Search results for "ENTEROCOLITICA"

Enterobacteria-infected T cells as antigen-presenting cells for cytotoxic CD8 T cells: a contribution to the self-limitation of cellular immune react…

1997

In enterobacteria-induced reactive arthritis (ReA), different T cell subsets play a role in the induction and maintenance of the synovitic process. Synovial fluid-derived alphabeta CD4, alphabeta CD8, and gammadelta T lymphocyte clones (TLC) that recognize Yersinia or Salmonella antigens on professional antigen-presenting cells (APC) have been characterized, and T cells themselves can function as nonprofessional APC. T cells were infected with the facultatively intracellular, arthritogenic enterobacterium Yersinia enterocolitica O:3. A CD8 TLC isolated from a patient with Yersinia-induced ReA recognized and efficiently lysed autologous and allogeneic Yersinia-infected T cells. Infected cyto…

Ambiguous Role of Interleukin-12 in Yersinia enterocolitica Infection in Susceptible and Resistant Mouse Strains

1998

ABSTRACT Endogenous interleukin-12 (IL-12) mediates protection against Yersinia enterocolitica in C57BL/6 mice by triggering gamma interferon (IFN-γ) production in NK and CD4 + T cells. Administration of exogenous IL-12 confers protection against yersiniae in Yersinia -susceptible BALB/c mice but exacerbates yersiniosis in resistant C57BL/6 mice. Therefore, we wanted to dissect the different mechanisms exerted by IL-12 during Yersinia infections by using different models of Yersinia -resistant and -susceptible mice, including resistant C57BL/6 mice, susceptible BALB/c mice, intermediate-susceptible wild-type 129/Sv mice, 129/Sv IFN-γ-receptor-deficient (IFN-γR −/− ) mice and C57BL/6 tumor n…

Yersinia enterocolitica biotyypin 1A ja Y. enterocolitican kaltaisten bakteerikantojen geneettisen monimuotoisuuden ja lämpökestoisten enterotoksiini…

2007

HLA-B27-restricted CD8 T cells derived from synovial fluids of patients with reactive arthritis and ankylosing spondylitis.

1993

Ankylosing spondylitis and seronegative spondylarthropathies such as Reiter's syndrome and reactive arthritis are strongly associated with HLA-B27. However, the mechanisms by which HLA-B27 is involved in disease susceptibility and pathogenesis are unknown. If the disease association is a consequence of HLA-B27's physiological function in antigen presentation, the disease should be mediated by cytotoxic T lymphocytes (CTLs) that recognise bacterial or self peptides presented by HLA-B27. Proof of this arthritogenic peptide model requires isolation of B27-restricted CD8 T cells from arthritic joints of patients with spondylarthropathies. An important question is whether "arthritogenic" bacteri…

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…

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 …

Persistence ofYersinia antigens in peripheral blood cells from patients withYersinia enterocolitica O:3 infection with or without reactive arthritis

1998

Objective To assess the persistence of bacterial antigens in peripheral blood cells from patients with Yersinia enterocolitica O:3-triggered reactive arthritis (ReA). Methods Peripheral blood samples were obtained from 20 patients with Y enterocolitica O:3 infection (11 with ReA and 9 without). These samples were studied by immunochemical techniques for the presence of Yersinia antigens at the beginning of infection and up to 4 years thereafter. Synovial fluid samples from 6 of the 11 ReA patients were also studied. Results The Yersinia antigens lipopolysaccharide and heat-shock protein (HSP) were detected in peripheral blood mononuclear cells and polymorphonuclear phagocytes from all patie…

No augu izcelsmes pārtikas produktiem izolētu Yersinia enterocolitica ģenētiskā daudzveidība un virulences potenciāls

2022

Yersinia enterocolitica ir ievērojams pārtikas patogēns ar lielu ģenētisko daudzveidību. Virulences gēnu noteikšana celmiem no daudzveidīgiem avotiem var palīdzēt izvērtēt jersiniozes riskus sabiedrības veselībai. Darba mērķis bija raksturot no augu valsts izcelsmes produktiem iegūto Y. enterocolitica izolātu virulences potenciālu un ģenētisko daudzveidību, veicot pilna genoma sekvenēšanu. Darbā iekļauti 66 celmi no svaigiem dārzeņiem un salātiem. Iegūtās sekvencēs konstatēja ail (4,6%), inv (95,4%) un ystB (98,5%) virulences gēnu klātbūtni. Visi izpētītie Y. enterocolitica izolāti pieder pie nosacīti nepatogēna biotipa 1A. Izmantojot cgMLST, noteikts, ka izolāti nav ģenētiski saistīti savā…

Activation of NF-kappaB and IL-8 by yersinia enterocolitica invasin protein is conferred by engagement of rac1 and MAP kinase cascades.

2003

International audience; Yersinia enterocolitica triggers activation of the nuclear factor (NF)-kappaB and production of the proinflammatory chemokine interleukin (IL)-8 in intestinal epithelial cells. This activation is due to adhesion of the bacteria via their outer membrane protein invasin to the host cells. Using Clostridium difficile toxins that specifically inactivate small GTPases, and transfection of inhibitory proteins of the Rho-GTPases, we demonstrate that Rac1, but not Cdc42 or Rho, is required for activation of NF-kappaB by invasin. Invasin activated the mitogen activated protein kinases (MAPK) p38 and c-Jun N-terminal protein kinase (JNK) but not extracellular signal regulated …