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| 2. |
- Vilia, Maria Giovanna, et al.
(författare)
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The inhibitory receptor toll interleukin-1R 8 (TIR8/IL-1R8/SIGIRR) is downregulated in chronic lymphocytic leukemia
- 2017
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Ingår i: Leukemia and Lymphoma. - : Taylor & Francis. - 1042-8194 .- 1029-2403. ; 58:10, s. 2419-2425
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Tidskriftsartikel (refereegranskat)abstract
- Toll interleukin-1 receptor 8 (also known as TIR8, SIGIRR, or IL1R8) is a transmembrane receptor that inhibits inflammation. Accordingly, genetic inactivation of this protein exacerbates chronic inflammation and inflammation-associated tumors in mice. In particular, lack of TIR8 triggers leukemia progression in a mouse model of chronic lymphocytic leukemia (CLL), supporting its role as a novel tumor restrainer. The aim of this study was to measure the amount of TIR8 mRNA and protein in CLL cells, and to analyze its regulation of expression. Circulating leukemic cells expressed lower levels of TIR8 compared to normal B-lymphocytes. Treatment of CLL cells with Azacytidine restored higher levels of TIR8 suggesting that DNA methylation may be involved in modulating TIR8 expression, with implications for novel therapeutic strategies.
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| 3. |
- Chatzouli, Maria, et al.
(författare)
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Heterogeneous Functional Effects of Concomitant B Cell Receptor and TLR Stimulation in Chronic Lymphocytic Leukemia with Mutated versus Unmutated Ig Genes
- 2014
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Ingår i: Journal of Immunology. - : The American Association of Immunologists. - 0022-1767 .- 1550-6606. ; 192:10, s. 4518-4524
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Tidskriftsartikel (refereegranskat)abstract
- We recently reported that chronic lymphocytic leukemia (CLL) subgroups with distinct clonotypic BCRs present discrete patterns of TLR expression, function, and/ or tolerance. In this study, to explore whether specific types of BCR/TLR collaboration exist in CLL, we studied the effect of single versus concomitant BCR and/or TLR stimulation on CLL cells from mutated (M-CLL) and unmutated CLL (U-CLL) cases. We stimulated negatively isolated CLL cells by using anti-IgM, imiquimod, and CpG oligodeoxynucleotide for BCR, TLR7, and TLR9, respectively, alone or in combination for different time points. After in vitro culture in the absence of stimulation, differences in p-ERK were identified at any time point, with higher p-ERK levels in U-CLL versus M-CLL. Pronounced p-ERK induction was seen by single stimulation in U-CLL, whereas BCR/TLR synergism was required in M-CLL, in which the effect was overall limited in scale. An opposite pattern was observed regarding induction of apoptosis, as studied by Western blotting for the cleaved fragment of poly(ADP-ribose) polymerase, and the active isoform of caspase-8, with M-CLL responding even to single stimulation, contrasting with U-CLL that showed minimal response. Our findings suggest that concomitant engagement of BCR and TLR leads to differential responses in CLL depending on the mutational status of the BCR. Differential intensity and duration of responses in M-CLL versus U-CLL indicates that the differences in signal transduction between the two subgroups may be primarily quantitative rather than qualitative.
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- Ntoufa, Stavroula, et al.
(författare)
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B Cell Anergy Modulated by TLR1/2 and the miR-17 similar to 92 Cluster Underlies the Indolent Clinical Course of Chronic Lymphocytic Leukemia Stereotyped Subset #4
- 2016
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Ingår i: Journal of Immunology. - : The American Association of Immunologists. - 0022-1767 .- 1550-6606. ; 196:10, s. 4410-4417
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Tidskriftsartikel (refereegranskat)abstract
- Chronic lymphocytic leukemia (CLL) patients assigned to stereotyped subset #4 (mutated IGHV4-34/IGKV2-30 BCR Ig) display a particularly indolent disease course. Immunogenetic studies of the clonotypic BCR Ig of CLL subset #4 suggested a resemblance with B cells rendered anergic through chronic autoantigenic stimulation. In this article, we provide experimental evidence that subset #4 CLL cells show low IgG levels, constitutive ERK1/2 activation, and fail to either release intracellular Ca2+ or activate MAPK signaling after BCR cross-linking, thus displaying a signature of B cell anergy at both biochemical and functional levels. Interestingly, TLR1/2 triggering restored BCR functionality, likely breaching the anergic state, and this was accompanied by induction of the miR17 similar to 92 cluster, whose members target critical BCR-associated molecules, including MAPKs. In conclusion, we demonstrate BCR anergy in CLL subset #4 and implicate TLR signaling and the miR-17 similar to 92 cluster in the regulation of the anergic state. This detailed signaling profiling of subset #4 has implications for advanced understanding of the complex regulation of intracellular signaling pathways in CLL, currently a major therapeutic target of the disease.
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| 5. |
- Ntoufa, Stavroula, et al.
(författare)
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Toll-like receptors signaling : A complex network for in B-cell lymphoid malignancies NF-kappa B activation
- 2016
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Ingår i: Seminars in Cancer Biology. - : Elsevier BV. - 1044-579X .- 1096-3650. ; 39, s. 15-25
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Forskningsöversikt (refereegranskat)abstract
- Malignancies of mature B cells are quite distinctive in originating from well-differentiated cells. Hence, it is not paradoxical that, similar to their normal counterparts, most mature B cell lymphoma subtypes are critically dependent on microenvironmental cues. Such external signals are sensed by various receptors present on the malignant cells, including the Toll-like receptors (TLRs), eliciting a range of cellular responses, including proliferation but also anergy and apoptosis, often with disease-specific patterns. Critically, the TLR signaling pathways are intertwined with other receptor pathways in malignant B cells, most notably the B-cell receptor pathway, and converge on NF-kappa B, leading to its activation. In the present review, we summarize the literature on TLR expression and functionality and its impact on NF-kappa B activation in different B cell malignancies including chronic lymphocytic leukemia where TLR9 induces activation, cell proliferation and chemoresistance in a proportion of patients while apoptosis can be induced in others. Additionally, we also discuss the therapeutic potential of strategies targeting TLR signaling in lymphoma.
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