bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanisms of fungal pathogenicity: correlation of virulence in vivo, susceptibility to killing by polymorphonuclear neutrophils in vitro, and neutrophil superoxide anion induction among Blastomyces dermatitidis isolates
Authors: Morrison C J , Stevens D A
Published: January 2020

Seven Blastomyces dermatitidis isolates varying in virulence for mice were compared for susceptibility to polymorphonuclear neutrophil (PMN) killing and the ability to induce superoxide anion (O2-) production by PMNs in vitro. In vitro killing of six B. dermatitidis isolates by murine peripheral blood PMNs or by PMNs elicited from the peritoneal cavity by a local immune reaction (B. dermatitidis-immune mice given killed B. dermatitidis intraperitoneally 24 h earlier) inversely correlated with in vivo virulence (most to least virulent) isolates: VV, V, V40, KL-1, A2, and GA-1). The capacity of isolates to induce O2- production by PMNs also inversely correlated with in vivo virulence. Isolate A, of intermediate in vivo virulence, was a good inducer of O2- production in vitro but was no more susceptible to in vitro killing by PMNs than isolate V, VV, or V40. Fungal intracellular superoxide dismutase or catalase content did not correlate with in vivo virulence or in vitro killing by PMNs. Isolate A, however, had two to four times the intracellular catalase activity as did other B. dermatitidis isolates, suggesting a possible mechanism for its enhanced resistance to in vitro killing by PMNs. Therefore, while in vitro killing by PMNs and the capacity to induce O2- production by PMNs inversely correlated with virulence for six B. dermatitidis isolates, isolate A was an exception: its resistance to killing by PMN-generated oxygen metabolites in vitro but its susceptibility to killing in vivo suggest that its in vivo killing occurs by other, perhaps nonoxidative, mechanisms.
Potentiation of human natural killer cell cytotoxicity by Salmonella bacteria is an interferon- and interleukin-2-independent process that utilizes CD2 and CD18 structures in the effector phase
Authors: Tarkkanen J , Saksela E
Published: January 2020

Incubation of large granular lymphocytes (LGL) with glutaraldehyde-fixed bacteria stimulated in the supernatant the production of interferon (IFN), which proved to be mainly IFN-gamma. Even though IFN-gamma was produced upon exposure of LGL to bacteria, anti-IFN-gamma antibodies failed to interfere with induction of cytotoxicity by bacterial contact. Anti-IFN-gamma receptor antibodies had no effect on the induction of activated killing by bacterial contact either. We also tested the effect of anti-IFN-alpha antibody, but it failed to interfere with induction of cytotoxicity by bacterial contact. No interleukin-2 (IL-2) was detected in the culture supernatant of bacterially activated LGL by the mouse HT2 cell assay, nor did we detect any IL-2 mRNA in bacterially activated LGL by Northern RNA blot assay. Neutralizing anti-IL-2 antiserum had no effect on the induction of activated killing by bacterial contact, and recombinant IL-4 did not interfere with the induction of activated killing. We then studied the membrane structures involved in bacterially activated killing. Anti-CD18 monoclonal antibody did not interfere with the induction phase of bacterially activated killing. However, both anti-CD18 and anti-CD2 antibodies inhibited the effector phase of bacterially activated killing. The effector pathways utilized by activated LGL depended on the mode of activation in that even though bacterially activated LGL were sometimes blocked by anti-CD2 monoclonal antibody, recombinant-IL-2-stimulated LGL were not. In conclusion, our present results suggest that there may be mediators other than exogenously secreted IFNs and IL-2 which are responsible for the induction of activated killing after bacterial contact. CD18 and CD2 structures were shown to be involved in the effector phase of bacterially activated killing.
Phospholipase activity of Mycobacterium leprae harvested from experimentally infected armadillo tissue
Authors: Wheeler P R , Ratledge C
Published: January 2020

Three types of phospholipase activity--phospholipase A1, A2, and lysophospholipase--were detected in Mycobacterium leprae harvested from armadillo tissue at about 25% of the specific activity found in a slowly growing mycobacterium, Mycobacterium microti, which was grown in medium to optimize its phospholipase activity. The highest activity found was lysophospholipase, which released fatty acid from 2-lyso-phosphatidylcholine. Phospholipase activity was detected by using phosphatidylcholine and phosphatidylethanolamine. Differences in relative activities with these three types of substrate distinguished phospholipase activity in M. leprae extracts from armadillo liver extracts. Furthermore, retention of activity in M. leprae after NaOH treatment showed that the activity associated with M. leprae was not host derived. The specific activity of phospholipase was 20 times higher in extracts of M. leprae than in intact M. leprae organisms. Diazotization, a treatment which abolishes activities of surface enzymes exposed to the environment by the formation of covalent azide bonds with exposed amino groups, did not affect M. leprae's phospholipase activity, with one exception: release of arachidonic acid from phosphatidylcholine, which was partially inhibited. Phenolic glycolipid I, the major excreted amphipathic lipid of M. leprae, inhibited phospholipase activity, including release of arachidonic acid, for both M. leprae- and armadillo-derived activity.
Stimulation of proteinase and amidase activities in Porphyromonas (Bacteroides) gingivalis by amino acids and dipeptides
Authors: Chen Z X , Potempa J , Polanowski A , Renvert S , Wikström M , Travis J
Published: January 2020

Proteolytic enzymes from the organism Porphyromonas gingivalis are believed to be involved in the development of periodontitis. Studies on both crude extracts and purified trypsinlike enzymes from this organism indicate that substantial stimulation of both amidase and proteinase activities can be obtained during incubation with glycine-containing compounds. We postulate that P. gingivalis may have developed this unusual property to take advantage of the glycine-rich environment which occurs during the periodontitis-associated degradation of gingival collagen. The finding of such a stimulation in crevicular fluids from discrete periodontal sites has been correlated with the presence of P. gingivalis and could be utilized for the early detection of infection by this organism during the onset of periodontitis.
Effect of site-directed mutagenic alterations on ADP-ribosyltransferase activity of the A subunit of Escherichia coli heat-labile enterotoxin
Authors: Lobet Y , Cluff C W , Cieplak W
Published: January 2020

Previous studies of the S1 subunit of pertussis toxin, an NAD(+)-dependent ADP-ribosyltransferase, suggested that a small amino-terminal region of amino acid sequence similarity to the active fragments of both cholera toxin and Escherichia coli heat-labile enterotoxin represents a region containing critical active-site residues that might be involved in the binding of the substrate NAD+. Other studies of two other bacterial toxins possessing ADP-ribosyltransferase activity, diphtheria toxin and Pseudomonas exotoxin A, have revealed the presence of essential glutamic acid residues vicinal to the active site. To help determine the relevance of these observations to activities of the enterotoxins, the A-subunit gene of the E. coli heat-labile enterotoxin was subjected to site-specific mutagenesis in the region encoding the amino-terminal region of similarity to the S1 subunit of pertussis toxin delineated by residues 6 through 17 and at two glutamic acid residues, 110 and 112, that are conserved in the active domains of all of the heat-labile enterotoxin variants and in cholera toxin. Mutant proteins in which arginine 7 was either deleted or replaced with lysine exhibited undetectable levels of ADP-ribosyltransferase activity. However, limited trypsinolysis of the arginine 7 mutants yielded fragmentation kinetics that were different from that yielded by the wild-type recombinant subunit or the authentic A subunit. In contrast, mutant proteins in which glutamic acid residues at either position 110 or 112 were replaced with aspartic acid responded like the wild-type subunit upon limited trypsinolysis, while exhibiting severely depressed, but detectable, ADP-ribosyltransferase activity. The latter results may indicate that either glutamic acid 110 or glutamic acid 112 of the A subunit of heat-labile enterotoxin is analogous to those active-site glutamic acids identified in several other ADP-ribosylating toxins.
Dynamic analysis of splenic Th1 and Th2 lymphocyte functions in mice infected with Schistosoma japonicum
Authors: Xu Y H , Macedonia J , Sher A , Pearce E , Cheever A W
Published: January 2020

Recent studies indicate that egg granuloma formation in murine Schistosoma mansoni infection is associated with Th2-mediated immune responses. The present study was designed to analyze dynamically the Th1 and Th2 responses in S. japonicum-infected animals and compare them with the results seen with S. mansoni. C3H mice were infected with 10 to 20 cercariae of S. japonicum and sacrificed 3 to 22 weeks later. Spleen cells were stimulated with parasite antigens (egg and adult worm) or the mitogen concanavalin A. Interleukin-2 (IL-2), IL-4, IL-5, and gamma interferon (IFN-gamma) levels were measured in the culture supernatants by enzyme-linked immunosorbent assay (ELISA) or bioassays. Additionally, cytokine-producing cells were enumerated by ELISPOT. The results show that Th2 cytokine production, characterized by IL-4 and IL-5, represents the major response in the first month after egg laying begins, while the Th1 functions of IFN-gamma and IL-2 production are greatly depressed. However, by 22 weeks Th2 responses have diminished and IFN-gamma production in response to concanavalin A is apparent. IL-2 responses are minimal at all times. In vitro depletion of T-cell subsets indicates that CD4+ cells are the major subset responsible for production of IL-5 at 7 weeks of infection. These findings suggest that, as in the case of S. mansoni infection, S. japonicum-induced immunopathology is temporally associated with the host Th2 response, although other experiments indicate that IFN-gamma is also involved.
Increase in tumor necrosis factor alpha- and interleukin-6-secreting cells in peripheral blood mononuclear cells from subjects infected with Mycobacterium tuberculosis
Authors: Ogawa T , Uchida H , Kusumoto Y , Mori Y , Yamamura Y , Hamada S
Published: January 2020

We detected and quantified tumor necrosis factor alpha (TNF-alpha) and interleukin-6 (IL-6) from monocytes/macrophages (M phi) in the peripheral blood of subjects from three different population groups, i.e., tuberculin-negative healthy subjects, tuberculin-positive healthy subjects, and patients with active pulmonary tuberculosis. TNF-alpha or IL-6 activity in the culture supernatant of these cells was determined by the cytotoxicity of murine L-929 cells or by enzyme-linked immunosorbent assay, respectively. Detection and enumeration of cells secreting either TNF-alpha or IL-6 were performed by an adaptation of the enzyme-linked immunospot assay. Monocytes/M phi from tuberculin-positive healthy subjects or patients with tuberculosis showed higher TNF-alpha- and IL-6-producing activities than those from tuberculin-negative healthy subjects. The number of TNF-alpha- and IL-6-secreting cells in either lipopolysaccharide- or muramyl dipeptide-stimulated mononuclear cells from tuberculin-positive healthy subjects and patients was significantly higher than that in cells from the tuberculin-negative healthy subjects.
Susceptibility of inbred mouse strains to infection with Serpula (Treponema) hyodysenteriae
Authors: Nibbelink S K , Wannemuehler M J
Published: January 2020

Several inbred strains of mice were inoculated with Serpula (Treponema) hyodysenteriae B204 to determine susceptibility to infection. Challenge doses of 10(7) or 10(8) spirochetes induced cecal lesions in C3H/HeJ mice and other C3H strains of mice. However, more than a 100-fold difference existed between the dose required to induce lesions in 50% of the infected C3H/HeJ mice (8.3 x 10(7)) and that required to induce them in 50% of the infected C3H/HeN mice (5 x 10(5)). C3H/HeJ mice lack a splenocyte mitogenic response to Escherichia coli lipopolysaccharide but exhibited a mitogenic response comparable to those of other C3H strains of mice when stimulated with S. hyodysenteriae endotoxin (butanol-water extract). Different inbred strains exhibited different susceptibilities to infection, with the strain C3H/HeN being the most susceptible on the basis of colonization and development of macroscopic cecal lesions. The ity gene had no apparent effect on susceptibility of mice challenged with S. hyodysenteriae. The involvement of the H-2 haplotype with susceptibility is unclear, but the mice bearing H-2k were more susceptible than mice with the H-2b, H-2d, or H-2q haplotype. These data support the hypothesis that the host's responsiveness to lipopolysaccharide influences the susceptibility to infection with S. hyodysenteriae. However, differences in susceptibility between inbred mice exist independent of the lps locus, suggesting that there are other inherent differences between mouse strains that affect susceptibility to infection by S. hyodysenteriae.
Development and characterization of a monoclonal antibody specific for Listeria monocytogenes and Listeria innocua
Authors: Bhunia A K , Ball P H , Fuad A T , Kurz B W , Emerson J W , Johnson M G
Published: January 2020

BALB/c mice were immunized with crude cell surface proteins of Listeria monocytogenes V7. Approximately 1,680 hybridomas were generated after two fusions, and the monoclone C11E9 was selected and used for further characterization. The monoclonal antibody (MAb) produced by C11E9 was immunoglobulin subclass G2b with kappa light chains. Dot and colony blot results indicated that MAb C11E9 was reactive to all the L. monocytogenes (34 of 34) and Listeria innocua (6 of 6) isolates without any cross-reaction to other organisms tested. Western blot (immunoblot) analysis of crude cell surface proteins in native polyacrylamide gel electrophoresis (PAGE) indicated that MAb C11E9 reacts with a single band in each species, with a molecular mass of 174 kDa for L. monocytogenes and 182 kDa for L. innocua. The MAb reacted with one major protein band in Western blot from acid-urea PAGE for both L. monocytogenes and L. innocua. Isoelectric focusing results indicated two immunoreactive protein bands with pIs of 8.1 and 7.4 for L. monocytogenes. Sodium dodecyl sulfate (SDS)-PAGE and Western blot analysis indicated several proteins with molecular masses of 76, 66, 56, and 52 kDa for L. monocytogenes and 66, 56, and 52 kDa for L. innocua. Reaction of MAb C11E9 to washed live cells indicated the possible binding of antibody to cell surface antigen. These cell surface antigens could be removed by 1 N HCl plus 9 M urea, 2% SDS-0.5% beta-mercaptoethanol, or 4 M guanidine-HCl. The epitope of MAb C11E9 binding site was shown to be protein in nature. Periodic acid-Schiff staining and glycoprotein immunoassay indicated that carbohydrate was absent in the epitope. The cellular locations of the MAb C11E9-reactive antigens were calculated to be 76 and 90% outside and 24 and 10% inside the cell membranes of L. monocytogenes and L. innocua, respectively, for 12- to 14-h cultures.
The genes coding for the antigen 85 complexes of Mycobacterium tuberculosis and Mycobacterium bovis BCG are members of a gene family: cloning, sequence determination, and genomic organization of the gene coding for antigen 85-C of M. tuberculosis
Authors: Content J , de la Cuvellerie A , De Wit L , Vincent-Levy-Frébault V , Ooms J , De Bruyn J
Published: January 2020

A gene encoding the 33-kDa secreted protein of Mycobacterium tuberculosis (antigen 85-C) was isolated and sequenced. The corresponding DNA sequence contains a 1,020-bp coding region. The deduced amino acid sequence corresponds to a 340-residue protein consisting of a 46-amino-acid signal peptide and a 294-amino-acid mature protein. Comparison with previously described genes for the 30-kDa antigen (the alpha antigen of M. bovis BCG, also called antigen 85-B) and the 32-kDa antigens from M. bovis BCG and M. tuberculosis (antigens 85-A) indicates that the three genes share considerable sequence homology (70.8 to 77.5%) but may also code for distinctive epitopes. Strong differences among the three sequences are clearly visible upstream and downstream from the region coding for the mature proteins. The three genes have been detected in the genome of M. bovis BCG by Southern blot hybridization with three type-specific probes. Furthermore, hybridization of large DNA fragments (100 to 1,000 kbp) from M. tuberculosis separated by pulsed-field gel electrophoresis showed that the three genes coding for the antigen 85 complex are not clustered within the bacterial genome.
Metabolism of
Rickettsia typhi
and
Rickettsia akari
in Irradiated L Cells
Authors: Weiss E. , Newman L. W. , Grays R. , Green A. E.
Published: January 2020

L cells that had been exposed to 3,000 r of
60
Co the previous day were used to study the growth and metabolism of
Rickettsia typhi
and
R. akari.
Viable (unirradiated) L cells were used to study the effect of rickettsial infection on host-cell metabolism. Monolayers were infected with a rickettsial multiplicity of 1.2 and given Eagle's minimal essential medium containing 25 m
m
N
-2-hydroxyethylpiperazine-
N
′-2′-ethanesulfonic acid buffer and 10% calf serum. At various intervals, cycloheximide (2 μg/ml) was added to one set of cultures, to inhibit eukaryotic protein and deoxyribonucleic acid (DNA) metabolism; phosphate-buffered saline (PBS) was added to another set. After 1 hr, the cultures received a mixture of 15
14
C-labeled amino acids or adenine-8-
14
C.
The cultures were harvested 16 hr later and were tested for incorporation of labeled carbon into the fraction precipitated by cold trichloroacetic acid. Viable cells were exposed to thymidine-
2
-
14
C
for 2-hr periods. Infectivity of
R. typhi
increased to a peak of 150 to 400 hemolytic units/culture on day 4; the titer remained approximately the same on days 5 and 6, and declined rapidly on day 7. Total amino acid incorporation was about the same in infected and uninfected cultures up to day 6, but metabolic activity was reduced to a negligible level on day 7 in infected cells. Cycloheximide-resistant activity was higher in the infected cultures, with a peak equivalent to one-half the total activity at day 4 to 5. Total as well as cycloheximide-resistant adenine incorporation was higher in the infected cells between days 3 and 5 after infection, with a peak at day 3 to 4. Somewhat similar results were obtained with
R. akari
, except that the cycle of infection and of cycloheximide-resistant activity proceeded and was completed more rapidly.
14
C-DNA of both rickettsiae was isolated from infected cultures that had received labeled adenine. With labeled thymidine, which was not incorporated by the rickettsiae, it was shown that
R. typhi
and
R. akari
differ considerably in their effects on the host cell.
R. typhi
elicited moderate inhibition, whereas
R. akari
infection led to a complete inhibition of thymidine incorporation by the third day, at the time of highest rickettsial activity. It is concluded that rickettsiae have the necessary enzymes for protein and nucleic acid synthesis, but, thus far, these enzymes have been activated or induced only in an intracellular environment.
Oral Immunization of Mice with Killed
Salmonella typhimurium
Vaccine
Authors: Waldman Robert H. , Grunspan Ruth , Ganguly Rama
Published: January 2020

A study was undertaken to assess the efficacy of oral, parenteral, and intraperitoneal immunization methods of administering killed
Salmonella typhimurium
vaccine to mice and to evaluate the effectiveness of single and multiple doses of the vaccine containing varied numbers of the killed bacteria. A further objective of this study was to evaluate the effect of adding substances to the vaccine to which have been ascribed “adjuvant” properties. The protection was estimated by isolation of bacteria from the spleen and feces after oral challenge of the mice with live
S. typhimurium.
The results showed that one or more doses of 10
10
organisms given orally led to significant protection. This rate of protection increased proportionately with the number of doses up to 10 doses, which offered 100% protection. Streptomycin, when added to multiple doses of 10
9
or more organisms given orally, increased the degree of protection, but beryllium sulfate and pertussis vaccine did not. Although multiple doses afforded similar systemic protection by all three routes of immunization, oral immunization yielded significantly greater local protection than that observed after subcutaneous or intraperitoneal immunization.
Serum Proteins of Gnotobiotic Rats
Authors: Balish Edward , Yale Charles E. , Hong Richard
Published: January 2020

Cellulose-acetate and agar gel immunoelectrophoresis were used to study the serum protein patterns of germfree rats before and after monoassociation with a pure culture of
Staphylococcus aureus
(phage type 80/81),
Streptococcus faecalis, Lactobacillus acidophilus, Bacteroides fragilis, Pseudomonas aeruginosa
, or
Proteus vulgaris.
All six bacteria quickly established themselves in the gastrointestinal tract of the germfree rat, and all six increased the animals' total serum proteins. Only
S. aureus
and
P. aeruginosa
caused a noticeable rise in gamma globulins.
L. acidophilus, S. faecalis
, and
B. fragilis
multiplied readily in the gastrointestinal tract but caused only minimal alterations in the serum proteins.
P. vulgaris
caused a marked increase in the alpha and beta, but not the gamma globulins.
Anti-Gamma Globulins and Chronic Infection: Comparative Studies of the Immune Response to Various Bacteria and Gamma Globulin Preparations
Authors: Williams Ralph C. , Mellbye Ove J. , Kronvall Göran
Published: January 2020

A study of the relationship of clinical states associated with prolonged infection (bacterial endocarditis and osteomyelitis) and generation of serum anti-gamma globulins was made with particular reference to quantitative amounts of staphylococcal protein A in various infecting strains. No correlation between individual strain amounts of protein A and presence of anti-gamma globulins was detected. Thirty-eight rabbits were immunized intravenously with various strains of bacteria (
Staphylococcus aureus
, enterococci,
Streptomyces viridans
, pneumococci, pseudomonas, and
Escherichia coli
) for periods of 6 weeks, and antibacterial as well as anti-gamma globulin antibodies were assayed. No single group or strain of bacteria stood out as being more prone to produce anti-gamma globulins than others tested. Most rabbits developed anti-gamma globulins reacting with human gamma globulins, whereas the specificity for rabbit gamma globulin appeared more restricted. In 16 rabbits immunized with eight different strains of
S. aureus
, quantitative elevation of serum gamma globulin above 2.5 g per 100 ml often seemed to be correlated with presence of detectable serum anti-gamma globulins. By contrast 15 rabbits immunized with autologous or isologous rabbit gamma globulins in many instances developed extremely high titers of anti-gamma globulins showing primary specificity for human rather than rabbit gamma globulin. These studies further amplify the remarkably heterogeneous anti-gamma globulin reactivity associated with various types of immune response.
Pyelonephritis XIV. Effect of Immunization on Experimental
Escherichia coli
Pyelonephritis
Authors: Montgomerie J. Z. , Kalmanson G. M. , Hubert E. G. , Guze L. B.
Published: January 2020

Mice immunized subcutaneously with heat-killed
Escherichia coli
were protected from pyelonephritis produced by the intravenous route, but there was little or no protection from ascending infection. No significant protection from ascending or hematogenous pyelonephritis was demonstrated when immunization was accomplished by injecting heat-killed
E. coli
into the bladder. Heat-killed
E. coli
injected either subcutaneously or into the bladder protected mice from early endotoxic death after intravenous or bladder challenge.
Scrapie-Induced Changes in the Percentage of Polymorphonuclear Neutrophils in Mouse Peripheral Blood
Authors: Licursi Pamela C. , Merz Patricia A. , Merz George S. , Carp Richard I.
Published: January 2020

A decrease in the percentage of polymorphonuclear neutrophils (PMN) in the peripheral blood of mice appeared 3 days after intracerebral (IC) inoculation with scrapie mouse brain homogenate. Mice inoculated IC with normal mouse brain had PMN percentages similar to those found for uninoculated mice. This difference between normal and scrapie-inoculated mice continued throughout the preclinical phase of the disease. In the clinical phase of the disease, the percentage of PMN was either higher or lower than that found in normals. The factor causing the decrease in PMN percentages was found in the filtrates from 220-, 100-, and 50-nm filters, but not in the filtrates from a 25-nm filter. Sodium periodate treatment of the scrapie brain samples eliminated their ability to cause the decrease in PMN percentages, whereas sodium iodate had no effect. In addition to two genetically different scrapie mouse brain isolates, homogenates of mouse spleen, sheep brain, and sheep spleen from scrapie-affected animals caused a decrease in percent PMN, whereas the corresponding normal tissue homogenates did not.
Correlation of Circulating Capsular Polysaccharide with Bacteremia in Pneumococcal Pneumonia
Authors: Kenny George E. , Wentworth Berttina B. , Beasley R. Palmer , Foy Hjordis M.
Published: January 2020

Immunoelectroosmophoresis with rabbit anticapsular antibody was used to detect type-specific pneumococcal polysaccharide in serum from bacteremic patients with pneumococcal pneumonia. The test could detect as little as 0.1 to 1.0 μg per ml or 0.2 to 2 ng per test of polysaccharide from types 1, 2, 3, 4, 5, 8, 12, and 18, and its sensitivity was 10 times that of double immunodiffusion. Although antigen could be detected by double immunodiffusion with types 7 and 14, no antigen could be detected by immunoelectroosmophoresis. Types 7 and 14 polysaccharides were found to be positively charged, whereas the other polysaccharides were negatively charged. Forty-six patients with pneumonia were selected for study because pneumococci corresponding to those types where the test was known to work had been isolated from blood or the respiratory tract. Antigenemia correlated strongly with bacteremia: 12 of 20 bacteremic patients with pneumonia showed antigenemia, whereas 26 patients negative for bacteremia did not show circulating antigen detectable with antisera against the pneumococcal type isolated from the respiratory tract. The apparent concentration of circulating polysaccharide ranged from 0.1 to 100 μg per ml of serum, and the concentration did not appear to diminish appreciably in 10 to 15 days. Three of 12 patients with antigenemia died, and two of these had the highest levels of circulating antigen observed.
Arenaviruses: Cellular Response to Long-Term In Vitro Infection with Parana and Lymphocytic Choriomeningitis Viruses
Authors: Staneck L. D. , Trowbridge R. S. , Welsh R. M. , Wright E. A. , Pfau C. J.
Published: January 2020

Persistent infections were established in suspension cultures of BHK21/13S cells with both Parana and lymphocytic choriomeningitis viruses. Four generations after infection with either virus, more than 90% of the cells scored as infective centers, with concomitant peaks in extracellular virus yields. In both cultures the synthesis of detectable plaque-forming units (PFU) ceased about the 50th generation postinfection, and this condition was maintained until the 350th cell generation when the cultures were discontinued. The generation time of each culture was identical to that of uninfected parent controls, and at no time were cytopathic effects evident. In spite of the absence of infectivity, over 90% of the cells sampled at various times contained viral antigen demonstrable by immunofluorescence. When either of these persistently infected cell lines was substituted for normal cells in the standard plaque assay, very low efficiencies of plating were observed for homotypic and heterotypic viruses. Plaque formation by several heterologous viruses was virtually unaffected. The mechanism of homotypic plaque exclusion in both cell lines was shown to occur beyond the virion adsorption stage. The original infecting virus genome persisted in both cell lines after standard virus was no longer detectable. This was shown with the lymphocytic choriomeningitis virus-infected cells after storage in liquid nitrogen. After thawing, such cells were found to synthesize standard virus for a brief period. Although the Parana virus-infected cells did not behave this way, the growth medium from these cells would initiate PFU synthesis in normal cells within 36 hr after infection.
The Primary Immune Response in Mice III. Retention of Sheep Red Blood Cell Immunogens by the Spleen and Liver
Authors: Franzl Robert E.
Published: January 2020

The antibody-inducing activities of foreign red blood cell immunogens sequestered in the spleens and livers of mice injected with sheep erythrocytes were evaluated during the early periods of the immune response. Estimates of immunogenicity, obtained from the magnitudes of anti-sheep red blood cell hemolysin responses evoked in sensitized recipient mice by subcellular tissue fractions prepared from these phagocytic organs, showed that the liver and spleen differ greatly in their handling of this particulate antigen. The liver, functioning primarily as a scavenger organ, destroys completely the immunogenicity of the heterologous erythrocytes in 12 hr. In contrast, the spleen handles foreign erythrocyte immunogens in at least two different ways: approximately 90% of the initially sequestered activity is rapidly destroyed by the spleen in 6 hr, but the remaining activity, associated chiefly with a tissue fraction possessing the sedimentation properties of “light mitochondria,” is retained at a significant level for 3 days, and then progressively decreases to a low level until the 7th day. A correlation of the observed changes in the properties of the immunogenic tissue fraction with known cellular events in the spleen stimulated by antigens indicates that the retention of the degradable erythrocyte immunogen is essential for stimulating and maintaining immune reactions in this antibody-producing organ.
Antibody and Immunoglobulin Response to Antirabies Vaccination in Man
Authors: Cho Han C. , Fenje Paul , Sparkes John D.
Published: January 2020

Serum neutralization antibody and immunoglobulin responses in 30 individuals were studied in paired serum samples which had been obtained before and 2 to 3 weeks after the administration of a recall dose of rabies tissue culture vaccine. The immune reaction consisted of a predominantly immunoglobulin G (IgG) antibody response. Also, a significant increase in neutralizing antibody titers was observed, but without a consistently correlated change of the IgG levels in the individual serum samples. The radial immunodiffusion test appears to contain the elements necessary for the development of a routine test to determine rabies antibody in single serum samples.
Enhanced Growth of a Murine Coronavirus in Transformed Mouse Cells
Authors: Sturman Lawrence S. , Takemoto Kenneth K.
Published: January 2020

Plaque formation by A59 virus, a murine coronavirus, was facilitated in AL/N and Balb mouse cells transformed by polyoma virus, simian virus 40, murine sarcoma virus, or mammary tumor virus. In these virus-transformed cells, A59 virus plaques were larger, they appeared earlier, and plaquing efficiencies were higher than in normal, untransformed cells. “Spontaneously” transformed AL/N cells behaved similarly to untransformed cells, whereas “spontaneously” transformed Balb cells resembled virus-transformed cell hosts. Both untransformed and transformed AL/N and Balb cells were permissive hosts for A59 virus. However, multiplication of A59 virus was enhanced at least fivefold in the virus-transformed AL/N cell hosts. Larger differences (100-fold or greater) in A59 virus production were obtained during the first cycle of infection in Balb cells at low multiplicities and in AL/N cells after multiple cycles of virus growth. In virus-transformed and “spontaneously” transformed Balb cells, A59 virus induced extensive syncytia formation.
Neutralization of
Staphylococcus aureus
Exfoliatin by Antibody
Authors: Miller Margaret M. , Kapral F. A.
Published: January 2020

Alum-precipitated exfoliatin was found to be an efficient antigen for eliciting high titers of neutralizing antibody in rabbits. Antitoxin thus produced, and transferred passively, was shown to protect neonatal mice against challenge with two to three lethal doses of preformed exfoliatin even when administration was delayed until 15 min before exfoliation began in control animals. The same dose of antitoxin afforded some protection against six to eight lethal doses of exfoliatin provided it was given before or at the time of challenge. Antitoxin, in the doses given, did not protect against infection with an exfoliatin-producing
Staphylococcus aureus
strain although the onset of exfoliation was delayed.
Identification and Quantitation of Equine Serum and Secretory Immunoglobulin A
Authors: McGuire T. C. , Crawford T. B.
Published: January 2020

Immunoglobulin A (IgA) was demonstrated in equine serum and secretions. This immunoglobulin had a molecular weight extending from 150,000 to 700,000 and reacted with specific antihuman alpha-chain antiserum. Antigenic determinants specific for secretory IgA were demonstrated and found to be absent on serum IgA. Antigen binding activity was detected in IgA from tears. Purified IgA was antigenically distinct from equine IgG, IgM, IgG(T), and aggregating immunoglobulin. Quantitative studies demonstrated that IgA was the predominant immunoglobulin in tears and milk but not in colostrum. The electrophoretic mobility, size, presence of secretory component, and reaction with specific antihuman alpha-chain antiserum demonstrates that this immunoglobulin is the equine homologue of human IgA.
Physicochemical Properties of
Neisseria meningitidis
Group X Polysaccharide Antigen
Authors: Apicella M. A. , Robinson John A.
Published: January 2020

Neisseria meningitidis
group X occurs in human carrier populations and is rarely implicated in serious disease. This organism possesses a capsular group antigen which is an acidic polysaccharide. It is composed of the amino sugars, glucosamine, glucosamine-6-phosphate, galactosamine, and the simple hexose, glucose. The group X capsular antigen has an
S
20,w
0
of 3.6, and the acidic nature of the polysaccharide is reflected in an isoelectric point of 3.65. The meningococcal A, B, C, and Y polysaccharide group antigens are also composed primarily of amino sugars. The chemical composition of the group X antigen most closely resembles the capsular antigen of
N. meningitidis
group Y, which is also predominately a carrier organism.
Hemagglutination by BK Virus, a Tentative New Member of the Papovavirus Group
Authors: Mäntyjärvi Rauno A. , Arstila Pertti P. , Meurman Olli H.
Published: January 2020

Some characteristics of hemagglutination (HA) by the BK virus, a new candidate for the papovavirus group, have been studied. Hemagglutinin prepared from cell cultures was found to be partially masked by inhibitors which could be dissociated from the virus by incubation at 37 C or by fluorocarbon extraction. Optimal conditions for HA are outlined. In routine tests, 0.5% human erythrocytes were used. The reaction was carried out at
p
H 7.0 on ice-water slurry. BK hemagglutinin receptors on human erythrocytes were found to be more resistant to neuraminidase than polyoma receptors. By gradient centrifugation analysis, two types of particles were found to be responsible for HA: (i) full, deoxyribonucleic acid-containing particles with a density of 1.325 g/cm
3
and (ii) empty capsids with a density 1.29 g/cm
3
. Based on particle counting, one HA unit was calculated to correspond to 3 × 10
6
virus particles.
Availability of Locally Synthesized and Systemic Antibodies in the Intestine
Authors: Fubara Ernest S. , Freter Rolf
Published: January 2020

The present studies are concerned with the parameters which control the appearance of locally synthesized or serum-derived antibodies in the intestine. The data show that intestinal antibody may be found in rabbits as well as in conventional or germfree mice after active immunization with
Vibrio cholerae.
However, a large fraction of the intestinal antibody in rabbits and conventional mice originated from the serum as indicated by (i) analysis of correlation between serum and intestinal antibody titers, and (ii) the occurrence of intestinal antibody after parenteral administration of antiserum. In contrast, only locally synthesized 11
S
immunoglobulin A antibody was detected in the intestine of actively immunized germfree mice. No intestinal antibody was demonstrable in germfree mice after parenteral injection of
V. cholerae
antiserum. With respect to the appearance of serum antibody in the intestine, the response of conventionalized (ex-germfree) mice was intermediate between that of rabbits or conventional mice and germfree mice. The availability of serum-derived coproantibody in germfree and conventional mice was related to the rates of intestinal degradation of serum antibody. When enzymes were removed by prior washing of intestinal segments, serum antibodies entered the intestine of germfree or conventional mice at similar rates. Rates of entry of serum antibodies into the lumen were comparable at different levels of the small intestine. The presence of a normal enteric flora appeared to protect intestinal antibody from degradation by lowering the concentration or activity of intestinal enzymes. The results are discussed in relation to the question of whether antibacterial immunity to cholera involves local or systemic mechanisms.
A 34- to 38-kilodalton Cryptococcus neoformans glycoprotein produced as an exoantigen bearing a glycosylated species-specific epitope
Authors: Hamilton A J , Jeavons L , Hobby P , Hay R J
Published: January 2020

Three monoclonal antibodies (MAbs), all of the immunoglobulin G1 subclass, were raised against Cryptococcus neoformans by using the technique of cyclophosphamide ablation of B-cell responses against shared epitopes of the cross-reactive fungus Trichosporon beigelii. MAb 3C2 was reactive against the encapsulated and nonencapsulated isolates of C. neoformans var. neoformans by enzyme-linked immunosorbent assay (ELISA) and Western blot (immunoblot), and in addition to a 34- to 38-kDa determinant, it recognized a series of lower-molecular-weight species. 3C2 also reacted strongly with culture supernatant preparations of C. neoformans var. neoformans by ELISA. 3C2 showed no recognition of either T. beigelii or C. neoformans var. gattii antigens. Enzymatic deglycosylation followed by reaction with 3C2 on Western blots revealed that sialic acid was an integral part of the determinant, together with N-acetylglucosaminyl-asparagine and alpha-mannose. Proteolytic digestion showed that the epitope was pepsin sensitive and that it also contained tryptophan and glycine and/or leucine as determinants of recognition by 3C2. The pI of the glycoprotein was 7.1. Affinity chromatography-purified antigen did not exhibit proteolytic activity on sodium dodecyl sulfate-polyacrylamide substrate gels. Indirect fluorescence antibody tests revealed that 3C2 labelling was confined to the cell membrane and cytoplasm of yeasts. The remaining MAbs, 7H4 and 5G5, recognized both capsulated and nonencapsulated strains of C. neoformans var. neoformans by both ELISA and Western Blot, identifying linear determinants with molecular masses of 36 and 30 kDa. They were unreactive against culture supernatant antigen (exoantigen) from either variant of C. neoformans.
Pertussis toxin partially inhibits phagocytosis of immunoglobulin G-opsonized Staphylococcus aureus by human granulocytes but does not affect intracellular killing
Authors: Hiemstra P S , Annema A , Schippers E F , van Furth R
Published: January 2020

The aim of the present study was to determine whether pertussis toxin (PT)-sensitive GTP-binding proteins (G proteins) are involved in the signal transduction pathway(s) used for phagocytosis and intracellular killing of bacteria by human granulocytes. Treatment of granulocytes with PT resulted in decreased phagocytosis of immunoglobulin G (IgG)-opsonized Staphylococcus aureus but did not affect subsequent intracellular killing of these bacteria. PT also caused a decrease in the extracellular release of superoxide anion (O2-) and hydrogen peroxide (H2O2) by granulocytes in response to S. aureus opsonized by IgG. However, neither the phagocytosis nor the intracellular killing of S. aureus opsonized by fresh serum was affected by PT, and the release of O2- was partially inhibited. The release of O2- in response to serum-treated zymosan, opsonized mainly by complement components, was also only partially inhibited by PT. It is therefore possible that PT inhibits responses mediated through complement receptors to a lesser extent than those mediated via Fc gamma receptors. The results of this study indicate that PT-sensitive G proteins are involved in the signal transduction pathways that mediate the phagocytosis of IgG-opsonized bacteria and the accompanying respiratory burst.
Protection against Brucella melitensis or Brucella abortus in mice with immunoglobulin G (IgG), IgA, and IgM monoclonal antibodies specific for a common epitope shared by the Brucella A and M smooth lipopolysaccharides
Authors: Cloeckaert A , Jacques I , de Wergifosse P , Dubray G , Limet J N
Published: January 2020

Mice passively immunized prior to a challenge infection with immunoglobulin G (IgG) and IgM monoclonal antibodies (MAbs) specific for a common epitope of both A- and M-dominant strains had viable Brucella abortus 544 or Brucella melitensis H38 counts in the spleen reduced to the same extent as did mice passively immunized with MAbs specific for either the A or the M epitope. The IgA MAb was not effective.
Gonococcal lipooligosaccharide sialylation prevents complement-dependent killing by immune sera
Authors: Wetzler L M , Barry K , Blake M S , Gotschlich E C
Published: January 2020

Previous investigators have demonstrated that a sialic acid residue is added to the terminal galactose moiety of gonococcal lipooligosaccharide (LOS) when incubated with 5'-CMP-N-acetylneuraminic acid. When this in vitro sialylation occurs, gonococci become resistant to the bactericidal activity of normal human serum. This is believed to result because the added sialic acid residue blocks the binding of bactericidal anti-LOS antibodies present in normal human serum. We extend these studies by demonstrating that sialylated gonococci also become resistant to the bactericidal effect of immune sera containing antibodies that recognize exposed components of the outer membrane besides LOS. Prevention of antibody binding to the organism was not the cause, since the same percentage of bactericidal antibodies to the major outer membrane protein, Protein I, can be absorbed with sialylated organisms as with wild-type organisms. In addition, gonococcal sialylation prevents opsonophagocytosis by antigonococcal antisera. The negative effect of sialic acid on the complement pathway might be the reason for the findings in this study.
Identification of human T-cell epitopes on the S4 subunit of pertussis toxin
Authors: Petersen J W , Holm A , Ibsen P H , Hasløv K , Capiau C , Heron I
Published: January 2020

Ten adult humans were vaccinated with the Japanese acellular pertussis vaccine JNIH-3, containing detoxified pertussis toxin (PT), formaldehyde, and filamentous hemagglutinin. The vaccination induced a specific antibody response to PT and filamentous hemagglutinin, and a Western blot (immunoblot) analysis of the antibody response to PT revealed antibodies to PT subunits S1, S2, S3, S4 and S5. The response of peripheral lymphocytes to PT was assessed in an in vitro proliferation assay. A proliferative response to detoxified PT and PT dimers S2-S4 and S3-S4 was found, and it was further demonstrated that the proliferative response to detoxified PT and dimer S2-S4 was mediated by T cells of the CD4+ phenotype. The specificity of the proliferative response to subunit S4 was analyzed with a range of synthetic peptides synthesized on the basis of the primary sequence of subunit S4. The proliferative response to the peptides revealed two major and one minor T-cell epitope located in the NH2-terminal end of subunit S4.
Prevention of C3 deposition by capsular polysaccharide is a virulence mechanism of type III group B streptococci
Authors: Marques M B , Kasper D L , Pangburn M K , Wessels M R
Published: January 2020

Strains of type III group B streptococci isolated from patients with neonatal sepsis are generally resistant to complement-mediated phagocytic killing in the absence of specific antibody. It has been suggested that the resistance of type III group B streptococci to phagocytosis results from inhibition of alternative-complement-pathway activation by sialic acid residues of the type III polysaccharide. To better define the relationship between structural features of the type III capsule and resistance of type III group B streptococci to complement-mediated phagocytic killing, we measured deposition of human C3 on group B streptococcal strains with altered capsule phenotypes. C3 binding was quantified by incubating bacteria with purified human 125I-C3 in 10% serum. Wild-type group B Streptococcus sp. strain COH1 bound eightfold fewer C3 molecules than did either of two isogenic mutant strains, one expressing a sialic acid-deficient capsule and the other lacking capsule completely. Similar results were obtained when the incubation with 125I-C3 was performed in serum chelated with Mg-ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'- tetraacetic acid (MgEGTA), suggesting that the majority of C3 deposition occurred via the alternative pathway. In contrast to the wild-type strain, which was relatively resistant, both mutant strains were killed by human leukocytes in 10% serum with or without MgEGTA. We also measured C3 binding to 14 wild-type strains of type III group B streptococci expressing various amounts of capsule. Comparison of degree of encapsulation with C3 binding revealed a significant inverse correlation (r = -0.72; P less than 0.01). C3 fragments released by methylamine treatment of wild-type strain COH1 were predominantly in the form of C3bi, while those released from the acapsular mutant were predominantly C3b and those from the asialo mutant represented approximately equal amounts of C3b and C3bi. We conclude from these studies that the sialylated type III capsular polysaccharide inhibits alternative-pathway activation, prevents C3 deposition on group B streptococci, and protects the organisms from phagocytic killing.