bluuebunny/crossref_metadata_2025 huggingface dataset:
Monoclonal antibodies directed against a cell surface-exposed outer membrane protein of Haemophilus influenzae type b
Authors: Robertson S M , Frisch C F , Gulig P A , Kettman J R , Johnston K H , Hansen E J
Published: January 2020

Monoclonal antibodies directed against several different Haemophilus influenzae type b outer membrane proteins with apparent molecular weights of 45,000, 39,000, and 37,000 were identified by a radioimmunoprecipitation method. Five monoclonal antibodies, including both immunoglobulin G and M isotypes, were specific for the same H. influenzae type b major outer membrane protein (39,000 molecular weight). One of these immunoglobulin G monoclonal antibodies (6A2) was shown to be directed against a cell surface-exposed antigenic determinant of the 39,000-molecular-weight protein, whereas the other monoclonal antibodies directed against this same protein were apparently specific for antigenic determinants not exposed on the H. Influenzae type b cell surface. The cell surface-exposed protein antigenic determinant recognized by monoclonal antibody 6A2 was not unique to the H. influenzae type b strain used as the source of outer membrane vesicles for generating immune spleen cells, but was found in a majority of independently isolated strains of H. influenzae type b. These data indicate that there is antigenic cross-reactivity among H. influenzae type b strains with regard to cell surface-exposed proteins.
Two neutrophil populations in human blood with different chemotactic activities: separation and chemoattractant binding
Authors: Harvath L , Leonard E J
Published: January 2020

Normal human blood contains a population of neutrophils that migrates to various chemoattractants and a population that fails to migrate. The percentage of neutrophils migrating to optimal concentrations of chemoattractants was quantified: 20 to 40% migrated to N-formylmethionyl-leucyl-phenylalanine, 30 to 50% migrated to human C5a, 25 to 35% migrated to human leukocyte-derived chemotactic factors, 20 to 30% migrated to casein, 15 to 20% migrated to pepstatin, and 1 to 5% migrated to medium alone. Neutrophil migration to the most active chemoattractant was not increased when other chemoattractants were added, indicating that the population of neutrophils migrating to the most active attractant was the same population that was migrating to the other attractants. The percentage of neutrophils migrating to a chemoattractant was not altered by prolonging the assay incubation period or by replacing the attractant with new chemoattractant during the assay, and the percentage was independent of the neutrophil concentration added to the chemotaxis chamber. Nonmigrating neutrophils were isolated with a chemotaxis collection chamber, and they were examined for radiolabeled chemotactic peptide binding. The binding of radiolabeled N-formylmethionyl-leucyl-phenylalanine by nonmigrating and migrating neutrophils was identical.
Structural analysis of electrophoretic variation in the genome profiles of rotavirus field isolates
Authors: Clarke I N , McCrae M A
Published: January 2020

Detailed structural studies were undertaken on five isolates of bovine rotavirus which showed variability in the migration patterns of their genome segments on electrophoresis in polyacrylamide gels. The individual genome segments of each isolate were characterized by partial digestion of terminally radiolabeled RNA with a base-specific nuclease. This analysis showed that whereas mobility variations were always associated with detectable changes in nucleotide sequence, sequence changes at least as great as those found in segments showing electrophoretic mobility variations were also detected in segments showing no mobility variation. Evidence for the occurrence of genome segment reassortment between viruses in the field was obtained from analyzing the species 11 RNAs from these five isolates. The overall conclusion from these results is that great care is required in the interpretation of simple genome profile analysis of different isolates for epidemiological purposes and that classification of these viruses solely on the basis of genome electropherotype could be misleading.
Outer membrane protein and biotype analysis of pathogenic nontypable Haemophilus influenzae
Authors: Barenkamp S J , Munson R S , Granoff D M
Published: January 2020

The techniques of biotype determination and sodium dodecyl sulfate-polyacrylamide gel electrophoresis of outer membrane protein preparations were applied to 35 epidemiologically unrelated isolates of pathogenic nontypable Haemophilus influenzae. Three of five isolates obtained from the blood of unrelated newborns with sepsis had concordant major outer membrane from the blood of unrelated older children or adults with bacteremia had concordant major outer membrane protein profiles, distinct from the common profile of neonatal strains, and were biotype II. The outer membrane protein profiles of the remaining 5 isolates from blood, 2 isolated from cerebrospinal fluid, and 23 isolated from middle ear aspirates of children with otitis media were unique, although each isolate had peptides with apparent molecular weights of 16,000 and 31,500. These results suggest that a subset of nontypable isolates associated with bacteremia has distinctive strain markers. Their pathogenicity may relate to a prediction for colonizing the female genital tract in the case of the common neonatal strain or an increased ability to evade host defenses.
Production of alpha and gamma interferons by spleen cells from cytomegalovirus-infected mice
Authors: Kelsey D K , Overall J C , Glasgow L A
Published: January 2020

Antigen-induced lymphocyte proliferation and the production of a murine immune or type II interferon (MuIFN-gamma) by spleen cells in vitro were used to examine the cellular immune response to a cytomegalovirus infection of mice. Lymphocyte blastogenesis was induced by interaction with cytomegalovirus-infected mouse embryo fibroblasts in spleen cells from mice infected at least 6 days previously with cytomegalovirus. The peak of the blastogenic response occurred after 72 hr in culture with antigen. MuIFN was detected in cultures of cytomegalovirus-infected mouse embryo fibroblasts and spleen cells from both normal and infected mice. The MuIFN produced by spleen cells from normal or infected mice early during the course of the infection (days 1 to 2) was predominantly viral or type I interferon (MuIFN-alpha). Peak titers of MuIFN-alpha were present 24 to 48 h after exposure to antigen in vitro and before the peak of the blastogenic response. In contrast, spleen cells from mice infected at least 6 days previously produced both MuIFN-alpha and MuIFN-gamma in culture with the infected mouse fibroblasts. MuIFN-alpha was present early in the culture, before peak blastogenic activity. Peak levels of MuIFN-gamma were detected as lymphocyte blastogenic activity subsided. These results indicate that the cellular immune system of the murine host is capable of responding to cytomegalovirus infection, the afferent limb by antigen recognition and the efferent limb by the production of the lymphokine MuIFN-gamma.
Immunogenicity of type-specific C-mycoside glycopeptidolipids of mycobacteria
Authors: Barrow W W , Brennan P J
Published: January 2020

Specific rabbit antibodies were obtained from the inoculation of a complex composed of methylated bovine serum albumin and the superficial type-specific C-mycoside glycopeptidolipid (GPL) antigens from serovar 20 of the Mycobacterium avium-M. intracellulare-M. scrofulaceum complex. Although the GPLs on their own are serologically active, they require the protein carrier for immunogenicity. Antibodies to the complex were detected by seroagglutination, gel diffusion, and indirect immunofluorescence. Cross-reaction was observed in the case of just one of 16 M. avium-M. intracellulare-M. scrofulaceum complex serovars tested (serovar 41). Double gel diffusion and immunoelectrophoresis showed two major antigen-antibody complexes in the reaction between anti-GPL-methylated bovine serum albumin and the GPL antigens. The studies of migration pattern and absorption indicated that immunoglobulin M was responsible for one of these complexes, whereas the antibody responsible for the second complex was unidentified. The specific anti-GPL serum is a useful tool for the identification and classification of atypical mycobacteria and for the study of the fate of the organisms and their superficies during phagocytosis.
Effect of parenteral vaccination of dams on intestinal Escherichia coli in piglets with diarrhea
Authors: Söderlind O , Olsson E , Smyth C J , Möllby R
Published: January 2020

To evaluate the effect of widely used parenteral vaccination of dams against neonatal colibacillosis, the virulence factors of the intestinal Escherichia coli flora, namely, O serogroup, enterotoxin(s) produced (heat labile, porcine heat stable, and murine heat stable) and adhesins (K88, K99, and 987P antigens) of 149 piglets from different herds in Sweden were investigated. Three categories were investigated: healthy piglets, diarrheal piglets born to unvaccinated dams, and diarrheal piglets born to dams vaccinated with a polyvalent Formalin-killed whole-cell vaccine containing K88 antigen (Porcovac; Hoechst Pharmaceuticals, Hounslow, England). Piglets less than 1 week old and those 1 to 8 weeks old were evaluated separately. Diarrheal piglets less than 1 week old from vaccinated dams yielded a higher incidence of K99 antigen-positive E. coli of the murine heat-stable enterotoxigenicity type compared with piglets of the same age group from unvaccinated dams. The percentage of diarrheal cases from which E. coli lacking recognized virulence attributes were isolated was also higher in the former compared with the latter group. In the 1- to 8-week-old diarrheal piglets of vaccinated dams, the overall incidence, enterotoxigenicity type, and serotype of the E. coli isolates resembled those of diarrheal piglets less than 1 week of age from unvaccinated herds. Enterotoxigenic E. coli bearing 987P antigen detectable in vitro was rare. Most of the enterotoxigenic isolates lacking K88, K99, and 987P antigens produced only ST. The investigation pinpoints some of the inadequacies of vaccines of the type studied under field conditions.
Phorbol ester replacement of helper cell and interleukin 2 requirements in gamma interferon production
Authors: Johnson H M , Torres B A
Published: January 2020

Immune interferon (IFN-gamma) production by mitogen-stimulated C57BL/6 mouse spleen cells required both Lyt 1+,2- and Lyt 1-,2+ lymphocytes. The Lyt 1-,2+ cells were the IFN-gamma producers, whereas the Lyt 1+,2- cells were the helpers. Interleukin 2 mediated the Lyt 1+,2- cell help. Phorbol myristic acetate (10 ng/ml) completely replaced Lyt 1+,2- helper cell or interleukin 2 requirements in IFN-gamma production. The phorbol ester exerted its helper effects by direct interaction with IFN-gamma-producing Lyt 1-,2+ cells and not through stimulation of production of interleukin 2 by Lyt 1+, 2- cells. Suppressor cell effects in IFN-gamma production were also completely abrogated by phorbol myristic acetate. The data suggest a mechanism for phorbol myristic acetate regulation of IFN-gamma production at the cellular level.
Effects of antiviral agents on murine cytomegalovirus-induced macrophage dysfunction
Authors: Shanley J D , Pesanti E L
Published: January 2020

Infection of murine peritoneal macrophages with murine cytomegalovirus (MCMV) led to disruption of phagocytosis. This alteration of cellular behavior appeared to be an early event in viral replication appearing 24 to 36 h before virus production and 84 to 108 h before cell death. The effects of a variety of antiviral agents on both MCMV replication and MCMV-induced depression of phagocytosis were evaluated in vitro. Although all compounds thought to act by preventing viral DNA replication inhibited MCMV replication in macrophages, none prevented expression of virus-induced alteration of phagocytosis. Cycloheximide at 1 microM blocked viral replication and viral antigen expression and prevented depression of phagocytic activity.
Isolation and characterization of a cross-reacting antigen in strains of Bacteroidaceae
Authors: Marx A , Petcovici M , Bittner J , Antohi M , Ardeleanu J
Published: January 2020

A Bacteroidaceae cross-reacting antigen (BCA) was isolated from several strains belonging to species in the genera Fusobacterium and Bacteroides. We showed that each of the 28 strains examined synthesized either BCA or the O-specific lipopolysaccharide (LPS). The structural difference between the two antigens was demonstrated by passive hemagglutination. BCA coated erythrocytes spontaneously and reacted with equal intensity to all bacterial antisera of BCA+ strains, whereas LPS was species specific and also coated erythrocytes after the antigen was treated with NaOH. BCA is an acid polysaccharide as proven by immunoelectrophoresis and by its capacity to form a salt linkage with lysozyme. Chemical analysis demonstrated the presence of galactosamine, glucosamine, galactose, glucose, mannose, and N-acetyl. BCA was nontoxic and did not contain lipid A in its molecule. The small particle size of BCA determined its hapten character. When attached to acid-treated Salmonella minnesota Re cells, it acted as an immunogen. By immunizing rabbits with this hapten-bacterial cell suspension, we obtained a highly potent antiserum that agglutinated all BCA+ strains.
Immunoglobulin E-suppressing and immunoglobulin G-enhancing tetanus toxoid prepared by conjugation with pullulan
Authors: Mitani S , Yamamoto A , Ikegami H , Usui M , Matuhasi T
Published: January 2020

Immunoglobulin E (IgE) antibody response was found to be suppressed selectively and antigen specifically in mice given an antigen conjugated with pullulan, a linear copolymer of maltotriose, whereas IgM and IgG antibody responses were enhanced. On the basis of this finding, tetanus toxin was conjugated with pullulan by cyanuric chloride in the hope that the toxin would be detoxified by the conjugation procedure and could be used as an IgE-suppressing and IgG-enhancing toxoid without the aid of an aluminum adjuvant. This procedure of tetanus toxoid-pullulan conjugation apparently detoxified the toxin. Administration of the resulting tetanus toxoid, tetanus toxin-pullulan conjugate, to mice induced strong suppression of IgE antibody response with fairly good IgG response, whereas the alum-precipitated toxoid or plain toxoid, customarily used for vaccination, elicited high IgE antibody formation. The IgE antibody response was minimal, but the IgG antibody response was maximal in the conjugate-primed mice even after a booster injection with an IgE antibody-inducing dose of the alum-precipitated toxoid.
Experimental cryptosporidiosis in laboratory mice
Authors: Sherwood D , Angus K W , Snodgrass D R , Tzipori S
Published: January 2020

Eight strains of laboratory mice were susceptible to subclinical infections with Cryptosporidium sp. at 1 to 4 days of age, but only a transient infection could be established at 21 days of age or older. Immunosuppression of 21-day-old mice failed to render them more susceptible to infection. Laboratory storage conditions for Cryptosporidium sp. were investigated by titration in 1- to 4-day-old mice. Storage by freezing with a variety of cryoprotectants was unsuccessful, but storage at 4 degrees C in phosphate-buffered saline or 2.5% potassium dichromate was possible for 4 to 6 months.
In vitro effect of murine-derived transfer factor on Salmonella-specific rosette formation
Authors: Smith R A , Esa A
Published: January 2020

The splenic lymphocytes from Salmonella-immune ICR Swiss or C3H/HeJ mice formed greater than 0.2% antigen-specific rosettes with sheep erythrocytes coated with a spent-medium protein antigen of Salmonella typhimurium. These rosette-forming lymphocytes were found to be sensitive to the effects of antithymocyte serum plus complement. Transfer factor prepared from the Salmonella-immune splenic lymphocytes of ICR Swiss mice was active in sensitizing nonimmune ICR Swiss or C3H/HeJ lymphocytes to form greater than or equal to 0.2% rosettes with salmonella antigen-coated sheep erythrocytes. These rosettes were also sensitive to antithymocyte serum and complement. Few rosettes were formed between the transfer factor-treated lymphocytes and sheep erythrocytes coated with a Listeria protein antigen. A nonimmune dialysate preparation was inactive in sensitizing nonimmune lymphocytes, as indicated by a lack of rosette formation. Neither the immune transfer factor nor the nonimmune dialysate had any enhancing or abrogating effect upon rosette formation by splenic lymphocytes from Salmonella-immune mice. The enumeration of antigen-specific rosettes may be a useful means of assaying for transfer factor activity.
Silica enhancement of murine endotoxin sensitivity
Authors: Vogel S N , English K E , O'Brien A D
Published: January 2020

Silica has been used for many years as an agent which selectively alters macrophage functions and, as such, has been used to assess the role of macrophages in the immune response to a variety of microbial and chemically defined agents. Silica treatment of C3H/HeN mice 1 day before challenge with protein-free Escherichia coli endotoxin (lipopolysaccharide [LPS]) resulted in a marked increase in LPS sensitivity, as evidenced by accelerated signs of endotoxemia as well as a fourfold decrease in the LPS 50% lethal dose. The silica-mediated increase in responsiveness to LPS was associated with increased production of macrophage-derived soluble factors both in vivo (interferon) and in vitro (Interleukin 1; previously referred to as lymphocyte activating factor or LAF) upon endotoxin stimulation. These findings support the central role of the macrophage and its products in mediating endotoxic reactions.
Serotype-specific opsonization of Treponema hyodysenteriae
Authors: Nuessen M E , Joens L A
Published: January 2020

Treponema hyodysenteriae was shown to attach to mouse peritoneal cells in the absence of serum opsonins in vitro. If serotype-specific antiserum from pigs was added to the media and treponemes of that corresponding serotype were employed in the assay, the amount of attachment increased an average of 3.7 times that of the control without pig sera. However, the amount of attachment was increased an average of only 1.5 times that of the control if organisms of any noncorresponding serotype of T. hyodysenteriae were used in the assay. Since the lipopolysaccharide (LPS) extracted from T. hyodysenteriae is the basis for serotyping the treponeme, the ability of these distinct LPS types to block attachment by blocking opsonization of the organisms was tested. Attachment, using corresponding antisera and treponemes, was blocked by LPS extracted from treponemes of that serotype, but not by LPS extracted from treponemes of other serotypes. These results indicate that antibody response to T. hyodysenteriae infection in pigs is serotype-specific. Furthermore, since opsonization and subsequent attachment of bacteria to phagocytes is known to be a protective mechanism, we suggest that the LPS may be an important antigen in the stimulation of host defense against the treponeme.
Detection of antibodies to pre-early nuclear antigen and immediate-early antigens in patients immunized with cytomegalovirus vaccine
Authors: Friedman A D , Michelson S , Plotkin S A
Published: January 2020

To define the role of antibody to immediate early antigens of human cytomegalovirus (CMV) in diagnosing acute infection, we studied antibody responses of adult volunteers and renal transplant candidates receiving CMV vaccine. In addition, CMV antibodies in healthy adults were determined. Antibody to pre-early nuclear antigen, one of the immediate early antigens, did not develop in all of the volunteers or renal transplant candidates receiving the vaccine. In those vaccinees who developed an antibody response, the duration of the response was variable. Antibody to pre-early nuclear antigen and immediate early antigens was also detected in some healthy adults with serological evidence of past CMV infection, but without clinical evidence of recent infection. In view of these results, antibody to immediate early antigens and specifically to pre-early nuclear antigen does not appear to be suitable for rapid diagnosis of acute CMV infection.
Humoral and cell-mediated responses to a ribosomal preparation from Streptococcus mutans
Authors: Gregory R L , Shechmeister I L
Published: January 2020

Streptococcus mutans 6715 ribosomes disrupted in a Braun homogenizer were isolated in sodium dodecyl sulfate by differential centrifugation. This preparation contained 80% RNA and 20% protein, and carbohydrate was not detected by phenol-sulfuric acid and methyl pentose assays. The sedimentation coefficient of the ribosomes was 70S. After dialysis in 0.01 M phosphate buffer containing 10(-4) M MgCl2, the ribosomes dissociated into 54S and 32S particles. Leukocytes from rabbits immunized intramuscularly with the ribosomal preparation showed transformation and migration indices of 13.0 and 0.71, which were significantly different (P less than 0.05) from the respective indices of 0.9 and 0.98 in nonimmunized animals. Hyperimmune serum from these rabbits agglutinated representative Formalin-killed strains of all seven serotypes of S. mutans, inhibited adherence of live S. mutans 6715 to glass, and agglutinated S. mutans 6715 ribosomes adsorbed upon erythrocytes. These findings suggested that animals immunized with S. mutans ribosomes may be protected from caries caused by any of the seven serotypes of this organism.
Enhanced antibody responses induced by Candida albicans in mice
Authors: Cutler J E , Lloyd R K
Published: January 2020

Candida albicans may immunopotentiate antibody responses in mice to antigens unrelated to the fungus. This effect occurred best with cell-associated, rather than soluble, antigens. When dead yeasts, cell walls, or a water-soluble candidal polysaccharide were used, immunopotentiation was most dramatic when the antigen and fungal materials were given concomitantly via an intraperitoneal injection. However, mice infected with viable yeasts several days before antigen administration also developed heightened responses to the antigen. The mechanism of the C. albicans-induced adjuvanticity was not defined, but the effect seemed to correlate with induction of inflammation. The presence of C. albicans or other inflammatory agents in the peritoneal cavity caused a more rapid uptake of particulate antigen by the liver. The relationship between this event and immunopotentiation is not known. These studies demonstrate that C. albicans may have profound effects on host immune responses. Because immunological aberrations are commonly found in patients with candidiasis it may be important to determine whether some of these aberrations result from, rather than precede candidiasis.
Sensitivity of K1-Encapsulated
Escherichia coli
to Killing by the Bactericidal/Permeability-Increasing Protein of Rabbit and Human Neutrophils
Authors: Weiss Jerrold , Victor Michael , Cross Alan S. , Elsbach Peter
Published: January 2020

The presence of K1 capsular polysaccharides increases the resistance of
Escherichia coli
to killing by serum and phagocytosis by polymorphonuclear leukocytes (PMNs). To determine whether K1 capsule impedes the action of intracellular bactericidal systems of PMNs, we compared the sensitivity of several K1-encapsulated and non-encapsulated strains of
E. coli
to killing by the bactericidal/permeability-increasing protein (BPI) isolated from rabbit and human PMNs. BPI appears to be the principal bactericidal agent of PMNs toward
E. coli
and other gram-negative bacteria (Weiss et al., J. Clin. Invest.
69
:959-970, 1982). The presence of K1 capsule was monitored by sensitivity to K1-specific bacteriophages. The non-encapsulated strains used represent both random bacteremic isolates and non-encapsulated derivatives of K1-encapsulated strains obtained by selection for resistance to K1-specific phages. We found little or no difference in the sensitivity of K1-encapsulated and non-encapsulated
E. coli
to killing by neutralized acid extracts of rabbit PMNs. Bacterial killing by these crude fractions can be attributed to the action of BPI because: (i) bacterial killing was blocked by immune (anti-BPI) immunoglobulin but not by preimmune immunoglobulin and (ii) comparison of the dose-response curves of bacterial killing by crude extracts and by purified BPI showed that the bactericidal activity of crude fractions corresponded closely to the BPI content. Human and rabbit BPIs exhibited similar bactericidal potency toward K1-encapsulated
E. coli
; i.e., <5 μg of either protein killed >90% of 2.5 × 10
7
bacteria. Thus, the potent bactericidal action of BPI toward
E. coli
is not impeded by K1 capsule, suggesting that the virulence of K1-encapsulated
E. coli
is a consequence of extracellular survival but not of resistance to intracellular killing.
Effect of pregnancy on resistance to Listeria monocytogenes and Toxoplasma gondii infections in mice
Authors: Luft B J , Remington J S
Published: January 2020

Studies of the effect of pregnancy on the capacity of mice to resist Listeria monocytogenes and Toxoplasma gondii infection revealed significantly diminished resistance of pregnant mice to infection by both agents as measured by mortality. The development of immunity to listeria was assessed by studying the kinetics of listeria growth in the livers and spleens of virgin and pregnant mice infected intravenously with a sublethal dose of listeria. In both virgin and pregnant mice there was a rise in the number of listeria colony-forming units per organ during the first 3 days after infection. Thereafter, there was a decline in colony-forming units in these organs in virgin mice but a persistence of listeria in spleens and livers of pregnant mice. Paradoxically, during the first 3 days after infection, listeria counts in spleens of virgin mice were significantly higher than those in pregnant mice. Nonspecific resistance to listeria conferred by chronic infection with T. gondii was significantly diminished in pregnant mice when measured by mortality and quantitative cultures of listeria in livers and spleens. These studies demonstrate a remarkably decreased resistance of pregnant mice to two intracellular organisms and a diminished capacity of pregnant mice to develop immunity to listeria. This decrease in resistance may play an important role in congenital transmission of these organisms.
Host-parasite relationship in murine leishmaniasis: pathophysiological and immunological changes
Authors: Reiner N E
Published: January 2020

The host-parasite relationship in human visceral leishmaniasis remains poorly understood. In the present study, pathophysiological and immunological changes were examined in BALB/c mice infected with Leishmania donovani. These animals developed chronic infection with massive hepatosplenomegaly and hypergammaglobulinemia. In contrast to mice inoculated with 0.8 X 10(6) or 4 X 10(6) amastigotes, mice infected with 20 X 10(6) amastigotes failed to reduce liver parasite loads during 2 to 8 weeks of observation. At 8 weeks, liver size was increased by 26, 63, and 94%, respectively, in groups infected with 0.8 X 10(6), 4 X 10(6), or 20 X 10(6) amastigotes. Serum immunoglobulin G and M levels at 8 weeks in animals with the heaviest infection were increased by 53 and 80%, respectively, compared with controls. Specific antileishmanial antibodies were detected in the absence of antigen-specific delayed-type hypersensitivity or in vitro lymphocyte responses. Infection did not suppress the in vivo responses of mice to the non-parasite-related antigens sperm whale myoglobin or pneumococcal polysaccharide. Splenic mononuclear cell responses to phytohemagglutinin were suppressed as early as 2 weeks, and by 8 weeks, mice infected with 0.8 X 10(6), 4 X 10(6), or 20 X 10(6) amastigotes had phytohemagglutinin responses which were, respectively, 27.7, 13.9, and 15.8% of controls. Decreased phytohemagglutinin responses could not be related to reductions in splenic T cells; however, splenic B cells and macrophages were increased at 8 weeks of infection. The course of L. donovani infection and disease in BALB/c mice resembles events occurring in humans and should prove useful in defining mechanisms of immune alterations in visceral leishmaniasis.
Killing of an encapsulated strain of Escherichia coli by human serum
Authors: Taylor P W , Kroll H P
Published: January 2020

Changes in cell viability and in factors affecting metabolic integrity were examined after exposure of Escherichia coli LP1092 to human serum. Antibody-dependent classical pathway activity accounted for the rapid killing of strain LP1092 by complement. Removal of serum lysozyme by bentonite absorption or by neutralization with anti-human lysozyme immunoglobulin G resulted in a reduction in the rate of killing; optimal activity could be restored by the addition of physiological amounts of egg-white lysozyme. The pattern of 86Rb+ and alkaline phosphatase release obtained after serum treatment did not support the view that complement simultaneously disrupts cytoplasmic and outer membrane integrity. Macromolecular synthesis was affected late in the reaction sequence; complete inhibition of precursor incorporation into RNA, DNA, and protein occurred only after almost total loss of bacterial colony-forming ability. Addition of chloramphenicol, an inhibitor of protein synthesis, to the bactericidal system resulted in a marked reduction in the rate of serum killing. Killing was completely inhibited by an inhibitor (KCN) and an uncoupler (2,4-dinitrophenol) of oxidative phosphorylation. Exposure of LP1092 cells to serum was followed by a rapid and large increase in intracellular ATP levels; ATP synthesis did not occur when bacteria were exposed to dialyzed serum, which killed LP1092 cells at a much reduced rate. Addition of glucose or serum ultrafiltrate to dialyzed serum restored optimal bactericidal activity. We suggest that optimal killing of gram-negative bacteria is an energy-dependent process requiring an input of bacterially generated ATP.
Interferon potentiation occurs at a pretranscriptive stage
Authors: Schwarz L A , Fleischmann W R
Published: January 2020

Combination of interferon-gamma (IFN-gamma) with a mixture of IFN-alpha and IFN-beta (IFN-alpha/beta) produce a potentiated antiviral state. The onset of induction of the potentiated antiviral state was observed to be more rapid than the onset of induction of either IFN-gamma or IFN-alpha/beta separately. The onset of viral resistance to combined IFN-gamma and IFN-alpha/beta (25 U/ml each) began after 2 h, compared with 4 h for IFN-alpha/beta (25 U/ml) alone and 8 h for IFN-gamma (25 U/ml) alone. By adding actinomycin D at various times after interferon treatment, this more rapid onset of induction of the potentiated antiviral state was shown to be the result of a more rapid onset of cellular transcription. To determine whether increased concentrations of IFN-alpha/beta acted through a similar mechanism, we performed kinetic experiments with several concentrations of IFN-alpha/beta and with combined preparations of IFN-gamma and IFN-alpha/beta. The findings showed that treatment of cells with the combined interferons and with a high concentration of IFN-alpha/beta resulted in more rapid onset of cellular transcription and more rapid development of the antiviral state. Thus, the cellular response to potentiation appeared to involve perception by the cell of the combined interferons as a higher-than-expected effective concentration of interferon, resulting in more rapid onset of cellular transcription of mRNA for antiviral proteins.
Eubacterium saburreum
L13 Antigen Containing a Ketohexose as a Main Sugar Constituent
Authors: Skaug Nils , Hofstad Tor
Published: January 2020

A periodate-resistant antigen (PS L13) which contained ketohexose and glucose was isolated from the oral microorganism
Eubacterium saburreum
L13 by trypsin digestion and subsequent gel filtration and ion-exchange chromatography. The ketohexose reacted as fructose would in colorimetric and chromatographic analyses, but not in gas-liquid chromatography. Rabbit antiserum to
E. saburreum
L13 agglutinated the bacteria and contained precipitins of the immunoglobulin G class specific for PS L13.
Fate of Pasteurella hemolytica in conventionally raised and germfree mice
Authors: Campbell S G , Mtero S S , Niderbuhl C J , Collins F M
Published: January 2020

When Pasteurella hemolytica was introduced into conventionally raised ICR mice by a variety of routes (intraperitoneal, aerogenic, and oral), the inoculum was rapidly eliminated, and none of the mice died. Even when the inoculum was injected intraperitoneally into sublethally irradiated (600 rads) mice, the organisms were eliminated rapidly unless suspended in 10% hog gastric mucin. When germfree ICR mice were orally infected with P. hemolytica, the infection established itself in the intestinal tract and spread to the mesenteric lymph nodes but did not progress beyond this point. Despite the inability of P. hemolytica to establish itself systemically, the organism multiplied freely in mouse blood and a homogenate of normal mouse lung in vitro. Normal mouse peritoneal macrophages could phagocytose P. hemolytica in vitro, although not as efficiently as the control Listeria monocytogenes suspensions. The addition of hyperimmune bovine serum (opsonin) to the P. hemolytica suspension increased phagocytosis but did not greatly affect the subsequent bactericidal activity of the macrophages in vitro. The reason for the lack of pathogenicity shown by P. hemolytica in normal mice remains enigmatic.
Analysis of cells of the mononuclear phagocyte series in experimental mycobacterial granulomas by monoclonal antibodies
Authors: Mathew R C , Katayama I , Gupta S K , Curtis J , Turk J L
Published: January 2020

Two distinct types of granulomas were produced in the draining lymph nodes by immunizing guinea pigs with Mycobacterium bovis BCG or Mycobacterium leprae, as reported earlier (Narayanan et al., J. Pathol. 134:253-265, 1981). In the BCG-induced granuloma there is successful containment, killing, and degradation of the organisms with the presence of epithelioid cells and fibrosis. M. leprae, on the other hand, induces a granuloma where there is an absence of organization of the cells, failure to completely degrade the organisms, absence of epithelioid cells, and minimal fibrosis. By using a macrophage-specific monoclonal antibody and an anti-Ia monoclonal antibody and applying the immunoperoxidase, immunofluorescence, and fluorescence-activated cell sorter analysis techniques, the epithelioid cells of the BCG granuloma were found to have macrophage-specific antigen, but not detectable amounts of Ia antigen. This suggests that these cells have a close relationship to other cells of the mononuclear phagocyte series with which they share a common antigen. The absence of Ia antigen, on the other hand, suggests that epithelioid cells may not be involved in antigen presentation or other accessory cell functions where the presence of Ia antigen is crucial. The macrophages in the M. leprae-induced granuloma expressed both macrophage-specific and Ia antigens.
Macrophage function in Mycobacterium lepraemurium infection: morphological and functional changes of peritoneal and splenic macrophages in vitro
Authors: Ha D K , Gardner I D , Lawton J W
Published: January 2020

Morphological and functional changes in peritoneal macrophages (PM) and splenic macrophages (SM) from mice infected with Mycobacterium lepraemurium were investigated. A decrease in the number but an increase in the size of PM were observed during the infection. PM were vacuolated, and a small proportion of them were observed in cell division. They demonstrated greater ability to adhere and spread in vitro, enhanced phagocytosis of immunoglobulin G (IgG) and IgM erythrocytes, and greater phagocytosis and killing of Candida sp., when compared with normal resident PM. In contrast, parasitized SM demonstrated significantly reduced phagocytic ability, whereas heavily parasitized SM neither spread nor phagocytosed Candida sp. The random migration and chemotactic responsiveness of PM from infected animals were also enhanced. These results indicated the persistent activation of PM but the suppression of some activities of SM during M. lepraemurium infection.
Destruction of Intracellular
Trypanosoma cruzi
After Treatment of Infected Macrophages with Cationic Electron Carriers
Authors: Alves Maria Julia M. , Rabinovitch Michel
Published: January 2020

Intracellular forms of
Trypanosoma cruzi
were destroyed in infected mouse macrophage cultures treated for 24 h with micromolar concentrations of phenazine methosulfate, brilliant cresyl blue, or crystal violet. Parasites were not killed in macrophages which were only treated with the dyes before infection, indicating that the drugs did not induce a protracted state of macrophage trypanocidal activity.
Killing of Blood-Stage Murine Malaria Parasites by Hydrogen Peroxide
Authors: Dockrell Hazel M. , Playfair John H. L.
Published: January 2020

Both nonlethal
Plasmodium yoelii
and lethal
Plasmodium berghei
were killed in vitro by hydrogen peroxide at concentrations as low as 10
−5
M. Higher concentrations were required in the presence of added normal erythrocytes. Injection of hydrogen peroxide in vivo significantly reduced
P. yoelii
parasitemia but had less effect on
P. berghei.
Serological analysis of the subgroup protein of rotavirus, using monoclonal antibodies
Authors: Greenberg H , McAuliffe V , Valdesuso J , Wyatt R , Flores J , Kalica A , Hoshino Y , Singh N
Published: January 2020

Ten monoclones directed to the 42,000-dalton inner structural protein of rotavirus were analyzed. Eight monoclones reacted broadly with antigenic domains common to virtually all mammalian rotaviruses. Two monoclones had specificities similar or identical to previously characterized subgroup specificities. These subgroup monoclones were more efficient in detecting subgroup antigen than either hyperimmune or postinfection antisera. Using the subgroup monoclones, we determined that some animal as well as human rotavirus strains carry subgroup 2 specificity and that epizootic diarrhea of infant mice virus and turkey rotavirus are antigenically distinct from other mammalian rotavirus strains.
HeLa cell invasiveness and O antigen of Shigella flexneri as separate and prerequisite attributes of virulence to evoke keratoconjunctivitis in guinea pigs
Authors: Okamura N , Nagai T , Nakaya R , Kondo S , Murakami M , Hisatsune K
Published: January 2020

Many rough mutants selected from isogenic smooth virulent and avirulent strains of Shigella flexneri were examined for virulence, using tissue culture infection and Sereny tests. Many of the rough mutants isolated from a virulent smooth strain were capable of penetrating tissue culture cells but incapable of producing a positive Sereny test. In contrast, we could not obtain from smooth avirulent strains any rough mutants capable of penetrating HeLa cells. Chemical analysis of lipopolysaccharide of some representative rough strains showed several patterns of sugar composition with a range of from Ra to Re chemotypes. There was no correlation between HeLa cell invasiveness and chemotypes of lipopolysaccharides, thus indicating little significance of oligosaccharides of the rough core as well as O antigens in the ability of S. flexneri to penetrate HeLa cells. When these invasive rough strains were given O antigen genes from a smooth avirulent Shigella Hfr strain, most of the transconjugants that expressed O antigens regained the ability to evoke keratoconjunctivitis in guinea pigs. We also examined the chromosomal loci of HeLa cell invasion by transferring carbohydrate fermentation genes of Escherichia coli K-12 Hfr and found two chromosomal loci, the rha and lac-gal regions, which control the ability to penetrate HeLa cells. These results suggested that O antigens and ability to penetrate tissue culture cells are independent and prerequisite attributes of virulence in Shigella flexneri to evoke keratoconjunctivitis in guinea pigs.
Hemolysin Production as a Virulence Marker in Symptomatic and Asymptomatic Urinary Tract Infections Caused by
Escherichia coli
Authors: Hughes Colin , Hacker Jörg , Roberts Anthony , Goebel Werner
Published: January 2020

Potential virulence, as defined by combined levels of adhesion to urinary epithelial cells, serum resistance, and mouse toxicity, was assessed for
Escherichia coli
strains causing symptomatic and asymptomatic urinary tract infections in relation to the carriage of hemolysin and other suspected virulence determinants. Hemolysin production (Hly), associated with certain O (O4, O6, O18, and O75), K (5), and hemagglutination (VI and VII) antigenic types but not colicin V production (Cva), was evident in 83 and 60% of isolates in groups possessing high potential virulence and in only 11 and 6% of those with low virulence. Strains of particular O-types were not more virulent per se, but among the serotypes, specific combinations of virulence factors appeared decisive, e.g., O18 HAVI B/D/G Hly
+
K5
+/−
and O18 HAIII/IVB/V Hly
−
Cva
+/−
K1
+/−
strains were, respectively, of high and low potential virulence. Isolates with high potential virulence were found to a similar extent in symptomatic and asymptomatic infections.
Effective immunity to dental caries: gastric intubation of Streptococcus mutans whole cells or cell walls induces protective immunity in gnotobiotic rats
Authors: Michalek S M , Morisaki I , Harmon C C , Hamada S , McGhee J R
Published: January 2020

Gnotobiotic rats were given Streptococcus mutans 6715 whole cells (WC), purified cell walls (CW), or cell wall lysate by gastric intubation (GI), and assessments were made of humoral immune responses in serum and saliva and of caries protection. Levels of secretory immunoglobulin A (IgA) and IgG antibodies to S. mutans WC in saliva samples from experimental rats were determined by an enzyme-linked immunosorbent assay. Serum antibody levels of the IgM, IgG, and IgA isotypes were also determined. Similar levels of salivary antibodies were induced in rats given S. mutans WC or CW by GI, whereas lower salivary antibody titers were observed in rats given cell wall lysate by the oral route. The level of serum antibodies in the various groups of rats also reflected the oral antigen used. The specificity of salivary IgA and serum IgG antibodies in the various groups of rats was determined by enzyme-linked immunosorbent assay with lipoteichoic acid, serotype g carbohydrate, dextran, CW, and WC as coating antigens. Salivary IgA and serum IgG antibodies in rats given S. mutans WC or CW by GI were primarily directed to lipoteichoic acid and serotype g carbohydrate. The presence of salivary IgA antibodies to S. mutans in rats given either S. mutans WC or CW by GI correlated with a significant reduction in the levels of plaque, numbers of viable S. mutans in plaque, and caries scores when compared with the control animals (infected only). These results demonstrate that particulate antigens of S. mutans induce salivary immune responses when given by GI to gnotobiotic rats and that the presence of these antibodies correlates with caries protection.
Reactivation of Chlamydia trachomatis lung infection in mice by cortisone
Authors: Yang Y S , Kuo C C , Chen W J
Published: January 2020

To study the latency, chronicity, and recurrent nature of chlamydial infection, we attempted to reactivate Chlamydia trachomatis lung infection in mice by immunosuppressive therapy with cortisone. Mice were treated with subcutaneous injections of cortisone acetate (125 mg/kg) every other day, starting on day 14 after intranasal inoculation of C. trachomatis serotype B (TW-5). C. trachomatis was recovered from the lungs beginning day 6 after the start of cortisone treatment until the end of the observation period on day 12 of treatment. Overall, the reactivation was successful in 8 of 55 mice treated with cortisone, in contrast to 0 of 41 inoculated, untreated mice (P = 0.009) and 0 of 35 uninoculated, treated mice. Cortisone treatment affected the ability of peritoneal exudate cells to respond to migratory inhibition after exposure to purified whole organisms of C. trachomatis serotype B (TW-5) but had little effect on serum antibody titers, indicating a possible role for cellular immunity in resistance against C. trachomatis infection in the lung.
Hemagglutination and adhesiveness of epidemiologically distinct strains of Vibrio parahaemolyticus
Authors: Reyes A L , Crawford R G , Spaulding P L , Peeler J T , Twedt R M
Published: January 2020

Twelve strains of Vibrio parahaemolyticus from four epidemiologically distinct groups were examined for their ability to hemagglutinate human, bovine, chicken, guinea pig, and rabbit erythrocytes and to adhere to human buccal mucosal epithelial cells in the presence and absence of mannose. Four of six Kanagawa-positive but none of six Kanagawa-negative strains showed mannose-sensitive hemagglutination with erythrocytes of rabbits and of one or more additional species. Mannose-resistant hemagglutination was shown by one strain in each group with no apparent relationship to strain source or hemolytic capability. All strains adhered to human buccal mucosal cells, with but a single strain showing significant difference in adherence at the alpha = 0.05 level. The adherence pattern had no relationship to the four epidemiological groups. Although adhesive processes may well be involved in disease caused by V. parahaemolyticus, our results do not support a role for adherence as a predictor of pathogenicity.
Pneumotropism of Sendai Virus in Relation to Protease-Mediated Activation in Mouse Lungs
Authors: Tashiro Masato , Homma Morio
Published: January 2020

The pneumotropism of Sendai virus in mice was studied in relation to the activation and replication of the virus in the lung. Inactive Sendai virus grown in LLC-MK
2
cells, which possessed an uncleaved precursor glycoprotein, F, and was noninfectious to tissue culture cells, neither grew nor caused pathological changes in the lung of mice. When trypsin treatment was made which cleaved F into F
1
and F
2
subunits, the virus became activated so that it could initiate replication in the bronchial epithelium of the lung. In this case, the progeny virus was produced in the activated form and multiple-cycle replication occurred successively. A parallel relationship was found between the degree of the viral replication and that of clinical signs of the respiratory disease, body weight loss, and histopathological changes in the lung. A protease mutant, TR-2, which was able to be activated only by chymotrypsin but not by trypsin, could also initiate replication in the bronchial epithelium, when activated by chymotrypsin before inoculation into mice. The progeny virus, however, remained inactive, and the replication was limited to a single cycle, which resulted in the limited lung lesion. The overall results suggest that some activating mechanism for the progeny virus of wild-type Sendai virus exists in the lung of mice and the principle (activator) responsible for this phenomenon has a character similar to trypsin. The possible location of the activator is discussed.