45 research outputs found

    B Cell Antigen Presentation Promotes Th2 Responses and Immunopathology during Chronic Allergic Lung Disease

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    Background: The role of B cells in allergic asthma remains undefined. One mechanism by which B cells clearly contribute to allergic disease is via the production of specific immunoglobulin, and especially IgE. Cognate interactions with specific T cells result in T cell help for B cells, resulting in differentiation and immunoglobulin secretion. Proximal to (and required for) T cell-dependent immunoglobulin production, however, is antigen presentation by B cells. While interaction with T cells clearly has implications for B cell function and differentiation, this study investigated the role that B cells have in shaping the T cell response during chronic allergic lung disease. Methodology/Principal Findings: In these studies, we used a clinically relevant mouse model of chronic allergic lung disease to study the role of B cells and B cell antigen presentation in this disease. In these studies we present several novel findings: 1) Lung B cells from chronically allergen challenged mice up-regulated MHC II and costimulatory molecules CD40, CD80 and CD86. 2) Using in vitro studies, B cells from the lungs of allergen challenged mice could present antigen to T cells, as assessed by T cell proliferation and the preferential production of Th2 cytokines. 3) Following chronic allergen challenge, the levels of Th2 cytokines IL-4 and IL-5 in the lungs and airways were significantly attenuated in B cell 2/2 mice, relative to controls. 4) B cell driven Th2 responses and mucus hyper secretion in the lungs were dependent upon MHC II expression by B cells. Conclusions/Significance: Collectively, these results provide evidence for antigen presentation as a novel mechanism b

    M tuberculosis in the adjuvant modulates time of appearance of CNS-specific effector T cells in the spleen through a polymorphic site of TLR2

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    DC deliver information regulating trafficking of effector T cells along T-cell priming. However, the role of pathogen-derived motives in the regulation of movement of T cells has not been studied. We hereinafter report that amount of M tuberculosis in the adjuvant modulates relocation of PLP139-151 specific T cells. In the presence of a low dose of M tuberculosis in the adjuvant, T cells (detected by CDR3 BV-BJ spectratyping, the so-called "immunoscope") mostly reach the spleen by day 28 after immunization ("late relocation") in the SJL strain, whereas T cells reach the spleen by d 14 with a high dose of M tuberculosis ("early relocation"). The C57Bl/6 background confers a dominant "early relocation" phenotype to F1 (SJL 7C57Bl/6) mice, allowing early relocation of T cells in the presence of low dose M tuberculosis. A single non-synonymous polymorphism of TLR2 is responsible for "early/late" relocation phenotype. Egress of T lymphocytes is regulated by TLR2 expressed on T cells. Thus, pathogens engaging TLR2 on T cells regulate directly T-cell trafficking, and polymorphisms of TLR2 condition T-cell trafficking upon a limiting concentration of ligand

    The Role of Passenger Leukocytes in Rejection and “Tolerance” after Solid Organ Transplantation: A Potential Explanation of a Paradox

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    Lycopene suppresses the lipopolysaccharide-induced phenotypic and functional maturation of murine dendritic cells through inhibition of mitogen-activated protein kinases and nuclear factor-κB

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    Dendritic cells (DC) are the most potent of antigen-presenting cells. The most important function of DC is to initiate the immune response by presenting antigens to naïve T lymphocytes. Currently, little is known about the basic action of lycopene in murine bone marrow (BM)-derived DC. In the present study, we have revealed that lycopene significantly attenuates the phenotypic and functional maturation of murine BM-DC, especially in lipopolysaccharide-induced DC maturation. We found that lycopene down-regulates the expression of costimulatory molecules (CD80 and CD86) and major histocompatibility complex type II molecules. We also determined that lycopene-treated DC were poor stimulators of naïve allogeneic T-cell proliferation and induced lower levels of interleukin-2 in responding T cells. They also exhibited impaired interleukin-12 production. Additionally, lycopene was able to inhibit mitogen-activated protein kinases, such as ERK1/2, p38 and JNK, and the transcription factor, nuclear factor-κB. Assessment of the in vivo effects of lycopene may reveal an inability to induce a normal cell-mediated immune response, despite the ability of the cells to migrate to the spleen. This data provides new insight into the immunopharmacology of lycopene and suggests a novel approach to the manipulation of DC for therapeutic application

    Revision of reversed total shoulder arthroplasty. Indications and outcome

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    BACKGROUND: The complications of reversed total shoulder arthroplasty (RTSA) requiring an additional intervention, their treatment options and outcome are poorly known. It was therefore the purpose of this retrospective study, to identify the reasons for revision of RTSA and to report outcomes. METHODS: Four hundred and forty-one performed RTSA implanted between 1999 and 2008 were screened. Sixty-seven of these cases had an additional intervention to treat a complication. Causes were identified in these 67 cases and the outcome of the first 37 patients who could be followed for more than two years after their first additional intervention was analyzed. RESULTS: Of 441 RTSA, 67 cases (15%) needed at least one additional intervention to treat a complication, 30 of them needed a second, eleven a third and four a fourth additional intervention. The most common complication requiring a first intervention was instability (18%) followed by hematoma or superficial wound complications (15%) and complications of the glenoid component (12%). Patients benefitted from RTSA despite the need of additional interventions as indicated by a mean increase in total Constant-Murley score from 23 points before RTSA to 46 points at final follow-up (p < 0.0001). CONCLUSIONS: Instability, hematoma or superficial wound complications and complications of the glenoid component are the most common reasons for an additional intervention after RTSA. Patients undergoing an additional intervention as treatment of these complications profit significantly as long as the prosthesis remains in place
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