bluuebunny/crossref_metadata_2025_split huggingface dataset:
Capsule-Transmitted Gut Symbiotic Bacterium of the Japanese Common Plataspid Stinkbug,
Megacopta punctatissima
Authors: Fukatsu Takema , Hosokawa Takahiro 
Published: July 2002

ABSTRACT

The Japanese common plataspid stinkbug,
Megacopta punctatissima
, deposits small brown particles, or symbiont capsules, on the underside of the egg mass for the purpose of transmission of symbiotic bacteria to the offspring. We investigated the microbiological aspects of the bacteria contained in the capsule, such as microbial diversity, phylogenetic placement, localization in vivo, and fitness effects on the host insect. Restriction fragment length polymorphism analysis of 16S ribosomal DNA clones revealed that a single bacterial species dominates the microbiota in the capsule. The bacterium was not detected in the eggs but in the capsules, which unequivocally demonstrated that the bacterium is transmitted to the offspring of the insect orally rather than transovarially, through probing of the capsule content. Molecular phylogenetic analysis showed that the bacterium belongs to the γ-subdivision of the
Proteobacteria
. In adult insects the bacterium was localized in the posterior section of the midgut. Deprivation of the bacterium from the nymphs resulted in retarded development, arrested growth, abnormal body coloration, and other symptoms, suggesting that the bacterium is essential for normal development and growth of the host insect.
Modeling Yeast Spoilage in Cold-Filled Ready-To-Drink Beverages with
Saccharomyces cerevisiae
,
Zygosaccharomyces bailii
, and
Candida lipolytica
Authors: Battey Alyce Stiles , Duffy Siobain , Schaffner Donald W. 
Published: July 2002

ABSTRACT

Mathematical models were developed to predict the probability of yeast spoilage of cold-filled ready-to-drink beverages as a function of beverage formulation. A Box-Behnken experimental design included five variables, each at three levels: pH (2.8, 3.3, and 3.8), titratable acidity (0.20, 0.40, and 0.60%), sugar content (8.0, 12.0, and 16.0 °Brix), sodium benzoate concentration (100, 225, and 350 ppm), and potassium sorbate concentration (100, 225, and 350 ppm). Duplicate samples were inoculated with a yeast cocktail (100 μl/50 ml) consisting of equal proportions of
Saccharomyces cerevisiae
,
Zygosaccharomyces bailii
, and
Candida lipolytica
(∼5.0 × 10
4
CFU/ml each). The inoculated samples were plated on malt extract agar after 0, 1, 2, 4, 6, and 8 weeks. Logistic regression was used to create the predictive models. The pH and sodium benzoate and potassium sorbate concentrations were found to be significant factors controlling the probability of yeast growth. Interaction terms for pH and each preservative were also significant in the predictive model. Neither the titratable acidity nor the sugar content of the model beverages was a significant predictor of yeast growth in the ranges tested.
Degradation of 17β-Estradiol by a Gram-Negative Bacterium Isolated from Activated Sludge in a Sewage Treatment Plant in Tokyo, Japan
Authors: Fujii Katsuhiko , Kikuchi Shintaro , Satomi Masataka , Ushio-Sata Noriko , Morita Naoki 
Published: July 2002

ABSTRACT

A 17β-estradiol (E2)-degrading bacterium was isolated from activated sludge in a sewage treatment plant in Tokyo, Japan. The isolate was suggested to be a new
Novosphingobium
species. Gas chromatography-mass spectrometry and
1
H nuclear magnetic resonance analyses of the metabolites of E2 degradation suggested that no toxic products accumulated in the culture medium.
Structural and Functional Lesions in Brush Border of Human Polarized Intestinal Caco-2/TC7 Cells Infected by Members of the Afa/Dr Diffusely Adhering Family ofEscherichia coli
Authors: Peiffer Isabelle , Guignot Julie , Barbat Alain , Carnoy Christophe , Moseley Steve L. , Nowicki Bogdan J. , Servin Alain L. , Bernet-Camard Marie-Françoise 
Published: July 2002

ABSTRACTDiffusely adheringEscherichia coli(DAEC) strains expressing F1845 fimbrial adhesin or Dr hemagglutinin belonging to the Afa/Dr family of adhesins infect cultured polarized human intestinal cells through recognition of the brush border-associated decay-accelerating factor (DAF; CD55) as a receptor. The wild-type Afa/Dr DAEC strain C1845 has been shown to induce brush border lesions by an adhesin-dependent mechanism triggering apical F-actin rearrangements. In the present study, we undertook to further characterize cell injuries following the interaction of wild-type Afa/Dr DAEC strains C1845 and IH11128 expressing fimbrial F1845 adhesin and Dr hemagglutinin, respectively, with polarized, fully differentiated Caco-2/TC7 cells. In both cases, bacterium-cell interaction was followed by rearrangement of the major brush border-associated cytoskeletal proteins F-actin, villin, and fimbrin, proteins which play a pivotal role in brush border assembly. In contrast, distribution of G-actin, actin-depolymerizing factor, and tubulin was not modified. UsingdraEmutants, we found that a mutant in which cysteine replaces aspartic acid at position 54 conserved binding capacity but failed to induce F-actin disassembly. Accompanying the cytoskeleton injuries, we found that the distribution of brush border-associated functional proteins sucrase-isomaltase (SI), dipeptidylpeptidase IV (DPPIV), glucose transporter SGLT1, and fructose transporter GLUT5 was dramatically altered. In parallel, SI and DPPIV enzyme activity decreased.
Mutations in the S1 Subunit of Pertussis Toxin That Affect Secretion
Authors: Craig-Mylius Kathleen A. , Stenson Trevor H. , Weiss Alison A. 
Published: July 2002

ABSTRACT

Pertussis toxin is a member of the AB
5
family of toxins and is composed of five subunits (S1 to S5) present in a 1:1:1:2:1 ratio. Secretion is a complex process. Each subunit has a secretion signal that mediates transport to the periplasm, where processing and assembly occur. Secretion of the assembled 105-kDa toxin past the outer membrane is mediated by the nine proteins encoded in the
ptl
operon. Previous studies have shown that S1, the catalytically active A subunit of pertussis toxin, is necessary for efficient secretion, suggesting that a domain on S1 may be required for interaction with the secretion apparatus. Previously, recombinant S1 from four different mutants (serine 54 to glycine, serine 55 to glycine, serine 56 to glycine, and arginine 57 to lysine) was shown to retain catalytic activity. We introduced these mutations into
Bordetella pertussis
and monitored pertussis toxin production and secretion. No pertussis toxin was detected in the serine 54-to-glycine mutant. The other S1 mutants produced periplasmic pertussis toxin, but little pertussis toxin secretion was observed. The arginine 57-to-lysine mutant had the most dramatic secretion defect. It produced wild-type levels of periplasmic pertussis toxin but secreted only 8% as much toxin as the wild-type strain. This phenotype was similar to that observed for strains with mutations in the
ptl
genes, suggesting that this region may have a role in pertussis toxin secretion.
Use of Pertussis Toxin Encoded by
ptx
Genes from
Bordetella bronchiseptica
To Model the Effects of Antigenic Drift of Pertussis Toxin on Antibody Neutralization
Authors: Hausman Sally Z. , Burns Drusilla L. 
Published: July 2002

ABSTRACT

Recently, concern has been voiced about the potential effect that antigenic divergence of circulating strains of
Bordetella pertussis
might have on the efficacy of pertussis vaccines. In order to model antigenic drift of pertussis toxin, a critical component of many pertussis vaccines, and to examine the effects of such drift on antibody neutralization, we engineered a strain of
B. pertussis
to produce a variant pertussis toxin molecule that contains many of the amino acid changes found in the toxin encoded by
Bordetella bronchiseptica ptx
genes. This altered form of the toxin, which is efficiently secreted by
B. pertussis
and which displays significant biological activity, was found to be neutralized by antibodies induced by vaccination as readily as toxin produced by wild-type
B. pertussis
. These findings suggest that significant amino acid changes in the pertussis toxin sequence can occur without drastically altering the ability of antibodies to recognize and neutralize the toxin molecule.
Enhanced Gamma Interferon Production through Activation of Vα14+Natural Killer T Cells by α-Galactosylceramide in Interleukin-18-Deficient Mice with Systemic Cryptococcosis
Authors: Kawakami Kazuyoshi , Kinjo Yuki , Yara Satomi , Uezu Kaori , Koguchi Yoshinobu , Tohyama Masaki , Azuma Masato , Takeda Kiyoshi , Akira Shizuo , Saito Atsushi 
Published: July 2002

ABSTRACTWe showed recently that activation of Vα14+natural killer T cells (NKT cells) by α-galactosylceramide (α-GalCer) resulted in increased gamma interferon (IFN-γ) production and host resistance to intravenous infection withCryptococcus neoformans. In other studies, interleukin-18 (IL-18) activated NKT cells in collaboration with IL-12, suggesting the possible contribution of this cytokine to α-GalCer-induced IFN-γ synthesis. Here we examined the role of IL-18 in α-GalCer-induced Th1 response by using IL-18KO mice with this infection. In these mice, levels of IFN-γ in serum and its synthesis in vitro by spleen cells stimulated with live organisms were not reduced, but rather enhanced, compared to those in wild-type (WT) mice, while such production was completely absent in IL-12KO mice. The enhanced production of IFN-γ correlated with increased IL-12 synthesis but not with reduced production of IL-4, which was rather increased. IFN-γ synthesis in IL-18KO mice was abolished by neutralizing anti-IL-12 antibody and significantly inhibited by neutralization of endogenous IL-4 with a specific monoclonal antibody. In addition, administration of recombinant IL-4 significantly enhanced the production of IFN-γ in WT mice. Finally, the enhanced production of IFN-γ in IL-18KO mice correlated with increased host defense against cryptococcal infection, as indicated by enhancement in α-GalCer-related clearance of microorganisms. Our results indicated that in IL-18KO mice, IFN-γ synthesis was enhanced through overproduction of IL-12 and IL-4 after intravenous infection withC. neoformansand a ligand-specific activation of Vα14+NKT cells.
Functional Characteristics of a Protective Monoclonal Antibody against Serotype A and C Lipooligosaccharides from
Moraxella catarrhalis
Authors: Hu Wei-Gang , Chen Jing , McMichael John C. , Gu Xin-Xing 
Published: July 2002

ABSTRACT

A monoclonal antibody (MAb), designated MAb 8E7 (immunoglobulin G3), specific for
Moraxella catarrhalis
lipooligosaccharide (LOS) was evaluated for its functional activity in vitro and in a mouse model of colonization. Enzyme-linked immunosorbent assay (ELISA) demonstrated that the MAb 8E7 could be prepared to a high titer against LOS of the homologous strain 035E, and that it had bactericidal activity. MAb 8E7 reacted with
M. catarrhalis
serotype A and C LOSs but not serotype B LOS, as measured by ELISA and Western blotting. On the basis of published structures of LOSs, this suggests that the epitope recognized by MAb 8E7 is directed to a common sequence of either α-GlcNAc-(1→2)-β-Glc-(1→ at the branch substituting position 4 of the trisubstituted Glc residue or a terminal tetrasaccharide α-Gal-(1→4)-β-Gal-(1→4)-α-Glc-(1→2)-β-Glc-(1→ at the branch substituting position 6 of the trisubstituted Glc residue. In a whole-cell ELISA, MAb 8E7 reacted with 70% of the 30 wild-type strains and clinical isolates tested. Immuno-electron microscopy demonstrated that MAb 8E7 reacted with a cell surface-exposed epitope of LOS on strain O35E. MAb 8E7 inhibited the adherence of strain O35E to Chang conjunctival epithelial cells by 90%. Passive immunization with MAb 8E7 could significantly enhance the clearance of strain O35E from mouse lungs in an aerosol challenge mouse model. This enhanced bacterial clearance was inhibited when MAb 8E7 was absorbed by
M. catarrhalis
serotype A LOS, indicating that the
M. catarrhalis
LOS-directed antibody may play a major role in the enhancement of
M. catarrhalis
clearance from lungs. These data suggest that MAb 8E7, which recognizes surface-exposed LOS of
M. catarrhalis
, is a protective antibody against
M. catarrhalis
.
Expression of Adhesion Molecules in Synovia of Patients with Treatment-Resistant Lyme Arthritis
Authors: Akin Evren , Aversa John , Steere Allen C. 
Published: July 2002

ABSTRACTThe expression of adhesion molecules in synovium in patients with Lyme arthritis is surely critical in the control ofBorrelia burgdorferiinfection but may also have pathologic consequences. For example, molecular mimicry between a dominant T-cell epitope ofB. burgdorferiouter surface protein A and an adhesion molecule, human lymphocyte function-associated antigen 1 (LFA-1), has been implicated in the pathogenesis of treatment-resistant Lyme arthritis. Using immunohistochemical methods, we examined synovial samples for expression of adhesion molecules in 29 patients with treatment-resistant Lyme arthritis and in 15 patients with rheumatoid arthritis or chronic inflammatory monoarthritis. In Lyme arthritis synovia, endothelial cells showed intense expression of P-selectin and vascular adhesion protein-1 (VAP-1). Expression of LFA-1 was also intense on infiltrating cells, particularly in lymphoid aggregates, and intercellular adhesion molecule-1 (ICAM-1) was markedly expressed on synovial lining and endothelial and infiltrating cells. Moderate expression of vascular cell adhesion molecule-1 (VCAM-1) was seen on synovial lining and endothelial cells, and mild expression of its ligand, very late antigen-4, was apparent in perivascular lymphoid infiltrates. Except for lesser expression of VCAM-1 in Lyme synovia, the levels of expression of these adhesion molecules were similar in the three patient groups. We conclude that certain adhesion molecules, including ICAM-1 and LFA-1, are expressed intensely in the synovia of patients with Lyme arthritis. Upregulation of LFA-1 on lymphocytes in this lesion may be critical in the pathogenesis of treatment-resistant Lyme arthritis.
Critical Role of Cytotoxic T Lymphocytes in Immune Clearance of Rickettsial Infection
Authors: Walker David H. , Olano Juan P. , Feng Hui-Min 
Published: July 2002

ABSTRACTCytotoxic T-lymphocyte (CTL) activity developed against the major infected target cells of rickettsial infections, endothelial cells and macrophages. Spleen cells from mice immune toRickettsia conoriiexerted specific major histocompatibility complex (MHC) class I-matched CTL activity againstR. conorii-infected SVEC-10 endothelial cells, with peak activity on day 10. Similarly, spleen cells fromRickettsia australis-immune mice exerted specific CTL activity against anR. australis-infected macrophage-like cell line. Gamma interferon (IFN-γ) gene knockout mice were more than 100-fold more susceptible toR. australisinfection than wild-type C57BL/6 mice. MHC class I gene knockout mice were the most susceptible, more than 50,000-fold more susceptible to a lethal outcome ofR. australisinfection than wild-type C57BL/6 mice. These results indicate that CTL activity was more critical to recovery from rickettsial infection than were the effects of IFN-γ. The observation that perforin gene knockout mice were more than 100-fold more susceptible than wild-type C57BL/6 mice indicates that perforin-mediated activity accounts for a large component, but not all, of the CTL-mediated antirickettsial effect. CTL activity was expressed by immune CD8 T lymphocytes. Adoptive transfer of immune CD8 T lymphocytes from IFN-γ gene knockout mice intoR. australis-infected IFN-γ gene knockout mice dramatically reduced the infectious rickettsial content in the organs, confirming that CD8 T lymphocytes provide immunity against rickettsiae besides that provided by the secretion of IFN-γ. CTLs appear to be crucial to recovery from rickettsial infection.
Chlamydia pneumoniaeMajor Outer Membrane Protein Is a Surface-Exposed Antigen That Elicits Antibodies Primarily Directed against Conformation-Dependent Determinants
Authors: Wolf Katerina , Fischer Elizabeth , Mead David , Zhong Guangming , Peeling Roseanna , Whitmire Bill , Caldwell Harlan D. 
Published: July 2002

ABSTRACTThe major outer membrane protein (MOMP) ofChlamydia trachomatisserovariants is known to be an immunodominant surface antigen. Moreover, it is known that theC. trachomatisMOMP elicits antibodies that recognize both linear and conformational antigenic determinants. In contrast, it has been reported that the MOMP ofChlamydia pneumoniaeis not surface exposed and is immunorecessive. We hypothesized that the discrepancies betweenC. trachomatisandC. pneumoniaeMOMP exposure on intact chlamydiae and immunogenic properties might be because the focus of the host's immune response is directed to conformational epitopes of theC. pneumoniaeMOMP. We therefore conducted studies aimed at defining the surface exposure of MOMP and the conformational dominance of MOMP antibodies. We present here a description ofC. pneumoniaespecies-specific monoclonal antibody (MAb), GZD1E8, which recognizes a conformational epitope on the surface ofC. pneumoniae. This MAb is potent in the neutralization ofC. pneumoniaeinfectivity in vitro. Another previously describedC. pneumoniaespecies-specific monoclonal antibody, RR-402, displayed very similar characteristics. However, the antigenic determinant recognized by RR-402 has yet to be identified. We show by immunoprecipitation ofC. pneumoniaewith GZD1E8 and RR-402 MAbs and by mass spectrometry analysis of immunoprecipitated proteins that both antibodies GZD1E8 and RR-402 recognize the MOMP ofC. pneumoniaeand that this protein is localized on the surface of the organism. We also show that human sera fromC. pneumoniae-positive donors consistently recognize the MOMP by immunoprecipitation, indicating that the MOMP ofC. pneumoniaeis an immunogenic protein. These findings have potential implications for bothC. pneumoniaevaccine and diagnostic assay development.
Stable Transfection of the BovineNRAMP1Gene into Murine RAW264.7 Cells: Effect onBrucella abortusSurvival
Authors: Barthel Robert , Feng Jianwei , Piedrahita Jorge A. , McMurray David N. , Templeton Joe W. , Adams L. Garry 
Published: July 2002

ABSTRACTGenetically based natural resistance to brucellosis in cattle provides for novel strategies to control zoonotic diseases. BovineNRAMP1, the homologue of a murine gene (Bcg), has been identified as a major candidate for controlling the in vivo resistant phenotype. We developed an in vitro model for expression of resistance- and susceptibility-associated alleles of bovineNRAMP1as stable transgenes under the regulatory control of the bovineNRAMP1promoter in the murine RAW264.7 macrophage cell line (Bcgs) to analyze the regulation of theNRAMP1gene and its role in macrophage function. We demonstrated that the 5′-flanking region of bovineNRAMP1, despite the lack of TATA and CAAT boxes, has a functional promoter capable of driving the expression of a transgene in murine macrophages. A polymorphism within a microsatellite in the 3′ untranslated region critically affects the expression of bovineNRAMP1and the control of in vitro replication ofBrucella abortusbut notSalmonella entericaserovar Dublin. We did not observe any differences in the production of NO by resting or gamma interferon (IFN-γ)- and IFN-γ–lipopolysaccharide (LPS)-treated transfected cell lines, yet the resistant transfected cell lines produced significantly less NO than other cell lines, following stimulation with LPS at 24 and 48 h.
Immunohistochemical Analysis of Lyme Disease in the Skin of Naive and Infection-Immune Rabbits following Challenge
Authors: Chong-Cerrillo Celeste , Shang Ellen S. , Blanco David R. , Lovett Michael A. , Miller James N. 
Published: July 2002

ABSTRACTIn this study, skin histopathology from naive and infection-derived immune rabbits was compared following intradermal challenge usingBorrelia burgdorferiB31 strain. The presence or absence of spirochetes in relationship to host cellular immune responses was determined from the time of intradermal inoculation to the time of erythema migrans (EM) development (∼7 days in naive rabbits) and through development of challenge immunity (∼5 months in naive rabbits). Skin biopsies were obtained and analyzed for the presence of spirochetes, B cells, T cells, polymorphonuclear cells (PMNs), and macrophages by immunohistochemical techniques. In infected naive animals, morphologically identifiable spirochetes were detected at 2 h and up to 3 weeks postinfection. At 12 and 24 h postinfection there was a marked PMN response that decreased by 36 to 48 h; by 72 h the PMNs were replaced by a few infiltrating macrophages. At the time of EM development and 14 days postinfection, the PMNs and macrophages were replaced by a lymphocytic infiltrate. There was a greater number of spirochetes at 14 days, a time when EM had resolved, than at 7 days postinfection. By 3 weeks postinfection there were few organisms and lymphocytes detectable. In contrast to infected naive rabbits, intact spirochetes were never visualized in skin biopsies from infection-immune rabbits; only spirochetal antigen was detected at 2, 12, and 24 h in the presence of a numerous PMN infiltrate. By 36 h postchallenge, spirochetal antigen could not be detected and the PMN response was replaced by a few infiltrating macrophages. By 72 h postchallenge, PMNs and macrophages were absent from the skin; B and T cells were never detected at any time point in skin from infection-immune rabbits. The destruction of spirochetes in immune animals in the presence of PMNs and in the absence of a lymphocytic infiltrate suggests that infection-derived immunity is antibody mediated.
Role of the Heat Shock Protein 90 in Immune Response Stimulation by Bacterial DNA and Synthetic Oligonucleotides
Authors: Zhu Fu-Gang , Pisetsky David S. 
Published: July 2002

ABSTRACTTo elucidate the mechanisms of immunostimulation by bacterial DNA and synthetic oligonucleotides, the effects of heat shock protein 90 (Hsp90) inhibitors on the activation of murine spleen cells and macrophages by these molecules were investigated. Murine spleen cells and J774 and RAW264.7 macrophages responded to a CpG-containing oligodeoxynucleotide (CpG ODN) andEscherichia coliDNA by increased production of interleukin 6 (IL-6), IL-12, tumor necrosis factor alpha, and nitric oxide (NO). Pretreatment with any of the three Hsp90 inhibitors geldanamycin, radicicol, and herbimycin A resulted in a dose-dependent suppression of cytokine production from the spleen cells and macrophages and of NO from macrophages stimulated with CpG ODN orE. coliDNA. These Hsp90 inhibitors, however, had no effect onStaphylococcus aureusCowan strain 1-induced IL-12 production from either the murine spleen cells or macrophages. CpG ODN andE. coliDNA induced increased intracellular levels of phosphorylated extracellular signal-regulated kinases (ERK1 and -2), which are members of the mitogen-activated protein (MAP) kinase family, while geldanamycin and radicicol blocked the phosphorylation of ERK1 and -2 in J774 and RAW264.7 cells. These data indicate that DNA-induced activation of murine spleen cells and macrophages is mediated by Hsp90 and that Hsp90 inhibitor suppression of DNA-induced macrophage activation is associated with disruption of the MAP kinase signaling pathway. Our findings suggest that Hsp90 inhibitors may provide a useful means of elucidating the mechanisms of immunostimulation by bacterial DNA and CpG ODN as well as a strategy for preventing adverse effects of bacterial DNA as well as lipopolysaccharide.