bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cytotoxicity in Macrophages Infected with Rough
Brucella
Mutants Is Type IV Secretion System Dependent
Authors: Pei Jianwu , Wu Qingmin , Kahl-McDonagh Melissa , Ficht Thomas A. 
Published: October 2007

ABSTRACT

Smooth
Brucella
spp. inhibit macrophage apoptosis, whereas rough
Brucella
mutants induce macrophage oncotic and necrotic cell death. However, the mechanisms and genes responsible for
Brucella
cytotoxicity have not been identified. In the current study, a random mutagenesis approach was used to create a mutant bank consisting of 11,354 mutants by mariner transposon mutagenesis using
Brucella melitensis
rough mutant 16MΔ
manBA
as the parental strain. Subsequent screening identified 56 mutants (0.49% of the mutant bank) that failed to cause macrophage cell death (release of 10% or less of the lactate dehydrogenase). The absence of cytotoxicity during infection with these mutants was independent of demonstrable defects in in vitro bacterial growth or uptake and survival in macrophages. Interrupted genes in 51 mutants were identified by DNA sequence analysis, and the mutations included interruptions in
virB
encoding the type IV secretion system (T4SS) (
n
= 36) and in
vjbR
encoding a LuxR-like regulatory element previously shown to be required for
virB
expression (
n
= 3), as well as additional mutations (
n
= 12), one of which also has predicted roles in
virB
expression. These results suggest that the T4SS is associated with
Brucella
cytotoxicity in macrophages. To verify this, deletion mutants were constructed in
B. melitensis
16M by removing genes encoding phosphomannomutase/phosphomannoisomerase (Δ
manBA
) and the T4SS (Δ
virB
). As predicted, deletion of
virB
from 16MΔ
manBA
and 16M resulted in a complete loss of cytotoxicity in rough strains, as well as the low level cytotoxicity observed with smooth strains at extreme multiplicities of infection (>1,000). Taken together, these results demonstrate that
Brucella
cytotoxicity in macrophages is T4SS dependent.
Functional Role of the PE Domain and Immunogenicity of the
Mycobacterium tuberculosis
Triacylglycerol Hydrolase LipY
Authors: Mishra Kanhu C. , de Chastellier Chantal , Narayana Yeddula , Bifani Pablo , Brown Alistair K. , Besra Gurdyal S. , Katoch Vishwa M. , Joshi Beenu , Balaji Kithiganahalli N. , Kremer Laurent 
Published: October 2007

ABSTRACT

PE and PPE proteins appear to be important for virulence and immunopathogenicity in mycobacteria, yet the functions of the PE/PPE domains remain an enigma. To decipher the role of these domains, we have characterized the triacylglycerol (TAG) hydrolase LipY from
Mycobacterium tuberculosis
, which is the only known PE protein expressing an enzymatic activity. The overproduction of LipY in mycobacteria resulted in a significant reduction in the pool of TAGs, consistent with the lipase activity of this enzyme. Unexpectedly, this reduction was more pronounced in mycobacteria overexpressing LipY lacking the PE domain [LipY(ΔPE)], suggesting that the PE domain participates in the modulation of LipY activity. Interestingly,
Mycobacterium marinum
contains a protein homologous to LipY, termed LipY
mar
, in which the PE domain is substituted by a PPE domain. As for LipY, overexpression of LipY
mar
in
Mycobacterium smegmatis
significantly reduced the TAG pool, and this was further pronounced when the PPE domain of LipY
mar
was removed. Fractionation studies and Western blot analysis demonstrated that both LipY and LipY(ΔPE) were mainly present in the cell wall, indicating that the PE domain was not required for translocation to this site. Furthermore, electron microscopy immunolabeling of LipY(ΔPE) clearly showed a cell surface localization, thereby suggesting that the lipase may interact with the host immune system. Accordingly, a strong humoral response against LipY and LipY(ΔPE) was observed in tuberculosis patients. Together, our results suggest for the first time that both PE and PPE domains can share similar functional roles and that LipY represents a novel immunodominant antigen.
L-Ficolin/Mannose-Binding Lectin-Associated Serine Protease Complexes Bind to Group B Streptococci Primarily throughN-Acetylneuraminic Acid of Capsular Polysaccharide and Activate the Complement Pathway
Authors: Aoyagi Youko , Adderson Elisabeth E. , Rubens Craig E. , Bohnsack John F. , Min Jin G. , Matsushita Misao , Fujita Teizo , Okuwaki Yoshiyuki , Takahashi Shinji 
Published: October 2007

ABSTRACTGroup B streptococci (GBS) are the most common cause of neonatal sepsis and meningitis. Most infants who are colonized with GBS at birth do not develop invasive disease, although many of these uninfected infants lack protective levels of capsular polysaccharide (CPS)-specific antibody. The lectin pathway of complement is a potential mechanism for initiating opsonization of GBS with CPS-specific antibody-deficient serum. In this study, we determined whether mannose-binding lectin (MBL)/MBL-associated serine protease (MASP) complexes and L-ficolin/MASP complexes bind to different strains of GBS to activate the lectin pathway, and we identified the molecules recognized by lectins on the GBS surface. We found that MBL did not bind to any GBS examined, whereas L-ficolin bound to GBS cells of many serotypes. L-ficolin binding to GBS cells correlated with the CPS content in serotypes Ib, III (restriction digestion pattern types III-2 and III-3), and V but not with the group B-specific polysaccharide (GBPS) content or with the lipoteichoic acid (LTA) content. L-ficolin bound to purified CPS and GBPS in a concentration-dependent manner but not to purified LTA. All strains to which L-ficolin/MASP complexes bound consumed C4. WhenN-acetylneuraminic acid (NeuNAc) was selectively removed from GBS cells by treatment with neuraminidase, the reduction in L-ficolin binding was correlated with the amount of NeuNAc removed. Additionally, L-ficolin was able to bind to wild-type strains but was able to bind only weakly to unencapsulated mutants and a mutant strain in which the CPS lacks NeuNAc. We concluded that L-ficolin/MASP complexes bind to GBS primarily through an interaction with NeuNAc of CPS.
Identification of NovelListeria monocytogenesSecreted Virulence Factors following Mutational Activation of the Central Virulence Regulator, PrfA
Authors: Port Gary C. , Freitag Nancy E. 
Published: October 2007

ABSTRACTUpon bacterial entry into the cytosol of infected mammalian host cells, the central virulence regulator PrfA ofListeria monocytogenesbecomes activated and induces the expression of numerous factors which contribute to bacterial pathogenesis. The mechanism or signal by which PrfA becomes activated during the course of infection has not yet been determined; however, several amino acid substitutions within PrfA (known as PrfA* mutations) that appear to lock the protein into a constitutively activated state have been identified. In this study, the PrfA activation statuses of severalL. monocytogenesmutant strains were subjected to direct isogenic comparison and the mutant with the highest activity, theprfA(L140F) mutant, was identified. TheprfA(L140F) strain was subsequently used as a tool to identify gene products secreted as a result of PrfA activation. By use of two-dimensional gel electrophoresis followed by liquid chromatography-electrospray ionization-tandem mass spectroscopy analyses, 15 proteins were identified as up-regulated in theprfA(L140F) secretome, while the secretion of two proteins was found to be reduced. Although some of the proteins identified were known to be subject to direct regulation by PrfA, the majority have not previously been associated with PrfA regulation and their expression or secretion may be influenced indirectly by a PrfA-dependent regulatory pathway. Plasmid insertion inactivation of the genes encoding four novel secreted products indicated that three of the four have significant roles inL. monocytogenesvirulence. The use of mutationally activatedprfAalleles therefore provides a useful approach towards identifying gene products that contribute toL. monocytogenespathogenesis.
Use of Peptide-Major Histocompatibility Complex Tetramer Technology To Study Interactions betweenStaphylococcus aureusProteins and Human Cells
Authors: Massey Ruth C. , Scriba Thomas J. , Brown Eric L. , Phillips Rodney E. , Sewell Andrew K. 
Published: October 2007

ABSTRACTIn this study, we report the use of peptide-major histocompatibility complex tetramer technology to study the interactions that occur betweenStaphylococcus aureusproteins and human leukocytes. We demonstrated that this technology can be used to study the activity of superantigens such as toxic shock syndrome toxin 1 and also found that despite similarities to known proteins (i.e., major histocompatibility complex [MHC] class II molecules and superantigens), theS. aureusEap protein does not block MHC-T-cell receptor interactions and is not a superantigen. Instead, it has nonspecific cross-linking activity that is dependent upon having at least two of its six 110-amino-acid repeats.
A Carcinoembryonic Antigen-Related Cell Adhesion Molecule 1 Homologue Plays a Pivotal Role in Nontypeable
Haemophilus influenzae
Colonization of the Chinchilla Nasopharynx via the Outer Membrane Protein P5-Homologous Adhesin
Authors: Bookwalter James E. , Jurcisek Joseph A. , Gray-Owen Scott D. , Fernandez Soledad , McGillivary Glen , Bakaletz Lauren O. 
Published: October 2007

ABSTRACT

In vitro studies suggest an important role for CEACAM1 (
c
arcino
e
mbryonic
a
ntigen-related
c
ell
a
dhesion
m
olecule 1) in infection by multiple gram-negative bacteria. However, in vivo evidence supporting this role is lacking, largely because the bacterial adhesins involved in this host-microbe association do not bind to murine-derived CEACAM1. One of several adhesins expressed by nontypeable
Haemophilus influenzae
(NTHI), the outer membrane protein P5-homologous adhesin (or P5), is essential for colonization of the chinchilla nasopharynx and infection of the middle ear. Here we reveal that NTHI P5 binds to the chinchilla homologue of CEACAM1 and that rabbit anti-human carcinoembryonic antigen blocks NTHI colonization of the chinchilla nasopharynx, providing the first demonstration of a role for CEACAM receptor binding by any bacterial pathogen in vivo.
Highly Polymorphic Family of Glycosylphosphatidylinositol-Anchored Surface Antigens with Evidence of Developmental Regulation in
Toxoplasma gondii
Authors: Pollard Angela M. , Onatolu Krystal N. , Hiller Luisa , Haldar Kasturi , Knoll Laura J. 
Published: October 2007

ABSTRACT

The life cycle of the apicomplexan parasite
Toxoplasma gondii
requires that an infectious cyst develop and be maintained throughout the life of the host. The molecules displayed on the parasite surface are important in controlling the immune response to the parasite.
T. gondii
has a superfamily of glycosylphosphatidylinositol (GPI)-anchored surface antigens, termed the surface antigen (SAG) and SAG-related surface antigens, that are developmentally regulated during infection. Using a clustering algorithm, we identified a new family of 31 surface proteins that are predicted to be GPI anchored but are unrelated to the SAG proteins, and thus we named these proteins SAG-unrelated surface antigens (SUSA). Analysis of the single nucleotide polymorphism density showed that the members of this family are the most polymorphic genes within the
T. gondii
genome. Immunofluorescence of SUSA1 and SUSA2, two members of the family, revealed that they are found on the parasite surface. We confirmed that SUSA1 and SUSA2 are GPI anchored by phospholipase cleavage. Analysis of expressed sequence tags (ESTs) revealed that SUSA1 had 22 of 23 ESTs from chronic infection. Analysis of mRNA and protein confirmed that SUSA1 is highly expressed in the chronic form of the parasite. Sera from mice with chronic
T. gondii
infection reacted to SUSA1, indicating that SUSA1 interacts with the host immune system during infection. This group of proteins likely represents a new family of polymorphic GPI-anchored surface antigens that are recognized by the host's immune system and whose expression is regulated during infection.
Malaria Vaccine-Related Benefits of a Single Protein ComprisingPlasmodium falciparumApical Membrane Antigen 1 Domains I and II Fused to a Modified Form of the 19-Kilodalton C-Terminal Fragment of Merozoite Surface Protein 1
Authors: Faber Bart W. , Remarque Edmond J. , Morgan William D. , Kocken Clemens H. M. , Holder Anthony A. , Thomas Alan W. 
Published: October 2007

ABSTRACTWe show that the smallest module ofPlasmodium falciparumAMA1 (PfAMA1) that can be expressed in the yeastPichia pastoriswhile retaining the capacity to induce high levels of parasite-inhibitory antibodies comprises domains I and II. Based on this, two fusion proteins, differing in the order of the modules, were developed. Each comprised one module of PfAMA1 (FVO strain, amino acids [aa] 97 to 442) (module A) and one module of PfMSP119(Wellcome strain, aa 1526 to 1621) (module Mm) in which a cystine had been removed to improve immune responses. Both fusion proteins retained the antigenicity of each component and yielded over 30 mg/liter purified protein under fed-batch fermentation. Rabbits immunized with purified fusion proteins MmA and AMm had up to eightfold-higher immune responses to MSP119than those of rabbits immunized with module Mm alone or Mm mixed with module A. In terms of parasite growth inhibition, fusion did not diminish the induction of inhibitory antibodies compared with immunization with module A alone or module A mixed with module Mm, and fusion outperformed antibodies induced by immunization with module M or Mm alone. When tested against parasites expressing AMA1 heterologous to the immunogen, antibodies to the fusion proteins inhibited parasite growth to a greater extent than did antibodies either to the individual antigens or to the mixture. These results suggest that compared with the individual modules delivered separately or as a mixture, fusion proteins containing these two modules offer the potential for significant vaccine-related advantages in terms of ease of production, immunogenicity, and functionality.
What is a significant difference between sequential laboratory results?Calf muscle pain can indicate localised vasculitis
Authors: Smellie W S A 
Published: October 2007

The uncertainty of a numerical laboratory result can be masked by the fact that the laboratory reports an absolute number, whereas users have limited knowledge of the confidence interval of the result. Interpretation of laboratory tests is in reality therefore an inexact science, a balance between clinical context and the likely relevance of a laboratory result.This review considers the factors which contribute to result variability and examines the implications for interpreting differences between sequential laboratory results. It offers suggestions to deal with a problem which has not yet been much addressed in routine practice. The examples used are restricted to the discipline of clinical biochemistry, although the issues and principles apply to numerical (and indeed qualitative) results in other disciplines.Laboratories could provide more guidance on the likelihood of a result being significant to assist users. There is a need for discussion about how this is best done, and compatible with electronic result delivery. Options for providing this information are considered.
Mozart's movements and behaviour: a case of Tourette's syndrome?
Authors: Ashoori A , Jankovic J 
Published: October 2007

Abstract
In this review, we intend to explore the often asked question: “Did Mozart have Tourette's syndrome?” Although there are numerous reports attributing Mozart's peculiar personality and behaviour to a spectrum of neurobehavioural disorders such as Tourette's syndrome, autistic disorder, Asperger's syndrome, attention deficit hyperactivity disorder, obsessive–compulsive disorder and paediatric autoimmune neuropsychiatric disorders associated with streptococcal infection, the evidence for any of these disorders is lacking. Whether Mozart's behaviour was nothing more than a reflection of his unique personality or a more complex neurological disorder, aggravated later in life by enormous demands by his father and society, his behaviour has been the subject of many biographies. It will also remain unknown to what extent his accomplishments and failures were shaped by his childhood experiences, pressured lifestyle, and his innate genius and extraordinary talent. Lessons from his life may have important implications for other gifted individuals and savants whose special attributes may lead them to succeed or, on the other hand, suppress their emotional growth and make them more vulnerable to stress and failure.
Effects of multidisciplinary inpatient rehabilitation for chronic back or neck pain: a register-linkage study of sickness absences and analgesic purchases in an occupational cohort
Authors: Suoyrjö H , Hinkka K , Oksanen T , Kivimäki M , Klaukka T , Pentti J , Vahtera J 
Published: October 2007

Objective:To determine the effects of multidisciplinary in-patient rehabilitation for chronic back or neck pain on sickness absences and analgesic purchases.Design:A prospective observational study.Setting:10 towns in Finland.Participants:34 838 local government employees, including 418 participants in rehabilitation for chronic back pain and 195 participants in rehabilitation for chronic neck pain between 1994 and 2002.Main outcome measures:The annual rates of short (1–3 days), long (>3 days), and very long (>21 days) sickness absences and the defined daily doses (DDD) of prescribed analgesics.Results:The rate of very long (>21 days) sickness absence among the chronic back pain rehabilitees was 3.03-fold (95% CI 2.55 to 3.60) compared to the non-rehabilitees in the year before rehabilitation. This ratio declined to 1.88 (95% CI 1.65 to 2.37) three years after rehabilitation. No further decline in the rate of very long sickness absence was observed in the subsequent years. For chronic neck pain rehabilitees, no evidence of the effectiveness of rehabilitation on sickness absence was found. In relation to consumption of analgesics, the mean rate of DDDs declined among the back and neck pain rehabilitees after rehabilitation compared to the non-rehabilitees.Conclusions:Multidisciplinary in-patient rehabilitation for chronic back pain may decrease the risk of very long sickness absence for three years. In relation to rehabilitation for chronic neck pain, no changes in sickness absences were found.
Adoptively Transferred Tumor-Specific T Cells StimulatedEx vivoUsing Herpes Simplex Virus Amplicons Encoding 4-1BBL Persist in the Host and Show Antitumor ActivityIn vivo
Authors: Yi Kyung H. , Nechushtan Hovav , Bowers William J. , Walker Gail R. , Zhang Yu , Pham Dien G. , Podack Eckhard R. , Federoff Howard J. , Tolba Khaled A. , Rosenblatt Joseph D. 
Published: October 2007

Abstract4-1BB is a T-cell costimulatory receptor which binds its ligand 4-1BBL, resulting in prolonged T cell survival. We studied the antitumor effects of adoptively transferred tumor-specific T cells expanded ex vivo using tumors transduced with herpes simplex virus (HSV) amplicons expressing 4-1BBL as a direct source of antigen and costimulation. We constructed HSV amplicons encoding either the 4-1BBL (HSV.4-1BBL) or B7.1 (HSV.B7.1) costimulatory ligands. Lewis lung carcinoma cells expressing ovalbumin (LLC/OVA) were transduced with HSV.4-1BBL, HSV.B7.1, or control HSV amplicons and used to stimulate GFP+ OVA-specific CD8+ T cells (OT-1/GFP) ex vivo. Naive or ex vivo stimulated OT-1/GFP cells were adoptively transferred into LLC/OVA tumor-bearing mice. Higher percentages of OT-1/GFP cells were seen in the peripheral blood, spleen, and tumor bed of the HSV.4-1BBL–stimulated OT-1/GFP group compared with all other experimental groups. OT-1 cells identified within the tumor bed and draining lymph nodes of the HSV.4-1BBL–stimulated OT-1 group showed enhanced bromodeoxyuridine (BrdUrd) incorporation, suggesting ongoing expansion in vivo. Mice receiving HSV.4-1BBL–stimulated OT-1/GFP had significantly decreased tumor volumes compared with untreated mice (P &lt; 0.001) or to mice receiving naive OT-1/GFP (P &lt; 0.001). Transfer of HSV.B7.1-stimulated OT-1/GFP did not protect mice from tumor. Mice that received HSV.4-1BBL–stimulated OT-1/GFP exhibited increased cytolytic activity against LLC/OVA and higher percentages of Ly-6C+ OT-1/GFP in the spleen and tumor bed compared with controls. Tumor-specific T cells stimulated ex vivo using tumor transduced with HSV.4-1BBL expand in vivo following adoptive transfer, resulting in tumor eradication and the generation of tumor-specific CD44+Ly-6C+CD62L− effector memory T cells. [Cancer Res 2007;67(20):10027–37]
A Cathepsin K Inhibitor Reduces Breast Cancer–Induced Osteolysis and Skeletal Tumor Burden
Authors: Le Gall Céline , Bellahcène Akeila , Bonnelye Edith , Gasser Jürg A. , Castronovo Vincent , Green Jonathan , Zimmermann Johann , Clézardin Philippe 
Published: October 2007

Abstract
Osteoclasts mediate bone destruction in breast cancer skeletal metastases. Cathepsin K is a proteinase that is secreted by osteoclasts and degrades bone. Here, immunohistochemistry revealed that cathepsin K was expressed not only by osteoclasts but also by breast cancer cells that metastasize to bone. Following intratibial injection with cathepsin K–expressing human BT474 breast cancer cells, tumor-bearing mice treated with a clinical dosing regimen of cathepsin K inhibitor (CKI; 50 mg/kg, twice daily) had osteolytic lesions that were 79% smaller than those of tumor-bearing mice treated with the vehicle. The effect of CKI was also studied in a mouse model in which the i.v. inoculation of human B02 breast cancer cells expressing cathepsin K leads to bone metastasis formation. Drug administration was started before (preventive protocol) or after (treatment protocol) the occurrence of osteolytic lesions. In treatment protocols, CKI (50 mg/kg, twice daily) or a single clinical dose of 100 μg/kg zoledronic acid (osteoclast inhibitor) reduced the progression of osteolytic lesions by 59% to 66%. CKI therapy also reduced skeletal tumor burden by 62% compared with vehicle, whereas zoledronic acid did not decrease the tumor burden. The efficacy of CKI at inhibiting skeletal tumor burden was similar in the treatment and preventive protocols. By contrast, CKI did not block the growth of s.c. B02 tumor xenografts in animals. Thus, CKI may render the bone a less favorable microenvironment for tumor growth by inhibiting bone resorption. These findings raise the possibility that cathepsin K could be a therapeutic target for the treatment of bone metastases. [Cancer Res 2007;67(20):9894–902]