bluuebunny/crossref_metadata_2025 huggingface dataset:
Immunoregulation in experimental murine candidiasis: specific suppression induced by Candida albicans cell wall glycoprotein
Authors: Carrow E W , Domer J E
Published: January 2020

Immune regulation in candidiasis is inferred from studies of both human and animal infection, with a suppressive role suggested for cell wall polysaccharide. To study the immunosuppressive potential of Candida albicans in a murine model, whole blastoconidia or purified cell wall components of C. albicans were tested for their effects on the development of acquired immune responses by superimposing a pretreatment regimen upon an established immunization protocol. CBA/J or BALB/cByJ mice were pretreated twice intravenously with 100 micrograms of mannan (MAN), 100 or 200 micrograms of glycoprotein (GP), or 5 X 10(7) heat-killed C. albicans blastoconidia, followed 1 week later by an immunization protocol of two cutaneous inoculations of viable C. albicans blastoconidia given 2 weeks apart. Delayed hypersensitivity (DTH) to GP or to a membrane-derived antigen, B-HEX, was tested 7 days after the second inoculation, and lymphocyte stimulation was tested with mitogens and Candida antigens after 12 days. To assess protection, mice were challenged intravenously with viable C. albicans blastoconidia 14 days after the second cutaneous inoculation and sacrificed 28 days later for quantitative culture of kidneys and brains. Sera were obtained for enzyme-linked immunosorbent assays at selected intervals. Pretreatment with GP resulted in specific in vivo suppression of DTH to GP but not to B-HEX antigen and specific in vitro suppression of lymphocyte stimulation to GP but not to other Candida antigens or mitogens. MAN and heat-killed C. albicans blastoconidia had no such effects. GP pretreatment also diminished the protective effect of immunization against challenge, demonstrable in the brain, while not altering significantly the production of antibody in response to infection. Contrary to clinical evidence, MAN was not immunosuppressive in this model, and in fact, the immunosuppressive potential of GP, which is composed largely of MAN, was found to be dependent upon the presence of its heat-labile protein moiety.
Evolution of cell types and T-cell subsets in the spleens of Mycobacterium bovis BCG-resistant and M. bovis BCG-susceptible strains of mice after infection with M. bovis BCG
Authors: Denis M , Forget A , Miailhe A C , Pelletier M , Skamene E
Published: January 2020

In mice, the early host response to intravenous infection with small doses of dispersed Mycobacterium bovis BCG is controlled by the Bcg gene. After infection with a low dose of M. bovis BCG, Lyt-1+ cells were generated in the spleens of BCG-susceptible mice (Bcgs) in parallel with an increase in the proportion of phagocytic cells. Very few changes occurred in the splenic cell types of BCG-resistant mice (Bcgr).
A beta-related corynebacteriophage which lacks a tox allele but can acquire it by recombination with converting phage
Authors: Cianciotto N , Groman N
Published: January 2020

Corynebacteriophage 782, a phage highly related to the beta family of corynebacteriophages but lacking a tox allele, was isolated from a nontoxinogenic clinical isolate of Corynebacterium diphtheriae. Phage 782 exhibits beta immunity but has a wider host range than beta, forming plaques on strains of C. ulcerans and C. pseudotuberculosis as well as on C. diphtheriae. Phage 782 and beta differed in their DNA mass and in their restriction endonuclease digest patterns, but were similar in possessing cos (cohesive) and attP (phage attachment) sites. Moreover, all the BamHI fragments of 782 and beta except one hybridized with a DNA probe of the other. The exception in both cases was the attP-containing fragment, which in beta also carries the tox gene. Recombinants between phage 782 and pi phage, a tox+ beta-related phage, were isolated which contained ca. 70% of phage 782 DNA but carried the attP-tox-bearing fragment of pi and were thus now converting phages. The recombinants had lost the wide-host-range phenotype of 782 and had the narrower host range of pi. The significance of the tox-less, beta-related phages to the natural history of diphtheria is discussed.
Identification of a surface antigen of Trichomonas vaginalis
Authors: Connelly R J , Torian B E , Stibbs H H
Published: January 2020

A major surface antigen of Trichomonas vaginalis was purified by using three independently derived monoclonal antibodies (two immunoglobulin M and one immunoglobulin G1) prepared against T. vaginalis PHS-2J. A 115,000-molecular-weight antigen and one or more components with a molecular weight of 58,000 to 64,000 were recovered when any of the three antibodies was used as an immunoadsorbent. The purified antigen reacted with all three monoclonal antibodies in an enzyme-linked immunosorbent assay, indicating that the antibodies recognized the same antigen but not necessarily the same determinant. The purified antigen was sensitive to both pronase digestion and periodate oxidation. The antigen was shown to be on the external surface of some but not all T. vaginalis isolates by agglutination of live organisms with the monoclonal antibodies.
In vitro parasite-monocyte interactions in human leishmaniasis: possible role of fibronectin in parasite attachment
Authors: Wyler D J , Sypek J P , McDonald J A
Published: January 2020

Leishmania spp. must attach to mononuclear phagocyte surfaces before entering this host cell. We investigated the potential role of fibronectin in facilitating parasite attachment. Human plasma fibronectin bound to axenically cultured promastigotes, and promastigotes and amastigotes preferentially bound to fibronectin-coated cover slips. Promastigotes grown in the absence of fibronectin were strikingly deficient in their ability to attach to human monocytes compared with promastigotes grown in the presence of fibronectin. Rabbit anti-human plasma fibronectin antiserum decreased promastigote and amastigote attachment to monocytes. Immunoglobulin G F(ab')2 and Fab fragments also reduced the ability of amastigotes to bind to monocytes. Antiserum pretreatment of amastigotes followed by washing resulted in reduced parasite binding, whereas antibody pretreatment of monocytes did not. Addition of exogenous fibronectin did not enhance parasite attachment to monocytes. These findings suggest that Leishmania spp. can bind fibronectin and may utilize this glycoprotein to facilitate attachment to the mononuclear phagocytes that they infect.
Surface proteins of Mycoplasma hyopneumoniae identified from an Escherichia coli expression plasmid library
Authors: Klinkert M Q , Herrmann R , Schaller H
Published: January 2020

A genomic library of Mycoplasma hyopneumoniae was constructed by cloning random DNA fragments approximately 300 base pairs long in a fusion expression plasmid, pEx29, containing the N terminus of the phage MS2 polymerase under the control of the PL promoter of phage lambda. Clones that produced fusion proteins carrying surface-specific antigenic determinants were identified by using antiserum raised in a pig by intranasal inoculation of viable mycoplasmas. Rabbit antisera produced against gel-purified fusion proteins synthesized in Escherichia coli were analyzed by Western blotting to identify antigenically related mycoplasma components. Distinct mycoplasma proteins termed P90, P68, P50, P30, and P26 were identified. Evidence for the surface location of P90, P68, and P50 was provided by their sensitivity to trypsin and their comigration with lactoperoxidase-catalyzed iodinated proteins of intact mycoplasmas. Immune electron microscopy, performed with antiserum against the hybrid MS2-mycoplasma protein produced in E. coli and corresponding to P90, also showed that its antigenic determinant is associated with the mycoplasma surface.
Role of glycosylation in expression of functional diphtheria toxin receptors
Authors: Hranitzky K W , Durham D L , Hart D A , Eidels L
Published: January 2020

We have previously demonstrated, by using a detergent-solubilized system, the existence of specific diphtheria toxin-binding glycoproteins on the surface of toxin-sensitive cells. We have now tested the effect of tunicamycin treatment on the sensitivity of cells in culture to diphtheria toxin and have investigated the toxin sensitivity of mutant cells with known defects in glycosylation of asparagine-linked glycoproteins. Treatment of CHO-K1 cells with tunicamycin, which blocks the synthesis of both high-mannose-type and complex-type oligosaccharide chains of asparagine-linked glycoproteins, resulted in a 50- to 100-fold decrease in sensitivity to diphtheria toxin. In contrast, CHO-K1 mutants, defective in the synthesis of either high-mannose-type or complex-type oligosaccharides, showed no difference in toxin sensitivity compared with that of their parental cell lines. When we used an acid shock system, which is believed to result in receptor-dependent direct toxin penetration at the cell surface, the toxin sensitivity of tunicamycin-treated cells was not restored to that of untreated cells, suggesting that tunicamycin treatment results in a decrease in functional toxin receptors. Direct binding studies with 125I-labeled toxin demonstrated that this decrease in functional receptors is due to a decrease in the affinity of the receptors rather than to a change in the number of receptors. Taken together, these data are consistent with the interpretation that the diphtheria toxin receptor is a glycoprotein and suggest that the toxin binds neither to carbohydrate residues unique to the high-mannose-type oligosaccharides nor to those unique to the complex-type oligosaccharides. Furthermore, these data are consistent with the hypothesis that diphtheria toxin binds to the peptide backbone of the glycoprotein receptor.
Antibodies to O-antigen of lipopolysaccharide are protective against neonatal infection with Escherichia coli K1
Authors: Pluschke G , Achtman M
Published: January 2020

Monoclonal IgM specific for the O18 antigen conferred passive protection to 1-week-old rats against bacteremia and killing after oral challenge with O18:K1 Escherichia coli. Specific protection of the pups was also achieved by immunizing the pregnant rats with purified O18 lipopolysaccharide. We suppose that most human newborns that are colonized by potentially invasive K1 E. coli are protected by the transplacental transfer of anti-lipopolysaccharide immunoglobulin G, and we suggest that treatment with such antibodies might in the future be considered a therapeutic option. Rat serum from 1-week-old animals had only about one-third of the complement hemolytic activity of adult rat serum. This low level of hemolytic activity correlated with a relatively poor bactericidal activity in antibody-dependent and antibody-independent bactericidal in vitro assays. Monoclonal anti-O18 immunoglobulin M, although protective in vivo and bactericidal when added to adult rat serum, only poorly inhibited the multiplication of O18:K1 cells in serum from 1-week-old rats. This suggests that other elements of host defense besides complement participate in antibody-mediated in vivo protection.
Ultrastructural studies of adherence of Staphylococcus aureus in experimental acute hematogenous osteomyelitis
Authors: Speers D J , Nade S M
Published: January 2020

A model of acute hematogenous osteomyelitis initiated by injection of Staphylococcus aureus into 29-day-old chickens was used. Transmission electron microscopy showed that the bacteria adhered to exposed cartilage matrix in the metaphyseal region of long bones but not to adjacent vascular linings or to erythrocytes. It is proposed that the combination of exposure of growth plate cartilage during normal bone growth and the ability of S. aureus to adhere to this cartilage is the mechanism for initiation of infection which proceeds to an osteomyelitic abscess.
Relationship between delayed hypersensitivity response and acquired cell-mediated immunity in C57BL/6J mice infected with Leishmania donovani
Authors: Fahey J R , Herman R
Published: January 2020

The relationship between the development of acquired cell-mediated immunity and the concomitant level of specific delayed hypersensitivity (DH) in C57BL/6J mice infected with the intracellular protozoan parasite Leishmania donovani was studied. It was determined that the intradermal injection of Leishmania antigen (heat- or phenol-killed flagellated forms of L. donovani) could elicit a DH response as early as day 10 and as late as day 120 postinfection in mice infected by the intravenous route. Dose-response studies showed that there is an inverse relationship between the size of the infecting dose of parasites and the magnitude of the DH response. Thus, increasing the degree of infection depressed the DH response. This depression, however, could be abrogated by treatment of mice with cyclophosphamide (201 mg/kg) before intradermal injection of antigen.
Granulocyte-macrophage colony-stimulating factor in the sera of Schistosoma japonicum-infected mice
Authors: Owhashi M , Nawa Y
Published: January 2020

Infection of mice with Schistosoma japonicum engendered high levels of granulocyte-macrophage colony-stimulating factor (GM-CSF) in serum. The rise in GM-CSF levels in serum was closely associated with the acute phase of the infection and seemed to be dependent on the dose of infection. GM-CSF activity was detected as a sharp single peak in DE-52 anion-exchange chromatography and Sephacryl S-200 and Sephadex G-200 gel chromatography and was almost entirely adsorbed to concanavalin A-Sepharose 4B affinity chromatography. The possible immunological and immunopathological importance of GM-CSF in S. japonicum infection is discussed.
Role of Pseudomonas aeruginosa exoenzymes in lung infections of patients with cystic fibrosis
Authors: Döring G , Goldstein W , Röll A , Schiøtz P O , Høiby N , Botzenhart K
Published: January 2020

We investigated the role of Pseudomonas aeruginosa exoenzymes in cystic fibrosis lung infection in the presence and absence of specific serum antibodies. In sputa of 21 cystic fibrosis patients, concentrations of P. aeruginosa proteases and exotoxin A were determined by sensitive radioimmunoassays. In all sputa, detection of exoenzymes was negative (less than or equal to 10 ng). Positive serum antibody titers to bacterial exoenzymes were found in the majority of patients. Purified immunoglobulin G (IgG) preparations from the sera of two patients revealing specific antibody titers to the bacterial proteases neutralized these enzymes at ratios of 1,000:1 to 5,600:1 (wt/wt). Above the neutralizing capacity of IgG, proteases caused cleavage of IgG; below that level, no enzymatic activity was observed. In vitro incubation of P. aeruginosa elastase, alkaline protease, or exotoxin A with elastase derived from polymorphonuclear leukocytes showed that polymorphonuclear leukocyte elastase: (i) was cleaved by bacterial elastase, (ii) was not inactivated by alkaline protease, and (iii) inactivated exotoxin A. The results suggest that soon after the onset of P. aeruginosa lung infection in cystic fibrosis patients, bacterial proteases, but not exotoxin A, become important virulence factors. The results also suggest that exoenzymes do not directly contribute to lung damage after immune response to bacterial antigens has begun.
Purification and antigenic relatedness of proteins II of Neisseria gonorrhoeae
Authors: Newhall W J , Mail L B , Wilde C E , Jones R B
Published: January 2020

Gonococcal proteins II from three strains were purified by chromatofocusing, and antisera was raised against them. These antisera were examined by immunoblotting to explore the antigenic relatedness of proteins II of seven different strains. The strongest reactions of the antisera were with the homologous proteins II. The antiserum against the proteins II of one strain also reacted with the proteins II present in all of the heterologous strains, whereas the antisera against the proteins II of two other strains showed little cross-reactivity with heterologous proteins II. Monoclonal antibodies produced against the three proteins II of strain F62 were specific for homologous proteins II and recognized epitopes unique to each individual protein II. These studies confirm the extensive intra- and interstrain variability in the antigenic structure of these proteins.
Stimulation of immunoglobulin-containing cells and isotype-specific antibody response in experimental Mycoplasma hyopneumoniae infection in specific-pathogen-free pigs
Authors: Suter M , Kobisch M , Nicolet J
Published: January 2020

The development of immunoglobulin-containing cells and antigen-specific plasma cells in retropharyngeal and bronchial lymph nodes, in lung tissue, and in nasal mucous membrane was followed during an experimental infection of pigs with Mycoplasma hyopneumoniae. An enzyme-linked immunosorbent assay was used to follow stimulation of the immunoglobulin isotypes (classes) M, G, and A directed against the infectious agent in tracheobronchial secretions and systemically. A significant increase of antigen-specific plasma cells in lymph nodes and lung tissue as well as antibodies in tracheobronchial secretions was demonstrated 2 weeks after infection. This specific reaction was followed by a marked increase of immunoglobulin-containing cells in lymph nodes and lung tissue. The data are discussed in terms of autoimmune reactions in the pathogenesis of enzootic pneumonia.
Lymphokine activation of J774G8 cells and mouse peritoneal macrophages challenged with Toxoplasma gondii
Authors: Sibley L D , Krahenbuhl J L , Weidner E
Published: January 2020

In vitro activation of macrophage cell line J774G8 and mouse peritoneal macrophages resulted in oxygen-dependent and oxygen-independent killing of intracellular Toxoplasma gondii. Activation was characterized by oxygen-dependent killing detectable by enhanced lysosome fusion and digestion of T. gondii. The toxoplasmacidal activity of activated J774G8 cells and peritoneal macrophages was prevented by adding the oxygen intermediate scavengers catalase or superoxide dismutase during culture. Activated J774G8 cells and peritoneal macrophages also inhibited replication of those Toxoplasma organisms which survived the initial microbicidal activity. The inhibition of Toxoplasma replication was not significantly affected by exogenous catalase or superoxide dismutase. Peritoneal macrophages from Toxoplasma-immune mice showed similar microbicidal and inhibitory responses, supporting the model that activation leads to destruction of intracellular parasites by two different mechanisms.
Isolation and characterization of an extracellular glucosyltransferase synthesizing insoluble glucan from Streptococcus mutans serotype c
Authors: Mukasa H , Tsumori H , Shimamura A
Published: January 2020

A glucosyltransferase which synthesized insoluble glucan in polyacrylamide gel was isolated from the culture supernatant of Streptococcus mutans Ingbritt (serotype c) by ultrafiltration, ethanol fractionation, isoelectric focusing, and preparative gel electrophoresis. The enzyme preparation was electrophoretically homogeneous and immunologically distinct from the highly branched 1,6-alpha-D-glucan synthase and fructosyltransferase from the same strain and glucosyltransferases from serotypes a and g. The molecular weight was 99,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and the isoelectric point was 8.5. The enzyme had the optimum pH of 6.0 and Km value for sucrose of 9.4 mM. Besides the insoluble glucan with 96% 1,3-alpha linkage, this enzyme synthesized a considerable amount of diffusible glucan with 84% 1,6-alpha linkage, separately. This enzyme may be the one released from the enzyme aggregates by extracellular proteases, because the addition of extraneous trypsin to the crude enzyme preparation increased the amount of the enzyme species.
Weight reduction of thymus and depletion of lymphocytes of T-dependent areas in peripheral lymphoid tissues of mice infected with Francisella tularensis
Authors: Ito M , Nishiyama K , Hyodo S , Shigeta S , Ito T
Published: January 2020

When BALB/c mice (young and adult animals of both sexes) were infected intraperitoneally with 10(3) viable cells of Francisella tularensis (10(2) 50% lethal dose), all mice in these groups died on day 4. Reductions in thymus weights and in numbers of thymic cortex lymphocytes were observed in all the groups, but the decline was not so severe in the young females. Increases of plasma corticosterone in the adult males began 1 day after infection, but in the young females, the levels did not increase until day 3, the same days on which the respective thymus weights began to decline. Depletion of the thymus weights in the infected mice was prevented by adrenalectomy. The lymphocytes of the thymus (T)-dependent areas in peripheral lymphoid tissues in all groups were destroyed. By using an electron microscope, we found a large quantity of F. tularensis within the macrophages in the T-dependent areas but not in the thymus. The destruction of lymphocytes in the T-dependent areas was not prevented by adrenalectomy. Therefore, it was concluded that the weight reduction of the thymus is due to the stress of the F. tularensis infection. However, we think other mechanisms are responsible for the depression of lymphocytes in the T-dependent areas of peripheral lymphoid tissues.
Effect of theophylline on differentiation of Trypanosoma brucei
Authors: Reed S L , Fierer A S , Goddard D R , Colmerauer M E , Davis C E
Published: January 2020

Differentiation of Trypanosoma brucei in the mammal limits the degree of parasitemia and prepares the trypanosome for passage back into the tsetse fly. In an attempt to define the signals that control differentiation, we found that theophylline, in contrast to indomethacin, blocked differentiation, prolonged parasitemia, elevated prostaglandin and cyclic AMP concentrations of rat plasma, and depressed intratrypanosomal cyclic AMP. Relatively nontoxic drugs that alter differentiation are powerful tools for elucidating the events that control this important process.
Hemagglutination Assay of Antibodies Associated with Pulmonary Acariasis in Rhesus Monkeys (
Macaca mulatta
)
Authors: Kim Chin S. , Bang Frederik B. , DiGiacomo Ronald F.
Published: January 2020

Antibodies associated with infection by lung mites (
Pneumonyssus simicola
) in rhesus monkeys were measured by passive hemagglutination methods. Tanned human Rh negative O red blood cells or sheep red blood cells coated with soluble acarine antigens were used to detect mite-specific antibodies. Large quantities of host-specific mite antigens (
P. simicola
) were difficult to obtain, so free-living mite species such as
Dermatophagoides farina, Acarina sheldonii
, and
Tyrophagus putrificiensis
were also utilized. Although the best serological specificity and sensitivity were obtained with
P. simicola
and its derivatives (1:640), several free-living acarine species were useful in detecting antibodies to mites. Skin tests carried out on a limited number of animals were positive for both immediate and delayed hypersensitivity.
Differential Immune Response to Attenuated Rubella Virus Vaccine
Authors: Gupta Jiban D. , Peterson Vincent J. , Murphy Alan M.
Published: January 2020

Serum samples collected from 18 volunteers 1, 2, and 3 months after vaccination with Cendehill strain of attenuated rubella virus vaccine were fractionated on a Sephadex G-200 column to test for immunoglobulin M (IgM) antibody. Seventeen of the 18 had demonstrable IgM antibody in serum collected 1 month postvaccination whereas only 5 and 3 had IgM antibody 2 and 3 months, respectively, post-inoculation. The geometric mean titers of hemagglutination-inhibiting antibody in the 19
S
fraction were 38, 7, and 6 at 1, 2, and 3 months after vaccination, whereas the corresponding 7
S
titers were 29, 53, and 57, respectively. Four other seronegative volunteers vaccinated with Cendevax were tested serially for total antibody only in whole blood obtained by finger pricks. Three of them showed appearance of antibody between 14 and 17 days and one between 17 and 21 days. It appears that vaccine-induced immune response is similar to natural infection especially with regard to the time of appearance of antibody and the relative proportions of IgM and IgG antibody thus produced.
Chronic Infection of the Rabbit Central Nervous System by a Slowly Growing Equine Herpesvirus
Authors: Plummer G. , Coleman P. L. , Henson D.
Published: January 2020

The spinal cords of rabbits were chronically infected by a slowly growing horse herpesvirus (a “cytomegalovirus”) inoculated directly therein. Virus was recovered from the central nervous systems of some of such animals after more than 1 year. The virus could be reisolated from all the animals killed during the first few weeks after its injection; acute focal meningomyelitis was present with involvement of gray and white matter of the cervical, thoracic, and lumbar levels of the spinal cords of these rabbits, though the nerve cells themselves remained undamaged. Thereafter, reisolation of the virus became sporadic, and no damage to the spinal cord could be histologically discerned even in animals from which the virus was recovered. No paralytic or other clinical effects could be attributed to the infection.
Host-Parasite Relationships in Experimental
Streptobacillus moniliformis
Arthritis in Mice
Authors: Savage N. L.
Published: January 2020

Several variables of host and parasite, relating to the establishment of the chronic
Streptobacillus moniliformis
-induced arthritis, were studied. Results from these studies indicated (i) that intravenous inoculation of the organism produced a progressive bacteremia and a polyarthritis, whereas subcutaneous inoculation into the top of the back foot produced an intermittent bacteremia and arthritis only in that foot, (ii) that serum-broth-grown cells were more virulent than serum-agar-grown cells, (iii) that young animals were more susceptible to infection than old, and (iv) that the organism apparently had a predilection for joints. It was also determined that the leukocyte and antibody responses of mice to infection were minimal with a slight neutrophilia and a maximum antibody titer of 1:640 detected after infection. Measurements of the effectiveness of antibody and leukocytes in prevention or resolution of infection indicated (i) that the presence of homologous antibody prior to infection prolonged the incubation period for development of the lesion, (ii) that the opsonic index was 1.2 to 1.4, and (iii) that the organism was apparently resistant to destruction by in vitro phagocytosis and actually increased in number in the presence of phagocytes. It was concluded that these represented some of the prime factors contributing to the establishment of the infection and its chronicity.
Vibrio fetus
Infection in Man: a Serological Test
Authors: Bokkenheuser Victor
Published: January 2020

Antigen preparations derived from a typical human strain of
Vibrio fetus
were employed in four tests. Of these, the indirect bacterial hemagglutination test proved most sensitive. By this test, antibodies titering 320 to 3,200 were found in five of eight patients with confirmed infections. Two patients without antibodies were on antimetabolites. Antigenic relationship with other compounds, and in particular with
Brucella
organisms, was not observed. No sero-reactors were found among 184 apparently healthy young men; of 401 unselected hospital patients, four had low sero-titers.
In Vitro Stimulation of Hamster Lymphocytes with Concanavalin A
Authors: Singh S. B. , Tevethia S. S.
Published: January 2020

The in vitro response of hamster lymphocytes to concanavalin A (Con A) was investigated by using the
3
H-thymidine incorporation assay, and the results obtained were compared to those with phytohemagglutinin (PHA-P). The optimum culture conditions for stimulation were obtained when one million lymph node cells were cultivated for 72 hr in 2 ml of RPMI-1640 medium supplemented with 10% heat-inactivated fetal calf serum in the presence of either 2 μg of Con A or 0.05 ml of PHA-P. The average ratios of stimulation using lymph node cells with Con A and PHA-P were 227 and 14, respectively. Bone marrow and thymus cells responded very poorly or not at all. Methyl α-
d
-glucopyranoside, when added to the culture medium at the time of addition of Con A, completely inhibited stimulation. The lymphocyte stimulation could be reversed by addition of the sugar as late as 18 hr after the addition of Con A. The lymphocyte response from hamsters bearing tumors induced by simian virus 40 tumor cells and from hamsters immune to tumor transplants was comparable to the response of lymphocytes from healthy donors.
Electron Microscopy Observations on a New Herpes-Type Virus Isolated from
Iguana iguana
and Propagated in Reptilian Cells In Vitro
Authors: Zeigel R. F. , Clark H. F.
Published: January 2020

Ultrastructural observations on a new viral isolate, designated iguana virus, indicate that it is consistently present in intranuclear inclusions, possesses a ± 115-nm nucleocapsid, ranges from 165 to 300 nm in diameter in the enveloped form, and exhibits cubic symmetry (probably 162 capsomeres). It is concluded that it is a herpes-type virus, the morphological evidence being in agreement with and supporting the biological and physical characteristics presented by Clark and Karzon. Several fine-structural features, among them the encapsidization of small 35-nm hexagonal bodies and the viral membrane envelope enclosure of cell-derived moieties are presented and discussed.
Cytoplasmic Antigens from
Nocardia
Eliciting a Specific Delayed Hypersensitivity
Authors: Ortiz-Ortiz Librado , Contreras Magdalena F. , Bojalil Luis F.
Published: January 2020

Purified cytoplasmic extracts from
Nocardia asteroides
and
N. brasiliensis
elicit delayed hypersensitivity in
Nocardia
-sensitized guinea pigs. The differences in skin reactivity clearly show that it is possible to distinguish between different
Nocardia
species. When peritoneal exudate cells from the latter animals were obtained and treated with the purified cytoplasmic extracts, their migration was inhibited to a significant degree only by means of the homologous antigen. A mild delayed reactivity was observed when the cytoplasmic antigens were used as skin test materials on animals sensitized with BCG. On the other hand, no inhibition of migration was observed when peritoneal exudate cells from BCG-sensitized guinea pigs were exposed to the cytoplasmic antigens.
Immunochemistry and End-Group Analyses of Group A Streptococcal M Proteins
Authors: Straus David C. , Lange Charles F.
Published: January 2020

Type-specific M proteins were examined to determine whether their immunological specificities were also reflected by major chemical differences. Sixteen different type-specific protein preparations were employed, including two from non-M-typable strains. These M proteins, acid-extracted from whole cells, were purified by ammonium sulfate fractionation and column chromatography and were compared by immunodiffusion, electrophoretic, amino acid, and N-terminal amino acid analyses. Although the data did not reflect major chemical distinctiveness in the types examined, some interesting results evolved. Four important factors were observed to be shared by all M protein types examined: (i) glutamic acid was the most prevalent amino acid, (ii) amino acid molar ratios were similar, (iii) each had
l
-alanine as a single N-terminus, and (iv) purified peaks from the column chromatograms still showed heterogeneity while giving type-specific reactivity for multiple bands. Thus, whereas chemical typing is apparently unfeasible, the data indicate that these may be unique proteins, reflected especially in the finding of the same N-terminus amino acid in all strains investigated.
Effects of cyclosporine in experimental cryptococcal meningitis
Authors: Perfect J R , Durack D T
Published: January 2020

We studied the effects of cyclosporine on experimental cryptococcal meningitis. Like cortisone, cyclosporine depressed the highly effective defense mechanisms of normal rabbits against inoculated Cryptococcus neoformans, causing them to develop progressive, fatal cryptococcal meningitis. Unlike cortisone, which causes a striking reduction in leukocytes in cerebrospinal fluid, cyclosporine depressed mononuclear cell function rather than numbers. Interleukin 2, a primary target for the immunodepressive action of cyclosporine, appears to be of central importance in central nervous system defenses against cryptococci. The findings suggest that humans receiving cyclosporine are likely to suffer increased incidence of cryptococcal infection.
Lack of correlation between known virulence properties of Aeromonas hydrophila and enteropathogenicity for humans
Authors: Morgan D R , Johnson P C , DuPont H L , Satterwhite T K , Wood L V
Published: January 2020

Five strains of Aeromonas hydrophila were selected for use in volunteer challenge trials. All five strains produced cytotoxin, hemolysin enterotoxin, lysine decarboxylase, acetylmethylcarbinol, and DNase. Two strains hydrolyzed esculin. All strains produced purulent hemorrhagic fluid accumulation in rabbit ileal loops, but failed to induce keratoconjunctivitis in guinea pigs. None of the strains produced mannose-resistant hemagglutinins. In challenge studies, diarrhea was demonstrated in only 2 of 57 human volunteers with doses ranging from 10(4) to 10(10) CFU. One person experienced mild diarrhea with 10(9) CFU of strain 6Y. A second person developed moderate diarrhea with 10(7) CFU of strain 3647. At higher doses, no diarrhea was seen in any of the volunteers. The other three strains (B158, SSU, 3284) failed to cause diarrhea and were not recovered from stools of volunteers. Additional virulence properties of A. hydrophila need to be sought before enteropathogenicity for humans can be established.
Regulation of glycolytic rate in Streptococcus sanguis grown under glucose-limited and glucose-excess conditions in a chemostat
Authors: Iwami Y , Yamada T
Published: January 2020

The biochemical mechanisms of the acidogenic potential of Streptococcus sanguis ATCC 10556 grown in glucose-excess and glucose-limited continuous culture were studied. The rate of acid production during the glucose metabolism by the cells grown under glucose limitation (glucose-limited cells) was 2.1 to 2.6 times that by the cells grown in an excess of glucose (glucose-excess cells). When the glucose-limited cells were metabolizing glucose, intracellular concentrations of glucose 6-phosphate, fructose 6-phosphate, 3-phosphoglycerate, and pyruvate were higher, and that of glyceraldehyde 3-phosphate was lower, than those when the glucose-excess cells were metabolizing glucose. The levels of fructose 1,6-bisphosphate and dihydroxyacetone phosphate were not significantly different between these cells. The activities of glucose-phosphoenolpyruvate phosphotransferase system in decriptified cells and glyceraldehyde-3-phosphate dehydrogenase in cell-free extracts of the glucose-limited cells were higher than those in the glucose-excess cells. The activities of glucokinase, phosphoglycerate kinase, and pyruvate kinase in cell-free extracts of these cells were not different significantly. We conclude that the high glycolytic activity of the glucose-limited cells results from the increase in the synthesis of glucose-phosphoenolpyruvate phosphotransferase and glyceraldehyde-3-phosphate dehydrogenase.
Interactions between Naegleria fowleri and Legionella pneumophila
Authors: Newsome A L , Baker R L , Miller R D , Arnold R R
Published: January 2020

Using electron microscopy we documented some of the intracellular events that occur in Naegleria fowleri suspended in Page amoeba saline after ingestion of Legionella pneumophila. Photomicrographs showed intracellular vacuoles containing bacteria in the process of binary fission that was accompanied by alignment of mitochondria and ribosome-like structures along the vacuole membrane. Although these intracellular events are remarkably similar to that seen in Legionella replication within human monocytes, we could not demonstrate an increase in the number of bacteria by CFU or dark-field microscopy. However, when the Naegleria cells were allowed to ingest Legionella cells while suspended in amoeba culture medium, the number of bacteria increased, and this was contingent upon the presence of viable amoebae.
Role of lipopolysaccharide and complement in susceptibility of Haemophilus ducreyi to human serum
Authors: Odumeru J A , Wiseman G M , Ronald A R
Published: January 2020

The role of lipopolysaccharide (LPS) in the susceptibility of Haemophilus ducreyi to human serum and the mechanism of complement activation by serum-susceptible (Sers) strains were investigated. Serum treated with 2 mM Mg2+ and 20 mM ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid was nonbactericidal, but inulin-treated serum remained bactericidal. Absorption of serum with heat-killed whole cells of an Sers strain removed its bactericidal activity against the absorbing strain and also against other Sers strains. LPS obtained from Sers strains inhibited the bactericidal activity of serum against all Sers strains, whereas LPS from serum-resistant (Serr) strains and an Serr isogenic strain did not. However, high concentrations of LPS from the Serr strain inhibited the bactericidal activity of serum, an indication that part of the structural site involved in serum susceptibility is retained in the LPS of this strain. The LPS of Sers strains exhibited higher anticomplement activity than the LPS of Serr strains. These findings suggest that the classical pathway of complement activation is involved in the serum killing of H. ducreyi and that LPS composition may contribute to their susceptibility to complement-mediated serum bactericidal activity.
Stimulation of lymphoid cell proliferation by Mycoplasma orale, a common cell culture contaminant
Authors: Mizushima Y , Quintans J , Cohen E P
Published: January 2020

Mycoplasma orale, maintained as a contaminant of a mouse hybrid cell line, induces an intense proliferation in short-term culture of lymphoid cells of inbred mice. Cell division induced by the contaminated cell culture fluid reaches a maximum on day four and declines rapidly thereafter. Culture fluids from hybrid cells freed of contamination do not cause proliferation. Cells from the spleen, bone marrow, and thymus of each of several strains of inbred mice, including xid CBA/N, poorly responsive to lipopolysaccharide, are stimulated by the mitogen, as are cells from BALB/c nude mice. The characteristics of the stimulatory effect are analogous in several important aspects to those of naturally occurring T cell-derived growth factors. In the absence of detectable numbers of T cells, both small and large B lymphocytes undergo mitosis in the presence of contaminated cell culture fluid, and B cells stimulated to divide by lipopolysaccharide are sustained for further rounds of replication by M. orale-containing cell culture fluid. The fluid also augments the stimulatory effect on thymocytes of suboptimum concentrations of phytohemagglutinin mimicking the effect of interleukin-1. Unlike with most naturally occurring lymphoid cell mitogens, however, the dividing cells do not go on to immunoglobulin secretion.
Elaboration of a 3.6-kilodalton lipooligosaccharide, antibody against which is absent from human sera, is associated with serum resistance of Neisseria gonorrhoeae
Authors: Schneider H , Griffiss J M , Mandrell R E , Jarvis G A
Published: January 2020

Neisseria gonorrhoeae strains that resist lysis by normal human sera (NHS) do so, in part, because NHS contain immunoglobulin M (IgM) specific for lipooligosaccharide (LOS) antigens of serum-sensitive strains, but lack antibodies for LOS antigens that can serve as loci for immune lysis of serum-resistant (serr) strains. We used a monoclonal antibody (McAb), specific for an epitope within a 3.6-kilodalton (kDa) component of Neisseria meningitidis L8 LOS, that binds a 3.6-kDa gonococcal LOS component so that we could explore further serr gonococcal strains. The McAb bound to the LOS of 6 of 7 serr of strains but not to the LOS of 0 of 14 serum-sensitive and serum-intermediate gonococcal strains of diverse origin. We studied three serr strains further. Strain 7134 does not elaborate the 3.6-kDa LOS component and does not bind the McAb; strains WR220 and WR302 do elaborate the 3.6-kDa LOS component. The titer (log2) at which the McAb, diluted in NHS, lysed strain WR220 was 7.7; for WR302 it was 3.7, and for 7134 it was 0. Addition of McAb to NHS caused increased classical and alternative-pathway C3 deposition onto strain WR220, but only classical-pathway-activated C3 deposition onto strain WR302. The difference in lytic effectiveness of the McAb for the two strains, therefore, may result from differences in alternative-pathway augmentation of McAb-dependent classical-pathway activation on their surfaces. None of 40 randomly selected normal young adults had serum antibody that could compete with the McAb for binding to WR220 LOS in a solid-phase RIA. We conclude that the 3.6-kDa LOS component is commonly expressed by serr strains of N. gonorrhoeae and that antibody to it would be lytic if present in human serum, but that it is infrequently, if ever, present. As a result, strains elaborating this LOS are resistant to lysis by NHS.
Haemophilus influenzae type b infection in childhood: history of bacteremia and antigenemia
Authors: La Scolea L J , Rosales S V , Ogra P L
Published: January 2020

Groups of children (mean age, 31.4 months) with Haemophilus influenzae type b meningitis, epiglottitis, or septic arthritis were tested for the presence and levels of bacteremia, capsular polyribophosphate (PRP) antigenemia, and development of specific antibody in serum after the onset of acute illness. Although bacteremia cleared promptly after antibiotic therapy, circulating PRP could be detected in serum for relatively long periods, with 51% of the patients still having detectable antigen after 30 days postinfection. Even in the presence of specific antibody, antigenemia persisted for as long as 47 days after admission. It was observed that there was no statistically significant correlation between the persistence of antigenemia and age (P greater than 0.2), the initial antigen concentration (P greater than 0.50), or the development of antibody (P greater than 0.20). The presence of a low magnitude of bacteremia (less than 300 organisms per ml) was associated with a maximum concentration of 10 ng of PRP per ml. On the other hand, bacterial counts in excess of 10(4)/ml were associated with greater than 1,000 ng of PRP per ml (r = 0.98, r2 = 0.96, P less than 0.001). It was observed that the amount of circulating PRP in the acute phase of illness was related to whether a child developed convalescent-phase antibody. Invariably, the younger children, who primarily had meningitis, had a PRP concentration of greater than 10 ng/ml and failed to develop an antibody response in any isotype, whereas the older patients, who primarily had infections other than meningitis, had a PRP concentration of less than 10 ng/ml and a 45.5% success rate in developing an antibody response (P = 0.006). These findings suggest that there is a direct correlation between the magnitudes of bacteremia and antigenemia, that antigen may persist for long periods even in the presence of antibody, and that the level of antigenemia in addition to the patient age is significantly related to the nature of the convalescent-phase antibody response.
Purification and characterization of a primer-independent glucosyltransferase from Streptococcus mutans 6715-13 mutant 27
Authors: McCabe M M
Published: January 2020

Affinity chromatography on Sephadex G-50 and subsequent ion-exchange chromatography on Trisacryl-M-DEAE were used to purify the glucosyltransferase (GTF) enzymes produced by mutant 27 of Streptococcus mutans 6715-13. Complete separation of three types of GTF, including a primer-independent GTF capable of synthesizing a slightly branched, water-soluble glucan (GTF-S), was obtained. The characteristics of this primer-independent GTF-S were compared with those of the normally occurring primer-dependent GTF-S. The Km for sucrose was easily obtained for each enzyme (10(-2) M), but the Km for dextran could only be determined for the primer-dependent GTF-S (5 X 10(-7) M for clinical dextran of molecular weight 60,000 to 90,000). The primer-independent GTF-S did not respond catalytically to the presence of either clinical dextran or the highly branched, water-soluble glucan produced by primer-dependent GTF-S, although it was capable of binding these polysaccharides at a noncatalytic site and of responding to the low-molecular-weight acceptor 1-O-methyl-alpha-D-glucopyranoside. The water-soluble glucan product of primer-independent GTF-S was a superior priming glucan for primer-dependent GTF enzymes as compared with the glucan product of primer-dependent GTF-S. The presence of primer-independent GTF-S in reaction mixtures stimulated glucan synthesis by primer-dependent GTF-S and by GTF synthesizing water-insoluble glucan by at least 10-fold, whereas the presence of similar amounts of primer-dependent GTF-S had no effect on synthesis by GTF synthesizing water-insoluble glucan. Primer-independent GTF-S appears to be a potent source of priming glucan for the primer-dependent GTF enzymes. Its possession of a noncatalytic binding site for glucan, the first observed for the GTF of S. mutans, suggests that it may also serve as a glucan receptor on the S. mutans cell surface.
Local transfer of delayed-type hypersensitivity after Salmonella infection in mice
Authors: Attridge S R , Kotlarski I
Published: January 2020

An adoptive local transfer system has been used to study the mediators of delayed-type hypersensitivity induced in mice by infection with Salmonella enteritidis 11RX. The cells which transfer this state of hypersensitivity to untreated recipients are nonadherent T lymphocytes with the surface phenotype Lyt 1+2-, and successful transfer requires compatibility at the I-A subregion of the H-2 complex. In these and other respects these cells are indistinguishable from those previously found to be responsible for in vitro lymphokine release upon culture with 11RX antigens.
Electron microscopic study of phagocytosis of Escherichia coli by human polymorphonuclear leukocytes
Authors: Rozenberg-Arska M , Salters M E , van Strijp J A , Geuze J J , Verhoef J
Published: January 2020

The fate of Escherichia coli strains within the polymorphonuclear leukocytes was studied by determining the killing of bacteria, measuring the release of degradation products, and examining the phagocytic bacteria by electron microscopy. When sufficiently opsonized, both unencapsulated and encapsulated E. coli strains were rapidly phagocytized by polymorphonuclear leukocytes. Once phagocytized, the two unencapsulated E. coli strains (K-12 and O111) were rapidly killed (99% of the bacteria were killed during the first 5 min of phagocytosis) and extensively degraded (about 40% of the radiolabeled material was released from bacteria after 15 min of phagocytosis). Electron micrographs taken after 15 min of phagocytosis revealed extensive structural changes in most of the internalized bacteria. In contrast to the rapid killing and extensive breakdown of these strains, encapsulated E. coli O78:K80 was more resistant to killing and withstood degradation by polymorphonuclear leukocytes (only 5% of the radioactivity was released from the radiolabeled bacteria after 1 h of phagocytosis). Electron micrographs of thin sections taken after 1 h of phagocytosis revealed virtually no structural changes. Most of the internalized bacteria were still surrounded by thick capsular material.