraction with sodium dodecyl sulfate, and treatment with sodium dodecyl sulfate and acid. Analysis of the Lactobacillus cell wall preparations suggested that lipoteichoic acid was responsible for the adherence of the Lactobacillus cells to uroepithelial cells but that steric hindrance was the major factor in preventing the adherence of uropathogens. This conclusion was also supported by blockage studies with reconstituted lipoteichoic acid-peptidoglycan, which was more effective at blocking adherence than lipoteichoic acid or peptidoglycan alone. The results suggest that the normal flora of the urinary tract may be used to protect against the attachment of uropathogens to the surfaces of uroepithelial cells. The long-term implications of these findings may lead to alternative methods for the management and prevention of recurrent urinary tract infections in females.
Immunogenic properties of octasaccharide-protein conjugates derived from Klebsiella serotype 11 capsular polysaccharide
Authors: Zigterman J W , van Dam J E , Snippe H , Rotteveel F T , Jansze M , Willers J M , Kamerling J P , Vliegenthart J F
Published: January 2020

The tetrasaccharide repeating unit of the capsular polysaccharide of Klebsiella serotype 11, K11PS, comprises the following sequence: [----3)-beta-D-GlcpA-(1----3)-alpha-D-Galp-(1----3)-beta-D-Glcp-(1 ----] with a 4,6-O-(1-carboxyethylidene)-alpha-D-galactopyranosyl residue linked to O-4 of the glucuronic acid residue. Octasaccharide (OS) derived from K11PS by bacteriophage phi 11-associated glycanase, was coupled to bovine serum albumin and to keyhole limpet hemocyanin. The immunogenicity of various antigens after intraperitoneal immunization was studied by measuring the levels of circulating antibodies. Injection of BALB/c mice with K11PS resulted in induction of 2-mercaptoethanol-sensitive immunoglobulin M antibodies. The responses observed in BALB/c nu/nu mice and in male (CBA/N X C3H/HeN)F1 mice indicate that K11PS is a thymus-independent type 2 antigen. Immunization of BALB/c mice with either OS-bovine serum albumin or OS-keyhole limpet hemocyanin resulted in the induction of circulating 2-mercaptoethanol-resistant immunoglobulin G antibodies. Results in BALB/c nu/nu mice indicate that the OS-protein conjugates are thymus-dependent antigens. Since the OS-keyhole limpet hemocyanin conjugate induced antibodies in both (CBA/N X C3H/HeN)F1 females and males, we propose to refer to this kind of antigen as a thymus-dependent type 1 antigen, whereas OS-bovine serum albumin, which evoked immunoglobulins in (CBA/N X C3H/HeN)F1 females only, can be referred to as a thymus-dependent type 2 antigen.
Influence of nutrient limitation and low pH on serogroup B Neisseria meningitidis capsular polysaccharide levels: correlation with virulence for mice
Authors: Masson L , Holbein B E
Published: January 2020

Neisseria meningitidis strain M986, which possesses a polyanionic sialic acid capsular polysaccharide, was resistant to the bactericidal effects of normal rabbit serum, but sensitive when immune serum and complement were present. An isogenic strain PRM102, deficient in the ability to produce capsular polysaccharide, was sensitive to normal serum. Strain M986, when grown under conditions of low pH or nutrient limitation, synthesized increased levels of capsular polysaccharide. This was accompanied by an increase in cell surface hydrophilicity and virulence for mice. Cells grown in low-pH, iron-limited medium synthesized the highest concentration of polysaccharide and exhibited the highest cell surface hydrophilicity and virulence among the cases examined. The increase in capsular polysaccharide was partly explained by a decrease in the specific activity of a membrane-bound cytidine monophosphate-N acetylneuraminic acid hydrolase. The results suggest that conditions of nutrient limitation and low pH exert profound effects on the physicochemical nature of the meningococcal cell surface which, in turn, cumulate in enhanced virulence of this organism for mice.
Survey of immunoglobulin A protease activity among selected species of Ureaplasma and Mycoplasma: specificity for host immunoglobulin A
Authors: Kapatais-Zoumbos K , Chandler D K , Barile M F
Published: January 2020

Because immunoglobulin A (IgA) is the predominant immunoglobulin at mucosal surfaces, IgA proteases produced by pathogenic bacteria are considered potential virulence factors for organisms that cause disease or gain entry at mucous membranes. To determine the role of IgA protease in the pathogenicity of mycoplasmal disease, a variety of human and animal mycoplasma and ureaplasma species were examined for IgA protease activity with human, murine, porcine, and canine IgA. None of the mycoplasma species examined showed detectable IgA protease activity with any of the IgAs tested. Twenty-eight strains of Ureaplasma urealyticum isolated from human urogenital tissues cleaved human IgA1, but no cleavage of human IgA2 or murine, porcine, or canine IgA was observed. Ureaplasmas isolated from nonhuman hosts (feline, canine, avian, and bovine [Ureaplasma diversum]) did not cleave human IgA1. Two strains of canine ureaplasmas were able to cleave canine IgA, but not murine IgA. Thus, ureaplasmas from other species can produce IgA protease, but the specificity of the enzyme was restricted to the IgA of the appropriate host. This finding suggests that IgA proteases could play a role in the selective host specificity of mucosal pathogens.
Interferon-induced inhibition of Chlamydia trachomatis: dissociation from antiviral and antiproliferative effects
Authors: de la Maza L M , Peterson E M , Goebel J M , Fennie C W , Czarniecki C W
Published: January 2020

The yield of infectious Chlamydia trachomatis was analyzed in human (HeLa) and mouse (McCoy) cell lines treated with the human interferon (IFN) subtypes IFN-alpha A and IFN-alpha D, with their hybrids [IFN-alpha AD (BglII), IFN-alpha AD (PvuII), and IFN-alpha DA (BglII)] constructed in vitro from their expression plasmids, or with IFN-beta 1 or buffy coat IFN. In HeLa cells, a significant inhibition of Chlamydia infectivity was obtained with IFN-alpha D, IFN-alpha DA (BglII), and buffy coat IFN. In McCoy cells, IFN-alpha AD (BglII) and IFN-alpha AD (PvuII) induced a strong degree of inhibition of Chlamydia infectivity. In McCoy cells, there was a correlation among the antichlamydial, antiviral, and antiproliferative activities of the different IFNs tested. In HeLa cells, however, the ability of a particular IFN subtype to inhibit Chlamydia infectivity did not always correlate with its inhibitory effects on encephalomyocarditis virus replication or with its antiproliferative activity.
Quantitation of adherence of mucoid and nonmucoid Pseudomonas aeruginosa to hamster tracheal epithelium
Authors: Marcus H , Baker N R
Published: January 2020

Adherence of mucoid and nonmucoid isolates of Pseudomonas aeruginosa to tracheal epithelium was quantitated by using hamster tracheas mounted in a perfusion chamber. The strains of P. aeruginosa used were clinical isolates from cystic fibrosis patients and a series of laboratory strains. Aseptically excised hamster tracheas were mounted in perfusion chambers and embedded in minimal essential medium containing 1.5% agarose. The tracheas were infected with various numbers of bacteria for various periods, rinsed, homogenized, and plated on Trypticase soy agar. A 4-mm segment from each trachea was prepared for quantitation, and the other segment was prepared for examination by scanning electron microscopy. Adherence increased with time and with increasing concentrations of inoculum. Standard conditions of inoculation were set at an inoculum of 10(7) CFU/ml and a 2-h incubation. Under these conditions, the mucoid organisms adhered to the ciliated epithelium 10- to 100-fold better than did the nonmucoid organisms. Adherence of the mucoid isolates did not appear to be pilus mediated and did not involve hydrophobic interactions. The mucoid P. aeruginosa isolates could be seen adhering to the epithelium in the form of microcolonies embedded in an extracellular matrix which attaches the organisms to the cilia and to each other. The adherence may be involved in the establishment of infection of the lungs of these patients and in the inability to clear the organisms from the lungs. The model will be useful in determining the mechanism of adherence of the bacteria to the ciliated epithelium of the respiratory tract.
Surface properties of Streptococcus sanguis FW213 mutants nonadherent to saliva-coated hydroxyapatite
Authors: Fives-Taylor P M , Thompson D W
Published: January 2020

Seventeen mutants of Streptococcus sanguis FW213 nonadherent to saliva-coated spheroidal hydroxyapatite were isolated after mutagenesis with ethyl methanesulfonate, nitrosoguanidine, nitrous acid, hydroxylamine, or 2-aminopurine. Enrichment for nonadherent mutants was accomplished by successive adsorptions of the adherent strains to saliva-coated hydroxyapatite. After enrichment, variant colonial morphology on tryptic agar was used as a screening technique for selection of nonadherent mutants, with loss of colonial opacity frequently associated with loss of adherence ability. These mutants were further characterized for additional surface properties, including twitching motility, saliva-induced aggregation, coaggregation with Actinomyces species, surface hydrophobicity, and presence of fimbriae. Results from these assays indicated that the nonadherent mutants fell into six phenotypic groups. A correlation between the loss of adherence ability, a decrease in cell fimbriation, and a decrease in surface hydrophobicity is apparent.
Protective vaccination against virulent Babesia bovis with a low-molecular-weight antigen
Authors: Wright I G , Mirre G B , Rode-Bramanis K , Chamberlain M , Goodger B V , Waltisbuhl D J
Published: January 2020

A Babesia bovis low-molecular-weight antigen was purified from crude material by using affinity adsorption techniques first with a mouse monoclonal antibody and then by adsorption with normal bovine sera. The antigen was then further purified by gradient gel electrophoresis. Analysis by Western transfer revealed only one antigen band, with an apparent molecular mass of 29 kilodaltons. A band (12 by 0.3 by 0.6 cm) corresponding to this antigen was excised from the acrylamide gel and injected twice 4 weeks apart, together with 2.5 ml of Freund complete adjuvant, into nine nonsplenectomized adult cattle. The vaccinated cattle and five susceptible control animals were challenged with a virulent homologous strain 4 weeks after the second vaccination. None of the vaccinated animals was clinically affected, whereas three of five controls were severely affected. Control animals had significantly greater declines in packed cell volume and greater rises in temperature and parasitaemias than vaccinated animals.
Expression of protective and cardiac tissue cross-reactive epitopes of type 5 streptococcal M protein in Escherichia coli
Authors: Poirier T P , Kehoe M A , Dale J B , Timmis K N , Beachey E H
Published: January 2020

The immunochemical properties of type 5 M protein antigens that were expressed in Escherichia coli K-12 by recombinant lambda bacteriophages isolated from a gene bank of serotype 5 Streptococcus pyogenes have been analyzed in detail. M proteins from partially purified bacteriophage lysates displayed precipitin lines of identity with a purified peptic extract of type 5 M protein (pep M5) in immunodiffusion assays. Immunoblot analyses of the M protein-positive lysates demonstrated that the cloned M protein component resided in five polypeptides with relative molecular weights of 57,900 (57.9K), 55.4K, 52.9K, 40.0K, and 32.6K. The hybrid lambda phage (lambda M5)-produced M protein contained immunoprotective epitopes; lambda M5 protein inhibited opsonization of type 5 streptococci by pep M5 antibodies, and antiserum raised against lambda M5 lysates opsonized type 5 streptococci. Each of the five antigenic polypeptides of the recombinant phage M protein also shared epitopes with human heart tissue, as demonstrated by the reactivity of immunoblots of lambda M5 antigens separated on sodium dodecyl sulfate gels with anti-pep M5 antibodies absorbed to and eluted from human heart sarcolemmal membranes. Moreover, antiserum raised against the lambda M5 lysates reacted with sarcolemmal membrane proteins with relative molecular weights of 200K, 59K, 55K, 53K, and 27K as determined by immunoblot analyses. These results demonstrate that the structural gene coding for type 5 streptococcal M protein which was inserted into lambda DNA expresses immunoprotective epitopes, some of which are shared with human heart tissue.
Immunopharmacological activities of a synthetic counterpart of a biosynthetic lipid A precursor molecule and of its analogs
Authors: Takada H , Kotani S , Tsujimoto M , Ogawa T , Takahashi I , Harada K , Katsukawa C , Tanaka S , Shiba T , Kusumoto S
Published: January 2020

Synthetic lipid A analogs (compounds 404 through 406) were examined for their immunopharmacological activities. These compounds had two amide-bound and two ester-bound (R)-3-hydroxytetradecanoyl groups at the C-2 and C-2' and the C-3 and C-3' positions, respectively, of beta (1-3)glucosamine disaccharide. In all of the in vitro assays, these synthetic compounds exhibited high activities comparable to those of a reference lipid A prepared from Escherichia coli O8:K27 Re-mutant strain F515. The compounds activated the clotting enzyme cascade of the horseshoe crab, activated the human complement via the classical pathway, caused polyclonal B-cell activation, stimulated the phagocytosis of sheep erythrocytes by murine peritoneal macrophages, and enhanced the migration of human polymorphonuclear leukocytes. They also increased the thymidine uptake of splenocytes of BALB/c nu/nu and C3H/HeN mice but not those of C3H/HeJ (a nonresponder to lipopolysaccharide). A dephosphorylated derivative, compound 403, was barely active in all of the above assays except for the enhancement of polymorphonuclear leukocyte migration. However, compounds 404 through 406 were feeble in pyrogenicity and could not prepare the local Shwartzman reaction, although they were very lethal to galactosamine-loaded mice. Therefore, synthetic lipid A analogs described here were fully immunopharmacologically active in in vitro assays, but all of them were far less active than natural E. coli F515 lipid A regarding the biological activities characteristic of endotoxic lipopolysaccharides and lipid A's. The high lethal toxicity of compound 406 (1,4'-bisphosphate) to the galactosamine-loaded mice may not reflect its real toxicity to normal mice. In all activities examined, compound 406 was quite comparable to a biosynthetic lipid A precursor, a natural counterpart of compound 406. The immunopharmacological activities of these newly synthesized lipid A analogs, especially compound 406, were much stronger than those of compounds that had been synthesized earlier by using the originally proposed model of the lipid A structure. The findings described in this report justify the acylation pattern of a disaccharide backbone of lipid A, revised on the basis of recent analytical studies. The low in vivo endotoxic activities of the present lipid A analogs are most probably due to the fact that the kinds of acyl groups were different from those of the complete lipid A from E. coli, although there were no differences in the acylation positions on the disaccharide backbone.
Effective protection against Listeria monocytogenes and delayed-type hypersensitivity to listerial antigens depend on cooperation between specific L3T4+ and Lyt 2+ T cells
Authors: Kaufmann S H , Hug E , Väth U , Müller I
Published: January 2020

Selected L3T4- and Lyt 2- T-cell subpopulations from Listeria monocytogenes-infected mice were transferred into syngenic recipients, and their capacity to adoptively mediate protection against L. monocytogenes and delayed-type hypersensitivity to listerial antigens was determined. Both functions were markedly reduced by pretreatment of cells with either anti-L3T4 or anti-Lyt 2.2 antibodies plus complement, but they could be restored by admixture of the two selected T-cell subsets. Thus, after systemic cell transfer effective protection against L. monocytogenes and delayed-type hypersensitivity to listerial antigens depend on cooperation between specific L3T4+ and Lyt 2+ T cells.
Systemic Chlamydia trachomatis infection in mice: a comparison of lymphogranuloma venereum and trachoma biovars
Authors: Brunham R C , Kuo C , Chen W J
Published: January 2020

We developed a murine model of systemic infection with Chlamydia trachomatis biovar lymphogranuloma venereum (LGV). The pathological features of this infection resemble those of human LGV infection since both are characterized by granuloma formation. Mice developed resistance to reinfection with LGV, and this resistance was based on cellular immune mechanisms since it was transferable with immune spleen cells but not with immune serum. Resistance required viable organisms for induction. We compared LGV biovar infection with trachoma biovar infection. Trachoma biovar produced similar but less marked microbiological and pathological features. Cross-immunity was less apparent between serovars from trachoma and LGV biovars than it was between serovars within the same biovar. This model of systemic C. trachomatis infection will be useful in exploring virulence features of LGV.
Purification and characterization of neurotoxin produced by Clostridium botulinum type C 6813
Authors: Terajima J , Syuto B , Ochanda J O , Kubo S
Published: January 2020

The toxin produced by Clostridium botulinum type C 6813 (C-6813) was purified 1,009-fold from the culture supernatant in an overall yield of 30%. The specific toxicity was 1.1 X 10(7) mouse minimum lethal doses per mg of protein. The toxin had a molecular weight of 144,000, composed of the light and heavy chains with molecular weights of 52,000 and 92,000, respectively, linked by one or two disulfide bond(s). The purified C-6813 toxin heavy and light chains reacted strongly with anti-type D heavy chain immunoglobulin G and anti-type C1 light chain immunoglobulin G, respectively. The amino acid compositions of C-6813 toxin heavy and light chains were more similar to those of type D heavy chain and type C1 light chain than to those of type C1 heavy chain and type D light chain, respectively. These results suggest that in the toxin produced by the type C strain at least two subtypes exist.
Impairment of granulomatous inflammatory response to Histoplasma capsulatum by inhibitors of angiotensin-converting enzyme
Authors: Deepe G S , Taylor C L , Srivastava L , Bullock W E
Published: January 2020

Systemic infection with Histoplasma capsulatum induced a granulomatous inflammatory response in the lymphoreticular organs of C57BL/6 mice that was associated with elevated levels of angiotensin-converting enzyme (ACE) in the spleens. To determine the influence of ACE on the granulomatous response, either captopril or MK 421, two inhibitors of ACE, were administered intraperitoneally to mice 6 h after intravenous injection of H. capsulatum and then daily for 1 week. Each ACE inhibitor sharply reduced ACE activity in the spleens of infected mice. Both drugs worsened the clinical severity of infection and significantly increased the growth of H. capsulatum in livers and spleens of mice infected for 1 week. The histopathological changes in mice given captopril were more severe, with massive infiltrates of macrophages in proximity to large aggregates of yeasts. Conversely, the administration of captopril for 2 weeks during the resolving phases of infection did not slow the healing of the granulomatous lesions, nor did it provoke a relapse of infection. Captopril did not promote the growth of H. capsulatum in artificial medium. This drug was not cytotoxic to peripheral blood leukocytes or to splenic leukocytes from normal and infected mice. Administration of captopril to normal mice for 1 week did not depress the response of splenocytes of concanavalin A or to phytohemagglutinin, nor did it diminish delayed-type hypersensitivity responses in vivo. Finally, captopril did not augment the growth of H. capsulatum within macrophages. Our results suggest that ACE may participate in the regulation of the granulomatous inflammatory response to H. capsulatum and that ACE inhibition impairs the protective effects of granulomatous inflammation during acute H. capsulatum infection.
Synergistic effect of glucantime and a liposome-encapsulated muramyl dipeptide analog in therapy of experimental visceral leishmaniasis
Authors: Adinolfi L E , Bonventre P F , Vander Pas M , Eppstein D A
Published: January 2020

A regimen of immunostimulation with 6-0-stearoyl-N-acetylmuramyl-L-alpha-aminobutyryl-D-isoglutamine, a lipophilic analog of muramyl dipeptide, combined with antimonial drug therapy was evaluated in the treatment of visceral leishmaniasis of mice and hamsters. The combined treatment was found to be more effective in the elimination of Leishmania donovani amastigotes from infected tissue macrophages than was either of the two treatments applied individually. In mice, it was found that immunostimulation of animals prophylactically, therapeutically, or both enhanced the effects of the antimonial drug (Glucantime) administered more than 1 week after a challenge of BALB/c and C57BL/6 mice. The superiority of the combined treatment of the parasite infection was demonstrable in both short-term (14 days) and long-term (40 to 45 days) infections of the two inbred strains of mice. The combined therapy was also effective in preventing the lethal course of leishmaniasis in hamsters which succumb to disseminated disease in the absence of therapeutic intervention. The efficacy of this dual approach to the therapy of disseminated leishmaniasis of experimental animals holds promise for similar application in the treatment of similarly afflicted human populations.
Alterations in lymphocyte subpopulations in copper-deficient mice
Authors: Lukasewycz O A , Prohaska J R , Meyer S G , Schmidtke J R , Hatfield S M , Marder P
Published: January 2020

Analyses of cell surface determinants of splenocytes from copper-deficient C58 mice indicate alterations in lymphocyte subpopulation characteristics. Both the absolute number and the relative percentage of surface immunoglobulin-bearing (B) cells from copper-deficient mice were significantly greater than those from copper-supplemented controls. The relative percentage of Thy 1.2-positive (T) cells was decreased, and the decrease was most prominent within the Lyt 1-positive (helper) T-cell subset. The functional responsiveness of both B cells and T cells was decreased in copper deficiency.
Analysis of polypeptide composition and antigenic components of Rickettsia tsutsugamushi by polyacrylamide gel electrophoresis and immunoblotting
Authors: Tamura A , Ohashi N , Urakami H , Takahashi K , Oyanagi M
Published: January 2020

Polyacrylamide gel electrophoresis of lysates of purified Rickettsia tsutsugamushi revealed as many as 30 polypeptide bands, including major bands corresponding to molecular sizes of 70, 60, 54 to 56, and 46 to 47 kilodaltons. Compared with the polypeptide composition of the rickettsiae of Gilliam, Karp, and Kato strains and a newly isolated Shimokoshi strain, the major polypeptide in the Kato strain (54-56K) and in the Karp strain (46-47K) migrated a little faster and slower, respectively, than the corresponding polypeptides in the other strains. The largest major polypeptide (54-56K) was digestible by the treatment of intact rickettsiae with trypsin and variable in content in separate preparations, suggesting that the polypeptide exists on the rickettsial surface and is easily degraded during the handling of these microorganisms. Several surface polypeptides of rickettsiae, including the 54-56K and 46-47K polypeptides, were detected by radioiodination of intact rickettsiae followed by polyacrylamide gel electrophoresis of the lysate; however, the 70K and 60K polypeptides were not labeled. Immunoblotting experiments with hyperimmune sera prepared in guinea pigs against each strain demonstrated that the 70K, 54-56K, and 46-47K polypeptides showed antigenic activities. The 54-56K polypeptide appeared to be strain specific, whereas the 70K and 46-47K polypeptides cross-reacted with the heterologous antisera.
Chronic chlamydial genital infection in congenitally athymic nude mice
Authors: Rank R G , Soderberg L S , Barron A L
Published: January 2020

Congenitally athymic nude mice and their heterozygous counterparts were inoculated intravaginally with the chlamydial agent of mouse pneumonitis, a Chlamydia trachomatis biovar. Heterozygous mice resolved their infections in 20 days, whereas nude mice developed chronic infections which lasted at least 265 days and did not resolve within the time course of the experiments. Heterozygous mice produced high levels of antibody in both serum and secretions in contrast to nude mice, which produced very low levels of antibody in serum alone.
Antibodies against the light chain of tetanus toxin in human sera
Authors: Lin C S , Habig W H , Hardegree M C
Published: January 2020

Tetanus toxoid elicits protective antibodies against tetanus toxin in humans and animals. It has been reported that antitoxin from immunized humans contains no anti-light chain antibodies, based on immunodiffusion and quantitative precipitin analyses. We confirmed the absence of precipitating anti-light chain antibodies in tetanus immune globulin. However, the presence of antibodies against the light chain of the toxin was shown by direct binding and inhibition analyses, using enzyme-linked immunosorbent assays. Using a neutralization inhibition test, we also found that about one-fourth of the neutralizing antibodies in tetanus immune globulin are directed against the light chain. These results suggest that the light chain of tetanus toxin contains immunogenic determinants and that antibodies directed against it may have a role in the prevention of tetanus or treatment of tetanus or both.
Enhanced superoxide release and tumoricidal activity by a postlavage, in situ pulmonary macrophage population in response to activation by Mycobacterium bovis BCG exposure
Authors: Drath D B
Published: January 2020

The monocytic phagocyte population of rat lungs is heterogeneous. In addition to the freely lavagable alveolar macrophages, there is a fixed in situ tissue-associated subpopulation of pulmonary macrophages. The response of this subpopulation to classical macrophage activation by Mycobacterium bovis BCG exposure was monitored. Results indicate that this population can be activated both metabolically and functionally, as evidenced by enhanced release of superoxide anions and demonstrable tumoricidal activity against syngeneic and xenogeneic target cells. The pattern of metabolic activation of in situ tissue-associated macrophages differed somewhat from that of alveolar macrophages and was observed only after subsequent exposure of the cells to either zymosan particles or phorbol myristate acetate. Upon such exposure, the activated zymosan-treated tissue macrophages released approximately twice as much superoxide as the nonactivated cells and amounts comparable to the amounts released by activated alveolar macrophages. The tissue macrophages also displayed greater levels of cytotoxicity toward xenogenic targets than the alveolar cells and may have an important role in preventing microbial or tumor cell colonization of respiratory systems.
Inhibition of ecological emergence of mutans streptococci naturally transmitted between rats and consequent caries inhibition by Streptococcus salivarius TOVE-R infection
Authors: Tanzer J M , Kurasz A B , Clive J
Published: January 2020

The ability of Streptococcus salivarius strain TOVE-R to inhibit the ecological emergence of virulent representatives of the most prevalent human mutans streptococci on the teeth of specific pathogen-free Osborne-Mendel rats was studied. Rats which were infected by TOVE-R, or either S. mutans 10449S or S. sobrinus 6715-13WT, or uninfected were transiently co-caged so as to allow natural fecal transfer of organisms due to coprophagy. The infectants were differentially recovered from swabs of the teeth over the time course of the experiments and from sonified teeth at termination. Data were expressed on both relative (percentage) and absolute (CFU) bases. Initial oral colonization of rats by TOVE-R inhibited the ecological emergence of fecally transmitted S. mutans 10449S and S. sobrinus 6715-13WT. There was a generally inverse relationship between the percentages and absolute numbers of TOVE-R and the mutans streptococci on the teeth, which strongly suggested their competition for tooth sites. Absolute numbers of total recoverable flora from the teeth upon sonification were correlated with caries scores, thus suggesting that total recoverable flora counts substantially reflect cavitation status. TOVE-R itself induced no apparent caries activity and its transmission to rats already infected by 10449S or its colonization of rats before 10449S infection inhibition caries induction by this S. mutans strain; similar anticaries effects were not statistically significant for TOVE-R against 6715-13WT in these experiments. These data on the inhibition of the ecological emergence of the mutans streptococci supplement the already reported ability of TOVE-R to preempt initial colonization of teeth and partially displace the colonization of teeth by the mutans streptococci.
Trypanolytic activity, agglutinins, and opsonins in sera from animals refractory to Trypanosoma lewisi
Authors: Ferrante A
Published: January 2020

An examination of sera from a range of animals refractory to Trypanosoma lewisi showed that some contain trypanolytic activity and agglutinins for this trypanosome. Trypanolytic activity was demonstrated in bovine, sheep, and rabbit serum. These sera were shown to also contain agglutinins. The trypanolytic activity in all three sera was abolished by heat inactivation at 56 degrees C for 30 min. Studies with bovine serum showed that the lytic activity was totally inhibited by the addition of EDTA but was only partially inhibited by ethylene glycol-bis(beta-aminoethyl ether)-N,N-tetraacetic acid-Mg2+, suggesting the involvement of both classical and alternate pathways of complement activation. Serum from the natural host, the rat but not mouse serum, was capable of inhibiting the trypanolytic activity of bovine serum. The agglutinins in bovine serum were specific, since they could be adsorbed out with T. lewisi but not T. musculi. They fractionated on gel filtration in the position expected for 19S antibodies. By using opsonization measuring techniques, it was found that mouse serum lacked opsonins to T. lewisi, although opsonic activity was detectable in human serum. The absence of agglutinins, trypanolysins, and opsonins in mouse serum suggests that other factors prevent the infection of mice by T. lewisi. From these findings, it would appear that the inability of T. lewisi to infect a range of mammals, with the exception of mice, could be due to the presence of antibodies, the ability to activate complement through the alternative pathway, or both. The absence of these recognition factors and the ability to evade the effects of alternative pathway activation may be important factors in the ability of this parasite to establish infections in rats.
Effect of aluminum ions on chemical and immunological properties of meningococcal group B polysaccharide
Authors: Moreno C , Lifely M R , Esdaile J
Published: January 2020

Soluble salts of aluminum were examined for their capacity to complex with purified meningococcal group B polysaccharide. The formation of the complexes resulted, first, in a markedly reduced rate of internal esterification at acid pH and, consequently, prolonged stability of the antigen as measured by its reactivity with antibody at pH 4 and, second, in an increased resistance to neuraminidase. Al3+ complexes of B polysaccharides were tested for immunogenicity in mice and found to be no better than the purified polysaccharide in the Na+ or Ca2+ form. However, when Neisseria meningitidis type 6 protein (outer membrane) complexed to B polysaccharide was tested, a substantial increase in anti-B titers was detected, whereas antiprotein titers remained unchanged. The possibility of using combinations of metal-polysaccharide-outer membrane protein complexes as vaccines for humans is discussed.
Macrophage-related fibrinolysis in experimental disseminated histoplasmosis
Authors: Tiku M L , McNabb P C , Tomasi T B
Published: January 2020

A model of disseminated histoplasmosis in CBA/J mice was developed. Cultures of Histoplasma capsulatum from the spleens of infected mice suggested almost complete clearance of fungi by week 3. The adherent spleen cells from infected mice showed a 2- to 20-fold increase in fibrinolysis. The increase in activity was maximal around 1 to 2 weeks and disappeared after week 3 of infection, and this paralleled the progressively decreasing number of culturable fungi from the spleen. In vitro coculture of infected spleen cells or nylon wool-purified immune T cells and proteose peptone-induced macrophages resulted in increased fibrinolysis. Peritoneal exudate cells from infected mice also showed increased fibrinolysis. The addition of soluble antigen to an in vitro culture system resulted not only in an increase in fibrinolytic activity of peritoneal exudate cells derived from infected mice but also of proteose peptone-induced macrophages. These observations suggest that spleen and peritoneal macrophages from H. capsulatum-infected mice exhibit increased fibrinolysis which in turn is indicative of macrophage activation. The mechanism of activation occurs as a result of immunologically specific T cell-macrophage interaction and by the action of histoplasma products on the macrophages. The significance of these findings and the role of the plasminogen activator assay in studies of disseminated fungal infection are discussed.
Complement activation and stimulation of chemotaxis by Chlamydia trachomatis
Authors: Megran D W , Stiver H G , Bowie W R
Published: January 2020

The stimulus for the migration of polymorphonuclear leukocytes (PMNs) in acute chlamydial infection was studied in vitro by examining the chemotaxigenic effect of L2 and DE Chlamydia trachomatis elementary bodies (EB) upon the plasma of three healthy donors. In each individual experiment, chemotactic response was assessed with PMNs and plasma from the same respective donor, and no specific antibodies against C. trachomatis were detected in the plasma of any donor. Chemotaxis was observed in an agarose plate assay and was quantitated as the chemotactic differential, or CD (directed migration of PMNs minus random movement of PMNs). For each donor, the mean CD was significantly greater (P less than 0.005) when plasma preincubated for 2 h with L2 EB was used as the chemoattractant than when (i) plasma alone, (ii) plasma preheated to 56 degrees C for 30 min before incubation with L2 EB, or (iii) L2 EB in phosphate-buffered saline (PBS) was used as the potential chemoattractant. Similarly, in the one donor in whom DE EB were studied, the mean CD was also significantly greater (P less than 0.005) for plasma preincubated with DE EB as compared with (i) plasma alone or (ii) DE EB in PBS. Complement activation by C. trachomatis EB was assessed by radioimmunoassay for C5a des-arginine in all chemoattractant preparations used in the chemotaxis assay. Mean C5a des-arginine levels were high in plasma samples preincubated with L2 EB (171.00 +/- 10.64, 107.00 +/- 4.76, and 89.70 +/- 1.74 ng per ml) or DE EB (37.40 +/- 15.76 ng per ml) but were undetectable (less than 4.0 ng per ml) in (i) plasma alone, (ii) preheated plasma incubated with L2 EB, and (iii) PBS containing L2 EB. Thus, L2 EB and DE EB of C. trachomatis exert a chemotaxigenic effect upon normal antibody-negative plasma, and this effect is at least in part a result of complement activation and generation of the potent chemotaxin C5a.