bluuebunny/crossref_metadata_2025 huggingface dataset:
Passive transfer of antibody to Ehrlichia risticii protects mice from ehrlichiosis
Authors: Kaylor P S , Crawford T B , McElwain T F , Palmer G H
Published: January 2020

Mice that recovered from Ehrlichia risticii infection were immune to a challenge dose of 100 50% lethal doses. Immune or normal mouse serum was passively transferred to mice challenged with E. risticii. Clinical signs of ehrlichiosis were completely prevented in 22 of 24 recipients of immune serum, and the onset of signs of illness was delayed in the remaining two mice compared with the onset of illness in 24 of 24 recipients of nonimmune serum. Purified immunoglobulin G (IgG) was used to passively protect mice from infection with E. risticii. All 15 mice that received IgG from normal serum but none of the 15 mice that received IgG from immune serum developed clinical signs of illness. Antibodies in immune mouse serum immunoprecipitated [35S]methionine metabolically labeled E. risticii proteins with apparent molecular masses ranging from 14 to 90 kDa. The major antigens recognized by dilute immune serum in immunoblot analysis had molecular masses of 62, 53, 40, 33, 27, and 25 kDa, and the 62- and 27-kDa antigens were prominent in immunoprecipitations with dilute antibody. Antigens with molecular masses of 62, 53, 40, 33, and 27 kDa are likely surface exposed, as determined by immunoprecipitation of 125I-labeled organisms with immune mouse serum.
Differential effects of monophosphoryl lipid A on expression of suppressor T cell activity in lipopolysaccharide-responsive and lipopolysaccharide-defective strains of C3H mice
Authors: Ekwunife F S , Taylor C E , Fauntleroy M B , Stashak P W , Baker P J
Published: January 2020

Lipopolysaccharide (LPS)-responsive and LPS-defective strains of C3H mice did not differ in the capacity to make an antibody response to type III pneumococcal polysaccharide or in the degree of thymus-derived suppressor cell (Ts) activity generated following exposure to type III pneumococcal polysaccharide. However, treatment with monophosphoryl lipid A (MPL) abolished the expression of Ts function in LPS-responsive but not LPS-defective mice. Since this effect was elicited by different preparations of MPL, it appears to be a general property of MPL mediated by direct action of MPL on activated Ts.
Detection of immunoglobulin G antibodies to cholesterol in antisera to mycoplasmas
Authors: Watanabe T , Kumazawa T
Published: January 2020

Antisera were produced by inoculation of mycoplasma cells grown in PPLO broth supplemented with rabbit serum alone or rabbit serum plus Freund complete or incomplete adjuvant. By using an enzyme-linked immunosorbent assay, immunoglobulin G antibodies to cholesterol were detected in antisera to mycoplasmas (Mycoplasma salivarium ATCC 23064, M. orale ATCC 15539, M. buccale IID 802, M. faucium IID 996, and M. hominis IID 801) and rabbit serum.
Characterization and immunogenicity of EX880, a Salmonella typhi Ty21a-based clone which produces Vibrio cholerae O antigen
Authors: Attridge S R , Dearlove C , Beyer L , van den Bosch L , Howles A , Hackett J , Morona R , LaBrooy J , Rowley D
Published: January 2020

EX645 is a derivative of Salmonella typhi Ty21a which carries a plasmid specifying production of Vibrio cholerae O antigen. When cultured with exogenous galactose to overcome the galE defect of the vector, EX645 also synthesizes S. typhi O antigen, and this can result in the masking of the shorter V. cholerae O antigen on the bacterial surface. To determine whether the potential for such masking at least partly underlies the inconsistency of anti-V. cholerae responses elicited by EX645, a derivative of this strain has been isolated, characterized, and tested for immunogenicity in human volunteers. EX880 has an rfb defect which prevents synthesis of S. typhi O antigen, and consequently V. cholerae O antigen is still detectable on the surface of the clone following growth in the presence of galactose. Compared with EX645, EX880 more consistently elicited significant rises in serum bactericidal antibody levels, although individual responses within a cohort still varied widely.
Human immunoglobulin G antibody response to iron-repressible and other membrane proteins of Porphyromonas (Bacteroides) gingivalis
Authors: Chen C K , DeNardin A , Dyer D W , Genco R J , Neiders M E
Published: January 2020

The human immunoglobulin G (IgG) immune response against Porphyromonas (Bacteroides) gingivalis A7A1-28 iron-repressible membrane proteins (IRMPs) and other membrane proteins was examined by immunoblot analysis. Thirty sera from patients with adult periodontitis and 30 sera from periodontally healthy subjects were included. Iron limitation of P. gingivalis was achieved by growing bacteria in brain heart infusion broth supplemented with protoporphyrin IX and 250 microM alpha, alpha'-dypyridyl, a ferrous iron chelator. Iron-sufficient growth was achieved by growing bacteria in the same medium without alpha, alpha'-dypyridyl. Human sera, in particular those from patients with periodontitis who exhibited high levels of IgG against whole cells of P. gingivalis A7A1-28 in serum in an enzyme-linked immunosorbent assay (ELISA), commonly reacted with five membrane proteins with apparent molecular masses of 80, 67.5, 51, 40.5, and 28 kDa and four IRMPs of 46, 43, 37.5, and 22 kDa. More than 80% of the sera from patients with periodontitis and high levels of IgG against strain A7A1-28 in serum by ELISA reacted with the 46-, 43-, and 37.5-kDa IRMPs, and 40% of these subjects expressed immunoreactivity against the 22-kDa IRMP. Sera from patients with periodontitis and low levels of IgG against strain A7A1-28 in serum by ELISA and sera from periodontally healthy subjects exhibited less immunoreactivity against IRMPs and the five membrane proteins of P. gingivalis. The present study indicates that P. gingivalis IRMPs are immunogenic and that these proteins are expressed in vivo.
Isolation and detection of urease genes in Ureaplasma urealyticum
Authors: Willoughby J J , Russell W C , Thirkell D , Burdon M G
Published: January 2020

Urease from ureaplasmas was purified by immunoaffinity chromatography, and the N-terminal amino acid sequence was determined for two of the three subunits. These sequences were used to design primers for a polymerase chain reaction (PCR) that amplified most of the gene coding for one of the subunits. By using a novel "PCR walking" technique, we synthesized almost the complete locus on two overlapping PCR products. We present here a partial nucleotide sequence of the urease locus from Ureaplasma urealyticum (serotype 8), which agrees with our N-terminal amino acid data but differs slightly from the sequence previously reported (A. Blanchard, Mol. Microbiol. 4:669-676, 1990). Also described are PCR primers, intended for diagnostic use, that amplify a sequence from all Ureaplasma strains tested but not from any other mycoplasmas or urease-positive bacteria.
Roles of interleukin-1 and tumor necrosis factor in lipopolysaccharide-induced hypoglycemia
Authors: Vogel S N , Henricson B E , Neta R
Published: January 2020

In this study, hypoglycemia induced by injection of lipopolysaccharide (LPS) or the recombinant cytokine interleukin-1 alpha or tumor necrosis factor alpha (administered alone or in combination) was compared. LPS-induced hypoglycemia was reversed significantly by recombinant interleukin-1 receptor antagonist.
Immunological characterization of recombinant antigens isolated from a Mycobacterium avium lambda gt11 expression library by using monoclonal antibody probes
Authors: Rouse D A , Morris S L , Karpas A B , Mackall J C , Probst P G , Chaparas S D
Published: January 2020

Nontuberculous mycobacteria, particularly Mycobacterium avium, have been isolated from a significant percentage of patients with AIDS. Early detection of M. avium infection is difficult, and treatment regimens are often ineffective. Much needs to be learned about antigens and factors responsible for immunity to and pathogenesis of the disease. Specific antigens and diagnostic procedures for infection need to be developed. To address some of these problems, we have generated 25 different monoclonal antibodies against a serovar 4 strain of M. avium isolated from a patient with AIDS. Protease sensitivity studies have demonstrated that each of these antibodies recognizes a protein-associated epitope. Immunoblot analyses suggest that seven of these monoclonal antibodies react specifically with M. avium and M. intracellular epitopes. Immunoreactive bacteriophages were identified from an M. avium lambda gt11 expression library with two of these monoclonal antibodies (3808 C3 and 3954 B12). Lambda lysogens, generated from the immunoreactive bacteriophages, overproduced beta-galactosidase fusion proteins which were reactive with the two monoclonal antibodies in immunoblot assays. The purified fusion proteins were shown to elicit skin test reactions in sensitized guinea pigs.
Effect of a factor released by K562 malignant cells in culture on human neutrophil bactericidal activity
Authors: Amar M , Amit N , Babin-Chevaye C , Huu T P , Hakim J
Published: January 2020

We have previously demonstrated that k562 malignant cells in culture contain and release a low-molecular-mass (8-kDa) factor that inhibits adherence-related functions of neutrophils but does not alter fMet-Leu-Phe- or phorbol ester-induced oxidative burst (M. Amar, N. Amit, T. Pham Huu, S. Chollet-Martin, M.T. Labro, M.A. Gougerot-Pocidalo, and J. Hakim, J. Immunol. 144:4749-4756, 1990). In this study, we investigated the effects of this factor, referred to as inhibitory factor 1 (IF1), on the bactericidal activity of human polymorphonuclear cells (PMNs) on Staphylococcus aureus opsonized in various ways. S. aureus was used either nonopsonized or opsonized with heat-inactivated serum or normal serum containing complement factors. The bactericidal activity of PMNs preincubated with IF1-treated or control medium was examined by counting the surviving bacteria. The ability of IF1-treated PMNs to kill bacteria was diminished when they were opsonized with normal serum. When S. aureus was not opsonized or was opsonized with heat-inactivated serum, the bactericidal activity of IF1-treated PMNs was similar to that of controls. Likewise, the phagocytosis of IF1-treated PMNs was diminished when S. aureus was opsonized with normal serum but was not altered when S. aureus was not opsonized or was opsonized with heat-inactivated serum. These results suggest that the decrease in killing might be due to defective ingestion. The chemiluminescence response of IF1-treated PMNs was inhibited when S. aureus was not opsonized or was opsonized with normal serum. No effect on chemiluminescence was observed when S. aureus was opsonized with heat-inactivated serum. These results suggest that IF1 interferes not only with S. aureus stimulation of PMNs via complement receptors but also with oxygen-dependent bactericidal activity.
Endotoxin tolerance: independent regulation of interleukin-1 and tumor necrosis factor expression
Authors: Zuckerman S H , Evans G F , Butler L D
Published: January 2020

The injection of lethal or sublethal doses of bacterial lipopolysaccharide (LPS) into mice results in transient increases in both serum tumor necrosis factor (TNF) and interleukin-1 (IL-1). The peak in serum TNF was detected prior to maximal elevation in endogenous corticosterone and was no longer apparent 3 to 4 h post-LPS injection, a point at which corticosterone and IL-1 levels had significantly increased. The initial increase in serum IL-1 may, in part, be modulated by the preceding TNF peak, as pretreating animals with a monoclonal antibody against murine TNF resulted in a significant decrease in IL-1 levels 3 h post-LPS injection. A second injection of LPS at 20 h failed to result in a secondary TNF peak, suggesting an endotoxin-tolerant state. However, in contrast to TNF, significant increases in serum IL-1 were detected in the endotoxin-tolerant animals following a repeated LPS stimulus. This secondary increase in IL-1 occurred despite the elevation in serum corticosterone. While peritoneal macrophages from endotoxin-tolerant mice demonstrated only a modest 10 to 15% increase in TNF and IL-1 mRNA relative to the levels after the primary 1-h LPS stimulus, a secondary increase in IL-1 but not TNF mRNA in the spleen was apparent following a second LPS injection. The spleen, however, was not essential for the increase in serum IL-1, as endotoxin-tolerant splenectomized mice had comparable increases in IL-1 following a repeated LPS stimulus. These results demonstrate the differential regulation of IL-1 and TNF in vivo during endotoxin tolerance.
Production of a suppressor factor by CD8+ lymphocytes activated by mycobacterial components
Authors: Sussman G , Wadee A A
Published: January 2020

The lipid component present in high-molecular-mass fractions with molecular masses of greater than 200 kDa derived from Mycobacterium tuberculosis extracts passaged through Sephacryl S.200 columns activate CD8+ lymphocytes to suppress lymphocyte blastogenesis. Suppression is mediated by the release of suppressor molecules by these CD8+ lymphocytes. Release of suppressor molecules occurs as early as 2 h following pulsing with the high-molecular-mass mycobacterial components and is maximal at 24 h, after which their release declines rapidly. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western immunoblotting indicates that the active components are carbohydrate moieties with approximate molecular masses of 122 to 148 kDa. Our results suggest a mechanism of interaction between mycobacteria and host mononuclear cells such that mycobacterial lipids, once exposed, activate CD8+ suppressor lymphocytes. Activation of these lymphocytes results in the release of carbohydrate-containing molecules that ultimately inhibit the blastogenesis of other lymphocytes.
Differential sensitivity of CD8+ suppressor and cytotoxic T lymphocyte activity to bacterial monophosphoryl lipid A
Authors: Esquivel F , Taylor C E , Baker P J
Published: January 2020

Treatment with a preparation of monophosphoryl lipid A, known to be capable of abolishing the expression of CD8+ suppressor T cell activity generated during the antibody response to type III pneumococcal polysaccharide (SSS-III), was found to have no adverse effect upon either induction or expression of CD8+ cytotoxic T lymphocyte activity specific for influenza A virus antigens. This suggests that suppressor T cells and cytotoxic T lymphocytes represent functionally distinct subsets of CD8+ T cells which can be differentiated on the basis of their sensitivities to inactivation by monophosphoryl lipid A.
Adherence of Candida albicans to tissues from mice with genetic immunodeficiencies
Authors: Brawner D L , Smith F O , Mori M , Nonoyama S
Published: January 2020

Ex vivo adherence comparisons were made between immunocompetent and immunocompromised mouse tissues, and the roles of serum immunoglobulin and macrophages in the adherence of Candida albicans were investigated. Spleen, lymph node, and kidney tissues were harvested from congenitally immunodeficient mice, including AKR/scid, C.B-17, C3Hscid, and N:NIH nu/bg/xid mice, and their normal counterparts into which the defects were bred (AKR/J, C3H/HeSnJ, and BALB/c-ByJ). Tissues were compared for the ability to bind C. albicans 219 in an ex vivo assay. In general, immunodeficiencies significantly decreased binding of C. albicans to spleen but not to lymph node or kidney tissue compared with immunocompetent mice. In C3Hscid and AKRscid mice, spleen tissues from "nonleaky" mice bound significantly fewer yeast cells (P = 0.0005 and 0.0009, respectively) than did those from C3H/HeSnJ or AKR/J mice. Numbers of adherent yeast cells were similar in "leaky" AKRscid and AKR/J mice. Yeast adherence to spleen tissue from N:NIH nu/bg/xid mice correlated with mouse age (P = 0.01). Measurements of total serum immunoglobulin indicated that the scid defect was most complete in C3Hscid mice and that yeast adherence in spleen tissue correlated with immunoglobulin titers. Results of adherence assays and macrophage-specific immunostains suggested that factors determining adherence differ among reticuloendothelial organs.
Antigenic differences between Coxiella burnetii cells revealed by postembedding immunoelectron microscopy and immunoblotting
Authors: McCaul T F , Banerjee-Bhatnagar N , Williams J C
Published: January 2020

The aim of this study was to investigate the antigenic structures of the morphologically distinct cells of the Coxiella burnetii developmental cycle. Postembedding immunoelectron microscopy with polyclonal antibodies produced in rabbits to (i) phase I cells, (ii) a chloroform-methanol residue fraction of cells, (iii) the cell walls (CW) of large and small cells and small dense cells (SDC), and (iv) the peptidoglycan-protein complexes of small cells and SDC labelled the continuum of morphologically distinct cells. But these antibodies did not distinguish between the antigenic structures of the various cells. Monoclonal antibodies to the phase I lipopolysaccharide labelled the CW of a majority of the smaller cells, but there was diminished reactivity to the larger cells. Although monoclonal antibodies to a 29.5-kDa outer membrane protein labelled the CW of the large mother cells, the large cells, and the small cells, a minority of the SDC with compact CW were not labelled. The endogenous spore within the mother cell was not labelled by the polyclonal or monoclonal antibodies to cellular components. A selected population of SDC was prepared by osmotic lysis of large cells, differential centrifugation, Renografin step-gradient fractionation, and breakage of the small cells in a French press at 20,000 lb/in2. The pressure-resistant SDC collected as fraction CL did not contain the 29.5-kDa protein, as evidenced by the lack of (i) Coomassie brilliant blue staining of protein in the 29.5-kDa region of sodium dodecyl sulfate-polyacrylamide gels and (ii) reactivity of the 29.5-kDa protein antigenic epitopes in immunoblotting with monoclonal antibodies to the protein. In contrast, CW of the pressure-sensitive small cells contained the 29.5-kDa protein. Therefore, the observed ultrastructural differences between large and small cells and SDC reflect differences in sensitivity to breakage by pressure treatment and in cell-associated antigens. Although the process of differentiation in C. burnetii remains an enigma, we have taken steps toward identifying cellular antigens as markers of differentiation. The pressure-resistant SDC in fraction CL that are devoid of the 29.5-kDa protein may be useful for answering questions about the physiological events required for triggering outgrowth and sequential regulation of the Coxiella developmental cycle.
Characterization of vir-activated TnphoA gene fusions in Bordetella pertussis
Authors: Finn T M , Shahin R , Mekalanos J J
Published: January 2020

The expression of many of the known virulence determinants of Bordetella pertussis is coordinately regulated by the vir regulatory locus and reduced in response to environmental signals called modulators. We have previously identified eight TnphoA gene fusions in B. pertussis in which the expression of alkaline phosphatase was maximal in the absence of the modulators nicotinic acid and MgSO4. We have termed the genes identified by these fusions vir-activated genes. Here we report the characterization of these TnphoA mutant strains. Four fusion strains were defective in known virulence determinants. For one of these, fusion strain SK39, Southern blot hybridization demonstrated that TnphoA was inserted in the S1 subunit gene of pertussis toxin. Hemagglutination assays, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and immunoblots identified three fusions strains, SK16, SK75, and SK91, that were defective in filamentous hemagglutinin. Whereas all three filamentous hemagglutinin-defective mutants showed either normal or enhanced colonization, the pertussis toxin-defective mutant showed a marked defect in pulmonary persistence. Of the four other fusion strains, two were deficient in outer membrane proteins. One of these, strain SK8, was defective in a major outer membrane protein of 95 kDa as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. This strain colonized mouse lungs less well and did not induce lymphocytosis after aerosol challenge. The other strain, SK34, was defective in four outer membrane proteins, three of which were detectable only on a Western blot with polyclonal sera against B. pertussis. Two of our gene fusion strains did not show any defect in identifiable vir-regulated proteins.
Strain variation of Babesia bovis merozoite surface-exposed epitopes
Authors: Palmer G H , McElwain T F , Perryman L E , Davis W C , Reduker D R , Jasmer D P , Shkap V , Pipano E , Goff W L , McGuire T C
Published: January 2020

Babesia bovis merozoites are exposed to antibodies during the extraerythrocytic phase, and surface polypeptides bearing exposed epitopes are possible immunogens. Monoclonal antibodies reactive with the merozoite surface bind either immunodominant epitopes expressed diffusely on the merozoite surface or, alternatively, epitopes expressed in a polar pattern. Epitopes expressed diffusely on the immunodominant 42- and 44-kDa merozoite polypeptides were not conserved among strains from geographically diverse regions. In contrast, epitopes expressed in a polar pattern on the merozoite surface were conserved among nine strains and clones. Identification of variables and conserved epitopes provides a basis for defining antigenic variation and cross-protective immunity.
Immunochemistry of the Capsular Polysaccharides from
Clostridium perfringens:
Selected Hobbs Strains 1, 5, 9, and 10
Authors: Cherniak Robert , Henderson Bernice G.
Published: January 2020

The properties of the immunochemically distinct substances isolated from four strains of
Clostridium perfringens
, mucoid variants of Hobbs 1, 5, 9, and 10, were shown to be compatible with the hypothesis that polysaccharides are generally responsible for the “type-specificity” of these organisms. The presence of “group-specific” substance was demonstrated by the cross-reaction of recent preparations of Hobbs 5 antisera with the isolated polysaccharides. The cross-reactions were not observed with specific antisera of the other strains studied and were independent of the “type-specific” phenomenon.
Growth of
Streptococcus faecium
in the Presence of Lysozyme
Authors: Metcalf Robert H. , Deibel R. H.
Published: January 2020

Streptococcus faecium
can grow normally in the presence of lysozyme, despite the observation that cell suspensions of the organism are lysed readily by the enzyme. Growth in the presence of lysozyme is not due to resistant cells, and the culture is lysed after growth if the
p
H of the medium is not allowed to drop too low for lysozyme activity. Growth followed by lysis in the presence of lysozyme was not exhibited by other organisms tested which were either significantly more resistant or more sensitive to lysozyme than
S. faecium.
Lysozyme was active on the cell wall of
S. faecium
during growth in the presence of 200 μg of the enzyme per ml in a complex medium. It appears that, when actively metabolizing,
S. faecium
can synthesize the cell wall at a greater rate than lysozyme can hydrolyze it. Thus, the organism is capable of growth in the presence of the enzyme. A large variation in the lytic responses of enterococcal cell suspensions to lysozyme was dependent on the strain used, the growth phase from which the culture was harvested, and the medium in which the culture was grown.
Nicotinamide Adenine Dinucleotide Glycohydrolase Activity in Guinea Pig Polymorphonuclear Leukocytes
Authors: DeChatelet Lawrence R. , McCall Charles E. , Shirley Pamela S.
Published: January 2020

An enzyme is present in extracts of guinea pig polymorphonuclear leukocytes which can catalyze the hydrolysis of pyridine nucleotides. The enzyme is equally active toward nicotinamide adenine dinucleotide (NAD) or NAD phosphate, has an acid
p
H optimum, and is inhibited by either nicotinamide or isonicotinic acid hydrazide. This enzyme might be involved in the regulation of the pyridine nucleotide concentration within the leukocyte.
Inhibition of Certain Deoxyribonucleic Acid Viruses by Liver Extracts
Authors: Lee Helen H. , Tinsley T. W.
Published: January 2020

A proteinaceous substance was detected in the liver of several animal species that inhibited the multiplication of certain deoxyribonucleic acid, but not ribonucleic acid, viruses. Preliminary experiments suggested that its site of action was not extracellular. It did not inhibit virus by interfering with adsorption to cells. It was suggested that this inhibiting substance acts directly upon cells by interfering with viral synthesis.
Immunization of Mice Against Encephalomyocarditis Virus I. Purification, Concentration, and Inactivation of Encephalomyocarditis Virus
Authors: Bogaerts W. J. C. , Durville-van der Oord B. J.
Published: January 2020

Methods are described for the concentration, purification, and inactivation of encephalomyocarditis virus grown in L-cell suspension cultures. Virus concentrates were obtained by the precipitation of crude virus lysates with polyethylene glycol and were purified by Genetron extraction. After column chromatography approximately 70% recovery of infectivity and hemagglutination (HA) activity was found. Exposure of the purified virus suspensions to ultraviolet light resulted in reduction of the infectivity by a factor of 10
9
with little or no loss of HA activity. The preparations are being evaluated as vaccines.
Detection of Protein Contaminants in Biological Preparations by Discontinuous Counterimmunoelectrophoresis
Authors: Wallis Craig , Melnick Joseph L.
Published: January 2020

Acidic proteins (serum albumin through beta
2
globulin) can be rapidly detected by the discontinuous counterimmunoelectrophoresis method in which the protein under test is allowed to react electrophoretically with specific antiserum. In the test, acidic proteins move towards the anode and cross over antibodies moving towards the cathode. The method is several thousand times more sensitive than the Lowry test, for it can detect picogram amounts of protein. With this method, foreign proteins (chicken allantoic fluids or bovine serum) were detected in virus vaccines manufactured for human use and in commercial “monospecific” immunological reagents.
Isolation and Characterization of a Thymic Factor
Authors: Robey G. , Campbell B. J. , Luckey T. D.
Published: January 2020

A protein was isolated from bovine thymus that was shown to accelerate the appearance of hemolysin to sheep erythrocytes in neonatal mice. The isolation procedure consisted of saline homogenization, ammonium sulfate precipitation, and methanol precipitation, followed by chromatography on diethylaminoethyl-cellulose and two chromatographies on Sephadex G-150. The protein was shown to be homogeneous by polyacrylamide gel electrophoresis and by sedimentation velocity and sedimentation equilibrium analytical ultracentrifugation. The molecular weight was determined to be 79,950. Additional physical and chemical characteristics were also determined.
Stimulation of Antibacterial Vaccination in Mice by Polyadenylic Acid: Polyuridylic Acid Complex
Authors: Renoux Gérard , Renoux Micheline , Branche Robert
Published: January 2020

The effect of polyadenylic acid:polyuridylic acid complex (poly A:U) on immunization was investigated in mice vaccinated by killed
Brucella melitensis
cells suspended in incomplete adjuvant or in saline. Addition of 300 μg of poly A:U to vaccines rendered 3 × 10
8
B. melitensis
cells in saline as immunogenic as 3 × 10
11
cells in oil adjuvant against a severe
B. abortus
challenge. In the mouse and
Brucella
system, poly A:U exerts an adjuvant effect on immunity but does not stimulate production of circulating antibodies that could be demonstrated at the time of autopsy.
Development of an Equine Herpesvirus in Two Cell Culture Systems: Light and Electron Microscopy
Authors: Fong C. K. Y. , Hsiung G. D.
Published: January 2020

Development of equine herpesvirus strain 82A was studied in cells from primary horse kidney (HOK) cultures and an equine dermis (ED) cell strain. HOK and ED cells are equally susceptible to the 82A virus infection and yield about the same amount of infectious virus. Intranuclear inclusions were present in both cell systems, but a ring-shaped syncytial formation was observed only in infected ED cells. Ultrastructural studies revealed the presence of dense granules 30 nm in diameter and characteristic star-like clusters of granules in the infected HOK cells, but these granules were rarely seen in the infected ED cells. Viral nucleocapsids were associated with homogenous nuclear matrices, with moderate electron density in both cell systems. Viral nucleocapsids acquired envelopes by budding into the nuclear vacuoles in both HOK and ED cells. Budding from inner nuclear membranes into perinuclear cisterna or into cytoplasmic vacuoles also was observed frequently in HOK cells but was not seen often in infected ED cells. Multiple, membrane-bound intranuclear inclusions of fibrillar material which may be associated with virus envelopes were seen only in infected ED cells. Enveloped virus particles seen in nuclear vacuoles or perinuclear cisterna were more regular in shape and had a 130-nm diameter, whereas the enveloped virus particles seen in the cytoplasm and extracellular space were more irregular in shape and had a 130- to 160-nm diameter.
Nonspecific Protective Action Against
Vibrio cholerae
of SK&F 42319, a Ribonucleic Acid Obtained from Bacteriophage-Infected
Escherichia coli
Authors: Actor Paul , Pitkin Donald , Goore Moshe Y. , Berry L. Joe
Published: January 2020

An interferon-inducing RNA, SK&F 42319, obtained from a lysate of phage-infected
Escherichia coli
, protected mice against
Vibrio cholerae
infection. This nonspecific protection was not attributable to endotoxin contamination.
Lymphocyte Transformation in Chagas Disease
Authors: Tschudi E. Irene , Anziano Dante F. , Dalmasso Agustin P.
Published: January 2020

The in vitro response of human peripheral lymphocytes to
Trypanosoma (Schizotrypanum) cruzi
antigens and to phytohemagglutinin was used to study the role of cellular immunity in Chagas disease (American trypanosomiasis). Solubilized
T. cruzi
antigens elicited 5 to 30% transformed cells in 5-day cultures of lymphocytes from adults chronically infected with
T. cruzi.
No major difference was noted between the response of 22 asymptomatic individuals and of 3 patients with chagasic cardiopathy. No correlation was found between degree of lymphocytic transformation and serum antibody titer. Lymphocytes from 15 normal controls yielded no significant transformation. Intradermal tests provoked a local delayed hypersensitivity reaction in infected individuals only, as evaluated clinically and histologically. The response to phytohemagglutinin of lymphocytes from chronically infected individuals was identical with that of normal controls.
Properties of the Cholera Exo-Enterotoxin: Effects of Dispersing Agents and Reducing Agents in Gel Filtration and Electrophoresis
Authors: Finkelstein Richard A. , LaRue Michael K. , LoSpalluto Joseph J.
Published: January 2020

Initial studies, by using polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS), led to the attractive hypothesis that the cholera exo-enterotoxin (choleragen) consisted of two noncovalently linked peptides of 56,000 and 28,000 molecular weight. The spontaneous toxoid (choleragenoid) appeared to be identical with the 56,000 molecular weight piece. The results appeared to be very similar to those obtained recently with diphtheria toxin. However, they did not agree with earlier studies which indicated that both the toxin and the toxoid consisted of subunits of approximately 14,000 molecular weight. More extensive investigation, by using gel filtration with
3
H-labeled toxin, ultracentrifugation, and immunologic studies, failed to support the observations of SDS-gel electrophoresis, suggesting the existence of a 28,000 molecular weight fragment which is unique to the toxin. The results were more compatible with our earlier observations regarding subunit composition. It is concluded that these proteins are relatively resistant to dissociation by SDS and need to be unfolded by prior treatment for more complete dissociation into subunits. Indirect evidence suggests that the 28,000 fragment may be a dimer, or larger aggregate, of a smaller subunit which can be integrated in the formation of choleragenoid. It is also evident that caution should be exercised in the interpretation of results, however pleasing, obtained only by SDS-gel electrophoresis.
Effect of Urea on the Hemagglutinating and Complement-Fixing Antigens of Type 2 Dengue Virus
Authors: Cornesky Robert A. , Hammon William McD. , Atchison Robert W. , Sather Gladys E.
Published: January 2020

Sephadex G-200 filtration was used for fractionating dengue type 2 (DEN-2)-infected suckling mouse brain (SMB) supernatant fluids. The high-molecular-weight fraction, which was eluted in the void volume, showed no increase in type specificity when tested against immune ascitic fluid to the four prototype dengue viruses. A void-volume fraction obtained after the infected SMB supernatant fluids were treated with urea displayed significant increases in complement fixation (CF) type specificity. Immune ascitic fluid prepared against the more typespecific DEN-2 antigen demonstrated neutralizing ability and greater CF type specificity. When DEN-2 sucrose-acetone-extracted hemagglutinating (HA) antigens were treated with 6
m
urea at 37 C for various time intervals, all HA antigen was destroyed in 15 min. Urea treatment of infected SMB supernatant fluids indicated that the CF antigens were more stable to the effect of urea than were the HA antigens. After urea treatment of the SMB supernatant fluids, the CF type specificity increased as the hemagglutination inhibition titer decreased.
Evidence for proteolytic cleavage of the 120-kilodalton outer membrane protein of rickettsiae: identification of an avirulent mutant deficient in processing
Authors: Hackstadt T , Messer R , Cieplak W , Peacock M G
Published: January 2020

The 120-kDa rickettsial outer membrane protein (rOmpB) is encoded by a gene with the capacity to encode a protein of approximately 168 kDa. The carboxy-terminal end of the molecule is apparently cleaved to yield 120- and 32-kDa products. Both polypeptides are surface exposed and remain associated with the outer membrane of intact rickettsiae. All species of rickettsiae examined display similar cleavage of rOmpB. Comparison of diverse species of rickettsiae demonstrate a conserved N terminus of the 32-kDa fragment, with a predicted procaryotic secretory signal peptide immediately upstream of the proposed cleavage site. Coprecipitation of the 120-kDa rOmpB protein and the 32-kDa peptide by monoclonal antibodies specific for the 120-kDa portion of the molecule suggests that the two fragments remain noncovalently associated on the surface of rickettsiae. Analysis of an avirulent mutant of Rickettsia rickettsii revealed reduced amounts of the 120- and 32-kDa fragments, but with a correspondingly larger rOmpB protein that displayed properties expected of the putative precursor. This avirulent mutant grows intracellularly but fails to cause the lysis of infected cells that is typical of R. rickettsii. DNA sequence analysis of the region of the gene encoding the cleavage site of the avirulent strain revealed no difference from the sequence obtained from virulent R. rickettsii. The 168-kDa putative precursor of the avirulent strain of R. rickettsii was not extracted from the surface by dilute buffers, as is the 120-kDa protein of virulent R. rickettsii or R. prowazekii. These latter results suggest that the 32-kDa C-terminal region of the molecule may serve as a membrane anchor domain.
Aggregation substance of Enterococcus faecalis mediates adhesion to cultured renal tubular cells
Authors: Kreft B , Marre R , Schramm U , Wirth R
Published: January 2020

The sex pheromone system of Enterococcus faecalis is a unique, highly efficient plasmid collection mechanism for this species. A crucial role in this system is played by an adhesin called aggregation substance which enables the cell-cell contact between donor and recipient strains. The existence of the amino acid motif Arg-Gly-Asp-Ser in the adhesin prompted us to look for a possible binding of E. faecalis cells expressing aggregation substance to eucaryotic cells. We were able to show that the adhesin mediated binding to cultured renal tubular cells (porcine cell line LLC-PK1) via light microscopic, electron microscopic, and enzyme-linked immunosorbent assay-based studies. Synthesis of the adhesin was induced by some component(s) of serum. These data are interpreted to mean that aggregation substance is an adhesin mediating not only cell-cell contact between different E. faecalis strains but also binding of E. faecalis to eucaryotic cells, and therefore it might contribute to virulence.
Immunochemical studies and complete amino acid sequence of the streptokinase from Streptococcus pyogenes (group A) M type 12 strain A374
Authors: Ohkuni H , Todome Y , Suzuki H , Mizuse M , Kotani N , Horiuchi K , Shikama N , Tsugita A , Johnston K H
Published: January 2020

The complete amino acid sequence of the streptokinase (SKase) of Streptococcus pyogenes M type 12 strain A374, isolated from a patient with poststreptococcal glomerulonephritis (PSGN), was determined. The epitope domain for the monoclonal antibody N-59, which cross-reacts with SKases of both the PSGN-associated strain and S. equisimilis H46A (a non-PSGN-associated strain), was predicted to be localized in residues 370 to 374. The epitope domain specific for monoclonal antibody RU-1, which reacts only with the PSGN-associated SKase, was localized to residues 164 to 236.
Analysis of expression of toxin-coregulated pili in classical and El Tor Vibrio cholerae O1 in vitro and in vivo
Authors: Jonson G , Holmgren J , Svennerholm A M
Published: January 2020

The expression of toxin-coregulated pili (TCP) and their structural subunit TcpA was compared in 20 strains of Vibrio cholerae of the classical and El Tor biotypes. Bacteria were isolated from the intestines of rabbits with experimental cholera and compared with the same strains grown under optimal TCP expression conditions in vitro. Immunoblotting revealed that TcpA production was induced in both biotypes after vibrios entered the intestinal milieu; TcpA-negative inocula gave rise to TcpA-positive vibrios after multiplication in the gut. The levels of TcpA expressed during growth in the intestine were, for most strains, comparable to those attained under optimal growth conditions in vitro. Of 11 classical strains tested, 10 expressed TCP antigen on the bacterial surface at levels comparable to or exceeding those seen after growth in vitro as determined by an inhibition enzyme-linked immunosorbent assay. In contrast, only one of the nine El Tor strains studied produced detectable amounts of TCP surface antigen in vivo and no fimbriae or surface antigen reacting with anti-TCP serum was found on El Tor vibrios from human cholera stools. Distinct TCP fimbriae were observed by immunoelectron microscopy on classical-biotype vibrios grown either in rabbit intestines or in vitro but were not detected on El Tor vibrios. The results show that TCP is expressed on V. cholerae O1 of the classical biotype but not on V. cholerae O1 of the El Tor biotype in the intestines of rabbits with experimental cholera infection.
Hemagglutination and adherence to plastic by Staphylococcus epidermidis
Authors: Rupp M E , Archer G L
Published: January 2020

Staphylococcus epidermidis is an important nosocomial pathogen responsible for intravenous catheter-related bacteremia and infections of other prosthetic medical devices. We found that the ability of S. epidermidis to hemagglutinate erythrocytes correlated with the adherence of bacteria to plastic and to intravenous catheters. S. epidermidis isolates responsible for prosthetic-valve endocarditis (n = 61) and isolates from intravenous catheters (n = 59) were significantly more likely to cause hemagglutination than isolates from the skin of preoperative cardiac surgery patients (n = 19) (P = 0.027). S. epidermidis isolates (n = 23) recovered from the skin of patients 7 to 10 days after cardiac surgery were significantly more likely to exhibit hemagglutination than the preoperative isolates (P = 0.015). By a quantitative adherence assay, we also observed that the hemagglutination titer and number of species of erythrocytes agglutinated correlated directly with adherence to polystyrene (P less than 0.001). In addition, hemagglutinating isolates were significantly more likely to be recovered in high number from intravenous catheters when semiquantitative catheter culture techniques were used (P less than 0.001). We speculate that hemagglutinin(s) either plays a direct role in adherence to polymers and thus prosthetic-device infection or serves as an easily demonstrable marker for adherence-prone isolates.
Lipid A in Helicobacter pylori
Authors: Mattsby-Baltzer I , Mielniczuk Z , Larsson L , Lindgren K , Goodwin S
Published: January 2020

Free lipid A of Helicobacter pylori was characterized with regard to chemical composition, reactivity with anti-lipid A antibodies, and activity in a Limulus lysate assay. The predominant fatty acids of H. pylori lipid A were 3-OH-18:0, 18:0, 3-OH-16:0, 16:0, and 14:0. Hexosamine was present in amounts similar to those in Campylobacter jejuni or Salmonella typhimurium lipid A. The lipopolysaccharide of H. pylori contained 2-keto-3-deoxyoctonic acid, a common constituent of enterobacterial and C. jejuni lipopolysaccharides. In the enzyme-linked immunosorbent assay, the doses of lipid A required to inhibit anti-lipid A by 50% (EI50 values) by absorption of the immune (rabbit) serum were 7.9, 1.2, and 1.4 micrograms of O-deacylated lipid A's from H. pylori, C. jejuni, and S. typhimurium per ml, respectively. The lower reactivity of H. pylori lipid A compared with those of the other two lipid A preparations (as shown by the higher EI50 value) was underscored by the use of a murine monoclonal anti-lipid A antibody in the inhibition assay. An EI50 value was not obtained at the concentrations tested for H. pylori lipid A; the corresponding figures for C. jejuni and S. typhimurium lipid A's were 13 and 14 micrograms/ml, respectively. No inhibition was obtained with H. pylori lipopolysaccharide, which showed a low-molecular-weight profile on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The activity of H. pylori lipid A in the Limulus assay was approximately 71 and 650 times lower than those of C. jejuni and S. typhimurium lipid A's, respectively. These findings suggest that lipid A is an integral part of the outer cell wall of H. pylori. The lower reactivity of H. pylori lipid A with anti-lipid A antibodies and in the Limulus assay compared with that of C. jejuni or S. typhimurium lipid A may be explained by a different composition of the fatty acids, especially the 3-hydroxy fatty acids, and a possible deviating phosphorylation pattern.
Recombinant interleukin-1 alpha augments granuloma formation and cytokine production but not parasite clearance in mice infected with Leishmania donovani
Authors: Curry A J , Kaye P M
Published: January 2020

In vivo administration of various doses of recombinant interleukin-1 alpha to B10.D2/n mice chronically infected with Leishmania donovani resulted in enhanced formation of granulomas and in vitro production of gamma interferon. By direct microscopical enumeration, reduction in gross parasite burden in the viscera was not observed, however. These data highlight an important discordance between granuloma formation per se and parasite elimination and suggest that interleukin-1 deficiency alone cannot account for the chronicity of this disease.
Antibodies to meningococcal class 1 outer membrane proteins in South African complement-deficient and complement-sufficient subjects
Authors: Orren A , Warren R E , Potter P C , Jones A M , Lachmann P J , Poolman J T
Published: January 2020

Inhibition assays were used to investigate human serum antibodies to the meningococcal class 1 outer membrane proteins. We adapted the whole-cell enzyme-linked immunosorbent assay technique to determine the ability of sera to inhibit the binding of murine subtyping monoclonal antibodies. Serum samples from 33 South African subjects with a deficiency in the sixth component of complement as well as serum samples from various groups of complement-sufficient subjects were investigated. Subjects were subdivided according to whether they were (i) convalescent from Neisseria meningitidis infections, (ii) nonconvalescent, or (iii) controls. Preliminary subtyping investigations had shown that P1.2 was present on 36% of meningococcal clinical isolates from Cape Province, South Africa. Assays with the anti-P1.2 antibodies showed the presence of high antibody levels in many deficient sera and moderately elevated levels in some sera from the complement-sufficient convalescent patients. P1.2, P1.4, P1.15, and P1.16 are epitopes situated on loop 4 of the class 1 outer membrane proteins, whereas P1.7 is on loop 1. Inhibition assays showed that human sera that inhibited binding by P1.2 monoclonal antibodies tended to inhibit the other monoclonal antibodies directed to loop 4 epitopes. This suggests that the epitopes recognized by the human antibodies are not exactly the same as the epitopes recognized by the murine monoclonal antibodies and raises the possibility of the importance of other epitopes.
Protective murine monoclonal antibodies to Cryptococcus neoformans
Authors: Mukherjee J , Scharff M D , Casadevall A
Published: January 2020

Several murine monoclonal antibodies (MAbs) specific for the capsular glucuronoxylomannan of Cryptococcus neoformans were studied for their capacity to confer protection when passively administered to lethally infected mice. The MAb group studied recognized at least three distinct epitopes and included immunoglobulin M (IgM), IgG3, IgG1, and IgA isotypes. The protection model used A/J and BALB/c mice infected intraperitoneally with 10(8) cryptococci. The MAbs were administered either immediately preceding or, in one experiment, 24 to 48 h prior to infection. Protective efficacy was assessed by the ability of passively administered MAbs to prolong the survival of lethally infected mice. Three IgM MAbs, each of which recognized a distinct epitope, were able to prolong survival of lethally infected mice to different extents. A set of IgM, IgG3, IgG1 and IgA MAbs which utilize the same immunoglobulin gene elements and were derived from the same B-cell clone exhibited significant class differences in protective efficacy with IgA, IgG1 > IgM > IgG3. The results confirm that protective MAbs against C. neoformans capsular polysaccharide exist and strongly suggest that both epitope specificity and isotype are important determinants of protective efficacy.