bluuebunny/crossref_metadata_2025 huggingface dataset:
Isolation from Mouse Spleen of Cell Populations with High Specific Infectivity for Scrapie Virus
Authors: Lavelle G. C. , Sturman L. , Hadlow W. J.
Published: January 2020

Spleen cells from mice infected with scrapie virus were separated into subpopulations on the basis of buoyant density in discontinuous gradients of isotonic albumin or differential adherence of cells to plastic. At three different intervals after infection, a population of “less dense” cells was found in albumin gradients that had 40-to 60-fold higher specific infectivity (cells per median lethal dose) than the total cell suspension before gradient sedimentation. The class of cells associated with high relative specific infectivity has a density characteristic of lymphoblasts, myeloblasts, and macrophages. Separation of “macrophage rich” cells on the basis of adherence to plastic did not result in significant enrichment of scrapie virus-infected cells.
Vascular Permeability Factor of
Pseudomonas aeruginosa
Authors: Kusama Hideo , Suss Robert H.
Published: January 2020

The production of vascular permeability factor (PF) by certain strains of
Pseudomonas aeruginosa
has been demonstrated in rabbits injected intradermally with culture filtrates followed by intravenous injection with Pontamine Sky Blue 6BX. The dose-response curve was found to be rectilinear when lesion diameters, within the range of 10 to 20 mm, were plotted against log dose. Thus, PF in test filtrates can be measured with reasonable accuracy by the concomitant testing of a reference PF. In contrast to the titers of PF obtained with
Vibrio cholerae
cultures, those with strains of
P. aeruginosa
were rather low. Thus far, PF has been demonstrated only in shallow still cultures of
P. aeruginosa
and not in shake cultures. A variety of commercial media were tested for the production of PF, but none was satisfactory. A synthetic medium that gave more reproducible and higher yields of PF was developed. Cultivation at 30 C generally gave higher yields of PF than at 37 C. PF was destroyed by heating at 60 C for 30 min or by digesting with trypsin or Pronase. Strains producing larger amounts of PF appeared to have greater virulence when inoculated onto the surface of burns in mice than those yielding little or no PF.
14
C-Glucose Oxidation in Whole Blood: a Clinical Assay for Phagocyte Dysfunction
Authors: Keusch Gerald T. , Douglas Steven D. , Mildvan Donna , Hirschman Shalom Z.
Published: January 2020

A screening test for chronic granulomatous disease is described; it is based on abnormal oxidation of glucose-
1
-
14
C
to
14
CO
2
during phagocytosis by leukocytes in whole blood.
Experimental Paracoccidioidomycosis in Mice
Authors: Linares Leonor I. , Friedman Lorraine
Published: January 2020

Virulence and infectivity of nine strains of
Paracoccidioides brasiliensis
were investigated in groups of mice which were inoculated intranasally or intravenously, and some of each were treated with corticosteroids. Fatal infections were not often seen among untreated mice, but mortality usually occurred when corticosteroids were given, regardless of the route of fungus inoculation. Prior treatment did not uniformly increase the incidence of infection, however; only in the case of intranasally inoculated mice was this effect seen. Most strains appeared to be more virulent when administered intravenously, with the exception of a single strain which, under the influence of corticosteroids, repeatedly displayed greatest virulence when given intranasally. All animals that died early in the course of the disease, irrespective of route of inoculation, always had acute pulmonary lesions and usually no other organ was involved. Animals which died later or were sacrificed always had chronic lung lesions. Whether or not chronically diseased animals had additional organ involvement correlated with how the organisms were administered; intravenously inoculated animals usually had extrapulmonary as well as pulmonary lesions, but lesions of those inoculated intranasally were almost exclusively pulmonary. Corticosteroids did not alter the histologic characteristics of either the acute or the chronic type of lesion, but the lesions of treated animals were usually more extensive. Most of the survivors appeared healthy even when infection was extensive.
Staphylococcidal Capability of Rabbit Peritoneal Macrophages in Relation to Infection and Elicitation: Induction and Elicitation of Activated Macrophages
Authors: Lenhart Nancy , Mudd Stuart
Published: January 2020

The capability of macrophages to inactivate ingested staphylococci can be augmented when repeated infection is followed by specific elicitation with staphylococcal lysate. The increase in staphylococcidal capability with specific elicitation after infection is not dramatic but is statistically significant. The percentage of change in staphylococcidal capability after infection and specific elicitation is systematically related to the staphylococcidal capability of the populations of macrophages in the same rabbits studied prior to infection. When the capability of the initial populations of macrophages has been high, the percentage of change after infection and elicitation may be slight or even negative. When the staphylococcidal capability of the initial population of macrophages in a given rabbit has been low, there is typically a significant increase in this capability after infection and elicitation. It is shown at the cellular level that it is possible to evoke a population of activated macrophages, by a procedure which is analogous to procedures reported as useful in human practice.
Immunity in Experimental Salmonellosis III. Comparative Immunization with Viable and Heat-Inactivated Cells of
Salmonella typhimurium
Authors: Germanier R.
Published: January 2020

Vaccination with viable cells of an avirulent
Salmonella typhimurium galE
mutant provides mice with solid specific immunity against subsequent infection with a virulent smooth strain. Such a live vaccine is markedly more potent than one prepared from inactivated cells of the virulent smooth strain. The superiority of the live vaccine is particularly well demonstrated when the oral route of application is used. The protective capacity of the
galE
mutant is based on its ability to synthesize complete smooth-like cell wall lipopolysaccharide in vivo.
Further Characterization of a Factor From Endotoxin-Treated Serum which Releases Histamine and Heparin from Mast Cells
Authors: Hook William A. , Snyderman Ralph , Mergenhagen Stephan E.
Published: January 2020

Upon incubation of hamster serum with bacterial endotoxin, a factor is produced which releases histamine and heparin from hamster mast cells and increases capillary permeability in guinea pig skin. The major histamine-releasing activity derived from hamster serum was characterized by gel filtration, found to have a molecular weight of approximately 60,000, and shown by electrophoresis to migrate with alpha-2- or beta-1-globulins. The ability to increase vascular permeability was not reversed by antihistamine. On the basis of these properties, the histamine-liberating factor generated by endotoxin in hamster serum differed significantly from known anaphylatoxins.
Selective Effects of Thermal Injury on Mouse Peritoneal Macrophages
Authors: Smith C. Wayne , Goldman A. S.
Published: January 2020

Normal mice or mice burned 6 days previously were injected intraperitoneally with either saline or 50 μg of concanavalin A. Four days after the injection the peritoneal macrophages were collected and examined in vitro. Macrophages from concanavalin A-injected mice appeared activated because several in vitro parameters of activity were increased. Examination of macrophages from burned animals revealed a selective depression of macrophage activity.
Visceral leishmaniasis in congenic mice of susceptible and resistant phenotypes: immunosuppression by adherent spleen cells
Authors: Nickol A D , Bonventre P F
Published: January 2020

Visceral leishmaniasis is one of several parasitic diseases of humans characterized by immune suppression. A murine model of disseminated leishmaniasis utilizing inbred strains of specific genetic constitution was used to study the mechanisms of immunosuppression elicited during the course of infection. Resistant (Lshr) and susceptible (Lshs) strains of mice were challenged with amastigotes of Leishmania donovani and evaluated as to immune status at intervals between 2 and 40 weeks after challenge. The proliferative responses of splenic lymphocytes to T-cell mitogens, a B-cell mitogen, and parasite antigens were measured to evaluate the relative immune status of parasitized mice and noninfected control mice. Lymphocytes from resistant C3Heb/FeJ (C3H) mice responded normally to concanavalin A and phytohemagglutinin throughout the course of infection. Parasite antigen responses appeared 2 weeks after challenge of C3H mice and remained vigorous for periods up to 6 months. In contrast, immune suppression during infection was profound in both the curing (C57B1/10) and noncuring (B10.D2) phenotypes of Lshs congenic mice. Both Lshs strains developed severe infection as evidenced by high parasite burdens in the liver and spleen 4 to 5 weeks after challenge; splenic lymphocytes taken from these mice between 2 and 8 weeks became increasingly unresponsive to the T-cell mitogens as well as to parasite antigens. The noncuring B10.D2 mice which suffered chronic infection continued to be suppressed for as long as 40 weeks. C57B1/10 (curing) mice, in contrast, cleared infection between 12 and 16 weeks. After spontaneous recovery or elimination of parasites by antimonial drug therapy, the response of spleen cells to T-cell mitogens or parasite antigens were restored to normal. The spleen cells from the Lshs strains of mice obtained during the height of infection suppressed the proliferative responses of spleen cells from their uninfected counterparts upon cocultivation in vitro. Removal of adherent cells from the suppressive spleen cell populations restored normal mitogen responses. On the basis of adherence characteristics, phagocytosis, and morphology, the suppressor was identified as a macrophage population which appears to be responsible for a nonspecific immunosuppression of Lshs mice with significant parasite burdens of L. donovani.
Monoclonal antibodies against surface antigens of Bacteroides gingivalis
Authors: Naito Y , Okuda K , Kato T , Takazoe I
Published: January 2020

Monoclonal antibodies against the various surface antigens of Bacteroides gingivalis were obtained by the fusion of murine myeloma cells (SP2/0-Ag14) with spleen cells of BALB/c mice immunized with the whole cells. Two monoclonal antibodies reacted with lipopolysaccharide, and the other two reacted strongly with capsule antigen. One showed reactivity with the hemagglutinin of the cells. The five monoclonal antibodies reacted with sonicated antigen from all B. gingivalis strains tested. No cross-reactivity of the monoclonal antibodies with antigens from nine species of other black-pigmented Bacteroids strains was observed. An immunoblotting test involving the use of these monoclonal antibodies indicated that the epitope of B. gingivalis lipopolysaccharide was polysaccharide with a high molecular weight of 40,000 to 60,000. The immunoblotting test also demonstrated that the epitopes of capsule antigen and of hemagglutinin were 27,000- and 40,000-molecular-weight proteins, respectively.
Degradation of muramyl dipeptide by mammalian serum
Authors: Harrison J , Fox A
Published: January 2020

Muramyl dipeptide, N-acetylmuramyl-L-alanine-D-isoglutamine (MDP), is the minimal biologically active subunit of bacterial peptidoglycan and elicits an acute inflammation in vivo. We now report that MDP is degraded by normal rat serum into its constituents, N-acetylmuramic acid and L-alanine-D- isoglutamine. The dipeptide is further degraded into its components L-alanine and D-isoglutamine. These results may help to explain how inflammation elicited by MDP is terminated in vivo.
Enzyme-linked immunosorbent assay antibody responses to a temperature-sensitive mutant of Pseudomonas aeruginosa
Authors: Sordelli D O , Rojas R A , Cerquetti M C , Hooke A M , Degnan P J , Bellanti J A
Published: January 2020

The serum immunoglobulin G and M responses induced by immunization of mice with temperature-sensitive mutant A/10/25 of Pseudomonas aeruginosa were evaluated by enzyme-linked immunosorbent assay. These antibody responses were immunotype specific, and the immunoglobulin G antibody level, although low, was still significant by day 52 after vaccination.
Liver macrophages (Kupffer cells) as cytotoxic effector cells in extracellular and intracellular cytotoxicity
Authors: Decker T , Kiderlen A F , Lohmann-Matthes M L
Published: January 2020

The potential of the resident murine Kupffer cell to be cytotoxic in extra- and intracellular killing systems in vitro was investigated. Kupffer cells exerted no spontaneous cytotoxicity but were readily susceptible to activation with lymphokines. Such activated Kupffer cells very efficiently killed extracellular P815 cells and intracellular Leishmania spp. parasites. Kupffer cells could be induced to proliferate in vitro under the influence of colony-stimulating factor (D.-M. Chen, H.-S. Lin, P. Stahl, and R. Stanley, Exp. Cell Res. 121:103-109, 1979). Kupffer cell-derived macrophages cultured in vitro were identical to their liver-derived progenitors in terms of macrophage-specific surface antigens and with respect to extra- and intracellular cytotoxicity. These results demonstrated that Kupffer cells have a strong self-renewing potential and that essential Kupffer cell properties like antigenic determinants and cytotoxic potential remained stable throughout the replicative process. The possibility of Kupffer cell self-renewal in the intact organism is also discussed.
Antigenic heterogeneity of an alkali-soluble, water-soluble cell wall extract of Coccidioides immitis
Authors: Cox R A , Britt L A
Published: January 2020

The antigenic composition of an alkali-soluble, water-soluble cell wall extract of Coccidioides immitis, designated C-ASWS, was assessed by two-dimensional immunoelectrophoresis against goat antisera to C-ASWS and coccidioidin. The results established that C-ASWS from mycelia or spherule cell walls is heterogeneous in composition, containing two distinct antigenic components. One is present as a polymer that is antigenically identical to a polymeric antigen in coccidioidin, designated antigen 2. The other component detected in C-ASWS presented an unusual precipitin pattern in that a cathodal leg was demonstrable in the absence of an anodal leg. This incomplete precipitinogen was also detected in coccidioidin. In addition to the finding that C-ASWS is antigenically heterogeneous, the results provide evidence that the conformational and/or configurational structure of the C-ASWS antigen 2 (or antigen 2-like polymer) is altered during physicochemical extraction. This conclusion is based upon the finding that the immunoelectrophoretic profile of the C-ASWS polymer differs from that of coccidioidin antigen 2. The C-ASWS polymer is characterized by having a small cathodal precipitin peak connected to a large anodal peak, whereas coccidioidin antigen 2 is characterized by a predominant cathodal peak.
Suppressor factor of T-cell activation and decreased interleukin 2 activity in experimental African trypanosomiasis
Authors: Alcina A , Fresno M
Published: January 2020

Spleen cells from Trypanosoma brucei-infected BALB/c mice were unable to respond to a T-cell mitogen, concanavalin A. Moreover, they were unable to produce detectable amounts of the growth factor required for T cell proliferation, interleukin 2. In addition, supernatants from 24-h in vitro cultures of these cells produced a slight but detectable suppressive activity of the interleukin 2-dependent proliferation of a T-cell line. Infected spleen cells also suppressed the response of T. brucei-immunized spleen cells as well as normal spleen cells to concanavalin A. However, a major difference was shown in the mechanism of the suppression in both systems. Suppression of normal spleen cells required cell-to-cell contact. In contrast, suppression of 30-day T. brucei-immune cells could be mediated by a soluble suppressor factor released by in vitro culture of infected spleen cells. This molecule had an apparent molecular weight of 18,000. Finally, similar suppression could be generated in 30-day T. brucei-immune spleen cells but not in normal cells, with living cells but not with extracts of T. brucei.
Plasmid-mediated virulence in Salmonella dublin demonstrated by use of a Tn5-oriT construct
Authors: Chikami G K , Fierer J , Guiney D G
Published: January 2020

Salmonella dublin, a serotype which causes invasive disease in cattle and humans, carries a characteristic 80-kilobase plasmid (pSDL2). We were able to cure the plasmid from a strain of S. dublin. The cured strain was avirulent for mice by either the oral or intraperitoneal route of infection. A derivative of Tn5 which contains the transfer origin of the broad-host-range plasmid RK2 (Tn5-oriT) was transposed onto pSDL2, allowing mobilization of the plasmid by an RK2 helper plasmid. Reintroduction of the pSDL2 derivative plasmid into the cured strain restored virulence, demonstrating that the plasmid is necessary for virulence. These studies also demonstrate the usefulness of the Tn5-oriT construct for genetic manipulations.
Phagocytes from flora-defined and germfree athymic nude mice do not demonstrate enhanced antibacterial activity
Authors: Czuprynski C J , Brown J F
Published: January 2020

In this study we directly compared the in vitro antibacterial activities of resident and inflammatory phagocytes obtained from athymic (nu/nu) and euthymic (nu/+) mice. Resident peritoneal macrophages obtained from flora-defined nu/nu and nu/+ mice both demonstrated little ability to restrict the growth of Listeria monocytogenes in vitro. Inflammatory peritoneal neutrophils and macrophages obtained from flora-defined nu/nu and nu/+ mice did not differ in their ability to kill L. monocytogenes in vitro. Likewise, inflammatory peritoneal neutrophils obtained from germfree nu/nu and nu/+ mice killed equivalent numbers of listeria. In marked contrast, however, inflammatory macrophages obtained from germfree nu/nu and nu/+ mice demonstrated very limited antilisteria activity in vitro. The reduced antilisteria activity of macrophages from germfree nu/nu and nu/+ mice was associated neither with reduced phagocytosis of L. monocytogenes nor with an inability to generate an oxidative response. Unlike those of previous reports, these data suggest that resident and inflammatory phagocytes obtained from athymic mice that were maintained under conditions such that they were not subjected to underlying infections are not constitutively activated for enhanced antibacterial activity. Furthermore, these data suggest that stimulation of macrophages by products of the bacterial flora is required for the expression of macrophage antibacterial activity.
Inactivation of key factors of the plasma proteinase cascade systems by Bacteroides gingivalis
Authors: Nilsson T , Carlsson J , Sundqvist G
Published: January 2020

The effect of Bacteroides gingivalis W83 on various key components of the human plasma proteinase cascade systems was studied. When purified C1-inhibitor was incubated with the bacterium, the inhibitor was rapidly inactivated by limited proteolytic cleavage. In citrated whole plasma, C1-inhibitor, antithrombin, plasminogen, prekallikrein, prothrombinase complex, the clotting factor X, and most of the alpha 2-antiplasmin were functionally eliminated after 30 min of incubation with the bacterium. Fibrinogen disappeared from the plasma almost immediately upon mixing with the bacterial suspension. In contrast, there was no appreciable decrease in the bulk of other plasma proteins, such as various transport proteins (albumin, prealbumin, transferrin) and immunoglobulins, during 4 h of incubation with the bacterium. Most of the observed effects can be assigned to the proteolytic activity of the bacterium itself, since there was little evidence for generation of intrinsic plasma proteinase activity, despite the loss of proteinase inhibitory activities. B. gingivalis W83 thus seems to be equipped with proteolytic enzyme systems which selectively recognize and rapidly inactivate the most important proteinase inhibitors and proenzymes present in human plasma. This bacterium therefore seems to be able to efficiently paralyze the host's various defenses against invading microorganisms.
Identification and antigenic characterization of virulence-associated, plasmid-coded proteins of Shigella spp. and enteroinvasive Escherichia coli
Authors: Hale T L , Oaks E V , Formal S B
Published: January 2020

Seven plasmid-coded polypeptides, designated a through g, were identified by two-dimensional nonequilibrium pH gradient electrophoresis of radiolabeled extracts from minicells of virulent Shigella flexneri serotypes 2a and 5 and enteroinvasive Escherichia coli O143. These polypeptides were deemed to be products of 140-megadalton (MDa) virulence-associated plasmids because they were not synthesized in minicells which were not harboring a 140-MDa plasmid or in minicells which were carrying an F lac plasmid of the same incompatibility group. Synthesis of these polypeptides was repressed in minicells incubated at 30 degrees C and in minicells isolated from a noninvasive opaque colonial variant, even though these strains harbored a 140-MDa plasmid. Enriched fractions of polypeptides b, c, and d were obtained from S. flexneri serotype 5 by preparative isoelectric focusing, and polyclonal rabbit antisera recognizing each polypeptide were raised. These antisera were able to detect cross-reacting plasmid-coded polypeptide antigens in S. flexneri serotype 3, Shigella sonnei, and enteroinvasive E. coli O143. In addition, Western blots of minicell extracts from S. flexneri serotype 5 or E. coli O143 indicated that plasmid-coded polypeptides a through d were recognized by convalescent antiserum from a monkey infected with S. flexneri serotype 2a.
Role of culture conditions and immunization in experimental nutritionally variant streptococcal endocarditis
Authors: van de Rijn I
Published: January 2020

The nutritionally variant streptococci (NVS) are usually isolated from patients with NVS endocarditis and recently have been serotyped into three groups. In the past, studies on microbial endocarditis have not analyzed the effect of the growth medium or growth phase on the bacteria used to induce the disease in the experimental rabbit model. Therefore, in this study various bacterial growth parameters were examined, including growth in semisynthetic or complex medium to the exponential or stationary phase of growth. The 50% infective dose ranged from 3.7 X 10(5) to 8.5 X 10(6) CFU for representative strains from each of the three serotypes grown under these conditions, indicating that there was no significant difference. The role of immunization was also examined in this model using organisms grown to the exponential phase in semisynthetic medium. Rabbits were immunized with heat-killed whole cells, high titres of specific antibody were produced as demonstrated by enzyme-linked immunosorbent assay, and then the rabbits were challenged with 20- to 100-fold 50% infective dose of the homologous strain. A total of 90 to 100% of the rabbits were protected from the disease process, as shown by the absence of the organisms from the heart valve 3 days after the challenge. Rabbits immunized with the amphiphile that replaces lipoteichoic acid in these organisms were not protected from challenge, demonstrating that another surface component is responsible for adherence or colonization or both. Finally NVS were incubated with radioiodinated fibronectin, fibrinogen, or laminin to determine whether these molecules aided in the adherence of the organisms to the heart valve. Only minor amounts of these components were bound to NVS as compared with controls. Therefore, NVS bind directly to the damaged heart valve or through an unknown mechanism.
Bacterial flora in spontaneously occurring aural cholesteatomas in Mongolian gerbils
Authors: Fulghum R S , Chole R A
Published: January 2020

Bacteria were isolated from 29 Mongolian gerbils, Meriones unguiculatus, with spontaneous aural cholesteatomas. We identified 148 cultures, 44 from the middle ear surface of cholesteatomas and 104 from cholesteatoma contents. We could only identify 63 cultures to the genus level, although we identified 85 cultures as belonging to 21 different species. We found on the surfaces of cholesteatomas representatives of 9 genera, from which 8 species could be identified, and representatives of 19 genera within the cholesteatoma sac, from which 21 species could be identified. The most common bacterial genera isolated were Staphylococcus, Pseudomonas, and Corynebacterium among the aerobic genera, and Bacteroides and Peptococcus among the anaerobic genera. The bacterial flora of gerbilline cholesteatomas was found to be diverse, resembling the flora found to be associated with human cholesteatomas. The flora also resembled the organisms found transitorily within the normal middle ear cavity of gerbils, except for a higher incidence of pseudomonads.
Effects of human serum on the growth and metabolism of Neisseria gonorrhoeae: an alternative view of serum
Authors: Britigan B E , Chai Y , Cohen M S
Published: January 2020

Humans are the sole reservoir of Neisseria gonorrhoeae, an organism which undergoes a marked increase in metabolic rate after exposure to a low-molecular-weight, heat-stable component(s) of human serum. Further studies on the effect of serum on gonococcal metabolism were undertaken. Gonococcal broth (GCB) is commonly used for in vitro cultivation of gonococci. Gonococci suspended in GCB plus 10% serum exhibited oxygen consumption rates of 139% (P less than 0.01) and 456% (P less than 0.01) of those suspended in GCB or Hanks balanced salt solution, respectively. A twofold increase in growth rate also resulted from the addition of 10% serum to GCB. Gonococcal 14C-labeled adenine incorporation increased threefold with 10% serum supplementation of Hanks balanced salt solution. Dialysis of serum in 1,000-molecular-weight exclusion tubing removed the stimulatory factor(s). Neither correction of anion-cation concentrations altered by dialysis nor addition of substances of known importance to the metabolism of gonococci (i.e., lactate, pyruvate, cysteine, ATP, AMP, NADPH, amino acids, malate, and glutathione) to dialyzed serum reconstituted stimulatory capacity. The effect of serum on gonococcal glucose-catabolic pathways was measured by modified radiospirometry. An apparent threefold increase in Entner-Doudoroff and pentose phosphate pathway activities was induced by 10% serum, as was the increased shunting of glucose-derived glyceraldehyde-3-phosphate into these pathways. These metabolic changes did not allow specific identification of the serum stimulatory factor(s). Acetate, the major by-product of gonococcal glucose catabolism, inhibited gonococcal oxygen consumption as previously reported. A high-molecular-weight serum component, probably albumin, reversed acetate-mediated inhibition of gonococcal oxygen consumption, identifying a second mechanism by which serum increases gonococcal metabolism. These results suggest that supplementation of growth media with serum should be considered to provide N. gonorrhoeae with conditions more consistent with its normal environment.
Skin reactivity of unsensitized monkeys upon challenge with staphylococcal enterotoxin B: a new approach for investigating the site of toxin action
Authors: Scheuber P H , Golecki J R , Kickhöfen B , Scheel D , Beck G , Hammer D K
Published: January 2020

The correlation between skin tests and emetic responses in unsensitized monkeys was used to elucidate the cellular site of action of staphylococcal enterotoxin B (SEB). Evidence is presented that SEB administered intradermally provoked immediate-type skin reactions associated with mild degranulation of cutaneous mast cells. The cytoplasma showed signs of synthetic and metabolic activity, with formation of vesicles and increased prominence of mitochondria. Carboxymethylation of histidine residues of SEB altered the molecule (cSEB) from more alkaline components to more acidic species with increased microheterogeneity. This modification caused a loss in toxicity and completely abrogated the skin-sensitizing activity without changing the immunological specificity. cSEB, however, could compete with SEB for binding sites on the target cell surface. Previously, compound 48/80-treated skin sites behaved refractively to challenge with SEB, indicating that mediators from cutaneous mast cells are required for SEB-induced skin reactions. Skin reactions as well as emetic responses challenged with SEB were completely inhibited by H2 receptor antagonists and calcium channel blockers but not by H1 antihistamine or competitive antagonists of serotonin. This new approach provides a model for investigating the mechanisms of SEB action.
Mechanisms of immunity to infection with typhus rickettsiae: infected fibroblasts bear rickettsial antigens on their surfaces
Authors: Rollwagen F M , Bakun A J , Dorsey C H , Dasch G A
Published: January 2020

As with any immune response to infectious organisms, both antibody and T cell-mediated immune responses to infection with Rickettsia typhi require the appropriate presentation of rickettsial antigens to immunocompetent cells. Considering the obligate intracellular nature of rickettsiae, the exact mechanisms by which lymphocytes and macrophages encounter and respond to rickettsial antigens may depend on certain aspects of pathogenesis and on the availability of organisms or their antigens to cells of the immune system. One potential mode of rickettsial antigen presentation, not previously identified, is the appearance in vitro of rickettsial antigens on the cell membrane of R. typhi-infected L-929 fibroblasts. Polyvalent fluoresceinated rabbit antisera directed against whole R. typhi cells used in flow cytometric analysis of infected fibroblasts showed an increasing presence of R. typhi antigen on the host cell membrane 1 to 3 days postinfection. The significance of this finding in the pathophysiology of rickettsia-host interactions and the generation of cytotoxic T cell-mediated immunity and antibody immunity is discussed.
Detection of the major adhesin P1 in triton shells of virulent Mycoplasma pneumoniae
Authors: Kahane I , Tucker S , Leith D K , Morrison-Plummer J , Baseman J B
Published: January 2020

Filamentous structures designated Triton shells were obtained from virulent Mycoplasma pneumoniae by treatment with Triton X-100. Monoclonal antibodies directed against M. pneumoniae were used in conjunction with radioimmunoprecipitation and Western blotting to detect immunologically reactive polypeptides in Triton shells. The major adhesin, protein P1, was associated with these structures.
Abilities of human oligodendroglial cells and mouse Schwann cells to phagocytose Mycobacterium leprae and other mycobacteria
Authors: Saito H , Tomioka H , Sato K , Watanabe T
Published: January 2020

Human oligodendroglial KG-1-C cells derived from human cerebral mixed glioma and mouse Schwann cells derived from dorsal root ganglion were studied with respect to their abilities to phagocytose various mycobacteria, especially Mycobacterium leprae, and other microorganisms. KG-1-C cells phagocytosed M. leprae at a markedly higher rate than BALB/3T3, BHK 21, HeLa S3, mKS-A TU-7, XC, TSV-5, N-18, and Schwann cells but at a lower rate than peritoneal macrophages. Schwann cells also exhibited substantial phagocytic ability against M. leprae, and their phagocytic rate against M. leprae was much higher than that of N-18 cells, derived from neurons. KG-1-C and Schwann cells phagocytosed mycobacteria other than M. leprae, and their phagocytic patterns with various mycobacteria were similar, thereby suggesting that their abilities to phagocytose mycobacteria were based on the same cellular mechanism. The time course of phagocytosis of M. leprae by KG-1-C cells markedly differed from that by macrophages, indicating differences in the cellular mechanisms of M. leprae phagocytosis. KG-1-C cells also ingested microorganisms other than acid-fast bacilli, such as Staphylococcus aureus, Listeria monocytogenes, Bacillus subtilis, and Escherichia coli but not Candida albicans. They also phagocytosed latex beads (0.8-micron diameter) but not sheep erythrocytes. Microscopically, most mycobacterial cells were ingested in the perikaryon of KG-1-C cells and Schwann cells.
Mechanisms of phagocytosis of Mycobacterium leprae and other mycobacteria by human oligodendroglial cells
Authors: Saito H , Tomioka H , Watanabe T , Sato K
Published: January 2020

The mechanisms by which human oligodendroglial cells, KG-1-C cells, phagocytose mycobacteria, especially Mycobacterium leprae, were studied. The ability of glial cells to phagocytose M. leprae was inhibited by azide, dinitrophenol (inhibitors of oxidative phosphorylation), and iodoacetamide but not fluoride (both are inhibitors of glycolysis). Thus, the energy metabolism dependency is somewhat different from that of peritoneal macrophages and polymorphonuclear leukocytes, the phagocytic capacities of which are mainly dependent on glycolysis. Phagocytosis of M. leprae by KG-1-C cells was markedly suppressed by a microfilament inhibitor (cytochalasin B) but not microtubule inhibitors (colchicine and vinblastine), as with macrophages. The phagocytosis of M. leprae by KG-1-C cells was dependent on the lipid and somewhat on the sugar ligands of the organism. Moreover, the phagocytosis of a given mycobacterium by KG-1-C cells correlated well with its hydrophobicity, thus revealing the importance of some lipid moieties on the surface of bacteria in the establishment of rigid binding interaction of bacteria with KG-1-C cells, before the onset of engulfment. Electric charge of a given microorganism did not correlate with its phagocytosis by KG-1-C cells.
Cercarial glycocalyx of Schistosoma mansoni activates human complement
Authors: Samuelson J C , Caulfield J P
Published: January 2020

Human complement activation by cercariae and schistosomula of the human parasite Schistosoma mansoni was studied in vitro. Cercariae are composed of tails which are shed after infection of the host and bodies which transform into the larvae or schistosomula after infection. After incubation in fresh normal human serum (NHS), cercarial tails bound more anti-C3 antibodies than did cercarial bodies (CB), and the tails were rapidly lysed, while the attached CB remained intact. Complement activation by cercariae was dependent on the alternative pathway but was independent of antibody, as shown by C3 deposition by hypogammaglobulinemic human sera. By transmission microscopy, the fibrillar glycocalyx on both CB and tails was stained by NHS but not by heat-inactivated serum (HI-NHS). The glycocalyx was labeled with periodate and tritiated borohydride, and parasites were incubated in NHS and HI-NHS. After solubilization, the labeled glycocalyx on organisms incubated in NHS but not HI-NHS bound anti-C3 antibodies. Of the CB incubated with eserine sulfate to prevent transformation, 78% +/- 10% were dead after culture for 24 h in NHS. In contrast, 21% +/- 12% of the CB were dead after culture in HI-NHS. Schistosomula incubated in NHS bound 37% of the amount of anti-C3 antibodies bound by cercariae but were not killed by NHS. In conclusion, the cercarial glycocalyx activated human complement, and schistosomula were less susceptible to killing than cercariae because they had less glycocalyx and activated less complement.
Arthropathic properties of cell wall polymers from normal flora bacteria
Authors: Stimpson S A , Brown R R , Anderle S K , Klapper D G , Clark R L , Cromartie W J , Schwab J H
Published: January 2020

Peptidoglycan-polysaccharide (PG-PS) fragments were purified from cell walls of group D streptococci (Streptococcus faecium, strains ATCC 9790 and F-24) with a protocol which minimizes autolytic activity and tested for ability to induce arthritis in rats. PG-PS fragments from cell walls of other normal flora bacteria (Peptostreptococcus productus, and Propionibacterium acnes), group A streptococci, and pseudomurein-PS fragments from cell walls of Methanobacterium formicicum, were similarly purified and tested. Upon intraarticular injection into rat ankles, all PG-PS polymers induced acute inflammation; pseudomurein-PS fragments were approximately five times less active than the PG-PS preparations. After intraperitoneal injection, P. acnes PG-PS induced a minimal acute arthritis, Peptostreptococcus productus PG-PS induced a moderately severe acute joint inflammation followed by a mild chronic arthritis, and both group A and group D streptococcal PG-PS induced severe acute arthritis which evolved into chronic, erosive joint disease; pseudomurein-PS fragments were without effect, consistent with a crucial role for the PG moiety of PG-PS. Chronic arthritis induced by group D streptococcal PG-PS subsided after 60 days, whereas that induced by group A streptococcal PG-PS was still active after 128 days. The arthropathic properties of this modest number of common normal flora bacteria suggest that different PG-PS structures derived from the normal flora have the potential to induce a wide range of responses, from transient acute to chronic erosive joint disease.
Variability in expression of cell surface antigens of Candida albicans during morphogenesis
Authors: Brawner D L , Cutler J E
Published: January 2020

The location and expression of two different cell surface antigens on germinating and nongerminating Candida albicans cells was examined by using transmission electron microscopy after labeling with monoclonal antibodies (H9 or C6) and immunocolloidal gold. Immunodeterminant expression of the two carbohydrate antigens was followed from early germination events through 20 h of development. The determinant detected by H9 antibody, which was initially lost from the mother cell surface and preferentially expressed only on hyphae during the first 4 h of germination, reappeared on the mother cell by 20 h, whereas the antigen detected by antibody C6 was continually expressed on mother cells and germ tubes throughout germination.
Alteration of alveolar macrophage functions after aerosol infection with bovine herpesvirus type 1
Authors: Bielefeldt Ohmann H , Babiuk L A
Published: January 2020

Calves were aerosol challenged with bovine herpesvirus type I, and bronchoalveolar cells were subsequently retrieved by lavage from days 1 to 8 postinfection. Alveolar macrophages (AM), which were depleted of contaminating cells, were characterized with respect to phenotypic markers and functional activities. In most aspects, the changes suggested a stimulation of the AM. With variations in kinetics the percentage of AM expressing an MHC II antigen and Fc (immunoglobulin G)-mediated phagocytosis increased, as did the activity level of two ectoenzymes and the lysosomal hydrolase beta-glucoronidase. The generation of prostaglandin E2 by the AM also rose significantly. However, selective suppression of cellular cytotoxicity and interleukin-1 generation was observed. These findings may have important implications for understanding the events involved in the virus-bacterial interaction in respiratory diseases.
Antigenic and phenotypic variations of Haemophilus influenzae type b lipopolysaccharide and their relationship to virulence
Authors: Kimura A , Hansen E J
Published: January 2020

Haemophilus influenzae type b (Hib) strains NO100 and COL10 were found to produce bacteremia in infant rats at a much lower frequency than other Hib strains previously tested. These relatively avirulent strains were the only Hib strains among 200 clinical isolates examined to date which failed to react with two Hib lipopolysaccharide (LPS)-specific monoclonal antibodies (MAbs). LPS analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that strains NO100 and COL10 possessed LPS which migrated faster than the LPS of Hib strains that reacted with one of the two or with both of these MAbs. These observations suggested that the relative lack of virulence of strains NO100 and COL10 might be related to their unusual LPS phenotype. To determine whether alteration of LPS structure would affect the virulence of these strains, we identified and isolated isogenic LPS antigenic variants of strains NO100 and COL10 using the LPS-specific MAbs 4C4 and 5G8 in a colony blot radioimmunoassay. Antigenic variation of LPS was found to occur spontaneously in these two strains at a relatively high frequency in terms of both acquisition and loss of MAb reactivity (ca. 0.2 to 16.7%). LPS antigenic variants of strains NO100 and COL10 reactive with both MAbs 4C4 and 5G8 (4C4+ 5G8+) were more virulent in the infant rat model than their respective 4C4- 5G8- parental strains (P less than 0.01). An antigenic variant of COL10 reactive with only MAb 4C4 (4C4+ 5G8-) was also significantly more virulent than its 4C4- 5G8- parent. These LPS antigenic variants with increased virulence synthesized altered LPS molecules which possessed apparent molecular weights higher than those of the LPS of the parental strains. Increased resistance of strain NO100 to the bactericidal activity of normal infant rat serum was associated with changes in LPS structure, while strain COL10 and its LPS variants were all uniformly resistant to serum bactericidal activity. Our results demonstrate that (i) spontaneous antigenic and phenotypic variation of LPS occurs at a relatively high frequency in some strains of Hib; (ii) the higher-molecular-weight type of LPS is associated with the full expression of Hib virulence; (iii) LPS phenotype may not correlate with Hib serum resistance; and (iv) serum resistance of Hib is not an accurate indicator of virulence.
Immunological cross-reactivity of anionic proteins from caries-free and caries-active salivas which differ in biological properties toward oral streptococci
Authors: Obenauf S D , Cowman R A , Fitzgerald R J
Published: January 2020

We examined whether the anionic antimicrobial proteins in the saliva of certain caries-free (CF) individuals are immunologically cross-reactive with proteins in caries-active (CA) saliva which display identical isoelectric points but which exhibit growth-supportive properties for the oral streptococci. In the immunoblotting experiments reported here, the proteins present in CF and CA whole salivas reacted similarly with an antiserum prepared against the anionic inhibitory proteins. This antiserum also showed identical reactivity with the purified protein fraction containing the anionic proteins of interest from whole saliva of either CF or CA subjects. Additionally, an antiserum to CA saliva was found to react with the CF anionic inhibitory proteins. The fact that the inhibitory and noninhibitory proteins react similarly with the antisera used provides further evidence for similarity between both classes of proteins.
Human immune responses to oral microorganisms: patterns of systemic antibody levels to Bacteroides species
Authors: Ebersole J L , Taubman M A , Smith D J , Frey D E
Published: January 2020

Human systemic antibody levels to oral members of the Bacteroides genus were assessed with an enzyme-linked immunosorbent assay. Antibody levels to B. gingivalis, two homology groups of B. intermedius, B. melaninogenicus, B. denticola, B. loescheii, B. corporis, B. oralis, B. buccae, and B. gracilis were determined in subjects with localized juvenile periodontitis, advanced destructive periodontitis, or adult periodontitis and in normal persons. Significantly elevated serum immunoglobulin G (IgG) antibody levels to B. gingivalis were seen in adult and advanced destructive periodontitis patients. Serum IgM and IgA antibodies were increased in diseased versus normal subjects, whereas negligible levels of serum IgE antibody were detected to this microorganism. Serum IgG antibody levels to B. intermedius were increased in advanced destructive periodontitis patients; however, the frequency of elevated responses were similar among the groups. Extreme antibody levels to the other Bacteroides spp. were occasionally observed in this population. Additionally, all of the elevated levels were found in diseased patients. Distribution analyses of the antibody levels indicated that most patients exhibited a pattern of elevated antibodies to a limited number of the oral Bacteroides spp. The results suggested that elevated systemic antibody levels to oral Bacteroides spp. are more frequently found in periodontal disease patients. These antibody responses presumably reflect a colonization of the patients. The distribution of the responses may indicate the potential pathogenicity of the microorganisms and is consistent with distinctive host-parasite interactions in this disease.
Salmonella typhimurium virulence genes necessary to exploit the Itys/s genotype of the mouse
Authors: Benjamin W H , Turnbough C L , Posey B S , Briles D E
Published: January 2020

The studies described in this paper provide evidence that the pathogenesis of Salmonella typhimurium in mice is dependent on interactions between particular genotypes of the infected mice and the infecting Salmonella strain. This conclusion was based on data obtained by infecting a panel of BXD recombinant inbred mice with each of three S. typhimurium strains. One of the S. typhimurium strains was a transconjugant (WB500) produced in an interrupted mating between the two other strains, one (SR-11) of high and the other (LT2-Z) of low virulence for BALB/c mice. We found that strain WB500 appeared to have inherited from SR-11 a gene (or genes) which was required to exploit the Itys/s genotype in mice. However, WB500 apparently lacked other SR-11 virulence gene(s), whose effect on the in vivo growth of SR-11 was independent of the Ity genotype of the mouse.
Human T-cell clones with reactivity to Mycobacterium leprae as tools for the characterization of potential vaccines against leprosy
Authors: Emmrich F , Kaufmann S H
Published: January 2020

T-cell clones with the T4 phenotype were established from patients with tuberculoid leprosy. The antigen reactivity of these clones ranged from stringent specificity for Mycobacterium leprae to broad cross-reactivity with other mycobacteria. Killed M. leprae had a weak stimulatory capacity which could be enhanced by ultrasonication. Among the three candidate antileprosy vaccines, M. leprae, M. bovis BCG, and the ICRC (Indian Cancer Research Center) strain, the last was superior in stimulating cross-reactive T4 clones. This finding argues for a differential masking of similar or identical membrane antigens in various mycobacterial species. T-cell clones with defined reactivity patterns for mycobacterial antigens could be helpful tools for the characterization of an antileprosy vaccine.