| 1. |
- Karlsson, S. C. Hannah, et al.
(författare)
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Combining CAR T cells and the Bcl-2 family apoptosis inhibitor ABT-737 for treating B-cell malignancy
- 2013
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Ingår i: Cancer Gene Therapy. - : Springer Science and Business Media LLC. - 0929-1903 .- 1476-5500. ; 20:7, s. 386-393
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Tidskriftsartikel (refereegranskat)abstract
- B-cell malignancies upregulate the B-cell lymphoma 2 (Bcl-2) family inhibitors of the intrinsic apoptosis pathway, making them therapy resistant. However, small-molecule inhibitors of Bcl-2 family members such as ABT-737 restore a functional apoptosis pathway in cancer cells, and its oral analog ABT-263 (Navitoclax) has entered clinical trials. Gene engineered chimeric antigen receptor (CAR) T cells also show promise in B-cell malignancy, and as they induce apoptosis via the extrinsic pathway, we hypothesized that small-molecule inhibitors of the Bcl-2 family may potentiate the efficacy of CAR T cells by engaging both apoptosis pathways. CAR T cells targeting CD19 were generated from healthy donors as well as from pre-B-ALL (precursor-B acute lymphoblastic leukemia) patients and tested together with ABT-737 to evaluate apoptosis induction in five B-cell tumor cell lines. The CAR T cells were effective even if the cell lines exhibited different apoptosis resistance profiles, as shown by analyzing the expression of apoptosis inhibitors by PCR and western blot. When combining T-cell and ABT-737 therapy simultaneously, or with ABT-737 as a presensitizer, tumor cell apoptosis was significantly increased. In conclusion, the apoptosis inducer ABT-737 enhanced the efficacy of CAR T cells and could be an interesting drug candidate to potentiate T-cell therapy.
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| 2. |
- Lindqvist, Camilla, et al.
(författare)
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Both CD4(+) FoxP3(+) and CD4(+) FoxP3(-) T cells from patients with B-cell malignancy express cytolytic markers and kill autologous leukaemic B cells in vitro.
- 2011
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Ingår i: Immunology. - : Wiley. - 0019-2805 .- 1365-2567. ; 133:3, s. 296-306
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Tidskriftsartikel (refereegranskat)abstract
- P>Cytotoxic CD4+ T cells have been found in patients with chronic lymphocytic leukaemia (CLL) and seem to be involved in the regulation of malignant B cells. The CD4+ T regulatory cells (Tregs) can regulate various immune cells, including B cells, by inducing their apoptosis. Hence, different subgroups of CD4+ T cells may be involved in the regulation of malignant B cells. In this study, the cytotoxic phenotype and function of various CD4+ T-cell subgroups were investigated in patients with B-cell malignancies. Peripheral blood was collected from patients with CLL, various B-cell lymphomas, healthy adult donors, children with precursor B-cell acute lymphoblastic leukaemia (pre-B ALL) and from healthy children. CD4+ T cells (CD3+ CD4+ FoxP3-), Tregs (CD3+ CD4+ CD127low FoxP3+) and CD127high FoxP3+ T cells (CD3+ CD4+ CD127high FoxP3+) were analysed for their expression of the cytolytic markers CD107a and Fas ligand. Patients with CLL had increased CD107a expression on all tested T-cell subgroups compared with healthy donors. Similar results were found in patients with B-cell lymphomas whereas the CD107a expression in children with pre-B ALL was no different from that in healthy controls. Fas ligand expression was similar between patient cells and cells of healthy donors. CD4+ T cells and Tregs from patients with CLL and healthy donors were subsequently purified and cultured in vitro with autologous B cells. Both subgroups lysed B cells and killing was confirmed by granzyme ELISAs. In conclusion, cytotoxic populations of CD4+ T cells, including Tregs, are present in patients with B-cell malignancy and may be an important factor in immune-related disease control.
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| 3. |
- Loskog, Angelica, et al.
(författare)
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Human bladder carcinoma is dominated by T-regulatory cells and Th1 inhibitory cytokines
- 2007
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Ingår i: Journal of Urology. - : Ovid Technologies (Wolters Kluwer Health). - 0022-5347 .- 1527-3792. ; 177:1, s. 353-358
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Immunotherapy has faced limited success, although many solutions have been proposed. Recently regulatory T cells have made a comeback in the immunological arena and the role of these cells in patients with cancer is in focus. It is under evaluation whether the immunological status of patients with cancer may affect their sensitivity to immunotherapy. We are developing immunostimulating gene therapy for treating bladder cancer. In this study we constructed an immunological profile of patients with bladder carcinoma to understand which obstacles must be circumvented. Materials and Methods: Biopsies and blood were used to identify immune cell populations by FACS®, histochemistry and proliferation assays, and cytokine production by polymerase chain reaction. Results: Results indicate that bladder carcinoma is a Tri dominated tumor, as shown by the infiltration of T-regulatory cells expressing FOXP3, and the presence of tumor necrosis factor-β and interleukin-10 mRNA copies. We further noted that circulating patient T cells were unresponsive to polyclonal T-cell activation compared to healthy donor cells. Moreover, CD4+CD25+ T cells were increased in patient blood and could suppress the expansion of allogeneic T cells from healthy donors. Conclusions: Patients with bladder carcinoma show an immunosuppressive regulatory profile, including nonresponsive T cells. Clinical protocols able to effectively counteract these mechanisms are warranted.
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