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  • The American Association of Immunologists  (4)
  • 2000-2004  (4)
  • 1
    In: The Journal of Immunology, The American Association of Immunologists, Vol. 169, No. 8 ( 2002-10-15), p. 4136-4146
    Abstract: FcR provides a critical link between ligands and effector cells in immune complex diseases. Emerging evidence reveals that angiotensin (Ang)II exerts a wide variety of cellular effects and contributes to the pathogenesis of inflammatory diseases. In anti-glomerular basement membrane Ab-induced glomerulonephritis (GN), we have previously noted that FcR-deficient mice (γ−/−) surviving from lethal initial damage still developed mesangial proliferative GN, which was drastically prevented by an AngII type 1 receptor (AT1) blocker. We further examined the mechanisms by which renin-Ang system (RAS) participates in this immune disease. Using bone marrow chimeras between γ−/− and AT1−/− mice, we found that glomerular injury in γ−/− mice was associated with CD4+ T cell infiltration depending on renal AT1-stimulation. Based on findings in cutaneous delayed-type hypersensitivity, we showed that AngII-activated renal resident cells are responsible for the recruitment of effector T cells. We next examined the chemotactic activity of AngII-stimulated mesangial cells, as potential mechanisms coupling RAS and cellular immunity. Chemotactic activity for T cells and Th1-associated chemokine (IFN-γ-inducible protein-10 and macrophage-inflammatory protein 1α) expression was markedly reduced in mesangial cells from AT1−/− mice. Moreover, this activity was mainly through calcineurin-dependent NF-AT. Although IFN-γ-inducible protein-10 was NF-κB-dependent, macrophage-inflammatory protein 1α was dominantly regulated by NF-AT. Furthermore, AT1-dependent NF-AT activation was observed in injured glomeruli by Southwestern histochemistry. In conclusion, our data indicate that local RAS activation, partly via the local NF-AT pathway, enhances the susceptibility to T cell-mediated injury in anti-glomerular basement membrane Ab-induced GN. This novel mechanism affords a rationale for the use of drugs interfering with RAS in immune renal diseases.
    Type of Medium: Online Resource
    ISSN: 0022-1767 , 1550-6606
    RVK:
    RVK:
    Language: English
    Publisher: The American Association of Immunologists
    Publication Date: 2002
    detail.hit.zdb_id: 1475085-5
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  • 2
    In: The Journal of Immunology, The American Association of Immunologists, Vol. 170, No. 6 ( 2003-03-15), p. 3243-3253
    Abstract: In immune complex (IC) diseases, FcR are essential molecules facilitating polymorphonuclear cell (PMN) recruitment and effector functions at the IC site. Although FcR-dependent initial tethering and FcR/integrin-dependent PMN accumulation were postulated, their underlying mechanisms remain unclear. We here addressed potential mechanisms involved in PMN recruitment in acute IC glomerulonephritis (nephrotoxic nephritis). Since some renal cells may be recruited from bone marrow (BM) lineages, reconstitution studies with BM chimeras and PMN transfer between wild-type (WT) and FcR-deficient mice (γ−/−) were performed. Severe glomerular damage was induced in WT and Wγ chimeras (BM from WT to irradiated γ−/−), while it was absent in γ−/− and γW chimeras (γ−/− BM to WT). Moreover, WT PMN transfer, but not γ−/− PMN, reconstituted the disease in γ−/−, indicating that FcR on resident cells is not a prerequisite for PMN recruitment in this disease. Surprisingly, transferred WT PMN were recruited coincidentally with NF-κB activation and TNF-α overexpression even in glomeruli with preformed IC (nephrotoxic Ab administered 3 days previously), suggesting that PMN can initially be recruited via its own FcR without previous chemoattractant release. Furthermore, H2O2 inhibition by catalase attenuated the acute WT PMN recruitment and the induction of NF-κB and TNF-α much more than integrin (CD18) blockade, indicating a role for the respiratory burst before integrin-dependent accumulation. In coculture experiments with IC-stimulated PMN and glomeruli, PMN caused acute glomerular TNF-α expression predominantly via FcR-mediated H2O2 production. In conclusion, glomerular IC, even preformed, can cause PMN recruitment and injury through PMN FcR-mediated respiratory burst during initial PMN tethering to IC.
    Type of Medium: Online Resource
    ISSN: 0022-1767 , 1550-6606
    RVK:
    RVK:
    Language: English
    Publisher: The American Association of Immunologists
    Publication Date: 2003
    detail.hit.zdb_id: 1475085-5
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  • 3
    Online Resource
    Online Resource
    The American Association of Immunologists ; 2000
    In:  The Journal of Immunology Vol. 165, No. 12 ( 2000-12-15), p. 6776-6782
    In: The Journal of Immunology, The American Association of Immunologists, Vol. 165, No. 12 ( 2000-12-15), p. 6776-6782
    Abstract: It has been described that peptides derived from a highly conserved region of the α1 helix of the first domain of HLA class I Ags exhibit immunomodulatory capacity blocking both T and NK cell cytotoxicity. In vivo treatment with these peptides prolongs survival of MHC-mismatched allografts. However, the molecular bases of these effects are still unclear. In this study, we further analyze the mechanisms by which the dimeric peptide HLA-B2702 (77–83/83–77) induces suppression of NK cell cytotoxicity. This peptide inhibits natural and redirected lysis mediated by NK cells without significantly affecting effector-target cell binding. We have also isolated and sequenced a protein that binds this inhibitory peptide, which structurally corresponds to β-tubulin. Tubulin is the major protein of microtubules and is involved in target cell killing. Furthermore, B2702 peptide promotes GTP-independent tubulin assembly, producing aggregates that cannot be depolymerized by cold. Treatment of NK cells with Taxol or demecolcine, which interfere with microtubule organization, also prevents NK cell cytotoxicity. Taken together, these results support the hypothesis that the peptide B2702 (77–83/83–77) exerts its inhibitory effect on NK cell cytotoxicity by inducing polymerization of microtubules and interfering with their normal assembly/disassembly dynamics.
    Type of Medium: Online Resource
    ISSN: 0022-1767 , 1550-6606
    RVK:
    RVK:
    Language: English
    Publisher: The American Association of Immunologists
    Publication Date: 2000
    detail.hit.zdb_id: 1475085-5
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  • 4
    In: The Journal of Immunology, The American Association of Immunologists, Vol. 172, No. 11 ( 2004-06-01), p. 6969-6977
    Abstract: Suppressors of cytokine signaling (SOCS) are cytokine-inducible proteins that modulate receptor signaling via tyrosine kinase pathways. We investigate the role of SOCS in renal disease, analyzing whether SOCS regulate IgG receptor (FcγR) signal pathways. In experimental models of immune complex (IC) glomerulonephritis, the renal expression of SOCS family genes, mainly SOCS-3, significantly increased, in parallel with proteinuria and renal lesions, and the proteins were localized in glomeruli and tubulointerstitium. Induction of nephritis in mice with a deficiency in the FcγR γ-chain (γ−/− mice) resulted in a decrease in the renal expression of SOCS-3 and SOCS-1. Moreover, blockade of FcγR by Fc fragment administration in rats with ongoing nephritis selectively inhibited SOCS-3 and SOCS-1, without affecting cytokine-inducible Src homology 2-containing protein and SOCS-2. In cultured human mesangial cells (MC) and monocytes, IC caused a rapid and transient induction of SOCS-3 expression. Similar kinetics was observed for SOCS-1, whereas SOCS-2 expression was very low. MC from γ−/− mice failed to respond to IC activation, confirming the participation of FcγR. Interestingly, IC induced tyrosine phosphorylation of SOCS-3 and Tec tyrosine kinase, and both proteins coprecipitated in lysates from IC-stimulated MC, suggesting intracellular association. IC also activated STAT pathway in MC, which was suppressed by SOCS overexpression, mainly SOCS-3. In SOCS-3 knockdown studies, specific antisense oligonucleotides inhibited mesangial SOCS-3 expression, leading to an increase in the IC-induced STAT activation. Our results indicate that SOCS may play a regulatory role in FcγR signaling, and implicate SOCS as important modulators of cell activation during renal inflammation.
    Type of Medium: Online Resource
    ISSN: 0022-1767 , 1550-6606
    RVK:
    RVK:
    Language: English
    Publisher: The American Association of Immunologists
    Publication Date: 2004
    detail.hit.zdb_id: 1475085-5
    Library Location Call Number Volume/Issue/Year Availability
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