Search results for "bacterial"
showing 10 items of 3246 documents
Case-specific performance of MM-PBSA, MM-GBSA, and SIE in virtual screening.
2015
In drug discovery the reliable prediction of binding free energies is of crucial importance. Methods that combine molecular mechanics force fields with continuum solvent models have become popular because of their high accuracy and relatively good computational efficiency. In this research we studied the performance of molecular mechanics generalized Born surface area (MM-GBSA), molecular mechanics Poisson-Boltzmann surface area (MM-PBSA), and solvated interaction energy (SIE) both in their virtual screening efficiency and their ability to predict experimentally determined binding affinities for five different protein targets. The protein-ligand complexes were derived with two different app…
A genomic reappraisal of symbiotic function in the aphid/Buchnera symbiosis: reduced transporter sets and variable membrane organisations.
2011
International audience; Buchnera aphidicola is an obligate symbiotic bacterium that sustains the physiology of aphids by complementing their exclusive phloem sap diet. In this study, we reappraised the transport function of different Buchnera strains, from the aphids Acyrthosiphon pisum, Schizaphis graminum, Baizongia pistaciae and Cinara cedri, using the re-annotation of their transmembrane proteins coupled with an exploration of their metabolic networks. Although metabolic analyses revealed high interdependencies between the host and the bacteria, we demonstrate here that transport in Buchnera is assured by low transporter diversity, when compared to free-living bacteria, being mostly bas…
Tolerance, Adaptation, and Cell Response Elicited by Micromonospora sp. Facing Tellurite Toxicity: A Biological and Physical-Chemical Characterization
2022
The intense use of tellurium (Te) in industrial applications, along with the improper disposal of Te-derivatives, is causing their accumulation in the environment, where oxyanion tellurite (TeO32−) is the most soluble, bioavailable, and toxic Te-species. On the other hand, tellurium is a rare metalloid element whose natural supply will end shortly with possible economic and technological effects. Thus, Te-containing waste represents the source from which Te should be recycled and recovered. Among the explored strategies, the microbial TeO32− biotransformation into less toxic Te-species is the most appropriate concerning the circular economy. Actinomycetes are ideal candidates in…
HLA-B27-restricted T cells from patients with ankylosing spondylitis recognize peptides from B*2705 that are similar to bacteria-derived peptides
2003
SUMMARY Ankylosing spondylitis (AS) is an inflammatory systemic disease affecting the spine, sacroiliacal and peripheral joints. Although the aetiology of AS remains unknown, the strong association with the HLA-B27 allele might reflect directly a detrimental effect of the HLA-B27 molecule itself, resulting from its potential capability to present ‘arthritogenic’ peptides to CD8+ T cells. Because some forms of SpA are triggered by enterobacterial infection, such arthritogenic peptides might originate from autologous and/or bacterial proteins triggering cross-reactive CD8+ T cell clones. Intriguingly, two peptides from the second extracellular domain of HLA-B*2705 share sequence homologies wi…
HLA-B27-restricted cytotoxic T lymphocyte responses to arthritogenic enterobacteria or self-antigens are dominated by closely related TCRBV gene segm…
1996
Identification of the T-cell receptors (TCR) used by synovial cytotoxic T lymphocytes (CTL) of patients with reactive arthritis (ReA) may be crucial to better understanding the pathogenetic mechanism underlying the HLA-B27 association of spondylarthropathies. The authors, therefore, sequenced 25 TCRB chains from HLA-B27-restricted CD8+ CTL clones and two clonal lines specific for self- or Yersinia enterocolitica antigen isolated from synovial fluids of 3 HLA-B27+ patients with ReA and PBL of one healthy HLA-B27+ individual. Fourteen non-HLA-B27-restricted CTL served as controls. Both autoreactive and Y. enterocolitica specific HLA-B27-restricted CTL used a highly limited set of VB genes wit…
Bacteria-specific cytotoxic CD8+ T cells: a missing link in the pathogenesis of the HLA-B27-associated spondylarthropathies.
1994
The term seronegative spondylarthropathies is used for an entity of rheumatic syndromes of peripheral joints and the spine (ankylosing spondylitis, reactive arthritis, Reiter's syndrome, arthritis in psoriasis and in inflammatory bowel disease) which are strongly associated with the MHC class I molecule HLA-B27. However, the mechanisms whereby HLA-B27 confers disease susceptibility have so far remained unknown. There is strong evidence that gut inflammation and infection with gram-negative bacteria play a role in the induction of B27-associated disease. HLA-B27, like other MHC class I molecules, physiologically binds antigenic peptides in its binding groove and presents them to CD8+ T lymph…
Enterobacterial Antigens with Tropism for Joint Structures and HLA-B27=Restricted Cytotoxic T-Cells in Reactive Arthritis
1995
In reactive arthritis (ReA), sterile synovitis is an immunological sequela following gastrointestinal or urogenital infection with facultatively intracellular bacteria (Yersinia, Salmonella, Shigella, Chlamydia). It is widely accepted now that the development of arthritis is closely related to the persistance of bacteria or bacterial antigens in extraarticular mucosal or lymphoid tissues (i.e. gut mucosa, gut associated lymphoid tissue, genitourinary mucosa); however, it is still unclear which host mechanisms are responsible for the poorer elimination of arthritis-causing microorganisms in those ReA patients. Bacterial components are also camed to the joints where they can be demonstrated i…
Significant interaction between high-dose methotrexate and high-dose piperacillin-tazobactam causing reversible neurotoxicity and renal failure in an…
2020
Introduction Pharmacokinetic interaction of high-dose methotrexate (MTX) and other concomitantly administered renally secreted medicinal products may lead to insufficient methotrexate serum level decrease and significant MTX toxicity. Case report We report the case of an 18-year-old male patient treated with high-dose MTX for an osteosarcoma and with high-dose piperacillin-tazobactam at the same time. MTX serum levels were severely elevated 24 hours after the MTX infusion and did not decrease in accordance with the specific calcium folinate rescue protocol. The patient experienced renal failure accompanied by neurological symptoms, most consistent with MTX-related renal and CNS toxicity. Ma…
Spinal anaesthesia in a patient with post-spine surgery dural ectasia.
2013
Dural sac ectasia is a very infrequent anatomical abnormality, usually caused by connective tissue diseases, as Marfan syndrome. Very few cases have been described being a consequence of a previous spine surgical procedure. We describe the case of an elderly patient who should be operated on twice due to sub-occlusive colon disease. Surgery was performed under spinal anaesthesia. A dural sac ectasia was suspected after the first procedure and the abdominal X-ray was reviewed. The characteristics of the anatomical alteration and the course of both anaesthetic procedures were described. X-ray and CT images were provided.
Identification of the Yersinia enterocolitica urease beta subunit as a target antigen for human synovial T lymphocytes in reactive arthritis.
1993
The local T-cell response to bacterial antigens is involved in the pathogenesis of reactive arthritis (ReA). Here, we have identified a 19-kDa antigen of Yersinia enterocolitica O:9 recognized by Yersinia-specific synovial fluid CD4+ T cells in two patients with Yersinia-induced ReA. N-terminal amino acid sequencing of this protein revealed that it was identical to the 19-kDa urease beta subunit of Y. enterocolitica O:9. This protein has previously been shown to be arthritogenic in preimmunized rats after intra-articular injection. Analysis of the T-cell response to this protein showed that it contains several T-cell epitopes, one of which cross-reacts with other enterobacteria not able to …