bluuebunny/crossref_metadata_2025_split huggingface dataset:
Early Local Cytokine Profiles in Strains of Mice with Different Outcomes from Chlamydial Genital Tract Infection
Authors: Darville Toni , Andrews Charles W. , Sikes James D. , Fraley Patrick L. , Rank Roger. G. 
Published: July 2002

ABSTRACTIn this study, we expand on the examination of genetically determined differences in host responses that correlate with clearance ofChlamydia trachomatisfrom the genital tract. We infected C57BL/6, BALB/c, and C3H/HeN mice with the mouse pneumonitis agent ofC. trachomatis(MoPn). C57BL/6 mice had the shortest course of infection (22 days) and the lowest incidence of severe hydrosalpinx. BALB/c mice also had a short course of infection (25 days), but all developed hydrosalpinx. C3H/HeN mice had the longest course of infection (38 days), and all developed severe hydrosalpinx. Determination of local cytokine responses by enzyme-linked immunosorbent assay (ELISA) of genital tract secretions revealed that the levels of the proinflammatory cytokines tumor necrosis factor-alpha (TNF-α) and interleukin-1β (IL-1β) were significantly increased in the C57BL/6 and BALB/c strains compared to those in the C3H/HeN strain whereas the level of IL-6 was not different. The level of the neutrophil chemokine macrophage inflammatory protein 2 (MIP-2) was increased during the first week of infection in all three strains but was significantly higher in the BALB/c strain, the strain with the most rapid influx of neutrophils into the genital tract. Prolonged detection of MIP-2 in C3H/HeN mice was associated with a protracted presence of neutrophils in the genital tract. Early increases in the levels of the proinflammatory cytokines TNF-α and IL-1β are associated with earlier eradication of infection in the C57BL/6 and BALB/c strains than in the C3H/HeN strain. Increased levels of MIP-2 and neutrophils in BALB/c and C3H/HeN mice relative to C57BL/6 mice suggest that these responses may contribute to pathology.
Selective Enhancement of Systemic Th1 Immunity in Immunologically Immature Rats with an Orally Administered Bacterial Extract
Authors: Bowman L. M. , Holt P. G. 
Published: July 2002

ABSTRACTInfant rats primed during the first week of life with soluble antigen displayed adult-equivalent levels of T-helper 2 (Th2)-dependent immunological memory development as revealed by production of secondary immunoglobulin G1 (IgG1) antibody responses to subsequent challenge, but in contrast to adults failed to prime for Th1-dependent IgG2b responses. We demonstrate that this Th2 bias in immune function can be redressed by oral administration to neonates of a bacterial extract (Broncho-Vaxom OM-85) comprising lyophilized fractions of several common respiratory tract bacterial pathogens. Animals given OM-85 displayed a selective upregulation in primary and secondary IgG2b responses, accompanied by increased gamma interferon and decreased interleukin-4 production (both antigen specific and polyclonal), and increased capacity for development of Th1-dependent delayed hypersensitivity to the challenge antigen. We hypothesize that the bacterial extract functions via enhancement of the process of postnatal maturation of Th1 function, which is normally driven by stimuli from the gastrointestinal commensal microflora.
Gene Fragments Distinguishing an Epidemic-Associated Strain from a Virulent Prototype Strain of
Listeria monocytogenes
Belong to a Distinct Functional Subset of Genes and Partially Cross-Hybridize with Other
Listeria
Species
Authors: Herd Martin , Kocks Christine 
Published: July 2002

ABSTRACT

Most major food-borne outbreaks of listeriosis in Europe and in the United States have been caused by genetically closely related
Listeria monocytogenes
strains of serotype 4b. In order to assess whether genomic loci exist that could underlie this increased epidemic potential, we subtracted the genome of the virulent prototype
L. monocytogenes
strain EGD from a prototype epidemic strain. A total of 39 DNA fragments corresponding to 20% of an estimated total of 150 to 190 kb of differential genome material were isolated. For 21 of these fragments, no function on the basis of homology could be predicted. Of the remaining 18 fragments, 15 had homologies to bacterial surface proteins, some of which have been implicated in virulence mechanisms such as cell invasion, adhesion, or immune escape. Southern hybridization of arrays containing the epidemic-clone-specific DNA segments with genomic DNA of different
L. monocytogenes
strains was consistent with the current lineage division. Surprisingly, however, some of the fragments hybridized in a mosaic-like fashion to genomes of two other
Listeria
species, the animal pathogen
L. ivanovii
and the nonpathogen
L. innocua
. Taken together, our results provide a starting point for the identification of epidemic-trait-associated genes.
Motility and the Polar Flagellum Are Required for
Aeromonas caviae
Adherence to HEp-2 Cells
Authors: Rabaan Ali A. , Gryllos Ioannis , Tomás Juan M. , Shaw Jonathan G. 
Published: July 2002

ABSTRACT

Aeromonas caviae
is increasingly being recognized as a cause of gastroenteritis, especially among the young. The adherence of aeromonads to human epithelial cells in vitro has been correlated with enteropathogenicity, but the mechanism is far from well understood. Initial investigations demonstrated that adherence of
A. caviae
to HEp-2 cells was significantly reduced by either pretreating bacterial cells with an antipolar flagellin antibody or by pretreating HEp-2 cells with partially purified flagella. To precisely define the role of the polar flagellum in aeromonad adherence, we isolated the
A. caviae
polar flagellin locus and identified five polar flagellar genes, in the order
flaA, flaB, flaG, flaH
, and
flaJ
. Each gene was inactivated using a kanamycin resistance cartridge that ensures the transcription of downstream genes, and the resulting mutants were tested for motility, flagellin expression, and adherence to HEp-2 cells. N-terminal amino acid sequencing, mutant analysis, and Western blotting demonstrated that
A. caviae
has a complex flagellum filament composed of two flagellin subunits encoded by
flaA
and
flaB
. The predicted molecular mass of both flagellins was ∼31,700 Da; however, their molecular mass estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis was ∼35,500 Da. This aberrant migration was thought to be due to their glycosylation, since the proteins were reactive in glycosyl group detection assays. Single mutations in either
flaA
or
flaB
did not result in loss of flagella but did result in decreased motility and adherence by approximately 50%. Mutation of
flaH, flaJ
, or both flagellin genes resulted in the complete loss of motility, flagellin expression, and adherence. However, mutation of
flaG
did not affect motility but did significantly reduce the level of adherence. Centrifugation of the flagellate mutants (
flaA, flaB
, and
flaG
) onto the cell monolayers did not increase adherence, whereas centrifugation of the aflagellate mutants (
flaH, flaJ
, and
flaA flaB
) increased adherence slightly. We conclude that maximum adherence of
A. caviae
to human epithelial cells in vitro requires motility and optimal flagellar function.
Type IHelicobacter pyloriLipopolysaccharide Stimulates Toll-Like Receptor 4 and Activates Mitogen Oxidase 1 in Gastric Pit Cells
Authors: Kawahara Tsukasa , Teshima Shigetada , Oka Ayuko , Sugiyama Toshiro , Kishi Kyoichi , Rokutan Kazuhito 
Published: July 2002

ABSTRACTGuinea pig gastric pit cells express an isozyme of gp91-phox, mitogen oxidase 1 (Mox1), and essential components for the phagocyte NADPH oxidase (p67-, p47-, p40-, and p22-phox). Helicobacter pylorilipopolysaccharide (LPS) andEscherichia coliLPS have been shown to function as potent activators for the Mox1 oxidase. These cells spontaneously secreted about 10 nmol of superoxide anion (O2−)/mg of protein/h under LPS-free conditions. They expressed the mRNA and protein of Toll-like receptor 4 (TLR4) but not those of TLR2. LPS from type IH. pyloriat 2.1 endotoxin units/ml or higher stimulated TLR4-mediated phosphorylations of transforming growth factor β-activated kinase 1 and its binding protein 1 induced TLR4 and p67-phoxand up-regulated O2−production 10-fold. In contrast, none of these events occurred withH. pyloriLPS from complete or partial deletion mutants of thecagpathogenicity island. Lipid A was confirmed to be a bioactive component for the priming effects, while removal of bisphosphates from lipid A completely eliminated the effects, suggesting the importance of the phosphorylation pattern besides the acylation pattern for the bioactivity.H. pyloriLPS is generally accepted as having low toxicity; however, our results suggest that type IH. pylorilipid A may be a potent stimulator for innate immune responses of gastric mucosa by stimulating the TLR4 cascade and Mox1 oxidase in pit cells.
Safety and Immunogenicity of a Proteosome-
Shigella flexneri
2a Lipopolysaccharide Vaccine Administered Intranasally to Healthy Adults
Authors: Fries Louis F. , Montemarano Andrew D. , Mallett Corey P. , Taylor David N. , Hale Thomas L. , Lowell George H. 
Published: July 2002

ABSTRACT

We studied the safety and immunogenicity of a
Shigella flexneri
2a vaccine comprising native
S. flexneri
2a lipopolysaccharide (LPS) complexed to meningococcal outer membrane proteins—proteosomes—in normal, healthy adults. A two-dose series of immunizations was given by intranasal spray, and doses of 0.1, 0.4, 1.0, and 1.5 mg (based on protein) were studied in a dose-escalating design. The vaccine was generally well tolerated. The most common reactions included rhinorrhea and nasal stuffiness, which were clearly dose related (
P
≤ 0.05). These reactions were self-limited and generally mild. The vaccine elicited
S. flexneri
2a LPS-specific immunoglobulin A (IgA), IgG, and IgM antibody-secreting cells (ASCs) in a dose-responsive manner. At doses of 1.0 or 1.5 mg, highly significant (
P
< 0.001) increases in ASCs of all antibody isotypes occurred and 95% of subjects had an ASC response in at least one antibody isotype. Dose-related serum antibody responses were observed, with geometric mean two- to fivefold rises in specific serum IgA and IgG titers and two- to threefold rises in IgM in the 1.0- and 1.5-mg-dose groups (
P
< 0.0001 for each isotype). Elevated serum antibody levels persisted through day 70. Increases in fecal IgG and IgA and also in urinary IgA specific for
S. flexneri
2a LPS were demonstrated. These were most consistent and approached statistical significance (
P
= 0.02 to 0.12 for various measures) on day 70 after the first dose. The magnitude of immune responses to intranasally administered proteosome-
S. flexneri
2a LPS vaccine is similar to those reported for live vaccine candidates associated with protective efficacy in human challenge models, and further evaluation of this product is warranted.
Brain Granulomas in Neurocysticercosis Patients Are Associated with a Th1 and Th2 Profile
Authors: Restrepo Blanca I. , Alvarez Jorge I. , Castaño Jorge A. , Arias Luis F. , Restrepo Margarita , Trujillo Judith , Colegial Carlos H. , Teale Judy M. 
Published: July 2002

ABSTRACTNeurocysticercosis (NCC) is a common central nervous system (CNS) infection caused byTaenia soliummetacestodes. Despite the well-documented importance of the granulomatous response in the pathogenesis of this infection, there is limited information about the types of cells and cytokines involved. In fact, there has been limited characterization of human brain granulomas with any infectious agent. In the present study a detailed histological and immunohistochemical analysis of the immune response was performed on eight craniotomy specimens where a granuloma surrounded eachT. soliummetacestode. The results indicated that in all the specimens there was a dying parasite surrounded by a mature granuloma with associated fibrosis, angiogenesis, and an inflammatory infiltrate. The most abundant cell types were plasma cells, B and T lymphocytes, macrophages, and mast cells. Th1 cytokines were prevalent and included gamma interferon, interleukin-18 (IL-18), and the immunosuppressive, fibrosis-promoting cytokine transforming growth factor β. The Th2 cytokines IL-4, IL-13, and IL-10 were also present. These observations indicate that a chronic immune response is elicited in the CNS environment with multiple cell types that together secrete inflammatory and anti-inflammatory cytokines. In addition, both collagen type I and type III deposits were evident and could contribute to irreversible nervous tissue damage in NCC patients.
Porphyromonas gingivalisFimbriae Inhibit Caspase-3-Mediated Apoptosis of Monocytic THP-1 Cells under Growth Factor Deprivation via Extracellular Signal-Regulated Kinase-Dependent Expression of p21 Cip/WAF1
Authors: Ozaki Ken , Hanazawa Shigemasa 
Published: July 2002

ABSTRACTApoptotic regulation of monocytes/macrophages appears to be closely associated with chronic inflammatory reactions. Since it was demonstrated earlier that certain bacterial cell components are involved in apoptotic regulation of these cells, in the present study, we investigated whether the bacterial fimbria, an important cell structure involved in bacterial adherence to host cells, regulates apoptosis of human monocytic THP-1 cells induced under growth factor deprivation. To investigate this point, we used fimbriae ofPorphyromonas gingivalis,a pathogen causing periodontal disease, which is a chronic inflammatory disease. The fimbriae inhibited apoptosis of the cells under growth factor deprivation. This inhibitory action of the fimbriae was completely neutralized by anti-fimbrial antibody. The fimbriae stimulated activation of extracellular signal-regulated kinase (ERK) and expression of cyclin-dependent kinase inhibitor p21 Cip/WAF1 (p21) in the cells. The stimulatory effect of the fimbriae on the expression of the p21 protein was inhibited by treatment with PD98059, a specific inhibitor of ERK. The cell apoptosis was inhibited by treatment with Ac-DEVD-CHO, an inhibitor of caspase-3. The fimbriae inhibited the serum withdrawal-induced cleavage of the caspase-3 proform and poly(ADP-ribose) polymerase, one of the caspase-3 substrates. Furthermore, PD98059 and antisense p21 oligonucleotide blocked the fimbrial inhibition of apoptosis and caspase-3 activation of the cells induced by serum withdrawal. These results show that the bacterial fimbriae inhibited apoptosis of THP-1 cells induced under growth factor deprivation via ERK-dependent expression of p21. The present study suggests that bacterial fimbriae act as potent regulators of chronic inflammatory disease, e.g., periodontal disease, through blocking apoptosis of monocytes/macrophages.
Monocytic Cell Activation by Nonendotoxic Glycoprotein fromPrevotella intermediaATCC 25611 Is Mediated by Toll-Like Receptor 2
Authors: Sugawara Shunji , Yang Shuhua , Iki Koichi , Hatakeyama Junko , Tamai Riyoko , Takeuchi Osamu , Akashi Sachiko , Espevik Terje , Akira Shizuo , Takada Haruhiko 
Published: July 2002

ABSTRACTLipopolysaccharide (LPS) preparations from gram-negative black-pigmented bacteria such asPorphyromonas gingivalisandPrevotella intermediaactivate cells from non-LPS-responsive C3H/HeJ mice, but it is still unclear whether this activity is due to the unique structure of LPS or to a minor component(s) responsible for the activity in the preparation. A nonendotoxic glycoprotein with bioactivity against cells from C3H/HeJ mice was purified from a hot phenol-water extract ofP. intermediaATCC 25611 and designatedPrevotellaglycoprotein (PGP). Treatment of human monocytic THP-1 cells with 22-oxyacalcitriol (OCT) induced maturation and marked expression of CD14 on the cells, but the cells constitutively expressed Toll-like receptor 2 (TLR2) and TLR4 on the cells irrespective of the treatment. PGP induced a high level of interleukin-8 production at doses of 100 ng/ml and higher in OCT-treated THP-1 cells compared withSalmonellaLPS, and the production was significantly inhibited by anti-CD14 and anti-TLR2 but not anti-TLR4 antibodies. Consistent with this, TLR2-deficient murine macrophages did not respond to PGP. It was also shown that PGP activity on the THP-1 cells was LPS-binding protein dependent and was inhibited by a synthetic lipid A precursor IVA. These results indicate that PGP activates monocytic cells in a CD14- and TLR2-dependent manner.
Purification, Characterization, and Immunogenicity of a Disulfide Cross-Linked
Plasmodium vivax
Vaccine Candidate Antigen, Merozoite Surface Protein 1, Expressed in
Escherichia coli
Authors: Dutta Sheetij , Ware Lisa A. , Barbosa Arnoldo , Ockenhouse Christian F. , Lanar David E. 
Published: July 2002

ABSTRACT

The
Plasmodium vivax
merozoite surface protein 1 (MSP-1) 42-kDa fragment (PvMSP-1 p42) is a promising vaccine candidate antigen against the blood stage of the malarial parasite. We have developed a process for the production of this vaccine target, keeping in mind its use in human volunteers. A novel strain, Origami(DE3), of
Escherichia coli
with mutations in the glutathione and thioredoxin reductase genes yielded 60% more soluble PvMSP-1 p42 than the conventional
E. coli
BL21(DE3) strain. Recombinant PvMSP-1 p42 was purified to ≥99% purity with a rapid two-step protocol designed for easy scaling up. The final product had a low endotoxin content and was stable in its lyophilized form. PvMSP-1 p42 was found to have the predicted primary and tertiary structures and consisted of a single conformer containing one free cysteine, as predicted. The product was recognized by conformational monoclonal antibodies against
P. vivax
MSP-1. Immunogenicity studies of PvMSP-1 p42 were carried out with two strains of mice and the adjuvants Montanide ISA51 and Montanide ISA720. Both formulations were found to induce high levels of immunoglobulin G1 (IgG1), IgG2b, and IgG2a antibodies along with low levels of IgG3. Lymphocytes from animals in all the PvMSP-1 p42-immunized groups showed proliferative responses upon stimulation with PvMSP-1 p42; the cytokines interleukin 2 (IL-2), gamma interferon, IL-4, and IL-10 were detected in the culture supernatants. These results indicate that PvMSP-1 p42 in combination with both of the adjuvants elicited cellular and humoral responses in mice.
pH-Enhanced Cytopathic Effects of
Clostridium sordellii
Lethal Toxin
Authors: Qa'Dan Maen , Spyres Lea M. , Ballard Jimmy D. 
Published: July 2002

ABSTRACT

Clostridium sordellii
lethal toxin (TcsL) is a large clostridial toxin (LCT) that glucosylates Ras, Rac, and Ral. TcsL differs from other LCTs because it modifies Ras, which does not cycle from cytosol to membrane. By using a suite of inhibitors, steps in cell entry by TcsL were dissected, and entry appears to be dependent on endosomal acidification. However, in contrast to TcdB, TcsL was substantially slower in its time course of entry. TcsL cytopathic effects (CPE) were blocked by bafilomycin A1 and neutralized by antiserum up to 2 h following treatment of cells with the toxin. The slow time course of intoxication and relatively high cytopathic dose were alleviated by exposing TcsL to acid pH, resulting in a time course similar to that of TcdB. The optimal pH range for activation was 4.0 to 5.0, which increased the rate of intoxication over 5-fold, lowered the minimal intoxicating dose by over 100-fold, and allowed complete substrate modification within 2 h, as shown by differential glucosylation. Fluorescence analysis of TcsL with 2-(
p
-toluidinyl) naphthalene-6-sulfonic acid as a probe suggested the acid pH stimulated a hydrophobic transition in the protein, a likely prelude to membrane insertion. Finally, acid entry by TcsL caused TcdB-like morphological changes in CHO cells, which suggestings that acid activation may impact substrate recognition profiles for TcsL.
Mutualism versus Independence: Strategies of Mixed-Species Oral Biofilms In Vitro Using Saliva as the Sole Nutrient Source
Authors: Palmer Robert J. , Kazmerzak Karen , Hansen Martin C. , Kolenbrander Paul E. 
Published: July 2002

ABSTRACT

During initial dental plaque formation, the ability of a species to grow when others cannot would be advantageous, and enhanced growth through interspecies and intergeneric cooperation could be critical. These characteristics were investigated in three coaggregating early colonizers of the tooth surface (
Streptococcus gordonii
DL1,
Streptococcus oralis
34, and
Actinomyces naeslundii
T14V). Area coverage and cell cluster size measurements showed that attachment of
A. naeslundii
and of
S. gordonii
to glass flowcells was enhanced by a salivary conditioning film, whereas attachment of
S. oralis
was hindered. Growth experiments using saliva as the sole carbon and nitrogen source showed that
A. naeslundii
was unable to grow either in planktonic culture or as a biofilm, whereas
S. gordonii
grew under both conditions.
S. oralis
grew planktonically, but to a much lower maximum cell density than did
S. gordonii
;
S. oralis
did not grow reproducibly as a biofilm. Thus, only
S. gordonii
possessed all traits advantageous for growth as a solitary and independent resident of the tooth. Two-species biofilm experiments analyzed by laser confocal microscopy showed that neither
S. oralis
nor
A. naeslundii
grew when coaggregated pairwise with
S. gordonii
. However, both
S. oralis
and
A. naeslundii
showed luxuriant, interdigitated growth when paired together in coaggregated microcolonies. Thus, the
S. oralis-A. naeslundii
pair formed a mutualistic relationship, potentially contact dependent, that allows each to grow where neither could survive alone.
S. gordonii
, in contrast, neither was hindered by nor benefited from the presence of either of the other strains. The formation of mutually beneficial interactions within the developing biofilm may be essential for certain initial colonizers to be retained during early plaque development, whereas other initial colonizers may be unaffected by neighboring cells on the substratum.
PcrV Immunization Enhances Survival of Burned
Pseudomonas aeruginosa
-Infected Mice
Authors: Holder Ian Alan , Neely Alice N. , Frank Dara W. 
Published: July 2002

ABSTRACT

Burned
Pseudomonas aeruginosa
-infected mice immunized against PcrV, a type III virulence system translocating protein, showed significantly enhanced survival compared to controls. Survival was non-O serotype specific and correlated with a reduced systemic microbial load. Infection with a high-level toxin A-producing strain required supplemental antitoxin treatment to enhance survival.