کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2001390 1066036 2008 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Stimulation of iNOS expression and apoptosis resistance in B-cell chronic lymphocytic leukemia (B-CLL) cells through engagement of Toll-like receptor 7 (TLR-7) and NF-κB activation
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Stimulation of iNOS expression and apoptosis resistance in B-cell chronic lymphocytic leukemia (B-CLL) cells through engagement of Toll-like receptor 7 (TLR-7) and NF-κB activation
چکیده انگلیسی

B-CLL cells are characterized by in vivo resistance to apoptosis due, in part, to the presence of an inducible nitric oxide synthase, iNOS, as the NO released plays anti-apoptotic role, notably by inhibiting caspases. The mechanisms leading to spontaneous expression of iNOS in these cells are presently unknown. The restricted use of some VH sub-groups and the sequences of the monoclonal immunoglobulins of the B-cell receptor expressed by the leukemia cells suggested that the latter have encountered specific auto-antigens and/or microbial derived antigens. Their binding to the BCR provides an activation signal resulting in enhanced survival, hence could be involved in the aetiology of the disease. At the interface of innate and cognate immunity, Toll-like receptors, TLR, recognize PAMPs (pathogen-associated molecular patterns) expressed by various bacteria and virus as well as some self-antigens. We thus hypothesized that TLR were involved in the early steps of B-CLL oncogenesis, notably apoptosis resistance through the induction of iNOS expression and the production of NO. Our results show that B-CLL cells express TLR-7 and TLR-9. Incubation of B-CLL cells with TLR-7 agonists effectively resulted in an increased resistance to apoptosis that was reverted with the NOS inhibitor l-NMMA. This resistance was associated with enhanced iNOS expression (protein and mRNA) and NO release, stimulation of NF-κB activation, phosphorylation of IκBα, all these events being suppressed with wedelolactone or Bay 11-7085, two inhibitors of IκBα phosphorylation. Our present data thus suggest that TLR-7 signaling stimulates apoptosis resistance, notably through an NF-κB-dependent activation of the NO pathway.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Nitric Oxide - Volume 19, Issue 2, September 2008, Pages 138–145
نویسندگان
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