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IFN-producing Cells (IFN-produce + cell)
Selected AbstractsE-box protein E2-2 is a crucial regulator of plasmacytoid DC development,EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 9 2008Eiji Esashi Abstract DC play central roles in priming both innate and adaptive immune responses. Multiple DC subsets have been identified on the basis of their phenotype and function. Plasmacytoid DC (pDC) are professional IFN-producing cells that play an essential role in anti-viral immunity. A series of recent studies demonstrates that the regulation of pDC development is different from other types of DC. In this issue of the European Journal of Immunology, new insight is provided into how human pDC development is regulated by various transcription factors, in particular by the Ets family protein Spi-B and E-box protein E2-2. [source] Plasmacytoid dendritic cell activation by foot-and-mouth disease virus requires immune complexesEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 7 2006Laurence Guzylack-Piriou Abstract Natural IFN-producing cells (NIPC), also called plasmacytoid dendritic cells, represent an essential component of the innate immune defense against infection. Despite this, not much is known about the pathways involved in their activation by non-enveloped viruses. The present study demonstrates that the non-enveloped foot-and-mouth disease virus (FMDV) cannot stimulate IFN-, responses in NIPC, unless complexed with FMDV-specific immunoglobulins. Stimulation of NIPC with such immune complexes employs Fc,RII ligation, leading to strong secretion of IFN-,. In contrast to the stimulation of NIPC by many enveloped viruses, FMDV induction of IFN-, production requires live virus. It is necessary for the virus to initiate its replicative cycle. Moreover, it is an abortive replication, as witnessed by the decrease of dsRNA levels and viral titers with time post infection. Sensitivity of the NIPC stimulation to wortmannin and chloroquin, but not leupeptin, indicates an essential role for the pre-lysosomal stage endosomal compartment. In conclusion, the present study demonstrates that immune complexes provide the means for a non-interferogenic virus to induce IFN-, responses by NIPC. This indicates an important link between NIPC and antibodies in immune responses against non-enveloped viruses such as FMDV. [source] Murine thymic plasmacytoid dendritic cellsEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 4 2003Tomoyuki Okada Abstract We report herein heterogeneous murine thymic cell subsets expressing CD11c and B220 (CD45R). The CD11c+B220+ subset expresses Ly6Chigh and MHC class IIlow in contrast with previously described thymic DC (CD11c+B220, cells). Freshly isolated thymic CD11c+B220+ cells show typical plasmacytoid morphology which differentiates to mature DC, in vitro with CpG oligodeoxynucleotides (ODN) 2216; we term this subset thymic plasmacytoid DC (pDC). These thymic pDC are highly sensitive to spontaneous apoptosis in vitro and induce low T cell allo-proliferation activity. Thymic pDC express low TLR2, TLR3 and TLR4 mRNA, normally found on human immature DC, and high TLR7 and TLR9 mRNA, normally found on human pDC. Thymic pDC also produce high amounts of IFN-, following culture with CpG ODN 2216 (TLR9 ligands) as compared with the previously defined thymic DC lineage which expresses low TLR9 mRNA and produce high IL-12 (p40) with CpG ODN 2216. These results indicate that thymic pDC are similar to IFN-producing cells as well as human pDC. The TLR and cytokine production profiles are consistent with a nomenclature of pDC. The repertoire of this cell lineage to TLR9 ligands demonstrate that such responses are determined not only by the quantity of expression, but also cell lineage. [source] Lupus-like disease and high interferon levels corresponding to trisomy of the type I interferon cluster on chromosome 9pARTHRITIS & RHEUMATISM, Issue 5 2006Haoyang Zhuang Objective Systemic lupus erythematosus (SLE) is associated with type I interferons (IFNs) and can be induced by IFN, treatment. This study looked for evidence of autoimmunity in a pedigree consisting of 4 family members with a balanced translocation 9;21 and 2 members with an unbalanced translocation resulting in trisomy of the short (p) arm and part of the long (q) arm of chromosome 9. These latter 2 subjects had 3 copies of the IFN gene cluster. Methods Subjects were evaluated clinically and serologically for autoimmune disease. Expression levels of IFN,4, IFN,, the type I IFN,inducible gene Mx1, the type I IFN receptor, interleukin-6, and tumor necrosis factor , were determined by real-time polymerase chain reaction. Circulating plasmacytoid dendritic cells, the main IFN-producing cells, were quantified by flow cytometry. Results Both subjects with trisomy of chromosome 9p had a lupus-like syndrome with joint manifestations and antinuclear antibodies: one had anti-RNP and antiphospholipid autoantibodies, and the other had anti,Ro 60. The 3 family members with a balanced translocation 9;21 had no clinical or serologic evidence of autoimmunity, similar to that in relatives who were unaffected by the chromosomal translocation. In the 2 subjects with trisomy of 9p, high levels of IFN,/, (comparable with those found in patients with SLE), increased signaling through the IFN receptor (as indicated by high Mx1 expression), and low levels of circulating plasmacytoid dendritic cells (as observed in patients with SLE) were evident. These abnormalities were not seen in individuals with a balanced translocation. Conclusion Trisomy of the type I IFN cluster of chromosome 9p was associated with lupus-like autoimmunity and increased IFN,/, and IFN receptor signaling. The data support the idea that abnormal regulation of type I IFN production is involved in the pathogenesis of SLE. [source] Clinical applications of natural killer T cell,based immunotherapy for cancerCANCER SCIENCE, Issue 4 2008Shinichiro Motohashi Human invariant V,24 natural killer T (NKT) cells are a novel, distinct lymphocyte population, characterized by an invariant T-cell receptor V,24 chain paired with V,11. V,24 NKT cells are activated by a specific glicolipid ligand, ,-GalCer, and rapidly produce a large amount of Th1 and Th2 cytokines, thereby modulating other immune cells such as antigen-specific CD4 and CD8 T cells, NK cells, and dendritic cells. Recent studies have shown that NKT cells play pivotal regulatory roles in many immune responses, including antitumor immunity. We herein review the quantitative alteration and functional deterioration of circulating V,24 NKT cells in various cancer-bearing patients. We also summarize the recent progress in the clinical studies of NKT cell-based tumor immunotherapy. Novel immunological results including the increased peripheral blood V,24 NKT cells and IFN-producing cells after the immunotherapy were revealed. The details of the safety profile and the antitumor responses were also disclosed. Although the objective clinical responses still remain unclear, some encouraging results have emerged. Therefore, NKT cell-based immunotherapy may potentially be an effective strategy for the treatment of cancer patients. (Cancer Sci 2008; 99: 638,645) [source] | ||||||||||