bluuebunny/crossref_metadata_2025_split huggingface dataset:
Construction and Immunological Characterization of a Novel Nontoxic Protective Pneumolysin Mutant for Use in Future Pneumococcal Vaccines
Authors: Kirkham Lea-Ann S. , Kerr Alison R. , Douce Gill R. , Paterson Gavin K. , Dilts Deborah A. , Liu Dai-Fang , Mitchell Tim J. 
Published: December 2005

ABSTRACT

Pneumolysin, the pore-forming toxin produced by
Streptococcus pneumoniae
, may have an application as an immunogenic carrier protein in future pneumococcal conjugate vaccines. Most of the 90
S. pneumoniae
serotypes identified produce pneumolysin; therefore, this protein may confer non-serotype-specific protection against pneumococcal infections such as pneumonia, meningitis, and otitis media. However, as pneumolysin is highly toxic, a nontoxic form of pneumolysin would be a more desirable starting point in terms of vaccine production. Previous pneumolysin mutants have reduced activity but retain residual toxicity. We have found a single amino acid deletion that blocks pore formation, resulting in a form of pneumolysin that is unable to form large oligomeric ring structures. This mutant is nontoxic at concentrations greater than 1,000 times that of the native toxin. We have demonstrated that this mutant is as immunogenic as native pneumolysin without the associated effects such as production of the inflammatory mediators interleukin-6 and cytokine-induced neutrophil chemoattractant KC, damage to lung integrity, and hypothermia in mice. Vaccination with this mutant protects mice from challenge with
S. pneumoniae
. Incorporation of this mutant pneumolysin into current pneumococcal vaccines may increase their efficacy.
Identification and Characterization of a Novel Bacterial Virulence Factor That Shares Homology with Mammalian Toll/Interleukin-1 Receptor Family Proteins
Authors: Newman Ruchi M. , Salunkhe Prabhakar , Godzik Adam , Reed John C. 
Published: December 2005

ABSTRACTMany important bacterial virulence factors act as mimics of mammalian proteins to subvert normal host cell processes. To identify bacterial protein mimics of components of the innate immune signaling pathway, we searched the bacterial genome database for proteins with homology to the Toll/interleukin-1 receptor (TIR) domain of the mammalian Toll-like receptors (TLRs) and their adaptor proteins. A previously uncharacterized gene, which we have namedtlpA(for TIR-like protein A), was identified in theSalmonella entericaserovar Enteritidis genome that is predicted to encode a protein resembling mammalian TIR domains, We show that overexpression of TlpA in mammalian cells suppresses the ability of mammalian TIR-containing proteins TLR4, IL-1 receptor, and MyD88 to induce the transactivation and DNA-binding activities of NF-κB, a downstream target of the TIR signaling pathway. In addition, TlpA mimics the previously characterizedSalmonellavirulence factor SipB in its ability to induce activation of caspase-1 in a mammalian cell transfection model. Disruption of the chromosomaltlpAgene rendered a virulent serovar Enteritidis strain defective in intracellular survival and IL-1β secretion in a cell culture infection model using human THP1 macrophages. Bacteria with disruptedtlpAalso displayed reduced lethality in mice, further confirming an important role for this factor in pathogenesis. Taken together, our findings demonstrate that the bacterial TIR-like protein TlpA is a novel prokaryotic modulator of NF-κB activity and IL-1β secretion that contributes to serovar Enteritidis virulence.
The Asymptomatic BacteriuriaEscherichia coliStrain 83972 Outcompetes UropathogenicE. coliStrains in Human Urine
Authors: Roos Viktoria , Ulett Glen C. , Schembri Mark A. , Klemm Per 
Published: December 2005

ABSTRACTEscherichia coliis the most common organism associated with asymptomatic bacteriuria (ABU). In contrast to uropathogenicE. coli(UPEC), which causes symptomatic urinary tract infections (UTI), very little is known about the mechanisms by which these strains colonize the human urinary tract. The prototype ABUE. colistrain 83972 was originally isolated from a girl who had carried it asymptomatically for 3 years. Deliberate colonization of UTI-susceptible individuals withE. coli83972 has been used successfully as an alternative approach for the treatment of patients who are refractory to conventional therapy. Colonization with strain 83972 appears to prevent infection with UPEC strains in such patients despite the fact that this strain is unable to express the primary adhesins involved in UTI, viz. P and type 1 fimbriae. Here we investigated the growth characteristics ofE. coli83972 in human urine and show that it can outcompete a representative spectrum of UPEC strains for growth in urine. The unique ability of ABUE. coli83972 to outcompete UPEC in urine was also demonstrated in a murine model of human UTI, confirming the selective advantage over UPEC in vivo. Comparison of global gene expression profiles ofE. coli83972 grown in lab medium and human urine revealed significant differences in expression levels in the two media; significant down-regulation of genes encoding virulence factors such as hemolysin, lipid A, and capsular polysaccharides was observed in cells grown in urine. Clearly, divergent abilities of ABUE. coliand UPEC to exploit human urine as a niche for persistence and survival suggest that these key differences may be exploited for preventative and/or therapeutic approaches.
Microbial Pattern Recognition Receptors Mediate M-Cell Uptake of a Gram-Negative Bacterium
Authors: Tyrer Peter , Foxwell A. Ruth , Cripps Allan W. , Apicella Michael A. , Kyd Jennelle M. 
Published: December 2005

ABSTRACT
The receptors involved in the sampling of particulate microbial antigens by the gut are largely unknown. Here we demonstrate for the first time in an in vitro M-cell model and in situ in isolated murine intestinal segments that the receptors TLR-4, PAF-R, and α5β1 integrin are all involved in mediating bacterial uptake associated with transcytosis. The pattern of expression of TLR-4 and α5β1 integrin differed between M cells and enterocytes. There was increased apical expression of TLR-4 in M-cell cultures, and it was present on the apical surface of murine M cells but not enterocytes in situ. In contrast, PAF-R was expressed equally by both cell types in vitro and was abundantly expressed throughout the intestinal epithelium. Inhibition of TLR-4 and PAF-R, but not TLR-2, reduced gram-negative bacterial uptake by both cell types, whereas inhibition of the apically expressed α5β1 integrin significantly reduced the ability of M cells to translocate bacteria. Hence, the involvement of each receptor was dependent not only on differences in the level of receptor expression but the cellular localization. Using bacteria that had mutations that affected the bacterial lipooligosaccharide structure indicated that the oligosaccharide moiety was important in bacterial uptake. Taken together, the data suggest that pathogen-associated molecular pattern interactions with pattern recognition receptors are key factors in M-cell recognition of intestinal antigens for mucosal immune priming.
Fusobacterium nucleatum
Transports Noninvasive
Streptococcus cristatus
into Human Epithelial Cells
Authors: Edwards Andrew M. , Grossman Tracy J. , Rudney Joel D. 
Published: December 2005

ABSTRACT

Analysis of human buccal epithelial cells frequently reveals an intracellular polymicrobial consortium of bacteria. Although several oral bacteria have been demonstrated to invade cultured epithelial cells, several others appear unable to internalize. We hypothesized that normally noninvasive bacteria may gain entry into epithelial cells via adhesion to invasive bacteria.
Fusobacterium nucleatum
is capable of binding to and invading oral epithelial cells. By contrast,
Streptococcus cristatus
binds weakly to host cells and is not internalized.
F. nucleatum
and
S. cristatus
coaggregate strongly via an arginine-sensitive interaction. Coincubation of KB or TERT-2 epithelial cells with equal numbers of
F. nucleatum
and
S. cristatus
bacteria led to significantly increased numbers of adherent and internalized streptococci.
F. nucleatum
also promoted invasion of KB cells by other oral streptococci and
Actinomyces naeslundii
. Dissection of fusobacterial or streptococcal adhesive interactions by using sugars, amino acids, or antibodies demonstrated that this phenomenon is due to direct attachment of
S. cristatus
to adherent and invading
F. nucleatum
. Inhibition of
F. nucleatum
host cell attachment and invasion with galactose, or fusobacterial-streptococcal coaggregation by the arginine homologue
l
-canavanine, abrogated the increased
S. cristatus
adhesion to, and invasion of, host cells. In addition, polyclonal antibodies to
F. nucleatum
, which inhibited fusobacterial attachment to both KB cells and
S. cristatus
, significantly decreased invasion by both species. Similar decreases were obtained when epithelial cells were pretreated with cytochalasin D, staurosporine, or cycloheximide. These studies indicate that
F. nucleatum
may facilitate the colonization of epithelial cells by bacteria unable to adhere or invade directly.
CD4+-T-Cell Effector Functions and Costimulatory Requirements Essential for Surviving Mucosal Infection withCitrobacter rodentium
Authors: Bry Lynn , Brigl Manfred , Brenner Michael B. 
Published: December 2005

ABSTRACTCitrobacter rodentiumcauses an attaching and effacing infection of the mouse colon. Surprisingly, protective adaptive immunity against this mucosal pathogen requires a systemic T-cell-dependent antibody response. To define CD4+T-cell effector functions promoting this systemic defense of infected epithelial surfaces, studies were undertaken in weaning-age mice lacking costimulatory molecules CD28 or CD40L or cytokines gamma interferon (IFN-γ) or interleukin-4 (IL-4). Adoptive transfer of CD4+T cells from wild-type, CD28−/−, CD40L−/−, or IFN-γ−/−donors to CD4−/−recipients delineated functions of these CD4+T-cell-expressed molecules on the outcome of infection. Wild-type and IL-4−/−mice successfully resolved infection, while 70% of IFN-γ−/−mice survived. In contrast, all CD28−/−mice succumbed during acute infection. While fewer than half of CD40L−/−mice succumbed acutely, surviving mice failed to clear infection, resulting in progressive mucosal destruction, polymicrobial sepsis, and death 1 to 2 weeks later than in CD28−/−mice. Downstream of CD28-mediated effects, CD4+T-cell-expressed CD40L proved essential for generating acute pathogen-specific immunoglobulin M (IgM) and early IgG, which reduced pathogen burdens. However, deficiency of CD4+T-cell-expressed IFN-γ did not adversely impact survival or development of protective antibody in adoptively transferred CD4−/−recipients, though it impacted Th1 antibody responses. These findings demonstrate that CD4+T-cell-expressed CD40L promotes the rapid production of protective systemic antibody during acute infection, while deficiencies of IL-4 or of CD4+T-cell-expressed IFN-γ can be overcome. These findings have important implications for understanding the role of T-helper-cell responses during infections involving mucosal surfaces.
Identification of the
Vibrio vulnificus wbpP
Gene and Evaluation of Its Role in Virulence
Authors: Park Na Young , Lee Jeong Hyun , Kim Myung Won , Jeong Hee Gon , Lee Byung Cheol , Kim Tae Sung , Choi Sang Ho 
Published: December 2005

ABSTRACT

A
wbpP
gene encoding a putative UDP-
N
-acetyl-
d
-glucosamine C
4
epimerase was identified and cloned from
Vibrio vulnificus
. The functions of the
wbpP
gene, assessed by the construction of an isogenic mutant and by evaluating its phenotype changes, demonstrated that WbpP is essential in both the pathogenesis and the capsular polysaccharide biosynthesis of
V. vulnificus
.
Association between Epithelial Cell Death and Invasion by Microspheres Conjugated to
Porphyromonas gingivalis
Vesicles with Different Types of Fimbriae
Authors: Inaba Hiroaki , Kawai Shinji , Kato Takahiro , Nakagawa Ichiro , Amano Atsuo 
Published: December 2005

ABSTRACT

Microspheres
(MS) conjugated to
Porphyromonas gingivalis
vesicles with type
II fimbriae were the most efficient human epithelial cell invaders
among the six types. Cell death was induced by MS, though becoming less
frequent over time, with invasion efficiency partially related to cell
death and gingipains likely the major
cause.
Novel Three-Dimensional Organoid Model for Evaluation of the Interaction of Uropathogenic
Escherichia coli
with Terminally Differentiated Human Urothelial Cells
Authors: Smith Yarery C. , Grande Kerian K. , Rasmussen Susan B. , O'Brien Alison D. 
Published: December 2005

ABSTRACT

Human bladder 5637 cells cultivated under microgravity conditions formed organoids that displayed characteristics of in vivo tissue-specific differentiation. Uropathogenic
Escherichia coli
(UPEC) strain CP9 colonized and penetrated the organoids and induced α-hemolysin-mediated exfoliation of uroepithelial cells. We propose these uro-organoids as models that simulate the interactions between UPEC and terminally differentiated human urothelium.
Immunization with Persistent Attenuated Δ
lpg2 Leishmania major
Parasites Requires Adjuvant To Provide Protective Immunity in C57BL/6 Mice
Authors: Kébaïer Chahnaz , Uzonna Jude E. , Beverley Stephen M. , Scott Phillip 
Published: December 2005

ABSTRACT

Leishmania major
parasites lacking the GDP-mannose transporter, termed Δ
lpg2
parasites, fail to induce disease in mice but persist long-term. We previously found that Δ
lpg2
organisms protect BALB/c mice from virulent
L. major
challenge. In contrast, we report here that Δ
lpg2
parasites induce protective immunity in C57BL/6 mice only when administered with CpG-containing oligodeoxynucleotides, indicating that parasite persistence alone is not sufficient to maintain protective immunity to
L. major
.
Molecular Characterization of the
Escherichia coli
Asymptomatic Bacteriuria Strain 83972: the Taming of a Pathogen
Authors: Klemm Per , Roos Viktoria , Ulett Glen C. , Svanborg Catharina , Schembri Mark A. 
Published: December 2005

ABSTRACT

Escherichia coli
83972 is a clinical asymptomatia bacteriuric isolate that is able to colonize the human urinary bladder without inducing an immune response. Here we demonstrate that one of the mechanisms by which this strain has become attenuated is through the mutation of its genes encoding type 1 and P fimbriae.
The Influence of Intraoperative Pretensioning on the Chondroprotective Effect of Meniscal Transplants
Authors: von Lewinski Gabriela , Pressel Thomas , Hurschler Christof , Witte Frank 
Published: December 2005

Background Meniscal replacement has become more common in recent years. The meniscal transplant's ability to transfer load effectively depends on its ability to bear circumferential loading. Hypothesis Intraoperative pretensioning on the meniscal transplant sutures has a positive influence on meniscal transplants’ chondroprotective effect. Study Design Controlled laboratory study. Methods Thirty-six sheep were divided into 6 groups (n = 6), subjected to a sham operation (group A), a meniscectomy (group B), or a meniscal autograft using tag sutures with different levels of pretensioning (group C, 0 N; group D, 20 N; group E, 40 N; group F, 60 N). Macroscopic (International Cartilage Repair Society score) and histologic evaluations (Mankin score) of the articular cartilage were performed after 6 months. Results Higher suture pretension (40 N, 60 N) resulted in less cartilage degeneration than in meniscectomized (P= .047; P= .036) and nonpretensioned (P= .028; P= .015) knees, with International Cartilage Repair Society scores of 1.63 ± 0.57 and 1.66 ± 0.51 in groups E and F, respectively, and scores of 2.40 ± 0.27 and 2.68 ± 0.46 observed after meniscectomy and meniscal transplantation with no pretensioning, respectively. Group F had a significantly better Mankin score of 6.66 ± 2.15 (P= .05) compared with group D. Regarding criterion cells, trends toward less degeneration compared with meniscectomized and nonpretensioned knees (P= .054 and P= .055) were found. The coefficient of variation of the Mankin scores was greater than that of the International Cartilage Repair Society score. Group A had significantly better cartilage than all other groups. Conclusion Adequate intraoperative pretensioning has a significant influence on the chondroprotective effect of meniscal transplants but did not prevent the development of articular cartilage degeneration. Clinical Relevance The results suggest that intraoperative pretensioning could improve the chondroprotective effect of meniscal transplantation.
The Role of Hip Muscle Function in the Treatment of Patellofemoral Pain Syndrome
Authors: Tyler Timothy F. , Nicholas Stephen J. , Mullaney Michael J. , McHugh Malachy P. 
Published: December 2005

Background Previous literature has associated hip weakness with patellofemoral pain syndrome. Hypothesis Improvements in hip strength and flexibility are associated with a decrease in patellofemoral pain. Study Design Cohort study; Level of evidence, 2. Methods Thirty-five patients with patellofemoral pain syndrome, aged 33 ± 16 years (29 women, 6 men; 43 knees), were evaluated and placed on a 6-week treatment program. Hip flexion, abduction, and adduction strengths, Thomas and Ober test results, and visual analog scale scores for pain with activities of daily living as well as with exercise were documented on initial evaluation and again 6 weeks later. Treatment consisted of strength and flexibility exercises primarily focusing on the hip. Results Hip flexion strength improved by 35% ± 8.4% in 26 lower extremities treated successfully, compared with –1.8% ± 3.5% in 17 lower extremities with an unsuccessful outcome (P< .001). Before treatment, there were positive Ober test results in 39 of 43 lower extremities; positive Thomas test results were seen in 31 of 43 lower extremities. A successful outcome with a concurrent normalized Ober test result was seen in 83% (20/24) of lower extremities, and successful outcomes with normalized Thomas test results were seen in 80% (16/20) of lower extremities. A combination of improved hip flexion strength (> 20%) as well as normal Ober and Thomas test results was seen in 93% of successfully treated cases (14/15 lower extremities), compared with 0% success (0/5 lower extremities) if there was no change in hip flexion strength (< 20%) and if Ober and Thomas test results remained positive. Conclusions Improvements in hip flexion strength combined with increased iliotibial band and iliopsoas flexibility were associated with excellent results in patients with patellofemoral pain syndrome.
Expansion of CD1d-restricted NKT cells in patients with primary HIV-1 infection treated with interleukin-2
Authors: Moll Markus , Snyder-Cappione Jennifer , Spotts Gerald , Hecht Frederick M. , Sandberg Johan K. , Nixon Douglas F. 
Published: December 2005

Abstract
Innate CD1d-restricted natural killer T (NKT) cells are infected and lost in HIV-1–infected patients, and this could contribute to HIV-1 pathogenesis because NKT cells play an important role in directing both adaptive and innate immunity. Administration of interleukin-2 (IL-2) to HIV-1–infected patients leads to substantial and sustained CD4+ T-cell expansion, involving both naive and memory cells. We investigated whether IL-2 treatment could restore the NKT cell compartment in patients with primary HIV-1 infection. We show that IL-2 combined with effective antiretroviral therapy (ART) resulted in significant expansion of CD1d-restricted NKT cells. Expansion occurred in both the CD4– and CD4+ subsets of NKT cells, and expanded cells expressed the CD161 maturation marker while expression of the HIV coreceptor CCR5 was reduced. These data indicate that IL-2 treatment in combination with effective ART is beneficial for the restoration of innate NKT cell immunity in patients with primary HIV-1 infection.
A novel mass spectrometry-based assay for GSK-3β activity
Authors: Bowley Erin , Mulvihill Erin , Howard Jeffrey C , Pak Brian J , Gan Bing Siang , O'Gorman David B 
Published: December 2005

Abstract

Background
As a component of the progression from genomic to proteomic analysis, there is a need for accurate assessment of protein post-translational modifications such as phosphorylation. Traditional kinase assays rely heavily on the incorporation of γ-P32 radiolabeled isotopes, monoclonal anti-phospho-protein antibodies, or gel shift analysis of substrate proteins. In addition to the expensive and time consuming nature of these methods, the use of radio-ligands imposes restrictions based on the half-life of the radionucleotides and pose potential health risks to researchers. With the shortcomings of traditional assays in mind, the aim of this study was to develop a high throughput, non-radioactive kinase assay for screening Glycogen Synthase Kinase-3beta (GSK-3β) activity.

Results
Synthetic peptide substrates designed with a GSK-3β phosphorylation site were assayed with both recombinant enzyme and GSK-3β immunoprecipitated from NIH 3T3 fibroblasts. A molecular weight shift equal to that of a single phosphate group (80 Da.) was detected by surface enhanced laser desorption/ionization time of flight mass spectrometry (SELDI-TOF-MS) in a GSK-3β target peptide (2B-Sp). Not only was there a dose-dependent response in molecular weight shift to the amount of recombinant GSK-3β used in this assay, this shift was also inhibited by lithium chloride (LiCl), in a dose-dependent manner.

Conclusion
We present here a novel method to sensitively measure peptide phosphorylation by GSK-3β that, due to the incorporation of substrate controls, is applicable to either purified enzyme or cell extracts. Future studies using this method have the potential to elucidate the activity of GSK-3β in vivo, and to screen enzyme activity in relation to a variety of GSK-3β related disorders.