bluuebunny/crossref_metadata_2025 huggingface dataset:
Role of monocytes in polyclonal immunoglobulin production stimulated by sonicates of periodontally associated bacteria
Authors: Carpenter A B , Sully E C , Palcanis K G , Bick P H
Published: January 2020

These studies were initiated to investigate monocyte regulation of polyclonal antibody responses of human peripheral blood lymphocytes stimulated by sonicates of periodontally associated bacteria. With pokeweed mitogen (PWM) as a positive reference, the role of monocytes in the peripheral blood lymphocyte response to Streptococcus sanguis and Wolinella HVS was examined by manipulating the number of monocytes and lymphocytes in culture. In comparison to PWM, optimal responses to the bacterial sonicates required very few monocytes (0.3% of the total cultured cells). Restoration of monocytes to physiological levels resulted in suppression of the response. PWM-stimulated responses were optimal at 5 to 15% monocyte content and were abolished after monocyte depletion. Individuals who were low responders or nonresponders to bacterial sonicates responded at normal levels after manipulation of monocyte concentration. Nonresponders produced normal levels of antibody when the monocyte concentration was reduced to 0.3% but were inhibited after monocyte reconstitution. The effects of monocyte concentration were tested over a wide dose range of bacterial sonicate and found to conform to the observed pattern throughout the dose range tested (10 to 1,000 micrograms/ml). The contrasting monocyte requirement of peripheral blood lymphocytes stimulated with PWM versus bacterial sonicates may reflect a quantitative difference in optimal macrophage concentration or may be due to a qualitative difference in lymphocyte-monocyte interactions in response to these activators.
Externally disposed membrane polypeptides of intact and protease-treated Trypanosoma lewisi correlated with sensitivity to alternate complement pathway-mediated lysis
Authors: Sturtevant J E , Balber A E
Published: January 2020

Reproducing forms of Trypanosoma lewisi isolated from X-irradiated rats and adult forms from intact rats were not lysed by fresh mammalian sera. Treating parasites with trypsin or chymotrypsin, but not with neuraminidase, under conditions which did not impair viability rendered the parasites sensitive to lysis by rat, mouse, rabbit, and human sera. Serum from animal strains or humans genetically deficient in complement component C3, C5, or C6 did not lyse protease-treated parasites. The lytic factors in serum displayed the heat sensitivity and the Mg2+ requirement characteristic of the alternate complement pathway. Lysis was resolved into two phases, Mg2+-dependent binding of serum factors to parasites and subsequent C5-dependent, Mg2+-independent lysis. Allowing protease-treated parasites to readsorb host proteins did not block lysis by serum. Protease-treated parasites regenerated components which prevented complement-mediated lysis during 2 h in culture at 37 degrees C. This regeneration was inhibited by cycloheximide but not by tunicamycin. Ten major components were resolved in radioautographs of sodium dodecyl sulfate-polyacrylamide gels of extracts of radioiodinated intact cells. Protease treatment before radioiodination reduced the amount of radioactivity associated with these components disproportionately. Components with apparent molecular weights of 102,000, 88,000, and 47,000 were strongly labeled in intact cells, poorly labeled after enzyme treatment, and again labeled in cells that were cultured at 37 degrees C after enzyme treatment. Cycloheximide blocked the reappearance of these components on cultured cells. The presence of these three components was therefore correlated with resistance to complement-mediated lysis.
Accessory cell function of liver granuloma macrophages of Schistosoma mansoni-infected mice
Authors: Schook L B , Wellhausen S R , Boros D L , Niederhuber J E
Published: January 2020

In murine schistosomiasis mansoni, the inflammatory macrophage comprises 30% of the granuloma which forms around parasite eggs in the tissue. These granuloma macrophages (GR-Mphi) displayed dense Fc and C3 receptors, and about 50% expressed H-2I region-encoded determinants (Ia antigens). These GR-Mphi were able to effectively reconstitute the burro erythrocyte-specific immunoglobulin M and G antibody response of primed macrophage-depleted spleen cells. However, in contrast to splenic macrophages, GR-Mphi gave only minimal reconstitution of the primary immunoglobulin M response. The reconstitution of the T-cell proliferative response to L-glutamic60-L-alanine30-L-tyrosine10, an antigen under Ir gene control, was also observed when GR-Mphi were added to purified lymph node T-cells. The addition of a monoclonal antibody recognizing a determinant on the Ia complex effectively blocked L-glutamic60-L-alanine30-L-tyrosine10 presentation by GR-Mphi. These studies demonstrated that inflammatory GR-Mphi could function as antigen-presenting cells and that this accessory function was mediated by H-2I region gene products.
Role of the capsule and the O antigen in resistance of O18:K1 Escherichia coli to complement-mediated killing
Authors: Pluschke G , Mayden J , Achtman M , Levine R P
Published: January 2020

Epidemiological data show that O18:K1 Escherichia coli is a common cause of neonatal bacteremia and meningitis. These bacteria were capable of multiplying in the bloodstream of newborn rats and were resistant to the bactericidal effects of complement in the absence of specific antibodies. The roles played by the O antigen and the K antigen in complement resistance were analyzed by comparing the bactericidal effects of normal sera and of sera deficient in various complement components or in immunoglobulins. These sera were tested on O18:K1 bacteria and on mutants lacking either the lipopolysaccharide O antigen or the K1 capsular polysaccharide. In addition, O1:K1 cells, which can cause pyelonephritis but which are rare in newborn meningitis and which do not multiply in the bloodstream of newborn rats, were also examined. Different mechanisms of protection against the alternative and classical pathways were recognized: K1-positive cells were resistant to the bactericidal activity of sera deficient in classical complement pathway components, whereas K1-negative cells were sensitive to these sera. Based on these results and on those from complement fixation assays, the K1 sialic acid polysaccharide impedes the activation of, and thus protects the bacteria against, the alternative complement pathway. Not only the K1-negative mutant cells but also O1:K1 bacteria and mutants lacking the O18 oligosaccharide repeating units of the lipopolysaccharide were sensitive to the classical complement pathway. These bactericidal effects were observed even in the absence of specific antibodies. It is proposed that both the K1 capsule and the O18 oligosaccharide restrict antibody-independent classical pathway activation by shielding deeper structures on the cell membrane that are capable of activating this pathway.
Persistence of influenza as an immunogen in pulmonary antigen-presenting cells
Authors: Lipscomb M F , Yeakel-Houlihan D , Lyons C R , Gleason R R , Stein-Streilein J
Published: January 2020

Influenza antigens inoculated into the lung induce local immune responses. It has been proposed that this induction might be partly regulated by local antigen-presenting cells. The purpose of the current study was to inoculate heat-inactivated influenza virus into the tracheae of guinea pigs and determine the quantity of antigens that became cell-associated. Second, we determined how long antigen-presenting bronchoalveolar cells that had taken up virus in vivo retained their ability to specifically stimulate virus-immune T lymphocytes. Radioiodinated heat-inactivated influenza virus was inoculated into the tracheae of guinea pigs. The animals were killed from 30 min to 14 days after intratracheal inoculation, and radioactivity was determined in cells isolated from lung tissue. At least one-third of the radioactivity in the lungs was cell-associated from 1 to 14 days post-inoculation. In separate studies, heat-inactivated virus was inoculated into the airways of guinea pigs, and animals were killed at various times thereafter. Bronchoalveolar cells from these animals were compared with those from uninoculated controls in their ability to specifically stimulate virus-immune T cells to proliferate in vitro. Bronchoalveolar cells from virus-inoculated animals specifically stimulated T lymphocytes for up to 7 days after virus inoculation. These studies suggest that immunogenic virus persists in the lung within antigen-presenting cells for at least 1 week and possibly for up to 2 weeks. The persisting immunogenic stimulus after the termination of viral infections might be critical in ensuring the development of a local protective immune response.
Detection of soluble peptidoglycan in urine after penicillin administration
Authors: Park H , Zeiger A R , Schumacher H R
Published: January 2020

A unique enzyme-linked immunosorbent assay was developed to detect soluble peptidoglycans in biological fluids. It makes use of the similar affinities of vancomycin and purified rabbit antibodies to peptidoglycan precursor sequences found in soluble peptidoglycans. This assay has been used to detect as little as 500 pg of soluble peptidoglycan per ml of serum and 5 pg/ml of urine. Studies of normal individuals and Staphylococcus aureus-infected patients revealed only a few sera with detectable levels of soluble peptidoglycans. Studies of normal volunteers who were given a single oral dose of 250 mg of penicillin VK showed that about half had detectable levels of soluble peptidoglycans in their urine up to 6 h after ingestion. This suggests that soluble peptidoglycans can be released by indigenous bacteria in detectable amounts. In one volunteer, a detectable level of soluble peptidoglycan in the urine at 6 h decreased to an undetectable level at 12 h. Such an ephemeral appearance of soluble peptidoglycan in the urine could account for the small number of human sera that had detectable levels of soluble peptidoglycan.
Specific and common antigens of Trichomonas vaginalis detected by monoclonal antibodies
Authors: Torian B E , Connelly R J , Stephens R S , Stibbs H H
Published: January 2020

Monoclonal antibodies to Trichomonas vaginalis were prepared by immunizing mice with a cloned isolate of T. vaginalis. Eight antibodies reacted with the same four isolates or strains but did not react with the other T. vaginalis strains or isolates tested. All eight antibodies reacted uniformly with both the body and flagella of T. vaginalis in the immunofluorescence assay but were unreactive by immunoblotting. The antigen(s) recognized by these antibodies was determined to be present on the surface membrane by indirect immunofluorescence assay of live organisms. The antigen(s) was found to be sensitive to periodate oxidation but resistant to pronase digestion. In addition, one monoclonal antibody was derived which reacted with all T. vaginalis isolates or strains tested, as well as with Trichomonas gallinae, Tritrichomonas foetus, and Giardia lamblia. This antibody reacted with the body but not the flagella of Formalin-fixed protozoa in the immunofluorescence assay but failed to react with live organisms. The antigen was found to be periodate resistant but pronase labile. In the immunoblot assay, this antibody detected a single T. vaginalis polypeptide with a molecular weight of 62,000.
Evidence for lipid-protein interactions in the attachment of antigens to a low-density membrane fraction isolated from Trypanosoma rhodesiense
Authors: McLaughlin J
Published: January 2020

A putative Trypanosoma rhodesiense flagella pocket membrane fraction (FPM) was previously found to possess a range of antigenic components that were released after exposure to a detergent mixture containing 0.1% Zwittergent 3-12 and 0.4% Triton X-100. In the present investigation, and effort was made to determine the role of membrane lipid in binding FPM antigens, using phospholipases A2 and C as membrane probes. Exposure to the former was notable for the release of one antigen in particular that was only poorly extracted with the above detergents. Evidence was obtained suggesting that this release was not due to the detergent action of degradation products formed by the action of phospholipase A2 on membrane phospholipids. This phospholipase-released antigen, as were most other FPM antigens, was a glycoprotein, although the carbohydrate sequences do not appear to influence antigenicity. It was also possible to demonstrate the presence of a group of three cross-reacting FPM antigens that partitioned as hydrophobic membrane proteins by using Triton X-114 extraction. This was in contrast to the predominantly hydrophilic nature of most other FPM antigens.
Amount and avidity of salivary and serum antibodies against Streptococcus mutans in two groups of human subjects with different dental caries susceptibility
Authors: Lehtonen O P , Gråhn E M , Ståhlberg T H , Laitinen L A
Published: January 2020

Immunoglobulin A (IgA) and IgG antibodies against Streptococcus mutans K1R and 10449 were measured in serum and in stimulated whole saliva from two groups of naval recruits, representing high or low caries susceptibility. The antibody assays were performed by using the enzyme-linked immunosorbent assay, and the results were expressed by a method able to estimate the amount of high-avidity and total specific antibodies. As a control, concentrations of salivary total immunoglobulins were related to the amounts of specific antibodies. Further, antibodies were assayed against three antigens, unrelated to the streptococci. No clear differences were observed in serum antibodies between the subjects with high or low caries susceptibility. However, in saliva, low caries susceptibility was associated with a high amount of total antigen-specific IgA, and possibly IgG, against S. mutans. This difference between the groups still existed when the amounts of specific antibodies were related to the amounts of salivary immunoglobulins. There were no differences in the amounts of total specific antibodies against the unrelated antigens. No differences were observed in the estimates of high-avidity anti-S. mutans antibodies between the groups, either in serum or saliva. Thus, within the limitations of the assays and crude antigen, lack of high-avidity antibodies is not responsible for caries susceptibility. Instead, the amount of anti-S. mutans antibodies seems to be linked with caries protection. The results of the present study indicate that salivary antibodies are linked with the control of human dental caries.
Inhibition of bacterial aggregation by serum- and blood-derived proteins
Authors: Malamud D , Brown C , Goldman R
Published: January 2020

Human and animal sera contain potent inhibitors of saliva-mediated aggregation of oral streptococci. The inhibitors consist of a high-molecular-weight heat-labile factor and a lower-molecular-weight heat-activated factor. The latter appears to be serum albumin. Analyses of purified blood-derived proteins indicated that several high-molecular-weight proteins (fibrinogen, fibronectin, and ferritin) were able to inhibit aggregation at low concentrations. These data suggest that high-molecular-weight proteins may modulate the aggregation process.
Loss of pigmentation in Shigella flexneri 2a is correlated with loss of virulence and virulence-associated plasmid
Authors: Maurelli A T , Blackmon B , Curtiss R
Published: January 2020

In this study, we examined the relationship between the virulence of Shigella flexneri 2a and the ability of strains of S. flexneri 2a to absorb Congo red. Spontaneous nonpigmented (i.e., unable to bind Congo red [Pcr-]) derivatives of a virulent, pigmented (Pcr+) strain of S. flexneri 2a were isolated and assayed for virulence as determined by their ability to invade epithelial cells. All Pcr- mutants examined lost the ability to invade epithelial cells and were thus avirulent. Agarose gel electrophoresis of plasmid DNA from these avirulent, Pcr- mutants showed that the majority of these strains had lost a plasmid band corresponding to a virulence-associated plasmid, pSf2a140. In many of the mutants, concomitant loss of pigmentation, virulence, and pSf2a140 was accompanied by the appearance of a new plasmid, smaller than pSf2a140. We believe these new plasmids to be deletion derivatives of pSf2a140 and that loss of pigmentation and loss of virulence are associated with deletions in pSf2a140. We transduced Pcr- mutants to Pcr+ and isolated transductants which suppressed the Pcr- phenotype. None of the Pcr+ transductants regained the ability to invade epithelial cells. Several suppressors of the Pcr- phenotype were identified as mutations in cell wall biosynthesis. These results support our belief that although pigmentation is usually associated with virulence, genetic determinants unrelated to virulence can also affect the ability of the cell to bind Congo red. Therefore, the ability of S. flexneri 2a to bind Congo red does not necessarily imply the ability to invade epithelial cells. However, loss of ability to bind Congo red is accompanied by loss of virulence.
Relationship between host age and persistence of Theiler's virus in the central nervous system of mice
Authors: Steiner C M , Rozhon E J , Lipton H L
Published: January 2020

This study has demonstrated that the ability of BeAn 8386 virus to persist in the central nervous system of mice declines with the increasing age of the host at the time of inoculation. Although persistent infection was established in 1-, 3-, 9-, and 40-week-old mice, there was a significant reduction in both the frequency of virus isolations and the mean virus titers in mice inoculated after 3 weeks of age. The incidence of clinical demyelinating disease (late disease) also decreased in animals infected after 3 weeks of age in parallel with the decline in virus persistence.
Indomethacin promotes differentiation of Trypanosoma brucei
Authors: Jack R M , Black S J , Reed S L , Davis C E
Published: January 2020

The treatment of mice with indomethacin lowered Trypanosoma brucei parasitemia 1 to 2 log10 because it quickly promoted the differentiation of rapidly dividing long, slender trypanosomes into short, stumpy forms that do not divide in the mammal but do develop a functional mitochondrion and the ability to infect the tsetse. Since natural resistance correlates with the rate of differentiation, this observation may provide important information about factors that control the severity of trypanosomiasis.
Antibody response of infected mice to outer membrane proteins of Pseudomonas aeruginosa
Authors: Hedstrom R C , Pavlovskis O R , Galloway D R
Published: January 2020

The antibody response to outer membrane proteins of Pseudomonas aeruginosa was studied in mice experimentally infected with P. aeruginosa 220. The infection consisted of an abscess established by subcutaneous injection of bacteria. Sera from these mice were analyzed by indirect radioimmunoprecipitation and immunoblot methods for the presence of antibodies to proteins of the isolated outer membrane. Sera from mice 14 days postinfection were shown to contain antibodies directed against proteins that comigrated with the major outer membrane proteins F (porin), H2, and I (lipoprotein). A 16,000-dalton protein that did not appear to be a major outer membrane protein also elicited a significant antibody response in some instances. It is concluded that mice, in response to infection, elicit an immunological response to outer membrane proteins of P. aeruginosa.
Immunoglobulin classes of Aleutian disease virus antibody
Authors: Porter D D , Porter H G , Suffin S C , Larsen A E
Published: January 2020

Aleutian disease virus (ADV) persistently infects mink and causes marked hypergammaglobulinemia. Immunoglobulin class-specific antisera were used to define the total immunoglobulin of each class by radial immunodiffusion and the immunoglobulin class of ADV-specific antibody by immunofluorescence in experimentally and naturally infected mink. Electrophoretic gamma globulin closely reflects the immunoglobulin G (IgG) level in mink, and the majority of the increased immunoglobulin and ADV antibody in infected mink is IgG. IgM becomes elevated within 6 days after infection, reaches peak levels by 15 to 18 days, and returns to normal by 60 days after infection. The first ADV antibody demonstrable is IgM, and most mink have virus-specific IgM antibody for at least 85 days postinfection. Serum IgA levels in normal mink are not normally distributed, and ADV infection causes a marked elevation of IgA. Low levels of ADV-specific IgA antibody can be shown throughout the course of infection. Failure of large amounts of virus-specific IgG antibody to inhibit the reaction of virus-specific IgM and IgA antibodies suggests that the various classes of antibodies are directed against spatially different antigenic determinants. The IgM and IgA were shown not to be rheumatoid factors.
Oral toxicities of Clostridium botulinum type A and B toxins from different strains
Authors: Ohishi I
Published: January 2020

The production and the oral toxicity for mice of Clostridium botulinum type A and B toxins of different strains were studied. All five type B strains produced both 16S (large or L) and 12S (medium or M) toxins, although the relative amounts varied with the strains. The culture supernatant of type B Okra strain was the most potent in oral toxicity. The L toxin of this culture was about 700 times more toxic in feeding tests with mice than the L toxin from type B strain NH-2, whereas the M toxins of the two strains had the same oral toxicity. These results indicate that the oral toxicity of type B toxin varies with the culture strain. Oral toxicities of L toxin produced by type A strains 62A and 97 were comparable but were 10 times higher than those of their M toxins. Hybrids of toxic and nontoxic components separated from L toxins of type B strains Okra and NH-2 revealed that the high oral toxicity of the B-L toxin of strain Okra is attributable not to the toxic but to the nontoxic component of the toxin. The present study suggests that the 16S molecular-sized toxin elaborated by a certain strain of C. botulinum type B is implicated in the high fatality rate in type B human botulism.
In vitro culture of coxsackievirus group B, type 3 immune spleen cells on infected endothelial cells and biological activity of the cultured cells in vivo
Authors: Huber S A , Job L P , Woodruff J F
Published: January 2020

Spleen cells from male BALB/c mice infected 7 days earlier by an intraperitoneal injection of 3 X 10(4) PFU of a myocarditic strain of coxsackievirus B-3 lysed virus-infected endothelial cells in a 51Cr release assay. Cytotoxic activity in the in vivo sensitized spleen cell population could be further increased by culturing the immune spleen cells from infected mice on virus-infected or uninfected endothelial cells for 6 to 7 days in vitro. Cytotoxicity of in vitro cultured spleen cells to infected targets was mediated by T lymphocytes since reactivity was abolished by treatment of the spleen cells with anti-thy 1.2 serum and complement. Reciprocal assays with BALB/c and C57BL cells indicated that maximum cytotoxicity occurred when spleen cells were sensitized on syngeneic endothelial cells. Other experiments showed that spleen cells sensitized to coxsackievirus B-3 or encephalomyocarditis virus were selectively cytolytic to targets infected with the homologous virus. Adoptive transfer of T cells cultured in vitro on infected endothelial cells retained their ability to induce myocarditis in T-lymphocyte-deficient mice.
Binding of Escherichia coli heat-stable enterotoxin to rat intestinal cells and brush border membranes
Authors: Frantz J C , Jaso-Friedman L , Robertson D C
Published: January 2020

The association of heat-stable enterotoxin (STa) produced by enterotoxigenic Escherichia coli 431 with isolated rat intestinal epithelial cells and brush border membranes was characterized. Specific binding of strain 431 125I-STa to a single class of specific high-affinity receptors was saturable and temperature dependent and reached a maximum between 5 and 10 min. A 1,000-fold excess of unlabeled 431 STa competitively displaced 90 to 95% of radiolabeled enterotoxin bound to brush border membranes. In contrast, specific binding of 431 125I-STa to intestinal cells ranged from 40 to 65%. The number of STa-specific receptors on rat intestinal cells determined by Scatchard analysis was 47,520 +/- 14,352 (mean +/- standard error of the mean) per cell, with affinity constants (KaS) of 2.55 X 10(11)and 4.32 x 10(11) liters/mol determined for intestinal cells and brush border membranes, respectively. Villus intestinal cells appeared to possess about twice as many STa receptors as did crypt cells. Dissociation of specifically bound 431 125I-STa from intestinal cells and brush border membranes was minimal (2 to 5%). In addition, neither the rate nor the extent of dissociation was increased by a 1,000-fold excess of unlabeled homologous 431 Sta. Binding experiments with 431 125I-STa and brush border membranes showed that purified unlabeled STas from enterotoxigenic E. coli strains 667 (class 1 porcine enteropathogen), B-41 (bovine enteropathogen), and human strains 213C2 (Mexico) and 153961-2 (Dacca, Bangledesh) exhibited patterns of competitive inhibition similar to those of homologous unlabeled 431 STa (class 2 enteropathogen). A lipid extract which contained gangliosides and glycolipids exhibited dose-dependent competitive inhibition of heat-labile enterotoxin binding to brush border membranes but did not inhibit binding of 431 125I-STa. Purified heat-labile enterotoxin from strain 286C2 did not inhibit binding of 431 STa to brush border membranes. Pronase treatment of brush border membranes reduced binding of 431 125I-STa by about 30%, suggesting that the STa receptor was a protein or a glycoprotein. The putative STa receptor was radiolabeled with 431 125I-STa and solubilized with sodium deoxycholate. One major radioactive band was detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, followed by radioautography. These data suggested that STas bind essentially irreversibly to a specific receptor on the cell surface of intestinal cells before activation of guanylate cyclase.
Monoclonal antibodies to staphylococcal enterotoxins B and C: cross-reactivity and localization of epitopes on tryptic fragments
Authors: Thompson N E , Ketterhagen M J , Bergdoll M S
Published: January 2020

Murine monoclonal antibodies reactive with staphylococcal enterotoxins B (SEB) and C1 (SEC1) were isolated by hybridoma techniques. Of the nine antibodies, three reacted only with SEB, two reacted with SEB and SEC1, three reacted with all subtypes of SEC, and one reacted only with SEC2 and SEC3. All of the antibodies reacted with protein blotted onto nitrocellulose from electrophoresis gels which corresponded to the enterotoxin band. Fragments of SEB and SEC1 were generated by limited digestion of the toxin with trypsin. With the immunoblot technique, four of the five antibodies reactive with SEB reacted with the tryptic fragment of molecular weight 17,000, and the five antibodies reactive with SEC1 reacted with the tryptic fragment of molecular weight 14,000.
Immunoglobulin A from bronchopulmonary secretions blocks bactericidal and opsonizing effects of antibody to nontypable Haemophilus influenzae
Authors: Musher D M , Goree A , Baughn R E , Birdsall H H
Published: January 2020

Patients with chronic bronchitis are colonized by and may develop acute bronchopulmonary infection due to nontypable Haemophilus influenzae (NTHI) despite the presence of bactericidal and opsonizing antibody to the infecting organism. To test the hypothesis that secretory immunoglobulin A (IgA) interferes with host defense mechanisms, we extracted secretory IgA from bronchopulmonary secretions of five patients with NTHI pneumonia. NTHI was incubated with IgA before or during incubation with each patient's own serum or normal human serum. IgA from four of these individuals blocked the bactericidal and opsonizing effects of normal human serum and/or their own serum against their own and/or other NTHI. IgA from bronchopulmonary secretions of patients not infected with NTHI or from the serum of a patient with an IgA myeloma had no such effect. Blocking appeared to result from a direct interaction between IgA and the bacteria. The presumed mechanism is an interaction with bacterial surface antigens, although it is not known whether this occurs at antigenic sites responsible for bactericidal and opsonizing activity or whether interaction with adjacent antigenic sites and subsequent steric interference is responsible. This blocking effect of IgA may be one mechanism that allows for the development of NTHI colonization or pneumonia in an individual who already has seemingly adequate antibody against the infecting organism.
Biphasic effects of muramyl dipeptide or lipopolysaccharide on superoxide anion-generating activities of macrophages
Authors: Yagawa K , Kaku M , Ichinose Y , Nagao S , Tanaka A , Tomoda A
Published: January 2020

The superoxide anion (O2-)-generating activity of guinea pig macrophages stimulated by wheat germ agglutinin (WGA), immune complexes, or phorbol myristate acetate (PMA) was studied after short- and long-term exposures of the cells to muramyl dipeptide (MDP) or lipopolysaccharide (LPS). Neither MDP nor LPS alone induced O2- release in macrophages. Short-term (30 min) exposure to these agents caused the enhanced release of O2- in response to WGA or immune complexes, though the PMA-induced O2- generation was not affected. On the other hand, long-term exposure (more than 24 h) to MDP or LPS progressively enhanced O2- generation of the cells induced by WGA, immune complexes, or even PMA. These results suggest that the mechanism for O2- generation of macrophages stimulated by WGA or immune complexes differs from that stimulated by PMA and that the differences also exist between short- and long-term exposure to MDP or LPS.
Effect of silica on resistance of mice to Entamoeba histolytica infection
Authors: Ghadirian E , Kongshavn P A
Published: January 2020

The role of macrophages in intestinal amoebiasis in mice has been investigated. The effect of injuring host macrophages on the course of infection was examined by using strains selected as being either genetically susceptible (C3H/HeJ, C57BL/6) or genetically resistant (A/J) to amoebiasis. Mice were treated with an intravenous injection of silica particles 1 day before infection with 2.5 X 10(5) or 5 X 10(5) polyxenic trophozoites of Entamoeba histolytica. The animals were killed at various times after infection, and the parasite burden in the cecum was measured. Silica treatment dramatically increased the growth of parasites in the susceptible mice. The same trend was evident, although less marked, in the resistant mice. The effect of silica treatment in experimental amoebiasis was much more pronounced in animals inoculated with 5 X 10(5) amoebae than in those with 2.5 X 10(5) amoebae. These data suggest that macrophages play an important role in host defense against amoebiasis in mice.
Endogenous interferon production by endotoxin-responsive macrophages provides an autostimulatory differentiation signal
Authors: Vogel S N , Fertsch D
Published: January 2020

Previous studies have demonstrated that peritoneal macrophages (resident or thioglycolate-induced) derived from mouse strains fully responsive to gram-negative endotoxins continue to differentiate in vitro, as evidenced by an increased capacity to phagocytose via the Fc receptor with time in culture. In contrast, macrophages derived from endotoxin-hyporesponsive mouse strains (e.g., C3H/HeJ or C57BL/10ScN) exhibit no such increase in phagocytic capacity, and, in fact, significantly lose the capacity to phagocytose particles opsonized with immunoglobulin G with time in culture. This defect was found to be fully correctable by the addition to the cultures of an exogenous source of alpha, beta, or gamma interferon. In this study, we compared C3H/HeN (endotoxin-responsive) and C3H/HeJ (endotoxin-responsive) and C3H/HeJ (endotoxin-hyporesponsive) macrophages in an attempt to elucidate the mechanism responsible for this difference in phagocytic (differentiative) potential. The following observations support the hypothesis that endotoxin-responsive macrophages, in contrast to endotoxin-hyporesponsive macrophages, produce significantly higher levels of an autostimulatory differentiation signal that appears to be macrophage-derived interferon. (i) Anti-alpha/beta-interferon antibody greatly reduces the ability of C3H/HeN macrophages to phagocytose opsonized erythrocytes: (ii) C3H/HeJ macrophages can be made more phagocytic by coculture with C3H/HeN macrophages or by treatment with supernatants derived from C3H/HeN macrophage cultures; and (iii) C3H/HeN macrophages spontaneously lose Mac-1 antigen with time in culture. C3H/HeJ macrophages must be interferon-treated to be equivalently down-regulated.
Phagosomal membranes of Mycobacterium bovis BCG-immune alveolar macrophages are resistant to disruption by Mycobacterium tuberculosis H37Rv
Authors: Leake E S , Myrvik Q N , Wright M J
Published: January 2020

Data obtained in this study reaffirm that virulent Mycobacterium tuberculosis H37Rv has a potent phagosome-destroying capacity when ingested by normal alveolar macrophages. In contrast, Mycobacterium bovis BCG-immune alveolar macrophages are highly resistant to this virulence mechanism. BCG-immune sera incubated with BCG-immune alveolar macrophages did not increase resistance of BCG-immune alveolar macrophages as compared with the data obtained from experiments with normal sera. BCG-immune sera failed to confer resistance to normal alveolar macrophages against the phagosomal membrane-destroying H37Rv virulence mechanism.
Extracellular phospholipase A2 and lysophospholipase produced by Vibrio vulnificus
Authors: Testa J , Daniel L W , Kreger A S
Published: January 2020

Phospholipase A2 and lysophospholipase activities were detected in the culture supernatant fluids of a virulent strain of Vibrio vulnificus. The phospholipase A2 was inactivated by heating at 56 degrees C for 30 min, had an apparent molecular weight of greater than or equal to 80,000 (estimated by gel filtration with Sephadex G-75), and a pI of ca. 5.0. Phospholipid hydrolysis was unaffected by Ca2+ or ethylene glycol-bis(beta-aminoethyl ether)-N,N-tetraacetic acid and was optimal at pH 5.0 to 5.5. The lysophospholipase was not affected by heating at 56 degrees C for 30 min but was inactivated at 100 degrees C and had an apparent molecular weight of greater than or equal to 80,000 and a pI of ca. 4.0. The enzymes were detected coincidentally with a previously described extracellular cytolysin of V. vulnificus; however, they were physically separable from the toxin (which did not possess phospholipase A, C, or D activity) by gel filtration with Sephadex G-75.
Corynebacterium ulcerans and Corynebacterium pseudotuberculosis responses to DNA probes derived from corynephage beta and Corynebacterium diphtheriae
Authors: Groman N , Schiller J , Russell J
Published: January 2020

Strains of Corynebacterium ulcerans and Corynebacterium pseudotuberculosis (Corynebacterium ovis) were examined for the production of diphtheria toxin. A majority of C. ulcerans strains (25 of 37) and 1 C. pseudotuberculosis strain (1 of 14) gave a positive Elek test for diphtheria toxin, and for all strains but 1, production of diphtheria toxin was inhibited at the same level of Fe2+ as was the Corynebacterium diphtheriae control. All Elek-positive cultures as well as two Elek-negative isolates of C. ulcerans gave a positive signal when hybridized with a DNA probe unambiguous for the diphtheria toxin gene (tox) under conditions of high stringency. The majority of probe-positive C. ulcerans strains contained three or more DNA restriction fragments that hybridized with converting corynephage beta, suggesting that in C. ulcerans as in C. diphtheriae there may be a relationship between toxinogeny and carriage of beta-related phage. Selected strains of C. diphtheriae, C. ulcerans, and C. pseudotuberculosis were examined for DNA homology by a semiquantitative technique. There was very little homology between C. diphtheriae and members of the other two species. Strains of C. ulcerans and C. pseudotuberculosis, although more closely related, appeared to belong to distinct species as well.
Serum antibody responses of juvenile and infant rhesus monkeys injected with Haemophilus influenzae type b and pneumococcus type 6A capsular polysaccharide-protein conjugates
Authors: Schneerson R , Robbins J B , Chu C , Sutton A , Vann W , Vickers J C , London W T , Curfman B , Hardegree M C , Shiloach J
Published: January 2020

Juvenile and infant rhesus monkeys were injected subcutaneously with saline solutions of Haemophilus influenzae type b (Hib) and pneumococcus type 6A (Pn6A) capsular polysaccharides conjugated to either tetanus toxoid (TT), horseshoe crab hemocyanin, or cholera toxin (CT), and the antibody responses of the monkeys to both bacterial components were measured. All three Hib conjugates were immunogenic and elicited booster responses; their comparative immunogenicity was Hib-CT greater than Hib-TT greater than Hib-horseshoe crab hemocyanin. Hib alone did not elicit antibodies in the juveniles. Juveniles responded earlier and with higher levels of antibodies than did infants. TT, as well as diphtheria-tetanus toxoids-pertussis vaccine adsorbed injected concurrently at a separate site, increased both Hib and TT antibody responses in juveniles (P less than 0.05). Concurrent injection of 5 Lf of fluid TT with a nonimmunogenic 5-micrograms dose in infants elicited levels of Hib antibodies comparable to those elicited by 50 micrograms of Hib-TT. Hib antibodies elicited by the conjugates remained at protective levels in both juveniles and infants 2 months after the last injection, were bactericidal, and conferred passive immunity against bacteremia in infant rats. Passive immunization of juveniles with tetanus immune globulin before each injection of Hib-TT did not suppress Hib antibodies. Hib-TT and Hib-CT elicited increases of Hib antibodies of the immunoglobulin M and G isotypes in the infants. The Pn6A-TT conjugate was considerably less immunogenic than the Hib-TT conjugate; only a few of the juveniles or infants responded with protective levels of Pn6A antibodies. Pn6A antibodies from responders conferred protection in mice against intraperitoneal challenge with Pn6A organisms. TT antibodies were elicited in both juvenile and infant animals after one injection of 50 micrograms of Hib-TT and in the infants injected with 5 micrograms of Hib-TT plus 5 Lf of TT; 5 micrograms of Hib-TT and Pn6A-TT in combination alone did not elicit TT antibodies. Hib-CT elicited CT antibodies in both juveniles and infants.
Binding of Streptococcus mutans antigens to heart and kidney basement membranes
Authors: Stinson M W , Barua P K , Bergey E J , Nisengard R J , Neiders M E , Albini B
Published: January 2020

Using indirect immunofluorescence, alkali-extracted components of Streptococcus mutans were found to bind in vitro to capillary walls and sarcolemmal sheaths of monkey cardiac muscle and to glomerular and tubular basement membranes of monkey kidney. Adsorption of S. mutans components to tissue fragments was also detected by indirect radioimmunoassay and immunoblotting on nitrocellulose paper. Antibodies did not bind to untreated, control tissues in these experiments, proving that antigens shared by S. mutans and tissue components were not involved. Rabbit and monkey heart and kidney components bound S. mutans antigens of 24,000, 35,000, and 65,000 Mr. Monkey heart also bound molecules of 90,000 and 120,000 Mr. Rabbits immunized by intravenous injection of disrupted S. mutans cells developed severe nephritis that was characterized by the deposition of immunoglobulins, complement component C3, and S. mutans antigens in the glomeruli. Immunoglobulin G eluted from nephritic kidneys reacted in immunoblots with the 24,000, 35,000, and 65,000 Mr components of S. mutans extract, indicating that the antigens that bound to tissue in vitro also bound in vivo and reacted with antibodies in situ. Antibodies to other S. mutans antigens were not detected in the kidney eluate, although they were present in the serum of the same rabbit.
Tubulin and high-molecular-weight polypeptides as Giardia lamblia antigens
Authors: Torian B E , Barnes R C , Stephens R S , Stibbs H H
Published: January 2020

We determined the antigenic specificities of nine murine monoclonal antibodies to Giardia lamblia. Four distinct antibody reaction patterns were detected by immunofluorescence with G. lamblia trophozoites. Four monoclonal antibodies which reacted with the body but not the flagella of the whole trophozoites recognized two polypeptides of 170,000 and 155,000 molecular weights by immunoblotting. Two antibodies reacting with both the flagella and body also reacted with 170,000- and 155,000-molecular-weight antigens. An antibody specific for the G. lamblia attachment disk and two specific for flagella by immunofluorescence were found to react with 53,000- and 55,000-molecular-weight polypeptides by immunoblotting. These antigens comigrated with purified bovine brain tubulin, and their respective antibodies reacted in immunoblots with purified bovine brain tubulin. The antigens identified in this report were found to be present in Giardia cytoskeletal preparations. All antigens were pronase labile and heat stable. Four strains of G. lamblia reacted similarly in immunofluorescence assays as well as in immunoblotting assays.
Gamma interferon production in response to homologous and heterologous strain antigens in mice chronically infected with Rickettsia tsutsugamushi
Authors: Palmer B A , Hetrick F M , Jerrells T R
Published: January 2020

The ability of antigen-responsive, thymus-derived lymphocytes to produce immune (gamma) interferon was investigated during the development and expression of cellular immunity to Rickettsia tsutsugamushi. C3H/HeDub mice infected subcutaneously with the Gilliam strain developed the ability to produce serum interferon in response to intravenously inoculated antigen which correlated with the development of resistance to intraperitoneal rechallenge. Antigen-responsive lymphocytes, measured by interferon production and proliferation, were first apparent in draining lymph node cells, but spleen cell responses were detectable relatively soon after the appearance of reactive lymph node cells. The peak spleen cell response was of a greater magnitude and was found to be relatively long-lived. Reactivity to heterologous strains of R. tsutsugamushi also developed after immunization and paralleled the homologous responses, although reactivity was greatest to homologous antigens. Responses to heterologous strains differed in magnitude and time of appearances; however, immune mice resisted challenge with all strains of R. tsutsugamushi tested.
Cloning and expression of an afimbrial adhesin (AFA-I) responsible for P blood group-independent, mannose-resistant hemagglutination from a pyelonephritic Escherichia coli strain
Authors: Labigne-Roussel A F , Lark D , Schoolnik G , Falkow S
Published: January 2020

The uropathogenic Escherichia coli KS52 strain expresses a mannose-resistant hemagglutinin involving an erythrocyte recognition site distinct from the alpha-digalactoside glycosphingolipid receptor identified for the uropathogenic E. coli strains specifying a P adhesin. The KS52 strain showed three major properties. (i) It agglutinated human erythrocytes of all tested blood groups. (ii) Hemagglutinin activity was found both in the supernatant fluid L-broth cultures and in cells grown on L-agar plates. (iii) No fimbriae in organisms grown on L-agar plates were detected by electron microscopy. Whole-cell DNA from the KS52 strain was size fractionated and cloned into the pHC79 cosmid vector. Three recombinant cosmids expressing a mannose-resistant hemagglutination (MRHA) phenotype were characterized and used to subclone the smallest DNA fragment able to confer the same MRHA properties as the parent strain. A 6.7-kilobase chromosomal DNA fragment cloned in pBR322 (pIL14) was shown to be necessary for host-cell MRHA expression and uroepithelial cell adherence. The insert encoded the production of a 16,000-dalton hemagglutinin. This polypeptide could be detected in culture supernatant fluids, in E. coli minicells harboring the pIL14 plasmid, and, by immunoblotting, in the KS52 strain and E. coli whole cells harboring the pIL14 plasmid. No homology was detected by Southern hybridization between the cloned insert and the DNA of the operon responsible for MRHA in the P-specifying, fimbriate strains (pap operon).
Functional heterogeneity of isopycnic fractions of rat alveolar macrophages
Authors: O'Neill S J , Hoehn S K , Lesperance E , Klass D J
Published: January 2020

Rat alveolar macrophages separated into four isopycnic fractions on Percoll gradients were functionally heterogeneous in bacterial phagocytosis, intracellular killing, superoxide anion release, and lysosomal enzyme activity but not in hydrogen peroxide release. With increasing alveolar macrophage density, phagocytosis, intracellular killing, superoxide anion release, and lysozyme activity increase, and acid hydrolase activity decreases.
Identification and characterization of a major surface antigen of Giardia lamblia
Authors: Einfeld D A , Stibbs H H
Published: January 2020

The surface antigens of Giardia lamblia trophozoites were characterized by crossed immunoelectrophoresis, radioiodination, and immunoprecipitation. Crossed immunoelectrophoretic analysis of trophozoites with hyperimmune rabbit anti-trophozoite antiserum revealed a prominent precipitin peak that disappeared upon adsorption of the antiserum with live or formaldehyde-fixed trophozoites. This peak was intensely labeled when the antigen was derived from surface-radioiodinated trophozoites. An antiserum monospecific for the antigen contained in this precipitin peak was prepared. The precipitin peak was shown to contain an antigen with an apparent molecular weight of 82,000 by Western blotting. The antiserum also detected this 82,000-molecular-weight antigen on nitrocellulose blots of trophozoites analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. On radioiodination of live trophozoites, an iodinated molecule of 82,000 apparent molecular weight was resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and was immunoprecipitated by the monospecific antiserum. Preliminary characterization of this antigen with the monospecific antiserum in crossed immunoelectrophoresis revealed that the surface antigen is hydrophobic and thus may be anchored in the plasma membrane, and that it is heat sensitive, but only partially sensitive to pronase or periodate. This antigen was shared by the four G. lamblia strains examined.
Monoclonal antibody against pertussis toxin: effect on toxin activity and pertussis infections
Authors: Sato H , Ito A , Chiba J , Sato Y
Published: January 2020

Antibody-producing hybridomas of myeloma SP2/O and spleen cells of BALB/c mouse immunized with pertussis toxoid and pertussis toxin were selected by the binding ability of the monoclonal antibody to the subunit protein of the toxin. Two monoclonal antibodies, 1B7 and 3F10, specific for a subunit which has no binding activity to haptoglobin and sheep erythrocytes, named S1, and one antibody, 1H2, for a subunit related to the binding activity of the pertussis toxin molecule to haptoglobin or sheep erythrocytes, named S4, were examined for mouse protective activity against pertussis infection. Antibody 1B7 not only neutralized leukocytosis-promoting and islet-activating activities of the toxin but also protected mice against intracerebral and aerosol challenge with Bordetella pertussis. The antibody, furthermore, showed therapeutic effects on mice showing severe clinical signs with pertussis infection. The other two antibodies, 3F10 and 1H2, showed neither neutralizing nor protecting activity, nor significant synergistic effects on antibody 1B7.