bluuebunny/crossref_metadata_2025 huggingface dataset:
Leishmania-reactive CD4+ and CD8+ T cells associated with cure of human cutaneous leishmaniasis
Authors: Da-Cruz A M , Conceição-Silva F , Bertho A L , Coutinho S G
Published: January 2020

Fourteen patients suffering from American cutaneous leishmaniasis were studied. Assays of the lymphocyte proliferative response induced in vitro by Leishmania braziliensis antigens were performed. After 5 days in culture, L. braziliensis-stimulated blast T cells were harvested for CD4+ and CD8+ phenotype analysis. When results before and at the end of therapy were compared, leishmaniasis patients showed an increase in the percentage of CD8+ blast T cells and a decline in the proportion of CD4+ blast T cells in cultures. The levels of gamma interferon in T-cell culture supernatants showed a tendency to increase when the patients were cured. These results show a pattern of higher proportions of Leishmania-reactive CD8+ T cells and lower proportions of Leishmania-reactive CD4+ T cells after cure.
Bactericidal activity of synthetic peptides based on the structure of the 55-kilodalton bactericidal protein from human neutrophils
Authors: Gray B H , Haseman J R
Published: January 2020

Short (10- to 11-mer) hydrophilic peptides based on the structure of the 55-kDa bactericidal protein (BP55, B/PI, and CAP57) from human neutrophil granules were identified from the hydropathy plot of the 456-amino-acid sequence predicted from the nucleotide sequences of cDNA clones for BP55 and B/PI. Peptides corresponding to amino acid residues 90 to 99 (peptide #90-99), 86 to 99, or 90 to 102 of BP55 were bactericidal toward 5 x 10(6) Pseudomonas aeruginosa cells at 0.6 x 10(-5) to 1.5 x 10(-5) M and killed an Escherichia coli rough strain at 3 x 10(-5) M. The #90-99 peptide with a cysteine added at the amino terminus (C#90-99) was approximately 10 times more active than #90-99, killing P. aeruginosa at 1.5 x 10(-6) M. Peptides representing amino acid residues 27 to 37, 118 to 127, and 160 to 170 and the first 10 amino acids of the signal sequence for BP55 were not bactericidal. When coupled to either keyhole limpet hemocyanin or ovalbumin protein carriers through the thiol group, the C#90-99 peptide was not diminished on a molar basis in its capacity for killing of P. aeruginosa. Two other relatively hydrophilic peptides with an added amino-terminal cysteine, peptides C#227-236 and C#418-427, were not bactericidal at 1.2 x 10(-4) M or at 100 times the effective bactericidal concentration of C#90-99. The C#90-99 peptide killed E. coli at 1.5 x 10(-5) M, or at 10 times the concentration required to kill an equal number of P. aeruginosa cells. Although Pseudomonas cepacia and Staphylococcus aureus were resistent to killing by the parent BP55 molecule, they were susceptible to the C#90-99 and #90-99 peptides in the same concentration range as was E. coli. When all peptides were compared for the ability to neutralize E. coli O55:B5 endotoxin in a Limulus amoebocyte lysate assay, the C#227-236, C#418-427, and #160-170 peptides completely inhibited gelation at a 10(-4) M concentration. All other synthetic peptides, including bactericidal peptide #90-99 and its congeners, lacked endotoxin-neutralizing activity at the highest concentration tested (4.5 x 10(-4) M). A hybrid of the C#227-236 and #90-99 peptides (CHybrid) was identical to the C#227-236 peptide component in effectiveness for carrying out endotoxin neutralization and was fivefold better than the #90-99 peptide in its capacity for killing P. aeruginosa.
T lymphocytes in host defense against bacterial translocation from the gastrointestinal tract
Authors: Gautreaux M D , Deitch E A , Berg R D
Published: January 2020

Flow cytofluorometric analyses of lymphocytes harvested from the mesenteric lymph node (MLN), mucosal epithelium, and lamina propria of C57BL/6 mice demonstrate that expression of alpha/beta or gamma/delta T-cell receptors (TCR) and CD4 or CD8 molecules by T lymphocytes in the intestinal immune system varies depending upon their anatomic location. The MLN contained equivalent numbers of CD4+ and CD8+ T cells, the vast majority of which were alpha/beta TCR positive (alpha/beta TCR+). The lamina propria T cells were predominantly CD4+ and alpha/beta TCR+, while the intestinal intraepithelial lymphocytes consisted of equivalent numbers of alpha/beta and gamma/delta T cells, the majority of which were CD8+. There were no significant changes in these T-cell phenotypic profiles when the mice were antibiotic decontaminated or monoassociated with Escherichia coli. Mice were depleted of CD4+ T cells and/or CD8+ T cells in vivo by intraperitoneal injections of monoclonal antibody GK 1.5 (rat anti-mouse CD4) and/or monoclonal antibody 2.43 (rat anti-mouse CD8). T-cell depletion was confirmed in the MLN, lamina propria, and the intestinal epithelium by flow cytometry. E. coli C25 translocation from the gastrointestinal (GI) tract to the MLN was significantly increased in mice depleted of CD4+ T cells, CD8+ T cells, or both. T-cell-deficient athymic beige/nude mice also exhibited greater levels of E. coli C25 translocation to the MLN than beige/het euthymic littermates. Salmonella typhimurium translocation also was increased following CD4+ and CD8+ T-cell depletion in mice monoassociated with S. typhimurium. Depletion of CD4+ and/or CD8+ T cells also increased the translocation to the MLN of certain indigenous GI flora bacteria. These results confirm that T-cell-mediated immunity is involved in the host defense against bacterial translocation from the GI tract.
Intermolecular relationships of major surface proteins of Anaplasma marginale
Authors: Vidotto M C , McGuire T C , McElwain T F , Palmer G H , Knowles D P
Published: January 2020

Immunization with Anaplasma marginale membranes containing major surface proteins (MSPs) induces protective immunity against clinical disease (N. Tebele, T. C. McGuire, and G. H. Palmer, Infect. Immun. 59:3199-3204, 1991). For use in design of a recombinant antigen subunit vaccine for A. marginale, intermolecular relationships of known A. marginale MSPs were analyzed. Under nonreducing conditions, MSP-2 and MSP-5 occur as multimers. A large (> 300-kDa-molecular-mass), nonreduced protein complex contained MSP-1a linked by disulfide bonds to MSP-1b and by noncovalent bonds to MSP-5. MSP-2 was also noncovalently bound to this complex. The nearest neighbor membrane proteins were identified by cross-linking reactions followed by immunoblotting with anti-MSP antibodies. A cross-linked aggregate retained in the stacking gel contained MSP-1a, MSP-1b, MSP-2, MSP-3, MSP-4, and MSP-5. Collectively, the data indicate that MSP-2 and MSP-5 occur as monomers and disulfide-bonded multimers. The MSP-1 complex occurs as both disulfide-bonded and noncovalently associated MSP-1 and MSP-1b, and MSP-2 and MSP-5 are noncovalently associated with MSP-1. Also, MSP-1, MSP-2, MSP-3, and MSP-4 are nearest neighbors, and MSP-5 is noncovalently associated with this cross-linked complex.
Early gamma interferon mRNA expression is associated with resistance of mice against Yersinia enterocolitica
Authors: Bohn E , Heesemann J , Ehlers S , Autenrieth I B
Published: January 2020

T cells in cooperation with macrophages play an important role in resolution of primary Yersinia enterocolitica infection in mice. Previous work from this laboratory demonstrated that gamma interferon (IFN-gamma) and tumor necrosis factor alpha (TNF-alpha) are essential mediators of these processes. In an attempt to elucidate early mechanisms of resistance, we investigated cytokine mRNA production, including that for interleukin-1 beta (IL-1 beta), IL-2, IL-4, IL-6, IL-10, TNF-alpha, and IFN-gamma, after primary as well as secondary Y. enterocolitica infection in Yersinia-susceptible BALB/c mice and Yersinia-resistant C57BL/6 mice. In both strains of mice, proinflammatory cytokines such as IL-1 beta, IL-6, and TNF-alpha were expressed rapidly and to comparable degrees, while IFN-gamma expression was enhanced two- to eightfold in C57BL/6 mice, as revealed by semiquantitative reverse transcription PCR. Similar results were found in both mouse strains after secondary Y. enterocolitica infection. IL-2 mRNA was detected only during secondary infection and disappeared rapidly in BALB/c mice. IL-4 mRNA expression was detectable in C57BL/6 but not BALB/c mice. The levels of cytokine mRNA expression correlated closely with the number of injected bacteria. The findings reported here support the hypothesis that early and enhanced production of IFN-gamma may be associated with a state of heightened resistance against Y. enterocolitica infection.
The eaeB gene of enteropathogenic Escherichia coli is necessary for signal transduction in epithelial cells
Authors: Foubister V , Rosenshine I , Donnenberg M S , Finlay B B
Published: January 2020

An enteropathogenic Escherichia coli mutant carrying an internal deletion in the eaeB gene (UMD864) was unable to activate epithelial cell signals, including tyrosine phosphorylation, cytoskeletal rearrangements, and the release of inositol phosphates, indicating that the eaeB locus encodes a product that is involved in stimulating signals in epithelial cells.
Streptococcus pyogenes type M12 protein shows selective binding to some human immunoglobulin G3 myeloma proteins
Authors: Johansson P J , Malone C C , Williams R C , Retnoningrum D S , Cleary P P
Published: January 2020

Purified, recombinant M12 protein from Streptococcus pyogenes CS24 has recently been demonstrated to bind human immunoglobulin G3 (IgG3). The binding site for IgG has been localized to an internal peptide encoded by a PvuII fragment of the gene emm12. We have investigated the ability of an isolated recombinant M12 protein consisting of the peptide encoded by the PvuII fragment to bind various monoclonal human IgG3 myeloma proteins representing a number of both Caucasian and Oriental IgG3 Gm(allotypic) phenotypes. Of nine Caucasian IgG3 myeloma proteins, only two bound strongly to the recombinant M12 protein in enzyme-linked immunosorbent assays. The allotypic phenotypes of the reactive proteins were IgG3m(b+)(g-) and IgG3m(b-)(g+). No binding was seen for seven IgG3 myeloma proteins of Oriental origin with G3m(st+)(u-)(b+)(g-), G3m(st-)(u+)(b+)(g-), G3m(st-)(u+)(b-)(g+), and G3m(st-)(u-)(b-)(g+) phenotypes. The binding of human IgG3 to M12 protein seems to be related to features other than its Gm allotypic markers. Selective reactivity of IgG3 myeloma proteins with M12 protein may provide another way to subclassify human IgG3 molecules. The biological significance of the selective reactivity is not known.
Interstrain conservation of babesial RAP-1 surface-exposed B-cell epitopes despite rap-1 genomic polymorphism
Authors: Suarez C E , McElwain T F , Echaide I , Torioni de Echaide S , Palmer G H
Published: January 2020

Members of the babesial rhoptry-associated protein 1 (RAP-1) family express surface-exposed B-cell epitopes and are candidate antigens for vaccine development. The relationship between rap-1 genomic polymorphism and surface-exposed B-cell epitope expression was analyzed by comparison of biological clones of Mexico strain Babesia bigemina and Babesia bovis with strains isolated in Argentina. Despite genomic polymorphism between strains, including sequences located within the open reading frame, defined RAP-1 B-cell surface epitopes and RAP-1 molecular size were conserved in both B. bovis and B. bigemina.
A urease-negative mutant of Helicobacter pylori constructed by allelic exchange mutagenesis lacks the ability to colonize the nude mouse stomach
Authors: Tsuda M , Karita M , Morshed M G , Okita K , Nakazawa T
Published: January 2020

The urease of Helicobacter pylori has been proposed to be one of its pathogenic factors. A kanamycin resistance determinant was inserted in a cloned urease gene, and transformation-mediated allelic exchange mutagenesis was carried out to introduce the disrupted gene into the corresponding wild-type chromosomal region of a clinical isolate of H. pylori, CPY3401. The resulting mutant, HPT73, had the null activity of urease. Nude mouse stomachs were challenged with these two isogenic strains to examine the role of urease in pathogenesis. Gastritis was found in the CPY3401-challenged stomachs, from which bacteria indistinguishable from CPY3401 were recovered. There was no gastritis in the HPT73-challenged stomachs, and we could not recover H. pylori from them. These results indicated that H. pylori urease is essential for colonizing the nude mouse stomach.
Structure-function relationships for polysaccharide-induced intra-abdominal abscesses
Authors: Tzianabos A O , Onderdonk A B , Smith R S , Kasper D L
Published: January 2020

We have previously shown that in an animal model of sepsis positively and negatively charged groups on polysaccharide A of Bacteroides fragilis are essential for the induction of intra-abdominal abscess formation (A. O. Tzianabos, A. B. Onderdonk, B. Rosner, R. L. Cisneros, and D. L. Kasper, Science 262:416-419, 1993). By introducing chemical modifications into the structures of B. fragilis polysaccharide B as well as other abscess-inducing bacterial polysaccharides, we observed the following. (i) The presence of a nonacetylated free amino group on these polysaccharides appears to be required for abscess induction. (ii) No specific type of negatively charged group is essential to abscess induction by these polysaccharides. (iii) The density of free amino groups on these polysaccharides influences this pathobiologic host response.
Molecular cloning, nucleotide sequence, and occurrence of a 16.5-kilodalton outer membrane protein of Brucella abortus with similarity to pal lipoproteins
Authors: Tibor A , Weynants V , Denoel P , Lichtfouse B , De Bolle X , Saman E , Limet J N , Letesson J J
Published: January 2020

Recombinant lambda gt11 phages were selected by screening a genomic library of Brucella abortus DNA with monoclonal antibodies specific for a 16.5-kDa Brucella outer membrane protein (Omp16). The corresponding gene, named pal, was subcloned on a 0.7-kb AluI fragment. Immunoblotting confirmed the expression of a recombinant Omp16 in the transformants. DNA sequence analysis revealed an open reading frame of 168 codons. The deduced amino acid sequence agrees with an internal peptide sequence of native Omp16 and contains a potential lipoprotein signal peptide cleavage site, giving rise to a predicted mature protein of 144 amino acids. The predicted sequence of Omp16 also shows a remarkable degree of similarity to the sequences of three peptidoglycan-associated bacterial lipoproteins. In immunoblotting with a monoclonal antibody specific for Omp16, we demonstrated that Omp16 was expressed in the 34 Brucella strains tested, representing all six species and known biovars.
Differential flagellin expression in a flaA flaB+ mutant of Campylobacter jejuni
Authors: Wassenaar T M , Bleumink-Pluym N M , Newell D G , Nuijten P J , van der Zeijst B A
Published: January 2020

Campylobacter jejuni 81116 has two genes coding for flagellin, flaA and flaB. Fully motile wild-type C. jejuni bacteria express the flaA gene, with no flaB message being detected. A nonmotile flaA flaB+ mutant, R1, produced detectable levels of flagellin B which was incorporated into truncated flagella. After R1 had invaded INT-407 cells, a variant with increased motility, R1-V2, was isolated. R1-V2 produced full-length flagella and an increased amount of flagellin B. Transcriptional analysis showed that R1-V2 contained more flaB mRNA than its parental strain, R1. The flaB gene promoter sequence and primer extension experiments confirmed that transcription of the flaB gene is initiated from a sigma 54 promoter. Neither the promoter sequence nor the coding sequence of flaB had changed in R1-V2. In contrast to R1, R1-V2 no longer produced (truncated) flaA mRNA. The sigma 28 flaA promoter sequence was not changed in R1-V2. We propose that expression of the two flagellin genes in C. jejuni 81116 is regulated at the transcriptional level, in such a way that predominantly one gene at a time is transcribed. We compared the levels of invasiveness of the wild-type strain, R1, and R1-V2 for INT-407 cells. The shift in expression from flaA to flaB occurred not only during invasion assays but also under different conditions in the absence of eukaryotic cells.
Characterization of defined ompR mutants of Salmonella typhi: ompR is involved in the regulation of Vi polysaccharide expression
Authors: Pickard D , Li J , Roberts M , Maskell D , Hone D , Levine M , Dougan G , Chatfield S
Published: January 2020

The ompB operon, comprising the ompR and envZ genes, was cloned from a Salmonella typhi Ty2 cosmid bank and characterized by DNA sequence analysis. The S. typhi ompR and envZ genes contained open reading frames encoding proteins of 240 and 451 amino acids, respectively. Comparison with the Salmonella typhimurium OmpB protein sequences revealed 99.5% homology. The DNA sequence data were used to identify appropriate restriction sites for generating a defined deletion of 517 bp within the open reading frame of the ompR gene. This deletion was introduced by homologous recombination into the chromosomes of two S. typhi strains which already harbored defined deletions in both the aroC and aroD genes. The presence of the deletions within ompR was confirmed by Southern hybridization and sequencing of the DNA fragments surrounding the deleted regions by PCR. The S. typhi ompR mutants displayed a marked decrease in OmpC and OmpF porin expression as demonstrated by examination of outer membrane preparations. It was also found that S. typhi strains harboring the defined ompR deletions no longer agglutinated with Vi antiserum. However, when a functional ompB operon was introduced back into the S. typhi ompR mutants, either on a multicopy plasmid or as a single-copy chromosomal replacement, the Vi+ phenotype was restored. The levels of Vi synthesis were also found to be sensitive to different concentrations of sodium chloride present in the growth medium, although the levels of sensitivity varied between different isolates of S. typhi. It is therefore concluded that the ompR-envZ two component regulatory system plays an important role in the regulation of Vi polysaccharide synthesis in S. typhi and that one of the environmental signals for this regulation may be osmolarity.
Effect of Hypersensitivity Pneumonitis on the Pulmonary Defense Mechanisms of Guinea Pig Lungs
Authors: Jakab George J. , Green Gareth M.
Published: January 2020

Many edemagenic and consolidating inflammatory diseases, such as virus pneumonias, of the lung are complicated by bacterial infection. Previous literature has stressed that edema and consolidation may promote bacterial proliferation by interfering with phagocytosis. To test that hypothesis, lung defense mechanisms were studied in guinea pigs with tuberculin-induced hypersensitivity pneumonitis, a noninfectious edemagenic, and consolidating inflammatory disease. Pulmonary bactericidal activity and particle clearance were measured with a mixed aerosol of
32
P-labeled
Staphylococcus aureus and
35
S-labeled
Proteus mirabilis
. Hypersensitivity pneumonitis enhanced the bactericidal activity of the lung but had no effect on particle clearance despite the presence of consolidation and edema. These data indicate that altered host resistance to bacterial infection in acute inflammatory lung diseases can not be attributed to edema, inflammation, consolidation, changes in lung weight, etc., per se and that causes must be sought in functional changes in the bactericidal system of the lung rather than in specific histopathological changes.
Cytotoxicity of Concanavalin A-Activated Hamster Lymphocytes
Authors: Singh S. B. , Tevethia S. S.
Published: January 2020

The ability of hamster lymphoid cells to become cytotoxic in vitro to xenogeneic human cells after stimulation with concanavalin A (ConA) was investigated by using the cell-mediated
51
Cr release test. Cytotoxicity developed by 12 to 16 hr with peak values acquired within 24 hr of stimulation with ConA. The cytotoxicity was found to be mediated by the lymphoid cells themselves rather than by soluble substances. Spleen cells were more efficient than lymph node cells in releasing radioactivity from human cells. The concentration of mitogen was found to be critical in the development of cytotoxicity. ConA concentrations of 12.5 μg or less per culture conferred upon the lymphoid cells the capacity to release
51
Cr from target cells whereas higher concentrations were ineffective and even inhibitory. The cell-mediated cytotoxicity could be reversed by methyl α-
d
-glucopyranoside, but only during the first 8 to 12 hr of stimulation. The lytic reaction did not require the presence of ConA.
Rickettsial Hemolysis: Adsorption of Rickettsiae to Erythrocytes
Authors: Ramm Louise E. , Winkler Herbert H.
Published: January 2020

The hemolysis of sheep red blood cells by
Rickettsia prowazeki
has been characterized. A requirement for the adsorption of the rickettsia to the erythrocyte was indicated. No indication of the production of a soluble hemolysin was observed. Neither adsorption nor hemolysis can proceed at 0 C. The hemolytic process is rapid with a half-time of less than 30 min, and both the rate and extent are proportional to the number of rickettsiae present.
Immunodepression by Rowson-Parr Virus in Mice. II. Effect of Rowson-Parr Virus Infection on the Antibody Response to Sheep Red Cells In Vivo and In Vitro
Authors: Bendinelli M. , Nardini L.
Published: January 2020

The effects of infection with Rowson-Parr virus (RPV), an associated virus present in Friend virus (FV) preparations, on the splenic plaque-forming cell response to sheep red cells in adult mice and on the plaque-forming cell response of peritoneal cells in vitro have been investigated. The results support the hypothesis that RPV might be responsible for a considerable proportion of the early immunodepressive effects caused by FV preparations.
Factors Influencing the Susceptibility of Mice to
Mycoplasma arthritidis
Authors: Cole B. C. , Ward J. R. , Golightly-Rowland L.
Published: January 2020

Concentrated broth constituents markedly enhanced the development of abscesses after subcutaneous injection of
Mycoplasma arthritidis
. Under appropriate conditions, both virulent and avirulent strains of
M. arthritidis
produced toxic effects in mice, as detected by the development of necrotic abscesses and death of the animals. The treatment of mice at birth with
M. arthritidis
antigens rendered the animals more susceptible to infection with
M. arthritidis
later in life, as evidenced by increased arthritis after intravenous injection. The injection of
M. arthritidis
into pregnant mice resulted in a high incidence of abortions. Comparative studies using different mouse strains showed that DBA mice were the most susceptible and BALB/c and C57BL mice were the most resistant to infection by
M. arthritidis
.
Fate of
Listeria monocytogenes
in Normal Rabbit Serum
Authors: Shultz Leonard D. , Wilder Martin S.
Published: January 2020

Viability of
Listeria monocytogenes
suspended in either normal rabbit serum or listericidal factor is significantly reduced before cell lysis. In normal serum
Listeria
populations are initially reduced by clumping of viable bacteria, and the cells within these clumps are morphologically altered and killed by the listericidal factor in serum. This clumping is complement independent and does not occur after suspension in purified listericidal factor. In electron micrographs, densely stained amorphous material was seen surrounding clumped cells suspended in serum. Initial damage to
Listeria
suspended in either serum or listericidal factor appears to be confined to plasma and mesosomal membranes. The mesosomes are rapidly disorganized, and the plasma membrane becomes crenated and separates from the cell wall. Subsequently, the fibrillar organization of the nuclear region disrupts, and the cytoplasm increases in granularity. Studies utilizing
Listeria
protoplasts provided evidence in support of the plasma membrane as the site of listericidal action. Cell death may be related to loss in enzyme function after crenation of the plasma membrane and mesosomal dissolution.
Mumps Class-Specific Immunoglobulins in Radioimmunoassay and Conventional Serology
Authors: Daugharty Harry , Warfield Donna T. , Hemingway Walter D. , Casey Helen L.
Published: January 2020

Antibodies against mumps virus have been studied by using immunoglobulin class-specific indicators labeled with
125
I in the radioimmunoassay (RIA) procedure. The immunoglobulins in paired acute and convalescent sera were allowed to react with mumps virus in a solid-phase RIA system. Class-specific immunoglobulin indicators (anti-immunoglobulin M [IgM] and anti-immunoglobulin G [IgG]) labeled with
125
I revealed that immunoglobulins of early antisera were preponderantly IgM, whereas immunoglobulins of late antisera were predominantly IgG. These indicators detected antibodies of the early (IgM) and late (IgG) phases of the immune response. These findings are consistent with the classical temporal order of appearance of 19
s
(IgM) and 7
s
(IgG) globulins. Specificity of these indicators for reacting with fractionated 7
s
and 19
s
globulins is also presented. Mumps virus RIA obtained with anti-IgG correlated well with conventional serological data obtained by neutralization and hemagglutination inhibition, but most strongly with complement-fixation data. In addition, antibody bound by solid phase was capable of distinguishing between related antigens of the myxovirus group.
Relationship of Antigen k to
Staphylococcus aureus
Bacteriophage Type 187, of Human and of Canine Origins
Authors: Live I.
Published: January 2020

Similarities as well as differences have been observed between phage type 187
Staphylococcus aureus
cultures of human and of canine origins. Thus, all strains susceptible to phage 187, regardless of their host specificity, were agglutinated by absorbed serum k. (Furthermore, agglutinability of the autoclaved bacteria indicated a reaction with the k
1
component of the k-antigen complex.) On the other hand, the strains of canine biotype were in addition agglutinated by absorbed serum 61218, and they possessed biochemical features which distinguished them from human strains of
S. aureus.
Attempts to Detect Homologous Autointerference In vivo with Influenza Virus and Vesicular Stomatitis Virus
Authors: Holland J. J. , Doyle M.
Published: January 2020

Von Magnus particles of influenza virus and defective interfering T particles of vesicular stomatitis virus were unable to provide significant protection of mice from disease or death when inoculated intranasally or intracerebrally along with moderate or high doses of homologous infectious challenge virus. However, yields of infectious virus from the affected organs were reduced as compared to controls inoculated with infectious virus alone. Serial intracerebral passage of vesicular stomatitis virus in mouse brain at high doses failed to produce T particles detectable by in vitro autointerference assays on BHK
21
cells, whether or not T particles were introduced along with B virions at the first passage. When very low challenge doses of infectious B virions were inoculated intracerebrally along with high doses of homologous defective particles, there was significant prolongation of life, although most mice died eventually of slowly progressing disease. Also, the virus yields in the brains of these mice were significantly reduced, and virus was no longer detectable in the brains of “protected” mice surviving for 10 days or more. Our results suggest that although homologous autointerference does occur in vivo, it is a more complex phenomenon than in vitro cell culture experiments might indicate.
Differences in Clinical and Convalescent-Phase Antibodies of Rhesus Monkeys Infected with Monkey Pox, Tanapox, and Yaba Poxviruses
Authors: Hall R. D. , Olsen R. G. , Pakes S. P. , Yohn D. S.
Published: January 2020

Complement-fixing and complement-fixing inhibiting (CFI) antibodies were demonstrated in the clinical and convalescent stages, respectively, of rhesus monkeys infected with either monkey poxvirus, Tanapoxvirus, or Yaba poxvirus. Specificity of the CFI antibody was confirmed by its failure to cross-react with heterologous poxvirus antigens and by experiments demonstrating the CFI test as being antigen dependent. Serum containing CFI antibody neutralized homologous poxvirus but failed to agglutinate antigen-coated, tanned red blood cells. The application of CFI test as a seroepidemiologic tool for studies of poxvirus infection of man and simian monkeys and the biologic role of CFI antibody in pathogenesis were discussed.
Biochemistry of
Vibrio cholerae
Virulence III. Nutritional Requirements for Toxin Production and the Effects of pH on Toxin Elaboration in Chemically Defined Media
Authors: Callahan Lynn T. , Richardson Stephen H.
Published: January 2020

The investigations described in this report concern the metabolic and physiologic parameters governing cholera enterotoxin production in chemically defined growth media. The results indicate that the minimal nutritional requirements for growth of pathogenic
Vibrio cholerae
are the same as those for toxin production, and that toxin production parallels growth of the organisms. Studies of the relationship between toxin accumulation and pH reveal that toxin biosynthesis can be separated from toxin release. Toxin is synthesized below pH 7.0, but release and accumulation of extracellular toxin occur only at neutral or alkaline pH values.
Immunity to Chlamydial Infections of the Eye II. Studies of Passively Transferred Serum Antibody in Resistance to Infection with Guinea Pig Inclusion Conjunctivitis
Authors: Watson Ronald R. , Mull J. Dennis , MacDonald A. Bruce , Thompson Sumner E. , Bear Susan E.
Published: January 2020

Conjunctival infection of guinea pigs by the chlamydial agent of guinea pig inclusion conjunctivitis confers immunity. However, the mechanism of resistance to this intracellular pathogen is not yet defined. In the study reported here, serum immunoglobulin was passively transferred with resultant titers in excess of those known to be associated with immunity. Nonetheless, when the passive transfer recipients were challenged, they acquired infection which was neither delayed nor attenuated. Eye secretion antibody titers appeared and increased only after 11 days of infection in both passive transfer recipients and control groups, suggesting but not proving de novo local synthesis of secretory antibody. This study suggests that cellular or secretory immune mechanisms may predominate in resistance to this infection.
Factors Affecting Virulence of
Shigella flexneri
: Avirulent Strain with Altered Metabolism of Succinate, Fumarate, and Malate
Authors: Kim Rosalind , Corwin Laurence M.
Published: January 2020

It has been found that a mutation of
Shigella flexneri
2a to avirulence can result in altered metabolism of tricarboxylic acid cycle acids, but the effect is strongly dependent on growth conditions. Mutant cells harvested from stationary-phase cultures grown with vigorous shaking in nutrient broth oxidize succinate, fumarate, and malate much more slowly than do wild-type cells. Cell-free extracts from such cells show similar differences in oxidative ability. These differences were less pronounced when cells were harvested from the exponential phase of growth and were nonexistent when the cells were grown without shaking. When tricarboxylic acid cycle acids were used as carbon sources with shaking, mutant cells from exponential phase cultures oxidized tricarboxylic cycle acids almost to the same extent as the wild type. Stationary-phase cells grown on succinate lost succinoxidase activity, but wild-type cells retained more than twice the activity of mutant cells. The effect of growth conditions on oxidative differences between the two strains was similar to the differences in succinate uptake observed under similar conditions.
Ribonucleic Acid and Protein Synthesis in Guinea Pig Liver During Q Fever
Authors: Thompson H. A. , Paretsky D.
Published: January 2020

Protein and ribonucleic acid (RNA) syntheses increase in the liver during Q fever, coincident with progressive increments in cortisol levels. Cell-free protein-synthesizing systems indicate that the pH 5 enzyme fraction was chiefly responsible for enhanced activity. Although the polysome profiles from normal and infected livers were similar, the number of liver ribosomes doubled during infection. There was a concomitant increase in orotate incorporation in the 28
s
, 18
s
, and 4
s
RNA species of infected liver.
Relationship of BCG-Induced Pulmonary Delayed Hypersensitivity to Accelerated Granuloma Formation in Rabbit Lungs: Effect of Cortisone Acetate
Authors: Moore Vernon L. , Myrvik Quentin N.
Published: January 2020

The role of local pulmonary delayed hypersensitivity in accelerated pulmonary granuloma formation was investigated using cortisone acetate, an immunosuppressive drug that appears to preferentially eliminate committed lymphocytes at appropriate doses. Data are presented showing that cortisone acetate suppressed local pulmonary delayed hypersensitivity at the time of and subsequent to challenge with BCG. Furthermore, cortisone damage appeared to involve primarily committed lymphocyte populations since the defect was repairable with sensitized spleen cells, an unlikely source of macrophage precursors.
Effects of Lysozyme and Chitinase on the Spherules of
Coccidioides immitis
In Vitro
Authors: Collins Michael , Pappagianis Demosthenes
Published: January 2020

Spherules of
Coccidioides immitis
strain Silveira produced in vitro were treated with chitinase and lysozyme. The walls of merthiolate-killed mature endosporulating spherules were degraded by chitinase (500 μg/ml) and by lysozyme (100 and 500 μg/ml). Thus, as was visible through the light microscope, the spherule wall was reduced in thickness from 1 to 2 μm to less than 0.5 μm. The degradation was evident also by release of
N
-acetylglucosamine, three times as much
N
-acetylglucosamine being released by chitinase in 12 h as was released by lysozyme in 3 days. However, the effect of lysozyme on living mature spherules was in marked contrast to the effect of chitinase in that treatment with lysozyme led to marked reduction in viability. Exposure to lysozyme (500 μg/ml) for 48 h permitted survival of only 0 to 0.2% of spherules. Thinning of the walls was observed only in the larger spherules (25-35 μm) treated with lysozyme. By contrast, chitinase (500 μg/ml) led to complete dissolution of the walls of living mature spherules but the viability of the liberated endospores was unaffected during contact with chitinase for 48 h. Living non-endosporulating immature spherules and free endospores were also rendered nonviable by lysozyme but not by chitinase.
Possible Transmission of Serum (Australia-Antigen-Positive) Hepatitis Via the Conjunctiva
Authors: Kew M. C.
Published: January 2020

A nursing sister developed Australia-antigen-positive hepatitis 101 days after the blood of an Australia-antigen-positive patient was accidentally introduced into her eye. There may be important implications for those caring for patients with Australia-antigenemia or undertaking laboratory investigations on their blood.
Host Defense Mechanisms Against Herpes Simplex Virus I. Control of Infection In Vitro by Sensitized Spleen Cells and Antibody
Authors: Ennis Francis A.
Published: January 2020

Sensitized mouse spleen cells decrease the spread of herpes simplex virus infection in cell culture lines derived from human and murine tissues. These washed, sensitized cells act alone and additively in combination with antibody to diminish the ability of single virus-infected cells to spread infection to contiguous cells. This control of infection is not species specific, unlike interferon, and appears to be distinct from the effect of antibody. Lymphotoxin was not detected in this lymphocyte-mediated response. This control of herpes simplex virus infection in vitro by sensitized lymphoid cells is immunologically specific; spleen cells from donor animals immunized with a heterotypic virus do not cause herpesvirus plaque size reduction. The ratio of spleen cells from immunized animals to target monolayer cells needed to produce this effect is > 4:1. Plaque size reduction of herpes simplex virus by spleen cells requires intact, immune, non-glass-adhering lymphoid cells.
Multiplicity of Scrapie Virus in Infected Mouse Spleen Cells In Vivo
Authors: Lavelle G. C.
Published: January 2020

Subpopulations of spleen cells from scrapie virus-infected mice were used to determine the average virus content of infected cells in vivo at a time when virus was rapidly increasing in titer in lymphoreticular tissues. Comparison of the mean lethal doses of lysed to intact cells indicated averages of 2 to 6 infectious units per infected cell. In another experiment, preparations of cytoplasmic nucleic acids extracted from spleen cells of infected mice had no detectable infectivity, which suggests that the transmissible form of the virus is not a free nucleic acid.
Consequences of Smallpox Vaccination in Leprosy Patients
Authors: Saha Kunal , Mittal Madan M. , Ray S. N.
Published: January 2020

This study illustrates the consequences of smallpox revaccination in 45 lepromatous, 28 tuberculoid, and 47 normal individuals. Results obtained with intradermal inoculations indicated that the patients with leprosy were associated with a relative anergy against the vaccinia virus, the anergy being minimal in the tuberculoid leprosy but marked in the cases with lepromatous leprosy. Major vaccinial reactions were observed more often in patients with lepromatous leprosy than in the controls or patients with tuberculoid leprosy. Furthermore in a patient with lepromatous leprosy, vaccinia necrosum also developed. The smallpox vaccination with live virus also appeared as a provocative factor for the precipitation of lepra reaction in the lepromatous leprosy cases. After 3 weeks of vaccination, the frequency of the specific humoral antibody response was the same in the tuberculoid patients and controls while it was higher in the cases with lepromatous leprosy. The prevaccination titer of total hemagglutination inhibition antibody was significantly higher in the lepromatous leprosy cases. However, the postvaccinial, humoral antibody response of the lepromatous patients was of the same magnitude as that observed in the normal individuals, and it was mainly due to a 2-mercaptoethanol-resistant antibody.
Ultrastructural Characterization of Genome of Epizootic Hemorrhagic Disease Virus
Authors: Tsai Kin-Son , Karstad Lars
Published: January 2020

Purified epizootic hemorrhagic disease (EHD) virus preparations were treated with urea and sodium perchlorate. The viral ribonucleic acid (RNA) released when spread on protein monolayers according to the Kleinschmidt technique was examined by rotary shadow-casting electron microscopy. The viral RNA released by urea treatment had filaments which frequently formed three to five loop-shaped figures of varied length. In 80% of the virus particles the lengths of the viral RNA released were 2.5 to 4.5 μm. The sodium perchlorate-released viral nucleic acid also appeared linear, and about 70% had lengths of 0.1 to 2.0 μm, the longest filament measuring 5.8 μm. Evidence was obtained that EHD virus contains double-stranded RNA as its genetic material and the molecular weight of the EHD viral RNA was calculated to be 12.2 × to 10
6
to 15.1 × 10
6
daltons.
Mechanisms of Immunity in Typhus Infections III. Influence of Human Immune Serum and Complement on the Fate of
Rickettsia mooseri
Within Human Macrophages
Authors: Gambrill Margaret R. , Wisseman Charles L.
Published: January 2020

Preincubation of
Rickettsia mooseri
with human typhus convalescent serum, which is not rickettsiacidal but which confers passive protection to animals, opsonizes the rickettsiae for enhanced phagocytosis by monocyte-derived human macrophages in cell culture and renders them susceptible to destruction within the macrophages. Nonspecific opsonization by preincubation of the rickettsia with methylated bovine serum albumin enhances phagocytosis, but the rickettsiae are not prepared for intracellular destruction. Instead, they grow within the macrophages and eventually destroy these cells. Thus, immune serum and macrophages, neither of which is capable of killing these rickettsiae alone, act in concert to destroy the virulent organisms. In this system, immune serum appears to exert two distinct, possibly dissociable, actions on the rickettsiae: enhancement of phagocytosis and preparation for intracellular destruction. Complement is not required for this action but, when present with immune serum, markedly enhances phagocytosis of the rickettsiae, often leading to rapid destruction of the macrophage.
Immunization with
Escherichia coli
Enterotoxin Protects Against Homologous Enterotoxin Challenge
Authors: Sack R. Bradley
Published: January 2020

Immunization of rabbits with the culture filtrate of an enterotoxigenic strain of
Escherichia coli
078: H12 resulted in the appearance of anti-enterotoxin activity in rabbit sera and protection of rabbit small intestine against homologous enterotoxin challenge.
Surface Morphology of Peritoneal Macrophages During the Attachment of
Brucella melitensis
Authors: Warfel Alwin H. , Elberg Sanford S. , Hayes Thomas L.
Published: January 2020

When macrophages from immunized rabbits are in the act of phagocytosis of the homologous organism, the macrophages are seen by scanning electron microscopy to possess undulating membranes and microvilli at various stages of formation and spatial relationships to the organisms.
Identification of Enterotoxigenic
Escherichia coli
and Serum Antitoxin Activity by the Vascular Permeability Factor Assay
Authors: Evans Dolores G. , Evans Doyle J. , Gorbach Sherwood L.
Published: January 2020

Twenty-five strains of enterotoxigenic (tox
+
)
Escherichia coli
isolated in India, Bangladesh, and the U.S.A. were shown to produce vascular permeability factor (PF) activity as well as diarrheagenic activity. Sixteen strains of non-enterotoxigenic
E. coli
were found to be PF negative. The PF response elicited by tox
+
E. coli
isolated in the U.S.A. from cases of infantile diarrhea was qualitatively different and more difficult to demonstrate. However, this problem was surmounted by assaying 25-fold concentrates of the crude enterotoxin of these strains. PF activity of various strains of tox
+
E. coli
was neutralized by anti-PF antiserum prepared against the enterotoxin of strain H-10407. This anti-PF antiserum also neutralized PF activity of
Vibrio cholerae
enterotoxin (choleragen). Antiserum containing antibody specific for purified choleragen neutralized
E. coli
PF activity. These and other results indicate that the PF activity of
E. coli
is a function of the diarrheagenic enterotoxin as is known to be the case with choleragen. We conclude that the PF assay can be employed for the identification of tox
+
E. coli
and for the detection of antitoxic antibody.
Serological Reactions of Glycolipids from Streptococcal L-Forms
Authors: Feinman Susan Birnbaum , Prescott Benjamin , Cole Roger M.
Published: January 2020

Parent bacteria and L-forms of some streptococci of group A, group D, and
Streptococcus
MG share common antigens as shown by cross-reactivity in growth inhibition, complement fixation, and Ouchterlony tests. Cross-reactivity between these streptococci or their L-forms with a staphylococcal L-form, or
Mycoplasma pneumoniae
, was found only rarely and only in low-titer complement fixation tests. Removal of all three serological reactivities from positive antisera by addition of chloroform-methanol (7:3) extracts of the streptococci or their L-forms, and failure to remove activities by protein extracts, indicated the glycolipid nature of the cross-reacting antigenic determinants.
Antibody-Forming Cells and Serum Hemolysin Responses of Pastel and Sapphire Mink Inoculated with Aleutian Disease Virus
Authors: Lodmell Donald L. , Bergman R. Kaye , Hadlow William J.
Published: January 2020

The effect of Aleutian disease virus (ADV) on serum hemolysin titers and antibody-forming cells in lymph nodes and spleens of sapphire and pastel mink inoculated with goat erythrocytes (G-RBC) was investigated. ADV injected 1 day after primary antigenic stimulation with G-RBC did not depress the immune responses of either color phase for a period of 26 days. However, when G-RBC were injected 47 days after ADV, both the number of antibody-forming cells and hemolysin titers were more markedly depressed in sapphire than in pastel mink. The results are discussed in relation to the greater susceptibility of sapphire mink and the variable susceptibility of pastel mink to the Pullman isolate of ADV.
Immunological Studies on the Envelope Component of Venezuelan Equine Encephalomyelitis Virus
Authors: Pedersen Carl E. , Slocum Donald R. , Eddy Gerald A.
Published: January 2020

Treatment of purified Venezuelan equine encephalomyelitis virus with the nonionic detergent Triton X-100 permitted spearation of the envelope from the core component. The isolated envelope was a noninfectious immunogen which reacted in hemagglutination, hemagglutination inhibition, complement fixation, and neutralization serological reactions.
Effects of Staphylococcal Alpha-, Beta-, Delta-, and Gamma-Hemolysins on Human Diploid Fibroblasts and HeLa Cells: Evaluation of a New Quantitative Assay for Measuring Cell Damage
Authors: Thelestam Monica , Möllby Roland , Wadström Torkel
Published: January 2020

Human diploid embryonic lung fibroblasts and HeLa cells were cultivated in Eagle minimaĺ essential medium supplemented with 10% calf serum. Monolayer cultures were labeled with
3
H-uridine and treated with highly purified staphylococcal alpha-, beta-, delta-, or gamma-hemolysin. The release of soluble radioactive substances into the medium was used as an indicator of damage to the cell membrane after treatment with each hemolysin. The assay method described is simple, sensitive, and rapid. It allows quantitative estimation of changes in membrane permeability to be detected before a morphological damage is observed microscopically. Upon incubation for up to 30 min with highly purified staphylococcal hemolysins, only delta-hemolysin caused release of a significant amount of tritiated substances from fibroblasts. Such leakage occurred immediately after addition of delta-lysin and was independent of temperature. With minor exceptions, this was similar to the release of isotopes after treatment of the cells with the nonionic detergent Triton X-100. Treatment of fibroblasts with combinations of two or three of these toxins gave neither a synergistic nor an antagonistic effect. Evidence is presented which indicates that delta-hemolysin is the only important fibroblast damaging activity in crude preparations of extracellular proteins of four strains of
S. aureus
, whereas HeLa cells are susceptible also to purified alpha-toxin.