bluuebunny/crossref_metadata_2025 huggingface dataset:
Epithelial Cells Infected withChlamydophila pneumoniae(Chlamydia pneumoniae) Are Resistant to Apoptosis
Authors: Rajalingam Krishnaraj , Al-Younes Hesham , Müller Anne , Meyer Thomas F. , Szczepek Agnes J. , Rudel Thomas
Published: July 2002

The obligate intracellular pathogenChlamydophila pneumoniae(Chlamydia pneumoniae) initiates infections in humans via the mucosal epithelia of the respiratory tract. Here, we report that epithelial cells infected withC. pneumoniaeare resistant to apoptosis induced by treatment with drugs or by death receptor ligation. The induction of protection from apoptosis depended on the infection conditions since only cells containing large inclusions were protected. The underlying mechanism of infection-induced apoptosis resistance probably involves mitochondria, the major integrators of apoptotic signaling. In the infected cells, mitochondria did not respond to apoptotic stimuli by the release of apoptogenic factors required for the activation of caspases. Consequently, active caspase-3 was absent in infected cells. Our data suggest a direct modulation of apoptotic pathways in epithelial cells byC. pneumoniae.
Human Lactoferrin and Peptides Derived from Its N Terminus Are Highly Effective against Infections with Antibiotic-Resistant Bacteria
Authors: Nibbering P. H. , Ravensbergen E. , Welling M. M. , van Berkel L. A. , van Berkel P. H. C. , Pauwels E. K. J. , Nuijens J. H.
Published: July 2002

Since human lactoferrin (hLF) binds to bacterial products through its highly positively charged N terminus, we investigated which of the two cationic domains is involved in its bactericidal activity. The results revealed that hLF lacking the first three residues (hLF
−3N
) was less efficient than hLF in killing of antibiotic-resistant
Staphylococcus aureus, Listeria monocytogenes
, and
Klebsiella pneumoniae
. Both hLF preparations failed to kill
Escherichia coli
O54. In addition, hLF
−3N
was less effective than hLF in reducing the number of viable bacteria in mice infected with antibiotic-resistant
S. aureus
and
K. pneumoniae
. Studies with synthetic peptides corresponding to the first 11 N-terminal amino acids, designated hLF(1–11), and fragments thereof demonstrated that peptides lacking the first three N-terminal residues are less effective than hLF(1–11) in killing of bacteria. Furthermore, a peptide corresponding to residues 21 to 31, which comprises the second cationic domain, was less effective than hLF(1–11) in killing of bacteria in vitro and in mice having an infection with antibiotic-resistant
S. aureus
or
K. pneumoniae
. Using fluorescent probes, we found that bactericidal hLF peptides, but not nonbactericidal peptides, caused an increase of the membrane permeability. In addition, hLF killed the various bacteria, most probably by inducing intracellular changes in these bacteria without affecting the membrane permeability. Together, hLF and peptides derived from its N terminus are highly effective against infections with antibiotic-resistant
S. aureus
and
K. pneumoniae
, and the first two arginines play an essential role in this activity.
Characterization ofHaemophilus ducreyi-Specific T-Cell Lines from Lesions of Experimentally Infected Human Subjects
Authors: Gelfanova Valentina , Humphreys Tricia L. , Spinola Stanley M.
Published: July 2002

Haemophilus ducreyiis the etiologic agent of chancroid, a sexually transmitted genital ulcer disease that facilitates the transmission of human immunodeficiency virus. In the human model of infection, the histopathology of infected sites in part resembles a delayed-type hypersensitivity (DTH) response. In this study, T cells were isolated from skin biopsy specimens obtained from 24 subjects who were infected for 7 to 14 days. One clone and 12 lines that responded toH. ducreyiantigens were obtained from 12 of the subjects. Fluorescence-activated cell sorter analysis showed that the antigen-responsive lines and clone were predominantly CD3+and CD4+. The lines and clone responded toH. ducreyiantigen in a dose-dependent manner and produced gamma interferon (IFN-γ) alone or IFN-γ and interleukin-10 (IL-10) but no IL-4 or IL-5 in response toH. ducreyi. Proliferation of T cells was dependent on the presence of autologous antigen-presenting cells. The lines showed little response to antigens prepared from other members of thePasteurellaceaeand responded to different fractions ofH. ducreyiseparated by preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis. We conclude that T cells that recognizeH. ducreyiantigens are recruited to sites experimentally infected with the organism. The lack of cross-reactivity to thePasteurellaceaeand the response of the lines to different antigen fractions suggest that subjects are sensitized toH. ducreyiduring the course of infection.
Expression of Genes Encoding Th1 Cell-Activating Cytokines and Lymphoid Homing Chemokines by Chlamydia-Pulsed Dendritic Cells Correlates with Protective Immunizing Efficacy
Authors: Shaw Jennifer H. , Grund Vernon R. , Durling Luke , Caldwell Harlan D.
Published: July 2002

We studied the expression of cytokines, chemokines, and chemokine receptors by the RNase protection assay in chlamydia-pulsed dendritic cells to better understand their potent anti-chlamydial immunizing properties. We found that chlamydia-pulsed dendritic cells express a complex profile of inflammatory and immunomodulatory molecules. These include CCR-7, interleukin-12, and interferon-induced protein 10, molecules that might influence the homing of pulsed dendritic cells to the site of chlamydial infection and the induction of a local protective CD4
+
Th1 cellular immunity.
Effects of Nonsteroidal Anti-Inflammatory Drugs on
Helicobacter pylori
-Infected Gastric Mucosae of Mice: Apoptosis, Cell Proliferation, and Inflammatory Activity
Authors: Kim Tae Il , Lee Yong Chan , Lee Kwang Hyoung , Han Jae Ho , Chon Chae Yoon , Moon Young Myoung , Kang Jin Kyung , Park In Suh
Published: July 2002

Helicobacter pylori
and nonsteroidal anti-inflammatory drugs (NSAIDs) are two well-known important causative factors of gastric damage. While
H. pylori
increases apoptosis and the proliferation of gastric epithelial cells and is an important factor in peptic ulcer and gastric cancer, NSAIDs induce cell apoptosis and have antineoplastic effects. We investigated the effects of NSAIDs (a nonselective cyclooxygenase [COX] inhibitor [indomethacin] and a selective COX-2 inhibitor [NS-398]) on the apoptosis and proliferation of gastric epithelial cells and gastric inflammation in
H. pylori
-infected mice. C57BL/6 mice were sacrificed 8 weeks after
H. pylori
SS1 inoculation. Indomethacin (2 mg/kg) or NS-398 (10 mg/kg) was administered subcutaneously once daily for 10 days before sacrifice. The following were assessed: gastric inflammatory activity, gastric COX protein expression by Western blotting; gastric prostaglandin E
2
levels by enzyme immunoassay, apoptosis by terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling, and cell proliferation by Ki67 immunostaining. Compared to the controls,
H. pylori
infection and/or NSAID treatment increased COX-1 and COX-2 protein expression. Gastric prostaglandin E
2
levels, apoptotic index, cell proliferation index, neutrophil activity, and the degree of chronic inflammation were all increased by
H. pylori
infection, and these effects were significantly decreased by indomethacin treatment. However, NS-398 treatment after
H. pylori
infection did not induce a significant reduction, although it did result in a tendency to decrease. These results show that NSAIDs can reverse the increased apoptosis and proliferation of epithelial cells and inflammatory activity in the stomachs of
H. pylori
-infected mice and that, like COX-2 activation, COX-1 induction contributes to the change of gastric mucosal cell turnover and inflammation induced by
H. pylori
infection.
Induction of Specific Cytotoxic Lymphocytes in Mice Vaccinated withBrucella abortusRB51
Authors: He Yongqun , Vemulapalli Ramesh , Zeytun Ahmet , Schurig Gerhardt G.
Published: July 2002

A safe, more sensitive, nonradioactive, neutral red uptake assay was adopted to replace the traditional51Cr release assay for detection ofBrucella-specific cytotoxic T lymphocyte (CTL) activity. Our studies indicated thatBrucella abortusstrain RB51 vaccination of mice induced specific CTLs against both strain RB51- and strain 2308-infected J774.A1 macrophages but not againstListeria monocytogenes-infected J774.A1 cells. The antigen-specific cytotoxic activity was exerted by T lymphocytes but not by NK cells. CD3+CD4+T cells secreted the highest level of gamma interferon (IFN-γ) and were able to exert a low but significant level of specific lysis ofBrucella-infected macrophages. They also exerted a low level of nonspecific lysis of noninfected macrophages. In contrast, CD3+CD8+T cells secreted low levels of IFN-γ but demonstrated high levels of specific lysis ofBrucella-infected macrophages with no nonspecific lysis. These findings indicate thatB. abortusstrain RB51 vaccination of mice induces specific CTLs and suggest that CD3+CD4+and CD3+CD8+T cells play a synergistic role in the anti-Brucellaactivity.
Analogous Cytokine Responses toBurkholderia pseudomalleiStrains Contrasting in Virulence Correlate with Partial Cross-Protection in Immunized Mice
Authors: Ulett Glen C. , Ketheesan Natkunam , Clair Timothy W. , McElnea Catriona L. , Barnes Jodie L. , Hirst Robert G.
Published: July 2002

Cytokine mRNA levels were assessed inBurkholderia pseudomallei-susceptible BALB/c mice andB. pseudomallei-resistant C57BL/6 mice following administration of a sublethal dose of less virulent (LV)B. pseudomallei, a candidate immunogen tested for protection against a highly virulent (HV) challenge. Compared on the basis of the bacterial loads, the cytokine patterns induced by HV and LVB. pseudomalleiwere similar, involving gamma interferon, interleukin-10, and other cytokines. Partial cross-protection betweenB. pseudomalleistrains is shown to be associated with cytokine profiles involving both type 1 and type 2 cytokines.
vrrB
, a Hypervariable Open Reading Frame in
Bacillus anthracis
Authors: Schupp James M. , Klevytska Alexandra M. , Zinser Guenevier , Price Lance B. , Keim Paul
Published: July 2002

Bacillus anthracis
appears to be the most molecularly homogeneous bacterial species known. Extensive surveys of worldwide isolates have revealed vanishingly small amounts of genomic variation. The biological importance of the resting-stage spore may lead to very low evolutionary rates and, perhaps, to the lack of potentially adaptive genetic variation. In contrast to the overall homogeneity, some gene coding regions contain hypervariability that is translated into protein variation. During marker analysis of diverse strains, we have discovered a novel ca. 750-nucleotide open reading frame (ORF) that contains in-frame, variable-number tandem-repeat sequences. Four distinct variable regions exist within
vrrB
, giving rise to 11 distinct alleles in eight different length categories among
B. anthracis
strains. This ORF putatively codes for a 241- to 265-amino-acid protein, rich in glutamine (13.2%), glycine (23.4%), and histidine (23.0%). The variable-region amino acids of the
vrrB
ORF are strongly hydrophilic. Coupled with putative transmembrane domains flanking the variable regions, this suggests a membrane-anchored cytosolic or extracellular location for the putative protein. Sequence analysis of the complete ORFs from three
Bacillus cereus
strains shows maintenance of the ORF across species boundaries, including strong conservation of the amino acid sequence and the capacity to vary among strains. The presence of 11 different alleles of the
vrrB
locus is in stark contrast to the near homogeneity of
B. anthracis
. Evolution of hypervariable genes can negate the lack of genetic variability in species such as
B. anthracis
and provide select rapid evolution in other more variable species.
Functional Characterization of the HasA
PF
Hemophore and Its Truncated and Chimeric Variants: Determination of a Region Involved in Binding to the Hemophore Receptor
Authors: Létoffé Sylvie , Omori Kenji , Wandersman Cécile
Published: July 2002

Hemophores are secreted by several gram-negative bacteria (
Serratia marcescens
,
Pseudomonas aeruginosa
,
Pseudomonas fluorescens
, and
Yersinia pestis
) and form a family of homologous proteins. Unlike the
S. marcescens
hemophore (HasA
SM
), the
P. fluorescens
hemophore HasA
PF
has an additional region of 12 residues located immediately upstream from the C-terminal secretion signal. We show that HasA
PF
undergoes a C-terminal cleavage which removes the last 21 residues when secreted from
P. fluorescens
and that only the processed form is able to deliver heme to the
S. marcescens
outer membrane hemophore-specific receptor, HasR
SM
. Functional analysis of variants including those with an internal deletion of the extra C-terminal domain show that the secretion signal does not inhibit the biological activity, whereas the 12-amino-acid region located upstream does. This extra domain may inhibit the interaction of the hemophore with HasR
SM
. To localize the hemophore regions involved in binding to HasR, chimeric HasA
PF
-HasA
SM
proteins were tested for biological activity. We show that residues 153 to 180 of HasA
PF
are necessary for its interaction with the receptor.
A Cyanobacterial Gene,
sqdX
, Required for Biosynthesis of the Sulfolipid Sulfoquinovosyldiacylglycerol
Authors: Güler Sinan , Essigmann Bernd , Benning Christoph
Published: July 2002

The sulfolipid sulfoquinovosyldiacylglycerol is present in the photosynthetic membranes of plants and many photosynthetic bacteria. A novel gene,
sqdX
, essential for sulfolipid biosynthesis in the cyanobacterium
Synechococcus
sp. strain PCC7942 is proposed to encode the cyanobacterial sulfolipid synthase catalyzing the last reaction of the pathway.
Signaling System in
Porphyromonas gingivalis
Based on a LuxS Protein
Authors: Chung Whasun O. , Park Yoonsuk , Lamont Richard J. , McNab Rod , Barbieri Bruno , Demuth Donald R.
Published: July 2002

The
luxS
gene of quorum-sensing
Vibrio harveyi
is required for type 2 autoinducer production. We identified a
Porphyromonas gingivalis
open reading frame encoding a predicted peptide of 161 aa that shares 29% identity with the amino acid sequence of the LuxS protein of
V. harveyi
. Conditioned medium from a late-log-phase
P. gingivalis
culture induced the luciferase operon of
V. harveyi
, but that from a
luxS
insertional mutant did not. In
P. gingivalis
, the expression of
luxS
mRNA was environmentally controlled and varied according to the cell density and the osmolarity of the culture medium. In addition, differential display PCR showed that the inactivation of
P. gingivalis luxS
resulted in up-regulation of a hemin acquisition protein and an arginine-specific protease and reduced expression of a hemin-regulated protein, a TonB homologue, and an excinuclease. The data suggest that the
luxS
gene in
P. gingivalis
may function to control the expression of genes involved in the acquisition of hemin.
Mutational Analysis of the
Rhizobium lupini
H13-3 and
Sinorhizobium meliloti
Flagellin Genes: Importance of Flagellin A for Flagellar Filament Structure and Transcriptional Regulation
Authors: Scharf Birgit , Schuster-Wolff-Bühring Henriette , Rachel Reinhard , Schmitt Rüdiger
Published: July 2002

Complex flagellar filaments are unusual in their fine structure composed of flagellin dimers, in their right-handed helicity, and in their rigidity, which prevents a switch of handedness. The complex filaments of
Rhizobium lupini
H13-3 and those of
Sinorhizobium meliloti
are composed of three and four flagellin (Fla) subunits, respectively. The Fla-encoding genes, named
flaA
through
flaD
, are separately transcribed from ς
28
-specific promoters. Mutational analysis of the
fla
genes revealed that, in both species, FlaA is the principal flagellin and that FlaB, FlaC, and FlaD are secondary. FlaA and at least one secondary Fla protein are required for assembling a functional flagellar filament. Western analysis revealed a ratio close to 1 of FlaA to the secondary Fla proteins (= FlaX) present in wild-type extracts, suggesting that the complex filament is assembled from FlaA-FlaX heterodimers. Whenever a given mutant combination of Fla prevented the assemblage of an intact filament, the biosynthesis of flagellin decreased dramatically. As shown in
S. meliloti
by reporter gene analysis, it is the transcription of
flaA
, but not of
flaB
,
flaC
, or
flaD
, that was down-regulated by such abortive combinations of Fla proteins. This autoregulation of
flaA
is unusual. We propose that any combination of Fla subunits incapable of assembling an intact filament jams the flagellar export channel and thus prevents the escape of an (as yet unidentified) anti-ς
28
factor that antagonizes the ς
28
-dependent transcription of
flaA
.
The
Brucella suis
Homologue of the
Agrobacterium tumefaciens
Chromosomal Virulence Operon
chvE
Is Essential for Sugar Utilization but Not for Survival in Macrophages
Authors: Alvarez-Martinez Maria-Teresa , Machold Jan , Weise Christoph , Schmidt-Eisenlohr Heike , Baron Christian , Rouot Bruno
Published: July 2002

Brucella
strains possess an operon encoding type IV secretion machinery very similar to that coded by the
Agrobacterium tumefaciens virB
operon. Here we describe cloning of the
Brucella suis
homologue of the
chvE-gguA-gguB
operon of
A. tumefaciens
and characterize the sugar binding protein ChvE (78% identity), which in
A. tumefaciens
is involved in virulence gene expression.
B. suis chvE
is upstream of the putative sugar transporter-encoding genes
gguA
and
gguB
, also present in
A. tumefaciens
, but not adjacent to that of a LysR-type transcription regulator. Although results of Southern hybridization experiments suggested that the gene is present in all
Brucella
strains, the ChvE protein was detected only in
B. suis
and
Brucella canis
with
A. tumefaciens
ChvE-specific antisera, suggesting that
chvE
genes are differently expressed in different
Brucella
species. Analysis of cell growth of
B. suis
and of its
chvE
or
gguA
mutants in different media revealed that ChvE exhibited a sugar specificity similar to that of its
A. tumefaciens
homologue and that both ChvE and GguA were necessary for utilization of these sugars. Murine or human macrophage infections with
B. suis chvE
and
gguA
mutants resulted in multiplication similar to that of the wild-type strain, suggesting that
virB
expression was unaffected. These data indicate that the ChvE and GguA homologous proteins of
B. suis
are essential for the utilization of certain sugars but are not necessary for survival and replication inside macrophages.
Complete Nucleotide Sequence of a 43-Kilobase Genomic Island Associated with the Multidrug Resistance Region ofSalmonella entericaSerovar Typhimurium DT104 and Its Identification in Phage Type DT120 and Serovar Agona
Authors: Boyd David , Peters Geoffrey A. , Cloeckaert Axel , Boumedine Karim Sidi , Chaslus-Dancla Elisabeth , Imberechts Hein , Mulvey Michael R.
Published: July 2002

This study describes the characterization of the recently describedSalmonellagenomic island 1 (SGI1) (D. A. Boyd, G. A. Peters, L.-K. Ng, and M. R. Mulvey, FEMS Microbiol. Lett. 189:285–291, 2000), which harbors the genes associated with the ACSSuT phenotype in a Canadian isolate ofSalmonella entericaserovar Typhimurium DT104. A 43-kb region has been completely sequenced and found to contain 44 predicted open reading frames (ORFs) which comprised ∼87% of the total sequence. Fifteen ORFs did not show any significant homology to known gene sequences. A number of ORFs show significant homology to plasmid-related genes, suggesting, at least in part, a plasmid origin for the SGI1, although some with homology to phage-related genes were identified. The SGI1 was identified in a number of multidrug-resistant DT120 andS. entericaserovar Agona strains with similar antibiotic-resistant phenotypes. The G+C content suggests a potential mosaic structure for the SGI1. Emergence of the SGI1 in serovar Agona strains is discussed.
Complementation of a Nonmotile
flaB
Mutant of
Borrelia burgdorferi
by Chromosomal Integration of a Plasmid Containing a Wild-Type
flaB
Allele
Authors: Sartakova Marina L. , Dobrikova Elena Y. , Motaleb M. Abdul , Godfrey Henry P. , Charon Nyles W. , Cabello Felipe C.
Published: July 2002

With the recent identification of antibiotic resistance phenotypes, the use of reporter genes, the isolation of null mutants by insertional inactivation, and the development of extrachromosomal cloning vectors, genetic analysis of
Borrelia burgdorferi
is becoming a reality. A previously described nonmotile, rod-shaped, kanamycin-resistant
B. burgdorferi flaB
::Km null mutant was complemented by electroporation with the erythromycin resistance plasmid pED3 (a pGK12 derivative) containing the wild-type
flaB
sequence and 366 bp upstream from its initiation codon. The resulting MS17 clone possessed erythromycin and kanamycin resistance, flat-wave morphology, and microscopic and macroscopic motility. Several other electroporations with plasmids containing wild-type
flaB
and various lengths (198, 366, or 762 bp) of sequence upstream from the
flaB
gene starting codon did not lead to functional restoration of the nonmotile
flaB
null mutant. DNA hybridization, PCR analysis, and sequencing indicated that the wild-type
flaB
gene in nonmotile clones was present in the introduced extrachromosomal plasmids, while the motile MS17 clone was a merodiploid containing single tandem chromosomal copies of mutated
flaB
::Km and wild-type
flaB
with a 366-bp sequence upstream from its starting codon. Complementation was thus achieved only when wild-type
flaB
was inserted into the borrelial chromosome. Several possible mechanisms for the failure of complementation for extrachromosomally located
flaB
are discussed.
TheBacillus subtilisSignaling Protein SpoIVB Defines a New Family of Serine Peptidases
Authors: Hoa Ngo T. , Brannigan James A. , Cutting Simon M.
Published: July 2002

The protein SpoIVB plays a key role in signaling in the ςKcheckpoint ofBacillus subtilis. This regulatory mechanism coordinates late gene expression during development in this organism and we have recently shown SpoIVB to be a serine peptidase. SpoIVB signals by transiting a membrane, undergoing self-cleavage, and then by an unknown mechanism activating a zinc metalloprotease, SpoIVFB, which cleaves pro-ςKto its active form, ςK, in the outer mother cell chamber of the developing cell. In this work we have characterized the serine peptidase domain of SpoIVB. Alignment of SpoIVB with homologues from other spore formers has allowed site-specific mutagenesis of all potential active site residues within the peptidase domain. We have defined the putative catalytic domain of the SpoIVB serine peptidase as a 160-amino-acid residue segment at the carboxyl terminus of the protein. His236 and Ser378 are the most important residues for proteolysis, with Asp363 being the most probable third member of the catalytic triad. In addition, we have shown that mutations at residues Asn290 and His394 lead to delayed signaling in the ςKcheckpoint. The active site residues suggest that SpoIVB and its homologues from other spore formers are members of a new family of serine peptidases of the trypsin superfamily.
Isolation of
Legionella anisa
Using an Amoebic Coculture Procedure
Authors: La Scola Bernard , Mezi Lyazid , Weiller P. J. , Raoult Didier
Published: July 2002

Conventional diagnostic tests for legionellosis were negative for a 61-year-old immunocompromised man with pneumonia. However, coculture of a sputum sample with
Acanthamoeba polyphaga
amoebae led to the recovery of
Legionella anisa
. This procedure may be a sensitive and convenient diagnostic method, especially for non-
Legionella pneumophila
species infections that can be diagnosed only by culture.
Geographical Heterogeneity between Far Eastern and Western Countries in Prevalence of the Virulence Plasmid, the SuperantigenYersinia pseudotuberculosis-Derived Mitogen, and the High-Pathogenicity Island amongYersinia pseudotuberculosisStrains
Authors: Fukushima Hiroshi , Matsuda Yuhou , Seki Ryotaro , Tsubokura Misao , Takeda Nobuaki , Shubin Felix Nikolaevich , Paik In Ki , Zheng Xue Bin
Published: July 2002

Yersinia pseudotuberculosisproduces novel superantigenic toxins designated YPMa (Y. pseudotuberculosis-derived mitogen), YPMb, and YPMc and has a pathogenicity island termed HPI (high-pathogenicity island) and R-HPI (the right-hand part of the HPI with truncation in its left-hand part) on the chromosome. Analysis of the distribution of these virulence factors allowed for differentiation of speciesY. pseudotuberculosisinto six subgroups, thus reflecting the geographical spread of two main clones: the YPMa+HPI−Far Eastern systemic pathogenic type belonging to serotypes O1b, -2a, -2b, -2c, -3, -4a, -4b, -5a, -5b, -6, -10, and UT (untypeable) and the YPMs−HPI+European gastroenteric pathogenic type belonging to serotypes O1a and -1b. The YPMa+HPI+pathogenic type belonging to serotypes O1b, -3, -5a, -5b, and UT and the YPMb+HPI−nonpathogenic type belonging to non-melibiose-fermenting serotypes O1b, -5a, -5b, -6, -7, -9, -10, -11, and -12 were prevalent in the Far East. The YPMc+R-HPI+European low-pathogenicity type belonging to non-melibiose-fermenting serotype O3 and the YPMs−HPI−pathogenic type belonging to 15 serotypes were found to be prevalent all over the world. This new information is useful for a better understanding of the evolution and spread ofY. pseudotuberculosis.
Infected Branchial Cleft Cyst Due to
Bordetella bronchiseptica
in an Immunocompetent Patient
Authors: Lo Re Vincent , Brennan Patrick J. , Wadlin Jill , Weaver Robert , Nachamkin Irving
Published: July 2002

A healthy 23-year-old man with fever and a tender mass in his right anterior neck was found to have a branchial cleft cyst infected with
Bordetella bronchiseptica
. Initial testing suggested a
Brucella
species, but further laboratory testing identified the organism definitively.
B. bronchiseptica
infection in healthy adults is an unusual event.
Invasive Fungal Sinusitis and Meningitis Due to
Arthrographis kalrae
in a Patient with AIDS
Authors: Chin-Hong Peter V. , Sutton Deanna A. , Roemer Marguerite , Jacobson Mark A. , Aberg Judith A.
Published: July 2002

We report the first described case of
Arthrographis kalrae
pansinusitis and meningitis in a patient with AIDS. The patient was initially diagnosed with
Arthrographis kalrae
pansinusitis by endoscopic biopsy and culture. The patient was treated with itraconazole for approximately 5 months and then died secondary to
Pneumocytis carinii
pneumonia. Postmortem examination revealed invasive fungal sinusitis that involved the sphenoid sinus and that extended through the cribiform plate into the inferior surfaces of the bilateral frontal lobes. There was also an associated fungal meningitis and vasculitis with fungal thrombosis and multiple recent infarcts that involved the frontal lobes, right caudate nucleus, and putamen. Post mortem cultures were positive for
A. kalrae
.
Case of Synovitis Potentially Caused by
Dolosigranulum pigrum
Authors: Hall G. S. , Gordon S. , Schroeder S. , Smith K. , Anthony K. , Procop G. W.
Published: July 2002

We report a case of synovitis in a 64-year-old man who developed the infection while on steroid therapy for rheumatoid arthritis.
Dolosigranulum pigrum,
a gram-positive catalase-negative coccus, was isolated from two sets of blood cultures prior to antibiotic therapy. The patient was treated with 4 weeks of appropriate antibiotics, and the synovial inflammation resolved. Although synovial aspirates were never positive for any bacteria or fungi, the timing of positive blood cultures and absence of other pathogens suggest the possible etiology as
D. pigrum
.
Pediatric Solid-Organ Transplant Recipients Carry Chronic Loads of Epstein-Barr Virus Exclusively in the Immunoglobulin D-Negative B-Cell Compartment
Authors: Rose Camille , Green Michael , Webber Steven , Ellis Demetrius , Reyes Jorges , Rowe David
Published: July 2002

Solid-organ transplant recipients are at risk for development of lymphoproliferative diseases. The purpose of this study was to examine the distribution of Epstein-Barr virus (EBV) load in the peripheral blood of pediatric transplant recipients who had become chronic viral load carriers (>8 copies/105lymphocytes for >2 months). A total of 19 patients with viral loads ranging from 20 to 5,000 viral genome copies/105lymphocytes were studied. Ten patients had no previous diagnosis of posttransplant lymphoproliferative disease (PT-LPD), while nine had recovered from a diagnosed case of PT-LPD. No portion of the peripheral blood viral load was detected in the cell-free plasma fraction. Viral DNA was found in a population of cells characterized as CD19hiand immunoglobulin D negative, a phenotype that is consistent with the virus being carried exclusively in the memory B-cell compartment of the peripheral blood. There was no difference in the compartmentalization based upon either the level of the viral load or the past diagnosis of an episode of PT-LPD. These results have implications for the design of tests to detect EBV infection and for the interpretation and use of positive EBV PCR assays in the management of transplant recipients.
Epidemiology of Tuberculosis in Hamburg, Germany: Long-Term Population-Based Analysis Applying Classical and Molecular Epidemiological Techniques
Authors: Diel Roland , Schneider Steffen , Meywald-Walter Karen , Ruf Christa-Maria , Rüsch-Gerdes Sabine , Niemann Stefan
Published: July 2002

To determine a detailed picture of tuberculosis (TB) epidemiology in Hamburg, Germany, 423
Mycobacterium tuberculosis
complex isolates from 77.0% of all patients with culture-confirmed TB diagnosed from 1997 to 1999 in Hamburg were analyzed by IS
6110
DNA fingerprinting. IS
6110
restriction fragment length polymorphism (RFLP) clusters were assumed to have arisen from recent transmission. Results of contact tracing and additional patient interviews were used for further epidemiological analyses. Of the 423 cases, 398 were included in the cluster analysis, of which 135 (33.9%) were classified into 35 clusters ranging from 2 to 23 patients. Epidemiological links verifying recent transmission could be confirmed for 87 of the 135 clustered patients. Risk factors for recent transmission were calculated by a two-step procedure: first, based on patients with clustered isolates; and second, based on patients with clustered isolates and transmission links. In both analyses, alcohol abuse appeared to be the strongest predictor for recent transmission, followed by a history of previous contact tracing and unemployment. Homelessness, foreign ethnicity, sex, drug addiction, and human immunodeficiency virus positivity were not independent risk factors for clustering in multivariate analyses. Classical contact tracing performed prior to IS
6110
RFLP analysis identified only 24 of the 135 clustered patient. In conclusion, recent transmission seems to be frequent in Hamburg and was found to be strongly associated with alcohol abuse. Conventional contact tracing appears to be insufficient for the detection of recent transmission chains. The data presented also indicate that improved TB control strategies, including the use of RFLP for the detection of transmission chains, are needed for TB control in the setting of countries with a low incidence of TB.
Neisseria meningitidis
Serogroups W135 and A Were Equally Prevalent among Meningitis Cases Occurring at the End of the 2001 Epidemics in Burkina Faso and Niger
Authors: Taha Muhamed-Kheir , Parent du Chatelet Isabelle , Schlumberger Martin , Sanou Idrissa , Djibo Saacou , de Chabalier François , Alonso Jean-Michel
Published: July 2002

Meningococcal infections occur as epidemics in the African meningitis belt.
Neisseria meningitidis
serogroup A is predominantly involved in these epidemics. We report here new data on the involvement of both serogroups A and W135 in meningitis cases in Burkina Faso and Niger at the end of the 2001 epidemic.
Distribution of Hepatitis B Virus Genotypes among American Blood Donors Determined with a PreS2 Epitope Enzyme-Linked Immunosorbent Assay Kit
Authors: Moriya Takashi , Kuramoto Isamu K. , Yoshizawa Hiroshi , Holland Paul V.
Published: July 2002

We genotyped 418 sera from volunteer blood donors from two large, regional blood centers in the United States who were HBsAg positive by an enzyme-linked immunosorbent assay (ELISA). The HBV genotypes were determined by a serological method using a preS2 epitope ELISA kit (Institute of Immunology, Tokyo, Japan) with monoclonal antibodies. Of the 418 samples, the genotypes of 320 could be determined (76.6%). One hundred forty-three (34.2%) were genotyped as A (preS2 subtype su), 31 (7.4%) were genotyped as B (subtype m), 59 (14.1%) were genotyped as C (subtype ks), 83 (19.9%) were genotyped as D or E (subtype ksu), and 4 (1.0%) were genotyped as F (subtype k). This kit cannot differentiate genotypes D and E. For 98 (23.4%) of the 418 samples, the genotype could not be determined; 11 of these 98 samples were positive for at least one of the preS2 genotype-specific epitopes (m, k, s, and u), but the combinations of positive epitopes were different from those of samples that could be genotyped; 45 had only the common epitope (b). In the group with a high signal-to-cutoff (S/C) ratio, the HBV genotype could be determined for 199 (84%) of 237 samples; in contrast, in the low-S/C-ratio group, only 10 (20%) of 51 samples could be genotyped (P< 0.001). These findings may indicate the limitation of genotyping samples with low S/C ratios for HBsAg by ELISA or the existence of genotype G or other new HBV genotypes in HBsAg-positive blood donors in the United States. Of the genotyped samples, 201 were assayed for HBeAg; only 9 (4.5%) were positive for HBeAg. The frequency of genotype C in HBeAg-positive donor samples (5 of 9 or 56%) was higher than that in HBeAg-negative donor samples (33 of 192, or 17%) (P= 0.022).
Design and Intracellular Activity of a Human Single-Chain Antibody to Human Immunodeficiency Virus Type 1 Conserved gp41 Epitope
Authors: Legastelois Isabelle , Desgranges Claude
Published: July 2002

A human lymphoid cell line (F172-D8) excreting a human immunodeficiency virus type 1 (HIV-1) anti-gp41 monoclonal antibody was used to construct a plasmid containing the cDNA of the single-chain variable fragment (scFvD8) corresponding to this antibody. A stable human osteosarcoma cell line was obtained which expressed the scFvD8 protein in the cytoplasm. Whereas a cell line transfected with a control construct (pCI-neo) was readily and productively infected with laboratory (Ba-L) or primary HIV-1 isolates, the scFvD8 cell line did not support productive infection. Binding of the virus, internalization, and reverse transcription were not altered by scFvD8 expression, but gp160 expression was dramatically reduced. These data suggest that cytoplasmic expression of this artificial single-chain antibody can interfere with gp160 expression, thereby reducing the production of mature viral envelope proteins.
Prostaglandin E2Increases Bovine Leukemia VirustaxandpolmRNA Levels via Cyclooxygenase 2: Regulation by Interleukin-2, Interleukin-10, and Bovine Leukemia Virus
Authors: Pyeon Dohun , Diaz Francisco J. , Splitter Gary A.
Published: July 2002

Prostaglandin E2(PGE2), produced by macrophages, has important immune regulatory functions, suppressing a type 1 immune response and stimulating a type 2 immune response. Type 1 cytokines (interleukin-2 [IL-2], IL-12, and gamma interferon) increase in freshly isolated peripheral blood mononuclear cells (PBMCs) of animals with an early disease stage of bovine leukemia virus (BLV) infection, while IL-10 increases in animals with a late disease stage. Although IL-10 has an immunosuppressive role in the host immune system, IL-10 also inhibits BLVtaxandpolmRNA levels in vitro. In contrast, IL-2 stimulates BLVtaxandpolmRNA and p24 protein expression in cultured PBMCs. The inhibitory effect of IL-10 on BLV expression depends on soluble factors secreted by macrophages. Thus, we hypothesized that PGE2, a cyclooxygenase 2 (COX-2) product of macrophages, may regulate BLV expression. Here, we show that the level of COX-2 mRNA was decreased in PBMCs treated with IL-10, while IL-2 enhanced the level of COX-2 mRNA. Addition of PGE2stimulated BLVtaxandpolmRNA levels and reversed the IL-10 inhibition of BLV mRNA. In addition, the specific COX-2 inhibitor, NS-398, inhibited the amount of BLV mRNA detected. Addition of PGE2increased BLVtaxmRNA regardless of NS-398 addition. PGE2inhibited antigen-specific PBMC stimulation, suggesting that stimulation of BLVtaxandpolmRNA levels by PGE2is independent of cell proliferation. These findings suggest that macrophage-derived COX-2 products, such as PGE2, regulate virus expression and disease progression in BLV infection.
Human Parechovirus 1 Utilizes Integrins αvβ3 and αvβ1 as Receptors
Authors: Triantafilou Kathy , Triantafilou Martha , Takada Yoshikazu , Fernandez Nelson
Published: July 2002

Human parechovirus 1 (HPEV1) displays an arginine-glycine-aspartic acid (RGD) motif in the VP1 capsid protein, suggesting integrins as candidate receptors for HPEV1. A panel of monoclonal antibodies (MAbs) specific for integrins αvβ3, αvβ1, and αvβ5, which have the ability to recognize the RGD motif, and also a MAb specific for integrin α2β1, an integrin that does not recognize the RGD motif, were tested on A549 cells. Our results showed that integrin αv-specific MAb reduced infectivity by 85%. To specify which αv integrins the virus utilizes, we tested MAbs specific to integrins αvβ3 and αvβ1 which reduced infectivity significantly, while a MAb specific for integrin αvβ5, as well as the MAb specific for α2β1, showed no reduction. When a combination of MAbs specific for integrins αvβ3 and αvβ1 were used, virus infectivity was almost completely inhibited; this shows that integrins αvβ3 and αvβ1 are utilized by the virus. We therefore proceeded to test whether αv integrins' natural ligands fibronectin and vitronectin had an effect on HPEV1 infectivity. We found that vitronectin reduced significantly HPEV1 infectivity, whereas a combination of vitronectin and fibronectin abolished infection. To verify the use of integrins αvβ3 and αvβ1 as HPEV1 receptors, CHO cells transfected and expressing either integrin αvβ3 or integrin αvβ1 were used. It was shown that the virus could successfully infect these cells. However, in immunoprecipitation experiments using HPEV1 virions and allowing the virus to bind to solubilized A549 cell extract, we isolated and confirmed by Western blotting the αvβ3 heterodimer. In conclusion, we found that HPEV1 utilises both integrin αvβ3 and αvβ1 as receptors; however, in cells that express both integrins, HPEV1 may preferentially bind integrin αvβ3.
Resistance to Friend Murine Leukemia Virus Infection Conferred by theFv-4Gene Is Recessive but Appears Dominant from the Effect of the Immune System
Authors: Zhang Fengmin , Ya Lamin Ta , Iwatani Yasumasa , Higo Kyoko , Suzuki Yasunori , Tanaka Masakazu , Nakahara Tomomi , Ono Takeshi , Sakai Hiroyuki , Kuribayashi Kagemasa , Ishimoto Akinori
Published: July 2002

Fv-4is a mouse gene that dominantly confers resistance to infection with Friend murine leukemia virus (F-MuLV) (S. Suzuki, Jpn. J. Exp. Med. 45:473–478, 1975). However, the resistance caused byFv-4is recessive in nude mice, which suggests that immunological effects play important roles in this resistance in vivo (K. Higo, Y. Kubo, Y. Iwatani, T. Ono, M. Maeda, H. Hiai, T. Masuda, K. Kuribayashi, F. Zhang, T. Lamin, A. Adachi, and A. Ishimoto, J. Virol. 71:750–754, 1997). To determine the immunological effect on the resistance in vivo, we infected immunologically immature newborn mice homozygous (Fv-4r/r) and heterozygous (Fv-4r/−) forFv-4. Although theFv-4r/rmice showed complete resistance to F-MuLV whether infected neonatally or as adolescents, theFv-4r/−mice showed high sensitivity to viral proliferation and disease induction when infected as newborns but complete resistance when infected as adolescent mice. To confirm the immunological effect on the resistance in adolescent mice with theFv-4r/randFv-4r/−genotypes, we examined the effect of an immunosuppressant drug, FK506, on the resistance. The mice with theFv-4r/rgenotype treated with FK506 still showed resistance, but the mice with theFv-4r/−genotype became highly sensitive to F-MuLV infection. Flow cytometric analysis to detect theFv-4gene product showed that theFv-4gene product was expressed on the cells from newborn and adolescent mice. TheFv-4gene product was also detected on the cells from the FK506-treated mice as well as on those from untreated mice. However, a quantitative difference in the gene product between the cells with theFv-4r/randFv-4r/−genotypes was detected by indirect staining for flow cytometry. These results show that the resistance to F-MuLV infection conferred by theFv-4gene is originally recessive, but it looks dominant in adolescent mice mainly because of the effect of the immune system.
Induction of Mucosal Homing Virus-Specific CD8+T Lymphocytes by Attenuated Simian Immunodeficiency Virus
Authors: Cromwell Mandy A. , Veazey Ronald S. , Altman John D. , Mansfield Keith G. , Glickman Rhona , Allen Todd M. , Watkins David I. , Lackner Andrew A. , Johnson R. Paul
Published: July 2002

Induction of virus-specific T-cell responses in mucosal as well as systemic compartments of the immune system is likely to be a critical feature of an effective AIDS vaccine. We investigated whether virus-specific CD8+lymphocytes induced in rhesus macaques by immunization with attenuated simian immunodeficiency virus (SIV), an approach that is highly effective in eliciting protection against mucosal challenge, express the mucosa-homing receptor α4β7 and traffic to the intestinal mucosa. SIV-specific CD8+T cells expressing α4β7 were detected in peripheral blood and intestine of macaques infected with attenuated SIV. In contrast, virus-specific T cells in blood of animals immunized cutaneously by a combined DNA-modified vaccinia virus Ankara regimen did not express α4β7. These results demonstrate the selective induction of SIV-specific CD8+T lymphocytes expressing α4β7 by a vaccine approach that replicates in mucosal tissue and suggest that induction of virus-specific lymphocytes that are able to home to mucosal sites may be an important characteristic of a successful AIDS vaccine.
Comparative Efficacy of Recombinant Modified Vaccinia Virus Ankara Expressing Simian Immunodeficiency Virus (SIV) Gag-Pol and/or Env in Macaques Challenged with Pathogenic SIV
Authors: Ourmanov Ilnour , Brown Charles R. , Moss Bernard , Carroll Miles , Wyatt Linda , Pletneva Liuobov , Goldstein Simoy , Venzon David , Hirsch Vanessa M.
Published: July 2002

Prior studies demonstrated that immunization of macaques with simian immunodeficiency virus (SIV) Gag-Pol and Env recombinants of the attenuated poxvirus modified vaccinia virus Ankara (MVA) provided protection from high levels of viremia and AIDS following challenge with a pathogenic strain of SIV (V. M. Hirsch et al., J. Virol. 70:3741–3752, 1996). This MVA-SIV recombinant expressed relatively low levels of the Gag-Pol portion of the vaccine. To optimize protection, second-generation recombinant MVAs that expressed high levels of either Gag-Pol (MVA-gag-pol) or Env (MVA-env), alone or in combination (MVA-gag-pol-env), were generated. A cohort of 24 macaques was immunized with recombinant or nonrecombinant MVA (four groups of six animals) and was challenged with 50 times the dose at which 50% of macaques are infected with uncloned pathogenic SIVsmE660. Although all animals became infected postchallenge, plasma viremia was significantly reduced in animals that received the MVA-SIV recombinant vaccines as compared with animals that received nonrecombinant MVA (P= 0.0011 by repeated-measures analysis of variance). The differences in the degree of virus suppression achieved by the three MVA-SIV vaccines were not significant. Most importantly, the reduction in levels of viremia resulted in a significant increase in median (P< 0.05 by Student'sttest) and cumulative (P= 0.010 by log rank test) survival. These results suggest that recombinant MVA has considerable potential as a vaccine vector for human AIDS.
Herpes Simplex Virus ICP27 Induces Cytoplasmic Accumulation of Unspliced Polyadenylated α-Globin Pre-mRNA in Infected HeLa Cells
Authors: Cheung Peter , Ellison Kimberly S. , Verity Robert , Smiley James R.
Published: July 2002

Transcripts of most intron-bearing cellular genes must be processed by the splicing machinery in order to efficiently accumulate and gain access to the cytoplasm. However, we found that herpes simplex virus induces cytoplasmic accumulation of both spliced and unspliced polyadenylated α-globin RNAs in infected HeLa cells. Accumulation of the unspliced RNA required the immediate-early protein ICP27, and ICP27 was sufficient (in combination with ICP4) to produce this effect in a transient-transfection assay. However, expression of ICP27 did not markedly alter the levels of fully spliced α-globin transcripts in infected cells. These data demonstrate that the previously documented effects of ICP27 on the cellular splicing apparatus do not greatly inhibit splicing of α-globin RNA and argue that ICP27 induces a splicing-independent pathway for α-globin RNA accumulation and nuclear export.
Virus Load and Sequence Variation in Simian Retrovirus Type 2 Infection
Authors: Rosenblum Lisa L. , Weiss Robin A. , McClure Myra O.
Published: July 2002

The natural history of type D simian retrovirus (SRV) infection is poorly characterized in terms of viral load, antibody status, and sequence variation. To investigate this, blood samples were taken from a small cohort of mostly asymptomatic cynomolgus macaques (
Macaca fascicularis
), naturally infected with SRV type 2 (SRV-2), some of which were followed over an 8-month period with blood taken every 2 months. Provirus and RNA virus loads were obtained, the samples were screened for presence of antibodies to SRV-2 and neutralizing antibody titers to SRV-2 were assayed.
env
sequences were aligned to determine intra- and intermonkey variation over time. Virus loads varied greatly among cohort individuals but, conversely, remained steady for each macaque over the 8-month period, regardless of their initial levels. No significant sequence variation was found within an individual over time. No clear picture emerged from these results, which indicate that the variables of SRV-2 infection are complex, differ from those for lentivirus infection, and are not distinctly related to disease outcome.
Defective Interfering RNAs of a Satellite Virus
Authors: Qiu Wenping , Karen-Beth Scholthof G.
Published: July 2002

Panicum mosaic virus
(PMV) is a recently molecularly characterized RNA virus with the unique feature of supporting the replication of two subviral RNAs in a few species of the family
Gramineae
. The subviral agents include a satellite RNA (satRNA) that is devoid of a coding region and the unrelated satellite panicum mosaic virus (SPMV) that encodes its own capsid protein. Here we report the association of this complex with a new entity in the RNA world, a defective-interfering RNA (DI) of a satellite virus. The specificity of interactions governing this four-component viral system is illustrated by the ability of the SPMV DIs to strongly interfere with the accumulation of the parental SPMV. The SPMV DIs do not interfere with PMV satRNA, but they do slightly enhance the rate of spread and titer of PMV. The SPMV-derived DIs provide an additional avenue by which to investigate fundamental biological questions, including the evolution and interactions of infectious RNAs.