bluuebunny/crossref_metadata_2025 huggingface dataset:
Expression of human choriogonadotropin-like material in coagulase-negative Staphylococcus species
Authors: Acevedo H F , Campbell-Acevedo E , Kloos W E
Published: January 2020

We identified 101 coagulase-negative Staphylococcus strains obtained from different laboratories, the American Type Culture Collection, and our collection, isolated from 23 patients with overt cancer and 34 normal individuals through Kloos and Schleifer conventional methods and the Staph-Ident staphylococcal system (Analytab Products, Plainview, N.Y.). In 40 strains, identity was further verified by DNA-DNA hybridization techniques. Identification revealed 39 S. epidermidis, 22 S. hominis, 8 S. haemolyticus, 9 S. capitis, 5 S. warneri, 5 S. cohnii, 8 S. saprophyticus, and 5 S. xylosus strains, all resident species found in humans. All bacteria were tested for the expression of human choriogonadotropin (hCG)-like material by the indirect fluorescein and peroxidase immunocytochemical labeling techniques by using specific antisera to the whole hormone, to its alpha and beta subunits, to the hCG beta COOH-terminal peptide, and to a monoclonal antibody to the hCG beta. The results demonstrated that the isolates from cancer patients were not unique bacteria, as has been postulated by others; the expression of immunoreactive hCG-like material is a strain, not a species, characteristic; not every bacterial strain isolated from a cancer patient is able to express the material; hCG-producing bacteria do not necessarily indicate the presence of active disease; 20% of the strains that we studied revealed a clonal variation of the expression of hCG-like material or its subunits or both as well as a variable expression of a single hCG epitope, an observation similar to that described for malignant cells; and a specific antiserum to the whole hormone with a high affinity and high sensitivity for immunocytochemistry can be a reliable reagent for screening purposes.
Iron deficiency protects inbred mice against infection with Plasmodium chabaudi
Authors: Harvey P W , Bell R G , Nesheim M C
Published: January 2020

Plasmodium chabaudi infections of NFR/N mice made anemic by dietary iron deficiency produced mortalities of 25% (male) and 7% (female) compared with 100% in iron-sufficient controls. When iron-deficient mice convalescing from the primary infection were returned to the normal diet, 100% experienced recrudescent parasitemia. No recrudescence occurred in mice maintained on the iron-deficient diet.
Lipopolysaccharide structures of Campylobacter fetus are related to heat-stable serogroups
Authors: Perez-Perez G I , Blaser M J , Bryner J H
Published: January 2020

To determine whether lipopolysaccharide (LPS) structures of Campylobacter fetus are related to the three known heat-stable serogroups, proteinase K-treated whole cell lysates obtained from strains of each serogroup were electrophoresed in polyacrylamide gels. All strains had smooth-type LPS with multiple high-molecular-weight repeating units. The profiles of serogroup A from C. fetus subsp. fetus and from C. fetus subsp. venerealis were identical, but they were different from those of C. fetus subsp. fetus serogroups B and AB. When we immunoblotted the LPS of these serogroups with normal or immune rabbit serum we found homologous recognition between serogroups A from C. fetus subsp. fetus and C. fetus subsp. venerealis. Similarly, serogroups AB and B from C. fetus subsp. fetus showed homologous recognition. However, antiserum against serogroup A did not recognize serogroups B and AB and vice versa. Absorption studies confirmed the identity of LPS from all serogroup A C. fetus strains and cross-reactivity of the serogroup B and AB strains with one another. Serogroup A strains were resistant to the bactericidal activity in normal human serum, whereas serogroup B and AB strains generally were susceptible; isolates from humans predominantly belonged to serogroup A. Results of these studies suggest that the LPS composition forms the basis for the heat-stable serotyping system for C. fetus and that the structural and antigenic variants are associated with differential serum susceptibility.
Rapid killing of monocytes in vitro by Candida albicans yeast cells
Authors: Danley D L , Polakoff J
Published: January 2020

To study the interaction between Candida albicans blastoconidia and human phagocytes, we incubated peripheral leukocytes with fungi for 1 h at 37 degrees C and stained the cells with fluorescent vital stains ethidium bromide (EB) and fluorescein diacetate. Fungi that had been phagocytosed showed little staining; however, some leukocytes containing blastoconidia exhibited nuclear staining with EB, even though their cell membranes showed no signs of penetration by fungi. The number of EB-positive leukocytes was related to viability of the yeast cells and the temperature at which they were maintained before use. Because efforts to quantitate EB-positive leukocytes microscopically were frustrated by cell aggregation, we labeled the leukocytes with 51Cr and measured isotope release. We determined that leukocytes incubated with viable fungi released significantly more isotope than cells incubated alone or with killed blastoconidia. Furthermore, 51Cr release correlated directly with concentration of fungi in the assay, time of incubation, and temperature at which fungi were maintained before use. Using a number of isolates of C. albicans and several other species of Candida, we found that all exhibited cytotoxic activity against leukocytes, but the level of activity varied among organisms. Finally, we depleted or enriched peripheral leukocytes for specific cell populations and determined that only monocytes released more 51Cr after incubation with viable blastoconidia. Blastoconidia can lyse phagocytic cells through germination and penetration of cell membranes within 1 to 2 h, but the cytotoxic phenomenon we describe occurs within 15 to 30 min after yeast cells have been phagocytosed. Therefore, this capacity may represent a more immediate response by blastoconidia against phagocytosis and killing by monocytes.
Enhanced recovery of murine alveolar macrophages: morphological and functional characteristics following intravenous injection of heat-killed Mycobacterium bovis BCG
Authors: Mbawuike I N , Luhr J E , Herscowitz H B
Published: January 2020

The kinetics of induction of the bronchoalveolar cell population (i.e., alveolar macrophages [AM], lymphocytes, and polymorphonuclear leukocytes) was studied in mice inoculated intravenously with heat-killed Mycobacterium bovis BCG. Injection of BCG at 100 and 500 micrograms but not at 10 micrograms per mouse resulted in an increase in the total number of bronchoalveolar cells (threefold) and in the number of AM (sixfold) recovered by bronchoalveolar lavage in a time-dependent manner, as compared with control mice. A significant increase in the number of lymphocytes was also observed between days 2 and 4 after injection, but this number returned to normal levels by day 8, whereas the number of polymorphonuclear leukocytes was not significantly altered. AM were characteristically phagocytic and stained positively for nonspecific esterase. AM recruited in response to BCG injection were activated, as indicated by elevated levels of acid phosphatase activity and decreased levels of membrane 5'-nucleotidase activity. However, both resident and BCG-induced AM suppressed the in vitro plaque-forming cell response of sheep erythrocyte-primed mice to the same extent. These results indicate that injection of heat-killed BCG induced increased numbers of activated AM, which appeared to be functionally similar to resident AM in their ability to phagocytize and modulate in vitro immune responses.
Identification and preliminary characterization of a lectinlike protein from Capnocytophaga gingivalis (emended)
Authors: Kagermeier A , London J
Published: January 2020

A polypeptide believed to be the monomeric form of the lectin responsible for the coaggregation of Capnocytophaga gingivalis (emended) and Actinomyces israelii has been identified. Denaturing polyacrylamide gel electrophoresis and immunoblot analyses were used to distinguish the protein from other proteins in the outer membrane of C. gingivalis. The subunit of the putative lectin has a pI of 8.6 and a molecular weight of 155,000.
Strain variations in the murine cellular immune response to the phenolic glycolipid I antigen of Mycobacterium leprae
Authors: Koster F T , Teuscher C , Matzner P , Umland E , Yanagihara D , Brennan P J , Tung K S
Published: January 2020

The cellular immune response to the Mycobacterium leprae-specific phenolic glycolipid I was examined in inbred mice immunized with M. leprae by in vivo delayed cutaneous hypersensitivity and in vitro lymphocyte proliferation. Whereas all mouse strains responded to M.leprae-induced delayed-type hypersensitivity and lymphocyte proliferation, only BALB.K was responsive in both assays to the glycolipid. Responsiveness was determined in part by non-H-2 genes, while the influence of H-2 genes was not apparent. Among congenic BALB/c mice differing only at Igh-C allotype loci, variations in responsiveness were found in both delayed-type hypersensitivity and lymphocytes proliferation assays, indicating a possible role for Igh-C loci-linked genes. Unresponsiveness in the lymphocyte proliferation assay to the glycolipid was inherited as a dominant trait in one set of responder X nonresponder F1 progeny. We conclude that after immunization with M. leprae organisms, the cell-mediated responses to the glycolipid, endowed with a single carbohydrate epitope, are under polygenic control, predominantly non-H-2-linked genes.
Purification and subunit heterogeneity of pili of Bordetella bronchiseptica
Authors: Lee S W , Way A W , Osen E G
Published: January 2020

Pili were isolated and purified from Bordetella bronchiseptica. Electron microscopic observations revealed that pili are ubiquitous in this species. The occurrence of pili and flagella appeared to correlate with growth phase and colonial morphology. Pili were about 3 to 4 nm in diameter and morphologically similar to pili isolated from other gram-negative bacteria. Internal core structure was not evident. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of purified pili showed that up to three different pilus subunit variants could be observed on a single strain, depending on the colonial phase and culture condition. Enzyme immunoassay and immunoblot, however, showed that these subunit variants are serologically related. Mice vaccinated with purified pili were protected against a virulent intraperitoneal challenge of B. bronchiseptica. B. bronchiseptica pili were also found to be similar to Bordetella pertussis pili in morphology and in the molecular size and antigenic structure of pilus subunits. The intact pili of B. bronchiseptica and B. pertussis, however, appeared to have weak serological cross-reactivity.
Adherence of oral treponemes and their effect on morphological damage and detachment of epithelial cells in vitro
Authors: Reijntjens F M , Mikx F H , Wolters-Lutgerhorst J M , Maltha J C
Published: January 2020

The present study shows adherence of Treponema denticola L12D and Treponema vincentii RitzA to guinea pig ear epithelial cells in vitro. The number of adhering organisms was positively related with the treponemal concentration and contact time. Incubation of washed T. denticola L12D and T. vincentii RitzA organisms or their culture supernatants with the epithelial cells induced morphological damage and detachment of these cells. In addition, indications for inhibition of epithelial cell proliferation were found. The activity of the supernatants was dose dependent, heat sensitive, and sensitive to sulfhydryl-containing components, suggesting the presence of enzymatic activity that might be of importance in the pathogenicity of these oral treponemes.
Contributions of C1q, bacterial lipopolysaccharide, and porins during attachment and ingestion phases of phagocytosis by murine macrophages
Authors: Euteneuer B , Störkel S , Loos M
Published: January 2020

In contrast to the S-form of Salmonella minnesota, its Re mutant binds to mouse peritoneal macrophages. The binding reaction triggers an oxidative burst, measured by a chemiluminescent reaction. The oxidative burst was abolished in the presence of either purified lipopolysaccharide or porins (outer membrane proteins) extracted from the Re mutant, suggesting that both components are involved in binding of the Re mutant to macrophages. In addition, Fc-recognizing membrane structures on the macrophage surface bind the Re mutant. Preincubation of macrophages with the Re mutant abolishes immunoglobulin G-sensitized erythrocyte-induced chemiluminescence. Macrophages preincubated with immunoglobulin G-sensitized erythrocytes had a low chemiluminescent signal, and after treatment of the cells with the Re mutant, there was an additional, higher signal. Binding of purified C1q to the Re mutant decreased the adherence of the Re mutant to macrophages, resulting in a diminished chemiluminescent signal. Blocking of endogenous macrophage membrane-associated C1q with a monoclonal antibody [F(ab')2 fragment] directed against mouse macrophages (recognizes the A and B chains of C1q) diminished the oxidative burst. Therefore, the endogenous C1q of macrophages also appears to be involved in attachment of the S. minnesota Re mutant.
Mechanisms underlying the depressed production of interleukin-2 in spleen and lymph node cell cultures of mice infected with Mycobacterium bovis BCG
Authors: Turcotte R , Legault D
Published: January 2020

Mice were infected intravenously with 1.0 mg of Mycobacterium bovis BCG. At various times thereafter, spleen and peripheral lymph node cells were stimulated with concanavalin A for 18 to 20 h, and their capacity to produce interleukin-2 (IL-2) was evaluated by means of a T-cell blast proliferation technique. A depression of IL-2 production that was complete in the spleen but partial in lymph node cell cultures occurred at 2 to 3 weeks and persisted till weeks 8 to 10 after infection. No direct evidence was found for an active suppressor mechanism depressing in vitro the production of IL-2. In spleen cell cultures the suppression of IL-2 production would result from a functional defect of the IL-2-producing T-cell subset, whereas in lymph node cell cultures the depression mainly results from a relative lack of IL-2-producing cells caused by an accumulation of immunoglobulin-positive and "null" cells. Spleen cells from BCG-infected mice maintained their capacity to acquire IL-2 receptors when activated by concanavalin A.
Requirement for lipopolysaccharide-responsive macrophages in galactosamine-induced sensitization to endotoxin
Authors: Freudenberg M A , Keppler D , Galanos C
Published: January 2020

Injection of D-galactosamine sensitizes mice many thousand-fold to the lethal action of endotoxin (lipopolysaccharide [LPS]). Comparable sensitization was practically absent in LPS-resistant C3H/HeJ mice, which after D-galactosamine treatment were about 500,000 times less sensitive to LPS lethality than histocompatible LPS-sensitive C3H/HeN mice. D-Galactosamine induces changes in the hepatocytes of treated animals, such as depletion of UTP and alterations in the pattern of UDP sugars. These early biochemical changes, which are necessary for development of sensitization, were similar in both mouse strains which we examined. High sensitivity to the lethal effects of LPS was achieved in C3H/HeJ mice after D-galactosamine treatment by transfer of C3H/HeN macrophages obtained in culture from bone marrow precursor cells.
Mimicry of human histocompatibility HLA-B27 antigens by Klebsiella pneumoniae
Authors: Ogasawara M , Kono D H , Yu D T
Published: January 2020

Anti-HLA-B27 monoclonal antibody M2, which was relatively specific for human histocompatibility antigen HLA-B27, was used to test several bacteria, some of which could potentially induce chronic arthritis in HLA-B27-positive individuals. Using the Western blot procedure, we observed positive reactions with 80,000- and 60,000-dalton antigens with one strain of Klebsiella pneumoniae. Reactivity was not observed with five other monoclonal antibodies which were not reactive with HLA-B27 antigens, nor was reactivity observed with seven other gram-negative bacteria, irrespective of their arthritis-causing potential. To test the validity of our observation, the 80,000-dalton Klebsiella cross-reactive antigen was isolated and used to generate an immune guinea pig serum. We found that the reactivity of this guinea pig serum with Klebsiella envelopes in an enzyme-linked immunosorbent assay was adversely affected by absorption with HLA-B27-positive cells. Our results support the existence of mimicry between HLA-B27 antigens and bacteria.
Identity of hemolysins produced by Vibrio cholerae non-O1 and V. cholerae O1, biotype El Tor
Authors: Yamamoto K , Ichinose Y , Nakasone N , Tanabe M , Nagahama M , Sakurai J , Iwanaga M
Published: January 2020

Hemolysins purified from non-O1 Vibrio cholerae (non-O1 hemolysin) and a Vibrio cholerae O1, biotype El Tor (El Tor hemolysin) were investigated for their homology. The hemolysins were isolated from the culture supernatant fluids by ammonium sulfate precipitation and gel filtration on Sephadex G-100 columns. The purified hemolysins gave single bands with an identical mobility on conventional polyacrylamide gel disc electrophoresis. The molecular weights of the non-O1 and El Tor hemolysins were estimated to be about 60,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and the amino acid compositions of the hemolysins were very similar. The specific activities of the hemolysins were identical, and both hemolysins were neutralized to the same extent with antisera against the homologous and heterologous hemolysins. Ouchterlony double immunodiffusion tests with both hemolysins and antihemolysin serum gave a common (fused) precipitin line. These data indicate that the non-O1 hemolysin is biologically, physicochemically, and immunologically indistinguishable from the El Tor hemolysin.
Role of cell surface receptors in the regulation of intracellular killing of bacteria by murine peritoneal exudate neutrophils
Authors: Hart P H , Spencer L K , Nikoloutsopoulos A , Lopez A F , Vadas M A , McDonald P J , Finlay-Jones J J
Published: January 2020

The role of the Fc and third component of complement (C3) receptors on mouse neutrophils in the control of killing of Proteus mirabilis, opsonized in normal mouse serum (NMS) or heated immune mouse serum (HIMS), was studied. The events following incubation of neutrophils with P. mirabilis and the events associated with bacterial killing were assayed. The respiratory burst was quantified by chemiluminescence (CL). Levels of leukocyte-associated bacteria were determined after a 20-min ingestion period as a measure of phagocytosis. Bacterial killing was measured while ingestion was allowed to continue or as a discrete process when extracellular, noningested bacteria had been removed and neutrophils with intracellular bacteria were incubated in the presence of serum. Modification of these responses in the presence of three monoclonal antibodies (MAb), NIMP-R10 and M1/70, which bind to different epitopes of the mouse C3 receptor, and 2.4G2, which binds to the mouse Fc receptor, was investigated. MAb to the C3, but not to the Fc, receptors reduced CL, ingestion, and intracellular killing of NMS-opsonized P. mirabilis. MAb to the Fc receptor diminished CL to and reduced the rate of ingestion of HIMS-opsonized bacteria. The two MAb to the C3 receptor each produced a similar inhibition of ingestion and intracellular killing of HIMS-opsonized bacteria, but they only partially blocked CL. A range of MAb preparations reactive with other murine antigens did not inhibit these events, either with NMS- or HIMS-opsonized P. mirabilis. The results suggest that C3 receptors on mouse neutrophils played a predominant role in regulation of the killing of P. mirabilis. Similar results were found for Staphylococcus aureus. C3 receptors were necessary for maximal expression of all functions culminating in bacterial kill. That MAb to the C3 receptor inhibited phagocytosis of HIMS-opsonized bacteria in similar fashion to the effect of MAb to the Fc receptor and in contrast to the lack of effect of control MAb may reflect steric hindrance of the Fc receptor by MAb binding to the C3 receptor, or it may reflect that the receptors are linked in murine neutrophils as they are in human neutrophils.
Arthropathic properties of gonococcal peptidoglycan fragments: implications for the pathogenesis of disseminated gonococcal disease
Authors: Fleming T J , Wallsmith D E , Rosenthal R S
Published: January 2020

We examined the arthropathic activity of purified peptidoglycan (PG) fragments derived from (i) lysozyme-resistant, extensively O-acetylated PG from Neisseria gonorrhoeae FA19 (O-PG), and (ii) lysozyme-sensitive, O-acetyl-deficient PG from N. gonorrhoeae RD5 (non-O-PG). Male Lewis rats were injected intradermally in the tail with 200 micrograms of PG emulsified in mineral oil and water (1:1) or with the oil and water emulsion alone (controls). Quantitation of hind paw size indicated that macromolecular PG of various chemical and physical forms induced paw swelling (P versus controls, less than 0.01) that was evident at about day 14 and that reached a maximum at about day 24. PG-mediated paw swelling was accompanied by intense synovitis with some cartilage and bone involvement. The minimal arthropathic dose of soluble macromolecular PG was 20 micrograms per rat. Of particular interest was that macromolecular O-PGs from strain FA19 caused considerably more extensive swelling than did either their RD5 non-O-PG counterparts or the homologous FA19 PG that had been de-O-acetylated by mild alkali treatment. This suggested that the persistence of hydrolase-resistant high-molecular-weight fragments, afforded by extensive O-acetylation, may be important for optimal expression of arthropathic activity. However, oligomeric PG was not an absolute requirement, since even low-molecular-weight fragments, including the anhydro-muramyl-containing disaccharide peptide monomer released by growing gonococci, were also arthritogenic. Experiments employing purified gonococcal lipopolysaccharide indicated that the arthropathic activity of PG preparations was not due to contaminating lipopolysaccharide. Based on the arthritogenicity of gonococcal PG in this model system, we suggest that PG may play a role in the pathogenesis of gonococcal arthritis, and that such an activity might be potentiated by the persistence of hydrolase-resistant O-PG.
Homologous regions within M protein genes in group A streptococci of different serotypes
Authors: Scott J R , Hollingshead S K , Fischetti V A
Published: January 2020

DNA hybridization with probes from the structural gene for the M6 protein shows that the carboxy-terminal region (proximal to the cell surface) is conserved among strains of different M serotypes. The amino-terminal region, which is more available to immunological surveillance, exhibits greater variation.
Monoclonal antibodies reactive with K1-encapsulated Escherichia coli lipopolysaccharide are opsonic and protect mice against lethal challenge
Authors: Kaufman B M , Cross A S , Futrovsky S L , Sidberry H F , Sadoff J C
Published: January 2020

Seven murine monoclonal antibodies (MAbs) directed against O-side-chain determinants of the K1-encapsulated Bortolussi strain of Escherichia coli (O18:K1:H7) were evaluated for their in vitro and in vivo activities. All the MAbs reacted well in Western blots against E. coli O18 lipopolysaccharide antigens. Two MAbs of the immunoglobulin G (IgG) class promoted in vitro opsonophagocytosis and protected mice lethally challenged with bacteria. Two IgM MAbs showed partial protection, although they had no in vitro opsonic activity, and the remaining three IgM MAbs showed no apparent functional activities. Monoclonal IgG antibodies against bacterial lipopolysaccharide can be opsonic and protective in spite of the presence of the K1 capsule on the bacterium.
Effect of sublethal gamma radiation on host defenses in experimental scrub typhus
Authors: Kelly D J , Rees J C
Published: January 2020

The effect of sublethal gamma radiation on inbred mice chronically infected with scrub typhus rickettsiae was examined. Inbred mice which were inoculated with the Gilliam or Karp strain of Rickettsia tsutsugamushi by the subcutaneous route harbored the infection for at least 1 year. Irradiation of these animals at 12 or 52 weeks postinoculation with normally sublethal levels induced a significantly higher percentage of rickettsemic mice (recrudescence) than was seen in the unirradiated, similarly infected control animals. In addition, sublethal irradiation at 12 weeks induced a quantitative increase in total rickettsiae. Homologous antibody titers to the rickettsiae were examined for 5 weeks after irradiation to determine the role of the humoral response in radiation-induced recrudescence. Unirradiated, infected mice showed consistent titers of about 320 throughout the 5-week observation period, and the titer was not affected by exposure of up to 500 rads of gamma radiation. Drug dose-dependent radioprotection and modification of recrudescence was noted in infected, irradiated mice treated with the antiradiation compound S-2-(3-aminopropylamino)ethyl phosphorothioic acid. The results of this investigation supported the conclusion that the recrudescence of a chronic rickettsial infection in the appropriate host after immunological impairment due to gamma radiation can result in an acute, possibly lethal rickettsemia.
Enhanced levels of attachment of fibronectin-primed Treponema pallidum to extracellular matrix
Authors: Thomas D D , Baseman J B , Alderete J F
Published: January 2020

Freshly extracted Treponema pallidum organisms treated with exogenous human fibronectin (Fn) (Fn-primed treponemes) showed a 6- to 15-fold increased level of attachment to Fn-coated cover slips and to extracellular matrix (ECM) when compared with unprimed treponemes. Treponemes primed with collagen or laminin showed no similar enhanced binding to immobilized Fn or ECM. Preexposure of immobilized Fn and ECM to anti-Fn serum but not to anti-collagen or anti-laminin serum prevented treponemal adherence. Also, the presence of proteoglycanlike molecules such as dextran sulfate or heparan sulfate inhibited Fn-primed treponemal attachment to Fn or ECM. In contrast Fn-primed treponemes did not exhibit elevated levels of attachment to eucaryotic cell monolayers. To understand the increased tropism of Fn-primed T. pallidum organisms for Fn and ECM-like surfaces, we radiolabeled freshly extracted treponemes with [35S]methionine and examined them for the presence of surface immunoreactive Fn. Magnetic protAspheres and glass beads coated with monospecific anti-Fn serum bound only 20 to 30% of radiolabeled treponemes. Nonadherent treponemes failed to bind to gelatin-agarose, further confirming the absence of surface Fn or Fn-like material. Fn-free organisms, however, did attach to Fn-coated cover slips and to cell monolayers like treponemes of the original population. Incubation of Fn-free treponemes with human Fn resulted in almost total binding of organisms to anti-Fn antibody on glass beads and also produced increased attachment to Fn-coated cover slips and ECM. These results suggest that enhanced interactions between T. pallidum and the host are dependent on the presence of Fn on syphilis spirochetes and the specific location and orientation of Fn in vivo.
Lung defenses against Pseudomonas aeruginosa in C5-deficient mice with different genetic backgrounds
Authors: Cerquetti M C , Sordelli D O , Bellanti J A , Hooke A M
Published: January 2020

Lung defenses against Pseudomonas aeruginosa were investigated in C5-deficient strains of mice with different genetic backgrounds. We studied pulmonary clearance and cell responses after aerosol exposure to P. aeruginosa in C5-deficient B10.D2/oSnJ and DBA/2J mice and their closest C5-sufficient counterparts, B10.D2/nSnJ and DBA/1J mice. Different patterns of lung clearance and pulmonary cell responses were found for the two C5-deficient strains. C5-deficient B10.D2/oSnJ mice showed defective lung clearance of P. aeruginosa 4 h after challenge compared with C5-sufficient B10.D2/nSnJ animals. This finding was associated with a decreased number of polymorphonuclear leukocytes recruited into the airways during the same time. Interestingly, C5-deficient DBA/2J mice recruited higher numbers of polymorphonuclear leukocytes than did C5-sufficient DBA/1J mice by 4 h after aerosolization. Nevertheless, lung clearance of P. aeruginosa in DBA/2J mice was not as effective as in C5-sufficient DBA/1J mice, suggesting that other functions of C5 besides chemotaxism could be involved. Lung clearance of P. aeruginosa was also investigated in C5-deficient and -sufficient hybrids sharing the same genetic background (DBA/2J X B10.D2). The results suggested that murine lung clearance of P. aeruginosa is markedly affected by lack of C5 in a specific genetic background (B10.D2).
Antibodies raised against rough mutants of Escherichia coli and Salmonella strains are opsonic only in the presence of complement
Authors: Vreede R W , Marcelis J H , Verhoef J
Published: January 2020

The opsonic capacity of antisera raised in rabbits against rough (R) mutants and smooth (S) parent strains of Escherichia coli and Salmonella typhimurium were studied. All specific antibodies in the antisera belonged to the immunoglobulin G (IgG) class. Radioactively labeled bacteria were preincubated in various dilutions of antisera, in which complement was inactivated. Fresh normal rabbit serum, as a standard complement source, was used in some experiments. After preincubation, washed bacteria were added to normal human neutrophils. Opsonization of R mutants for 5 min in 5% fresh normal rabbit serum resulted in effective phagocytosis; S strains needed at least a 30-min opsonization time or 20 to 50% serum. After incubation for 5 min in diluted, homologous antisera, phagocytosis of S strains was optimal, but preincubation of R mutants in diluted, homologous antisera did not lead to amelioration of phagocytosis compared with that of bacteria preincubated in buffer only. However, when fresh normal serum was added to homologous antisera, uptake of R mutants occurred at a faster rate than that of bacteria opsonized in fresh serum alone. Using six clinical isolates of members of the family Enterobacteriaceae, we found that, with or without complement, antisera raised against E. coli J5 or S. typhimurium Re had, with the exception of one strain, no opsonic activity for these strains. Thus, the protective effect of R antisera in gram-negative bacteremia, as shown by several investigators, is unlikely to be mediated through enhanced opsonization of invading bacteria by IgG antibodies directed against these R mutants.
Isolation of a germ-tube-forming revertant from Candida albicans B311V6
Authors: Buckley H R , Daneo-Moore L , Ahrens J C , Sobel J D
Published: January 2020

We describe and partially characterize the isolation of a germ-tube-positive revertant from Candida albicans B311V6. This revertant has all of the properties of a germ-tube-forming strain of C. albicans except that it appears to have a nutrition defect.
Oxidative and nonoxidative killing of Actinobacillus actinomycetemcomitans by human neutrophils
Authors: Miyasaki K T , Wilson M E , Brunetti A J , Genco R J
Published: January 2020

Actinobacillus actinomycetemcomitans is a facultative gram-negative microorganism which has been implicated as an etiologic agent in localized juvenile periodontitis and in subacute bacterial endocarditis and abscesses. Although resistant to serum bactericidal action and to oxidant injury mediated by superoxide anion (O2-) and hydrogen peroxide (H2O2), this organism is sensitive to killing by the myeloperoxidase-hydrogen peroxide-chloride system (K.T. Miyasaki, M.E. Wilson, and R.J. Genco, Infect. Immun. 53:161-165, 1986). In this study, we examined the sensitivity of A. actinomycetemcomitans to killing by intact neutrophils under aerobic conditions, under anaerobic conditions, and under aerobic conditions in the presence of the heme-protein inhibitor sodium cyanide. Intact neutrophils killed opsonized A. actinomycetemcomitans under aerobic and anaerobic conditions, and the kinetics of these reactions indicated that both oxidative and nonoxidative mechanisms were operative. Oxidative mechanisms contributed significantly, and most of the killing attributable to oxidative mechanisms was inhibited by sodium cyanide, which suggested that the myeloperoxidase-hydrogen peroxide-chloride system participated in the oxidative process. We conclude that human neutrophils are capable of killing A. actinomycetemcomitans by both oxygen-dependent and oxygen-independent pathways, and that most oxygen-dependent killing requires myeloperoxidase activity.
Proliferation induced by Plasmodium falciparum antigen and interleukin-2 production by lymphocytes isolated from malaria-immune individuals
Authors: Theander T G , Bygbjerg I C , Jepsen S , Svenson M , Kharazmi A , Larsen P B , Bendtzen K
Published: January 2020

Affinity-purified Plasmodium falciparum soluble antigens (SPAg) isolated from in vitro cultures of the parasite were shown to be relatively free of nonspecific polyclonal activators. To determine the presence of lymphocytes with specificity against SPAg in the peripheral blood of malaria-immune individuals, the proliferative response and the interleukin-2 (IL-2) production of SPAg-activated mononuclear cells (MNCs) from individuals unexposed, sensitized, and immune to malaria were measured. It was found that MNC isolated from malaria-immune individuals proliferated in response to SPAg and that this activation resulted in measurable IL-2 production in 5 of 10 MNC cultures. MNC isolates from most unexposed individuals did not respond to SPAg. To establish which cells responded to SPAg, different subpopulations of MNCs were tested. Only T helper cells were found to respond, and they responded only when cocultured with monocytes. The finding of parasite-specific T helper cells in the blood of malaria-immune individuals and the fact that some of these cells were able to produce IL-2 in vitro support the hypothesis that in malaria the cellular part of the protective immune response is initiated by immune T cells. These cells may activate nonspecific effector cells (i.e., macrophages) that eliminate the parasite.
Identification of Shigella sonnei form I plasmid genes necessary for cell invasion and their conservation among Shigella species and enteroinvasive Escherichia coli
Authors: Watanabe H , Nakamura A
Published: January 2020

A series of Tn1 insertions in pSS120, the 120-megadalton form I plasmid of Shigella sonnei, were constructed by a Tn1-mediated conduction system previously described (H. Watanabe and A. Nakamura, Infect. Immun. 48:260-262, 1985, and screened for cell invasion in a tissue culture assay. The analysis of Tn1 insertion sites of seven noninvasive mutants suggested that four separate HindIII fragments were necessary for cell invasion. HindIII fragments including Tn1 of mutant plasmids were cloned into a vector plasmid, pACYC184. The DNA was used as a DNA probe to identify the corresponding, parental HindIII fragments. We identified one contiguous molecule of 2.6- and 4.1-kilobase pair (kb) HindIII fragments as being responsible for restoring cell invasiveness to the three mutant plasmids, pHW505, pHW510, and pHW511. Polypeptide analysis in minicells demonstrated that the contiguous HindIII fragments of 2.6 and 4.1 kb coded for at least four polypeptides, of 38, 41, 47, and 80 kilodaltons (kDa). A comparison of polypeptides synthesized by parental and mutant plasmids strongly suggested that the 38-kDa protein was essential for cell invasion. The 4.1-kb DNA which encoded the 38-kDa protein was conserved among plasmids of Shigella species and enteroinvasive Escherichia coli.
A surface glycoprotein of Trypanosoma lewisi binds immunoglobulin G from the serum of uninfected rats
Authors: Balber A E , Sturtevant J E
Published: January 2020

Detergent extracts of whole Trypanosoma lewisi were fractionated by polyacrylamide gel electrophoresis and transferred to nitrocellulose for immunoblotting analysis. Antibody probes to rat immunoglobulin G (IgG) and IgM detected intact gamma chains, mu chains, and light chains in extracts. The amount of immunoglobulin detected increased as the infection progressed. Transfers were also incubated in serum from conventionally reared (CRS), specific-pathogen-free (SPFS), or germ-free rats before being probed with anti-rat IgG or anti-rat IgM. Components of 200, 175, and 120 kilodaltons (kDa) bound IgM from all sera tested and were present in extracts of trypanosomes isolated from lethally irradiated or intact rats on different days during infection. No parasite components bound IgG from serum of germ-free rats. However, 145-, 175-, and 200-kDa components bound IgG from CRS and SPFS. A 74-kDa protein was the major IgG-binding component in extracts of reproducing parasites. This component bound much more IgG from CRS than it bound from SPFS. The 74-kDa protein was removed from parasites by mild trypsinization and corresponded to a major surface glycoprotein detected when intact cells were radioiodinated. These results indicate that natural antibodies to T. lewisi exist in rats or that these parasites have surface proteins that bind immunoglobulins without regard to antigenic specificity.
Purification and characterization of type II heat-labile enterotoxin of Escherichia coli
Authors: Holmes R K , Twiddy E M , Pickett C L
Published: January 2020

Type II heat-labile enterotoxin (LT-II) of Escherichia coli has several biologic activities similar to cholera toxin (CT) and E. coli type I heat-labile enterotoxin (LT-I), but it is not neutralized by antiserum prepared against CT or LT-I. LT-II was purified from E. coli SA53 and from E. coli HB101(pCP3837), a strain that contains the cloned LT-II genes in a hybrid plasmid and produces up to 600 times more LT-II than does SA53. Purification involved sonic disruption of bacterial cells, ammonium sulfate fractionation, chromatography on Affi-Gel Blue, chromatofocusing, and gel filtration on Sephadex G-100. The LT-II purified to apparent homogeneity from HB101(pCP3837) had an isoelectric point of 6.8, induced increased vascular permeability in rabbit intracutaneous tests, caused rounding of cultured Y1 adrenal cells accompanied by increased intracellular cyclic AMP, and was 25 to 50 times more potent than CT or LT-I in the Y1 adrenal-cell assay. In contrast, purified LT-II did not cause secretion in ligated rabbit ileal segments at doses corresponding to CT controls that gave strongly positive reactions. LT-II was composed of two different polypeptides with MrS of 28,000 (A) and 11,800 (B); treatment of LT-II with trypsin cleaved the A polypeptide to fragments A1 (Mr, 21,000) and A2 (Mr, 7,000). The activity of LT-II was not blocked by ganglioside GM1 at concentrations that inactivated LT-I or CT. Antiserum against the LT-II from E. coli HB101(pCP3837) completely neutralized purified LT-II and the LT-II in crude extracts of SA53, but it did not neutralize purified LT-I or CT.
Antigenic analysis of the major outer membrane protein of Chlamydia trachomatis with murine monoclonal antibodies
Authors: Batteiger B E , Newhall W J , Terho P , Wilde C E , Jones R B
Published: January 2020

We prepared monoclonal antibodies against prototype strains of the 15 serovars of Chlamydia trachomatis and identified a subset of reagents that reacted with the major outer membrane protein(s) (MOMPs) of one or more serovars. We then determined the specificities of these anti-MOMP monoclonal antibodies by radioimmunoassay and immunoblot assays against the 15 serovars of C. trachomatis and a C. psittaci strain. We identified 14 different anti-MOMP antibody specificities, including serovar-, several orders of subspecies-, and species-specific determinants. In addition, one antibody reacted with all C. trachomatis serovars and a C. psittaci strain, indicating the presence of a genus-specific epitope on MOMP. Many of the cross-reactions of the subspecies-specific antibodies were similar to those previously reported by use of the microimmunofluorescence technique. We also observed a number of cross-reactions that were unexpected but consistent with data derived by the microimmunofluorescence test. All antibodies, except the genus-specific antibodies, reacted with whole elementary bodies in a radioimmunoassay, suggesting surface exposure of the epitopes. These data confirm and extend previous observations that MOMPs among C. trachomatis serovars are antigenically complex and diverse. In addition, these data indicate that the cross-reaction patterns of some monoclonal antibodies directed against MOMP are similar to those detected by the microimmunofluorescence test and are consistent with the hypothesis that such determinants are contained within MOMPs.
Superoxide dismutase activity of Mycobacterium avium, M. intracellulare, and M. scrofulaceum
Authors: Mayer B K , Falkinham J O
Published: January 2020

Superoxide dismutase (EC 1.15.1.1) (SOD) activity has been detected in crude cell extracts of representative strains of the Mycobacterium avium, M. intracellulare, and M. scrofulaceum (MAIS) group. Polyacrylamide gel electrophoresis demonstrated a single SOD activity band for each of the MAIS strains, though there were differences in mobility. All M. avium and M. intracellulare and two of five M. scrofulaceum strains demonstrated a single activity band of identical mobility (Rf = 0.83), while the SOD activity band for the three remaining M. scrofulaceum strains migrated farther (Rf = 0.85). The differences in mobility correlated with differences in sensitivity to NaN3 and H2O2. The SOD activities of the majority of the MAIS strains which displayed the slower-migrating activity band were inhibited 22 to 81% after 15 min of exposure to 5 mM H2O2, suggesting that both iron and manganese may be present in a single enzyme. The SOD activities of the three M. scrofulaceum strains which had the faster-migrating activity band were inhibited 100% after only 5 min of exposure to 5 mM H2O2 and exhibited greater sensitivity to 5 and 10 mM NaN3, characteristics of an iron-containing SOD. A concentration of 1 mM KCN did not cause inhibition of enzyme activity in any of the MAIS strains tested. Extracellular SOD activity was detected in four of six MAIS strains and was shown to be identical in mobility to the SOD activity of the crude extracts.
Interference with granulocyte function by Staphylococcus epidermidis slime
Authors: Johnson G M , Lee D A , Regelmann W E , Gray E D , Peters G , Quie P G
Published: January 2020

The interaction of Staphylococcus epidermidis slime with human neutrophils (PMN) was examined by using isolated slime and allowing bacteria to elaborate slime and other extracellular products in situ. S. epidermidis slime was found to contain a chemoattractant. Incubation of PMN with 50 micrograms or more of slime per ml inhibited subsequent chemotaxis of the PMN to n-formyl-methionyl-leucyl-phenylalanine by 27% and to zymosan-activated serum by 44 to 67% with increasing slime concentrations. S. epidermidis slime stimulated little degranulation of untreated PMN. After pretreatment of PMN with 5 micrograms of cytochalasin b per ml, slime predominantly induced release of specific granule contents (33.8% lactoferrin release by 250 micrograms of slime per ml versus 10% myeloperoxidase release by 250 micrograms of slime per ml). By a surface phagocytosis assay, PMN uptake of radiolabeled S. epidermidis which were incubated for 18 h on a plastic surface for slime expression was less than that for S. epidermidis adhered to the plastic for 2 h or grown in unsupplemented nutrient broth. These results suggest that S. epidermidis slime interaction with PMN may be potentially detrimental to host defense and may contribute to the ability of this organism to persist on surfaces of foreign bodies in the vascular or central nervous system.
Immunological activity of a 38-kilodalton protein purified from Mycobacterium tuberculosis
Authors: Young D , Kent L , Rees A , Lamb J , Ivanyi J
Published: January 2020

A 38-kilodalton (kDa) protein antigen from Mycobacterium tuberculosis was purified by monoclonal antibody TB71-based affinity chromatography. This molecule carries two nonoverlapping epitopes recognized by monoclonal antibodies TB71 and TB72, which are expressed substantially more strongly by M. tuberculosis than by Mycobacterium bovis. However, cross-reactive determinants between these two species were revealed on the 38-kDa protein by a rabbit anti-BCG serum. An immunoradiometric assay based on the TB71 and TB72 antibody pair specifically determined 38-kDa-antigen concentrations in mycobacterial extracts. Antibodies in sera from tuberculosis patients estimated by binding to 38-kDa-antigen-coated microtiter plates were positively correlated with TB72 competing titers. Unlike antibodies, T-cell proliferative responses to the 38-kDa protein were expressed equally by 60% of tuberculosis patients and healthy BCG-vaccinated subjects. Similarly, delayed-type hypersensitivity skin reactions were elicited in both M. tuberculosis- and M. bovis-sensitized guinea pigs. The results suggest the immunodominance of the species-specific B-cell and cross-reactive T-cell stimulatory epitopes.
Inhibition of caries in hamsters treated with staphylococcin 1580
Authors: Fitzgerald R J , Morhart R E , Marquez C , Adams B O
Published: January 2020

Littermate hamsters were infected orally with cariogenic Streptococcus mutans NS-50S and maintained on a high-sucrose diet to induce dental caries. Individual groups of animals were treated by single daily instillation of staphylococcin 1580 (100 micrograms) in the cheek pouches. Other groups were treated similarly with bacitracin (60 or 120 U) or saline. After 35 days on the caries test regimen, animals treated with staphylococcin 1580 had 49 or 60% less caries than the saline controls in two separate trials. Hamsters treated with 60 U of bacitracin had 40% less caries, while animals receiving 120 U of bacitracin had 58% less caries. Significant reductions in the oral and fecal levels of S. mutans NS-50S were also observed in the treated animals. In contrast to earlier, inconclusive experiments in which these agents were placed directly into the oral cavity, the inhibition of caries in this study is attributed to prolongation of the oral retention of these agents, with increased opportunity to interact with cariogenic microorganisms.
Antibody-independent interactions of fibronectin, C1q, and human neutrophils with Treponema pallidum
Authors: Baughn R E
Published: January 2020

Although recent evidence suggests that fibronectin may be involved in the attachment of treponemes to mammalian cells, its possible role in promoting phagocytosis of Treponema pallidum has not been investigated. In the present study, we examined the antibody-independent interactions of fibronectin, C1q, and human polymorphonuclear leukocytes with T. pallidum. Binding of [125I]fibronectin was specific and saturable with an affinity constant of approximately 2 X 10(7) M-1. The number of binding sites per treponeme at 37 degrees C, irrespective of the mammalian source of fibronectin, was between 2,500 and 7,500, with a mean of approximately 4,700. Binding of [125I]C1q to T. pallidum, in the absence of antibodies to the organism, also was saturable and specific. Pretreatment of treponemes with C1q enhanced binding of soluble [125I]fibronectin two- to threefold and also increased attachment of 125I-surface-labeled treponemes to fibronectin-coated surfaces. Treatment of 125I-labeled T. pallidum with fibronectin alone, or together with C1q, however, did not enhance surface phagocytosis by neutrophils.