Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0042384 (vasculitis)
 20,525 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Gamma-2 herpesviruses encode a homolog of mammalian D-type cyclins. The v-cyclin encoded by murine gammaherpesvirus 68 (gammaHV68) induces cell cycle progression and is an oncogene (L. F. van Dyk, J. L. Hess, J. D. Katz, M. Jacoby, S. H. Speck, and H. W. Virgin IV, J. Virol. 73:5110-5122, 1999). However, the role of the pro-proliferative v-cyclins in gamma-2 herpesvirus pathogenesis is not known. Here we report the generation and characterization of a gammaHV68 v-cyclin mutant (v-cyclin.LacZ) that is unable to express a functional v-cyclin protein. Notably, although the gammaHV68 v-cyclin is expressed from an early-late lytic transcript, v-cyclin. LacZ replicated normally in fibroblasts in vitro and during acute infection in the spleen, liver, and lungs in vivo. Moreover, v-cyclin.LacZ exhibited wild-type (wt) virulence in mice with severe combined immunodeficiency. In addition, in a model of gammaHV68-induced chronic disease in mice lacking the gamma interferon receptor (IFNgammaR(-/-)), v-cyclin.LacZ virus was similar to wt gammaHV68 in terms of the incidence of mortality and vasculitis. Further analysis revealed that the frequencies of splenocytes and peritoneal cells harboring the latent gammaHV68 genome in normal and B-cell-deficient mice infected with wt gammaHV68 or v-cyclin.LacZ were very similar. However, v-cyclin.LacZ was significantly compromised in its capacity to reactivate from latency. This phenotype was conclusively mapped to the v-cyclin gene by (i) generating a marker rescue virus (v-cyclin.MR) from the v-cyclin.LacZ mutant, which restored the frequency of cells in which virus reactivated from latency to the levels observed with wt gammaHV68; and (ii) generating a second v-cyclin mutant virus containing a translation stop codon within the v-cyclin gene (v-cyclin.stop), which was compromised in reactivation from latency. These studies demonstrate that despite expression as a lytic cycle gene, the pro-proliferative gammaHV68 v-cyclin is not required for gammaHV68 replication either in vitro or during acute infection in vivo but rather is a critical determinant of reactivation from latency.
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PMID:The murine gammaherpesvirus 68 v-cyclin is a critical regulator of reactivation from latency. 1090 98

Persistent T cell activation is a common finding in anti-neutrophil cytoplasmic autoantibodies (ANCA)-associated systemic vasculitis (AAV) patients. Because imatinib, a selective inhibitor of the ABL, ARG, PDGFR and c-KIT tyrosine kinases, inhibits T cell activation, this study was conducted to evaluate the potential use of imatinib for the treatment AAV patients refractory to conventional therapy. In particular, we investigated the inhibition of T cell activation by this drug and its efficacy on activated T cells from anti-neutrophil cytoplasmic autoantibodies (ANCA)-associated systemic vasculitides (AASV) patients. T cell stimulation has been induced by anti-CD3/anti-CD28 antibodies or by phorbol myristate acetate (PMA)/ionomycin. T cell proliferation was analysed by tritiumthymidine incorporation. Cell cycle progression was determined by propidium iodide staining using fluorescence activated cell sorter (FACS) analysis and by RNAse protection assay (RPA). Cytokine levels were assessed by enzyme-linked immunosorbent assay. T cell proliferation was inhibited significantly by imatinib, due most probably to cell cycle arrest in the G1-phase. This was paralleled by inhibition in the expression of cyclin-dependent kinases 1 and 2 mRNA. The expression of CD25 in naive and memory T cells was decreased significantly by imatinib in activated T cells. Similarly, conversion from naive to memory T cells after T cell activation was impaired by imatinib. Imatinib did not influence interleukin-2 and tumour necrosis factor-alpha production but increased interferon-gamma production. These observed effects of imatinib were similar in T cells from AASV patients and from healthy individuals. Imatinib might be an alternative therapeutical option for AASV patients refractory to conventional therapy.
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PMID:Imatinib mesylate, a new kid on the block for the treatment of anti-neutrophil cytoplasmic autoantibodies-associated vasculitis? 1819 Jun 1

During acute bacterial infections such as meningitis, neutrophils enter the tissue where they combat the infection before they undergo apoptosis and are taken up by macrophages. Neutrophils show pro-inflammatory activity and may contribute to tissue damage. In pneumococcal meningitis, neuronal damage despite adequate chemotherapy is a frequent clinical finding. This damage may be due to excessive neutrophil activity. We here show that transgenic expression of Bcl-2 in haematopoietic cells blocks the resolution of inflammation following antibiotic therapy in a mouse model of pneumococcal meningitis. The persistence of neutrophil brain infiltrates was accompanied by high levels of IL-1beta and G-CSF as well as reduced levels of anti-inflammatory TGF-beta. Significantly, Bcl-2-transgenic mice developed more severe disease that was dependent on neutrophils, characterized by pronounced vasogenic edema, vasculitis, brain haemorrhages and higher clinical scores. In vitro analysis of neutrophils demonstrated that apoptosis inhibition completely preserves neutrophil effector function and prevents internalization by macrophages. The inhibitor of cyclin-dependent kinases, roscovitine induced apoptosis in neutrophils in vitro and in vivo. In wild type mice treated with antibiotics, roscovitine significantly improved the resolution of the inflammation after pneumococcal infection and accelerated recovery. These results indicate that apoptosis is essential to turn off activated neutrophils and show that inflammatory activity and disease severity in a pyogenic infection can be modulated by targeting the apoptotic pathway in neutrophils.
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PMID:Apoptosis is essential for neutrophil functional shutdown and determines tissue damage in experimental pneumococcal meningitis. 1947 87