bluuebunny/crossref_metadata_2025_split huggingface dataset:
Altered Protein Expression of
Streptococcus oralis
Cultured at Low pH Revealed by Two-Dimensional Gel Electrophoresis
Authors: Wilkins Joanna C. , Homer Karen A. , Beighton David 
Published: July 2002

ABSTRACT

Streptococcus oralis
is the predominant aciduric nonmutans streptococcus isolated from the human dentition, but the role of this organism in the initiation and progression of dental caries has yet to be established. To identify proteins that are differentially expressed by
S. oralis
growing under conditions of low pH, soluble cellular proteins extracted from bacteria grown in batch culture at pH 5.2 or 7.0 were analyzed by two-dimensional (2-D) gel electrophoresis. Thirty-nine proteins had altered expression at low pH; these were excised, digested with trypsin using an in-gel protocol, and further analyzed by peptide mass fingerprinting using matrix-assisted laser desorption ionization mass spectrometry. The resulting fingerprints were compared with the genomic database for
Streptococcus pneumoniae
, an organism that is phylogenetically closely related to
S. oralis
, and putative functions for the majority of these proteins were determined on the basis of functional homology. Twenty-eight proteins were up-regulated following growth at pH 5.2; these included enzymes of the glycolytic pathway (glyceraldehyde-3-phosphate dehydrogenase and lactate dehydrogenase), the polypeptide chains comprising ATP synthase, and proteins that are considered to play a role in the general stress response of bacteria, including the 60-kDa chaperone, Hsp33, and superoxide dismutase, and three distinct ABC transporters. These data identify, for the first time, gene products that may be important in the survival and proliferation of nonmutans aciduric
S. oralis
under conditions of low pH that are likely to be encountered by this organism in vivo.
Seasonal and Spatial Variability in Lake Michigan Sediment Small-Subunit rRNA Concentrations
Authors: MacGregor Barbara J. , Moser Duane P. , Baker Brett J. , Alm Elizabeth W. , Maurer Max , Nealson Kenneth H. , Stahl David A. 
Published: July 2002

ABSTRACT
We have used molecular biological methods to study the distribution of microbial small-subunit rRNAs (SSU rRNAs), in relation to chemical profiles, in offshore Lake Michigan sediments. The sampling site is at a depth of 100 m, with temperatures of 2 to 4°C year-round. RNA extracted from sediment was probed with radiolabeled oligonucleotides targeting bacterial, archaeal, and eukaryotic SSU rRNAs, as well as with a universal probe. The coverage of these probes in relation to the present sequence database is discussed. Because ribosome production is growth rate regulated, rRNA concentrations are an indicator of the microbial populations active in situ. Over a 1-year period, changes in sedimentary SSU rRNA concentrations followed seasonal changes in surface water temperature and SSU rRNA concentration. Sedimentary depth profiles of oxygen, reduced manganese and iron, and sulfate changed relatively little from season to season, but the nitrate concentration was approximately fivefold higher in April and June 1997 than at the other times sampling was done. We propose that sediment microbial SSU rRNA concentrations at our sampling site are influenced by seasonal inputs from the water column, particularly the settling of the spring diatom bloom, and that the timing of this input may be modulated by grazers, such that ammonia becomes available to sediment microbes sooner than fresh organic carbon. Nitrate production from ammonia by autotrophic nitrifying bacteria, combined with low activity of heterotrophic denitrifying bacteria in the absence of readily degradable organic carbon, could account for the cooccurrence of high nitrate and low SSU rRNA concentrations.
Cloning and Expression of an Oligopeptidase, PepO, with Novel Specificity from
Lactobacillus rhamnosus
HN001 (DR20)
Authors: Christensson Camilla , Bratt Henrik , Collins Lesley J. , Coolbear Tim , Holland Ross , Lubbers Mark W. , O’Toole Paul W. , Reid Julian R. 
Published: July 2002

ABSTRACT

Oligopeptidases of starter and nonstarter lactic acid bacteria contribute to the proteolytic events important in maturation and flavor development processes in cheese. This paper describes the molecular cloning, expression, and specificity of the oligopeptidase PepO from the probiotic nonstarter strain
Lactobacillus rhamnosus
HN001 (DR20). The
pepO
gene encodes a protein of 70.9 kDa, whose primary sequence includes the HEXXH motif present in certain classes of metallo-oligopeptidases. The
pepO
gene was cloned in
L. rhamnosus
HN001 and overexpressed in pTRKH2 from its own promoter, which was mapped by primer extension. It was further cloned in both pNZ8020 and pNZ8037 and overexpressed in
Lactococcus lactis
subsp.
cremoris
NZ9000 from the
nisA
promoter. The purified PepO enzyme demonstrated unique cleavage specificity for α
s1
-casein fragment 1–23, hydrolyzing the bonds Pro-5-Ile-6, Lys-7-His-8, His-8-Gln-9, and Gln-9-Gly-10. The impact of this enzyme in cheese can now be assessed.
Semiautomated Quantification of Hepatitis B Virus DNA in a Routine Diagnostic Laboratory
Authors: Kessler Harald H. , Stelzl Evelyn , Daghofer Elisabeth , Santner Brigitte I. , Marth Egon , Lackner Herwig , Stauber Rudolf E. 
Published: July 2002

ABSTRACT

The Cobas Amplicor HBV Monitor test for quantitative determination of hepatitis B virus (HBV) DNA in serum has recently been introduced. To evaluate the performance of this assay in a routine diagnostic laboratory, reproducibility of results was determined with the First European Union Concerted Action HBV Proficiency Panel and the Accurun 325 HBV DNA Positive Control, Series 300. Results for 270 routine serum samples were additionally evaluated. To avoid the retesting of a large number of samples due to titers exceeding the upper limit for the linear range of the assay, sera of patients with chronic hepatitis B (CHB) were diluted prior to the assay to 10
−4
in normal human plasma, which is included in the assay. The mean coefficient of variation was 22.9% for all input HBV DNAs. Of 270 routine serum samples, 182 (150 sera from transplant donors and 32 sera from patients who had recovered from CHB) tested negative. Eighty-six sera were found to be HBV DNA positive; in six sera, HBV DNA levels were found to exceed the upper limit for the linear range of the assay and had to be retested. In the remaining two sera, inhibition occurred. The semiautomated Cobas Amplicor HBV Monitor test showed sufficient reproducibility and helped in avoiding human error. The relatively narrow linear range of detection is a limitation of the new assay.
Dose-Dependent Circulating Immunoglobulin A Antibody-Secreting Cell and Serum Antibody Responses in Swedish Volunteers to an Oral Inactivated Enterotoxigenic
Escherichia coli
Vaccine
Authors: Jertborn Marianne , Åhrén Christina , Svennerholm Ann-Mari 
Published: July 2002

ABSTRACT

The immunogenicity of different preparations of an oral inactivated enterotoxigenic
Escherichia coli
(ETEC) vaccine was evaluated in Swedish volunteers previously unexposed to ETEC infection. The vaccine preparations consisted of recombinant cholera toxin B subunit (CTB) and various amounts of formalin-killed whole bacteria expressing the most prevalent colonization factor antigens (CFAs). Significant immunoglobulin A (IgA) antibody-secreting cell (ASC) responses against CTB and the various CFA components were seen in a majority of volunteers after two doses of ETEC vaccine independent of the vaccine lot given. The IgA ASC responses against CTB were significantly higher after the second than after the first immunization, whereas the CFA-specific IgA ASC responses were almost comparable after the first and second doses of ETEC vaccine. Two immunizations with one-third of a full dose of CFA-ETEC bacteria induced lower frequencies of IgA ASC responses against all the different CFAs than two full vaccine doses, i.e., 63 versus 80% for CFA/I, 56 versus 70% for CS1, 31 versus 65% for CS2, and 56 versus 75% for CS4. The proportion of vaccinees responding with rises in the titer of serum IgA antibody against the various CFA antigens was also lower after immunization with the reduced dose of CFA-ETEC bacteria. These findings suggest that measurements of circulating IgA ASCs can be used not only for qualitative but also for quantitative assessments of the immunogenicity of individual fimbrial antigens in various preparations of ETEC vaccine.
Detection of Serum Thermolabile β-2 Macroglycoprotein (Hakata Antigen) by Enzyme-Linked Immunosorbent Assay Using Polysaccharide Produced by
Aerococcus viridans
Authors: Tsujimura Mitsushi , Ishida Chuzo , Sagara Yasuko , Miyazaki Takashi , Murakami Koichi , Shiraki Hiroshi , Okochi Kazuo , Maeda Yoshiaki 
Published: July 2002

ABSTRACT

Although a serum thermolabile β-2 macroglycoprotein (TMG) may play a role in host defense as a lectin, little is known of its related physiological functions, mainly due to a lack of appropriate methods for tracing the functions of TMG. We identified a polysaccharide from
Aerococcus viridans
, PSA, which reacts with TMG, and based on this finding, we developed an enzyme-linked immunosorbent assay to trace the functions of TMG. Using ethanol precipitation and DEAE-Sepharose and Sephacryl S-400 column chromatographies, we isolated PSA from cultured medium of
A. viridans
, and it exhibited specific binding against TMG in blood samples. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), the isolated PSA showed ladder bands that implied the existence of repeating units composed of
d
-glucose,
N
-acetyl-
d
-glucosamine,
d
-mannose, and
d
-xylose, as confirmed by gas chromatography-mass spectrometry. SDS-PAGE and immunochemical analysis, using rabbit anti-TMG antibody, showed that PSA specifically binds solely to intact serum TMG but not to TMG heated at 56°C for 30 min, a condition under which antigenicity is lost. TMG in serum samples bound to PSA in a dose-dependent manner, and this binding was clearly suppressed by addition of PSA. These observations indicate that PSA is a useful adsorbent to TMG and can be used to develop appropriate methods for tracing the functions of TMG.
Roles of Interleukin-12 and Gamma Interferon in MurineChlamydia pneumoniaeInfection
Authors: Geng Yuemei , Berencsi Klara , Gyulai Zsofia , Valyi-Nagy Tibor , Gonczol Eva , Trinchieri Giorgio 
Published: July 2002

ABSTRACTBALB/c and strain 129 mice infected intranasally withChlamydia pneumoniaedisplayed a moderate-to-severe inflammation in the lungs and produced interleukin-12 (IL-12), gamma interferon (IFN-γ), tumor necrosis factor alpha (TNF-α), and IL-10, with peak levels on days 1 to 3 postinfection (p.i.), returning to basal levels by day 16 p.i. Anti-IL-12 treatment resulted in less-severe pathological changes but higher bacterial titers on days 3 and 7 p.i. By day 16 p.i., the inflammatory responses of control antibody-treated mice subsided. The bacterial titers of both anti-IL-12- and control antibody-treated mice decreased within 3 weeks to marginally detectable levels. Anti-IL-12 treatment significantly reduced lung IFN-γ production and in vitro spleen cell IFN-γ production in response to eitherC. pneumoniaeor concanavalin A. In γ-irradiated infected mice, cytokine production was delayed, and this delay correlated with high bacterial titers in the lungs. FollowingC. pneumoniaeinfection, 129 mice lacking the IFN-γ receptor α chain gene (G129 mice) produced similar IL-12 levels and exhibited similarly severe pathological changes but had higher bacterial titers than 129 mice. However, by day 45 p.i., bacterial titers became undetectable in both wild-type 129 and G129 mice. Thus, duringC. pneumoniaelung infection, IL-12, more than IFN-γ, plays a role in pulmonary-cell infiltration. IFN-γ and IL-12, acting mostly through its induction of IFN-γ and Th1 responses, play an important role in controlling acuteC. pneumoniaeinfection in the lungs, but eventually all mice control the infection to undetectable levels by IL-12- and IFN-γ-independent mechanisms.
Disparate Requirement for T Cells in Resistance to Mucosal and Acute Systemic Candidiasis
Authors: Jones-Carson Jessica , Vazquez-Torres Andres , Warner Thomas , Balish Edward 
Published: July 2002

ABSTRACTAlthough highly susceptible to orogastric candidiasis, T-cell receptor δ- and α-chain knockout mice, deficient in γδ and αβ T cells, respectively, were found to be resistant to disseminated candidiasis of endogenous origin and to acute systemic candidiasis (resulting from intravenous injection).
A Subdominant CD8+Cytotoxic T Lymphocyte (CTL) Epitope from thePlasmodium yoeliiCircumsporozoite Protein Induces CTLs That Eliminate Infected Hepatocytes from Culture
Authors: Franke Eileen D. , Sette Alessandro , Sacci John , Southwood Scott , Corradin Giampietro , Hoffman Stephen L. 
Published: July 2002

ABSTRACTPrevious studies indicated that thePlasmodium yoeliicircumsporozoite protein (PyCSP) 57–70 region elicits T cells capable of eliminating infected hepatocytes in vitro. Herein, we report that the PyCSP58–67 sequence contains an H-2dbinding motif, which binds purified Kdmolecules in vitro with low affinity (3,267 nM) and encodes an H-2d-restricted cytotoxic T lymphocyte (CTL) epitope. Immunization of BALB/c mice with three doses of a multiple antigen peptide (MAP) construct containing four branches of amino acids 57 to 70 linked to a lysine-glycine core [MAP4(PyCSP57–70)] and Lipofectin as the adjuvant induced both T-cell proliferation and a peptide-specific CTL response that was PyCSP59–67 specific, H-2drestricted, and CD8+T cell dependent. Immunization with either DNA encoding the PyCSP or irradiated sporozoites demonstrated that this CTL epitope is subdominant since it is not recognized in the context of whole CSP immunization. The biological relevance of this CTL response was underlined by the demonstration that it could mediate genetically restricted, CD8+- and nitric-oxide-dependent elimination of infected hepatocytes in vitro, as well as partial protection of BALB/c mice against sporozoite challenge. These findings indicate that subdominant epitopes with low major histocompatibility complex affinity can be used to engineer epitope-based vaccines and have implications for the selection of epitopes for subunit-based vaccines.
Do Kinetics of the Humoral Response toCryptococcus neoformansProteins during Murine Cryptococcosis Reflect Outcome?
Authors: Neuville Segolene , Lortholary Olivier , Dromer Francoise 
Published: July 2002

ABSTRACTThe kinetics of the humoral response toCryptococcus neoformansproteins were studied in outbred mice infected with isolate NIH52D. Future nonsurvivors had earlier and stronger (i.e., more bands recognized) humoral responses than survivors. In addition, antibodies to a 56- to 60-kDa membrane antigen and to a 39- to 40-kDa cytosolic antigen were detected more frequently in samples from future nonsurvivors and from survivors, respectively (P< 0.05).
Safety and Immunogenicity of Two Different Lots of the Oral, Killed Enterotoxigenic
Escherichia coli
-Cholera Toxin B Subunit Vaccine in Israeli Young Adults
Authors: Cohen Dani , Orr Nadav , Haim Moti , Ashkenazi Shai , Robin Guy , Green Manfred S. , Ephros Moshe , Sela Tamar , Slepon Raphael , Ashkenazi Isaac , Taylor David N. , Svennerholm Ann-Mari , Eldad Arieh , Shemer Joshua 
Published: July 2002

ABSTRACT

Enterotoxigenic
Escherichia coli
(ETEC) is one of the leading causes of diarrhea among Israeli soldiers serving in field units. Two double-blind placebo-controlled, randomized trials were performed among 155 healthy volunteers to evaluate the safety and immunogenicity of different lots of the oral, killed ETEC vaccine consisting of two doses of whole cells plus recombinantly produced cholera toxin B subunit (rCTB). The two doses of vaccine lot E005 and the first dose of vaccine lot E003 were well tolerated by the volunteers. However, 5 (17%) vaccinees reported an episode of vomiting a few hours after the second dose of lot E003; none of the placebo recipients reported similar symptoms. Both lots of vaccine stimulated a rate of significant antibody-secreting cell (ASC) response to CTB and to colonization factor antigen I (CFA/I) after one or two doses, ranging from 85 to 100% and from 81 to 100%, respectively. The rate of ASC response to CS2, CS4, and CS5 was slightly lower than the rate of ASC response induced to CTB, CFA/I, and CS1. The second vaccine dose enhanced the response to CTB but did not increase the frequencies or magnitude of ASC responses to the other antigens. The two lots of the ETEC vaccine induced similar rates of serum antibody responses to CTB and CFA/I which were less frequent than the ASC responses to the same antigens. Based on these safety and immunogenicity data, an efficacy study of the ETEC vaccine is under way in the Israel Defense Force.
Antipeptide Antibody Responses following Intranasal Immunization: Effectiveness of Mucosal Adjuvants
Authors: Olszewska Wieslawa , Partidos Charalambos D. , Steward Michael W. 
Published: July 2002

ABSTRACTToxicity is a major factor limiting the development and use of potent adjuvants for human mucosally delivered vaccines. Novel adjuvant formulations have recently become available, and in the present study two have been used for intranasal immunization with a synthetic peptide immunogen (MAP-M2). This peptide represents a multiple antigenic peptide containing multiple copies of a mimotope M2, a peptide mimic of a conformational epitope of the fusion protein of measles virus. MAP-M2 was administered intranasally to experimental animals together with synthetic oligodeoxynucleotides containing unmethylated CpG motifs with or without a mutant of wild-type enterotoxin ofEscherichia coli(LTR72). The combination of the mutant toxin LTR72 and the CpG repeats, codelivered with a peptide immunogen, induced both local and systemic peptide- and pathogen-specific humoral and cellular immune responses comparable to those obtained after intranasal immunization with the wild-type toxin LT. In addition, this combination of adjuvants induced a predominantly immunoglobulin G2a antibody response. If both the LTR72 and CpG adjuvants are shown to be safe for use in humans, this particular combination would appear to have potential as an adjuvant for mucosally delivered vaccines in humans.
Role of
flm
Locus in Mesophilic
Aeromonas
Species Adherence
Authors: Gryllos Ioannis , Shaw Jonathan G. , Gavı́n Rosalina , Merino Susana , Tomás Juan M. 
Published: July 2002

ABSTRACT

The adherence mechanism of
Aeromonas caviae
Sch3N to HEp-2 cells was initially investigated through four mini-Tn
5
mutants that showed a 10-fold decrease in adherence. These mutants lost motility, flagella, and their lipopolysaccharide (LPS) O antigen (O-Ag). Three genes,
flmB-neuA-flmD
, were found to be interrupted by the transposon insertions; additionally, two other genes, one lying upstream (
flmA
) and one downstream (
neuB
), were found to be clustered in the same operon. While the
flmA
and
flmB
genes were present in all mesophilic
Aeromonas
spp. (
A. hydrophila
,
A. caviae
,
A. veronii
bv.
veronii
, and
A. veronii
bv.
sobria
) tested, this was not the case for the
neuA-flmD-neuB
genes. Construction and characterization of
flmB
insertion mutants in five other mesophilic
Aeromonas
strains revealed the loss of motility, flagella, and adherence but did not alter the LPS composition of these strains. Taking the above findings into consideration, we conclude (i) that flagella and possibly the LPS O-Ag are involved in the adherence of the mesophilic
Aeromonas
to human epithelial cells; (ii)
flmA
and
flmB
are genes widely distributed in the mesophilic
Aeromonas
and are involved in flagella assembly, and thus adherence; and (iii) in
A. caviae
Sch3N the
flmA
and
flmB
genes are found in a putative operon together with
neuA
,
flmD
, and
neuB
and are involved in LPS O-Ag biosynthesis and probably have a role in flagellum assembly.
B-Cell Deficiency Suppresses Vaccine-Induced Protection against Murine Filariasis but Does Not Increase the Recovery Rate for Primary Infection
Authors: Martin Coralie , Saeftel Michael , Vuong Phat N. , Babayan Simon , Fischer Kerstin , Bain Odile , Hoerauf Achim 
Published: July 2002

ABSTRACTTo establish the role of B cells and antibodies in destroying filariae, mice lacking mature B cells and therefore unable to produce antibodies were used.Litomosoides sigmodontisoffers a good opportunity for this study because it is the only filarial species that completes its life cycle in mice. Its development was compared in B-cell-deficient mice (BALB/c μMT mice) and wild-type BALB/c mice in two different in vivo situations, vaccination with irradiated larvae and primary infection. In all cases, mice were challenged with subcutaneous inoculation of 40 infective larvae. Vaccine-induced protection was suppressed in B-cell-deficient mice. In these mice, eosinophils infiltrated the subcutaneous tissue normally during immunization; however, their morphological state did not change following challenge inoculation, whereas in wild-type mice the percentage of degranulated eosinophils was markedly increased. From this, it may be deduced that the eosinophil–antibody–B-cell complex is the effector mechanism of protection in vaccinated mice and that its action is fast and takes place in the subcutaneous tissue. In primary infection, the filarial survival and growth was not modified by the absence of B cells. However, no female worm had uterine microfilariae, nor did any mice develop a patent infection. In these mice, concentrations of type 1 (gamma interferon) and type 2 (interleukin-4 [IL-4], IL-5 and IL-10) cytokines in serum were lower and pleural neutrophils were more numerous. The effects of the μMT mutation therefore differ from those in B1-cell-deficient mice described on the same BALB/c background, which reveal a higher filarial recovery rate and microfilaremia. This outlines B2-cell-dependent mechanisms as favorable to the late maturation ofL. sigmodontis.
Reciprocal Immunomodulatory Effects of Gamma Interferon and Interleukin-4 on Filaria-Induced Airway Hyperresponsiveness
Authors: Mehlotra Rajeev K. , Hall Laurie R. , Haxhiu Musa A. , Pearlman Eric 
Published: July 2002

ABSTRACTTropical pulmonary eosinophilia (TPE) is a severe asthmatic syndrome of lymphatic filariasis, in which an allergic response is induced to microfilariae (Mf) in the lungs. Previously, in a murine model for TPE, we have demonstrated that recombinant interleukin-12 (IL-12) suppresses pulmonary eosinophilia and airway hyperresponsiveness (AHR) by modulating the T helper (Th) response in the lungs from Th2- to Th1-like, with elevated gamma-interferon (IFN-γ) production and decreased IL-4 and IL-5 production. The present study examined the immunomodulatory roles of IL-4 and IFN-γ in filaria-induced AHR and pulmonary inflammation using mice genetically deficient in these cytokines. C57BL/6, IL-4 gene knockout (IL-4−/−), and IFN-γ−/−mice were first immunized with solubleBrugia malayiantigens and then inoculated intravenously with 200,000 live Mf. Compared with C57BL/6 mice, IL-4−/−mice exhibited significantly reduced AHR, whereas IFN-γ−/−mice had increased AHR. Histopathologically, each mouse strain showed increased cellular infiltration into the lung parenchyma and bronchoalveolar space compared with naı̈ve animals. However, consistent with changes in AHR, IL-4−/−mice had less inflammation than C57BL/6 mice, whereas IFN-γ−/−mice had exacerbated pulmonary inflammation with the loss of pulmonary architecture. Systemically, IL-4−/−mice produced significantly higher IFN-γ levels compared with C57BL/6 mice, whereas IFN-γ−/−mice produced significantly higher IL-4 levels. These data indicate that IL-4 is required for the induction of filaria-induced AHR, whereas IFN-γ suppresses AHR.