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- Christiansson, Lisa, et al.
(författare)
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Increased Level of Myeloid-Derived Suppressor Cells, Programmed Death Receptor Ligand 1/Programmed Death Receptor 1, and Soluble CD25 in Sokal High Risk Chronic Myeloid Leukemia
- 2013
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 8:1, s. e55818-
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Tidskriftsartikel (refereegranskat)abstract
- Immunotherapy (eg interferon α) in combination with tyrosine kinase inhibitors is currently in clinical trials for treatment of chronic myeloid leukemia (CML). Cancer patients commonly have problems with so called immune escape mechanisms that may hamper immunotherapy. Hence, to study the function of the immune system in CML is of interest. In the present paper we have identified immune escape mechanisms in CML with focus on those that directly hamper T cells since these cells are important to control tumor progression. CML patient samples were investigated for the presence of myeloid-derived suppressor cells (MDSCs), expression of programmed death receptor ligand 1/programmed death receptor 1 (PD-L1/PD-1), arginase 1 and soluble CD25. MDSC levels were increased in samples from Sokal high risk patients (p<0,05) and the cells were present on both CD34 negative and CD34 positive cell populations. Furthermore, expression of the MDSC-associated molecule arginase 1, known to inhibit T cells, was increased in the patients (p = 0,0079). Myeloid cells upregulated PD-L1 (p<0,05) and the receptor PD-1 was present on T cells. However, PD-L1 blockade did not increase T cell proliferation but upregulated IL-2 secretion. Finally, soluble CD25 was increased in high risk patients (p<0,0001). In conclusion T cells in CML patients may be under the control of different immune escape mechanisms that could hamper the use of immunotherapy in these patients. These escape mechanisms should be monitored in trials to understand their importance and how to overcome the immune suppression.
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- Christiansson, Lisa, 1983-
(författare)
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Myeloid-Derived Suppressor Cells and Other Immune Escape Mechanisms in Chronic Leukemia
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Chronic myeloid leukemia (CML) is characterized by the Philadelphia chromosome, a minute chromosome that leads to the creation of the fusion gene BCR/ABL and the transcription of the fusion protein BCR/ABL in transformed cells. The constitutively active tyrosine kinase BCR/ABL confers enhanced proliferation and survival on leukemic cells. CML has in only a few decades gone from being a disease with very bad prognosis to being a disease that can be effectively treated with oral tyrosine kinase inhibitors (TKIs). TKIs are drugs inhibiting BCR/ABL as well as other tyrosine kinases. In this thesis, the focus has been on the immune system of CML patients, on immune escape mechanisms present in untreated patients and on how these are affected by TKI therapy. We have found that newly diagnosed, untreated CML patients exert different kinds of immune escape mechanisms. Patients belonging to the Sokal high-risk group had higher levels of myeloid-derived suppressor cells (MDSCs) as well as high levels of the programmed death receptor 1 (PD-1)-expressing cytotoxic T cells compared to control subjects. Moreover, CML patients had higher levels of myeloid cells expressing the ligand for PD-1, PD-L1. CML patients as well as patients with B cell malignacies had high levels of soluble CD25 in blood plasma. In B cell malignacies, sCD25 was found to be released from T regulatory cells (Tregs). Treatment with the TKIs imatinib or dasatinib decreased the levels of MDSCs in peripheral blood. Tregs on the other hand increased during TKI therapy. The immunostimulatory molecule CD40 as well as NK cells increased during therapy, indicating an immunostimulatory effect of TKIs. When evaluating immune responses, multiplex techniques for quantification of proteins such as cytokines and chemokines are becoming increasingly popular. With these techniques a lot of information can be gained from a small sample volume and complex networks can be more easily studied than when using for example the singleplex ELISA. When comparing different multiplex platforms we found that the absolute protein concentration measured by one platform rarely correlated with the absolute concentration measured by another platform. However, relative quantification was better correlated.
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| 5. |
- Christiansson, Lisa, et al.
(författare)
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The Tyrosine Kinase Inhibitors Imatinib and Dasatinib Reduce Myeloid Suppressor Cells and Release Effector Lymphocyte Responses
- 2015
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Ingår i: Molecular Cancer Therapeutics. - : American Association for Cancer Research. - 1535-7163 .- 1538-8514. ; 14:5, s. 1181-1191
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Tidskriftsartikel (refereegranskat)abstract
- Immune escape mechanisms promote tumor progression and are hurdles of cancer immunotherapy. Removing immunosuppressive cells before treatment can enhance efficacy. Tyrosine kinase inhibitors (TKI) may be of interest to combine with immunotherapy, as it has been shown that the inhibitor sunitinib reduces myeloid suppressor cells in patients with renal cell carcinoma and dasatinib promotes expansion of natural killer-like lymphocytes in chronic myeloid leukemia (CML). In this study, the capacity of dasatinib and imatinib to reduce myeloid suppressor cells and to induce immunomodulation in vivo was investigated ex vivo. Samples from CML patients treated with imatinib (n = 18) or dasatinib (n = 14) within a Nordic clinical trial (clinicalTrials.gov identifier: NCT00852566) were investigated for the presence of CD11b(+)CD14(-)CD33(+) myeloid cells and inhibitorymolecules (arginase I, myeloperoxidase, IL10) as well as the presence of natural killer cells, T cells (naive/memory), and stimulatory cytokines (IL12, IFN gamma, MIG, IP10). Both imatinib and dasatinib decreased the presence of CD11b(+)CD14(-)CD33(+) myeloid cells as well as the inhibitory molecules and the remaining myeloid suppressor cells had an increased CD40 expression. Monocytes also increased CD40 after therapy. Moreover, increased levels of CD40, IL12, natural killer cells, and experienced T cells were noted after TKI initiation. The presence of experienced T cells was correlated to a higher IFNg and MIG plasma concentration. Taken together, the results demonstrate that both imatinib and dasatinib tilted the immunosuppressive CML tumor milieu towards promoting immune stimulation. Hence, imatinib and dasatinib may be of interest to combine with cancer immunotherapy. (C) 2015 AACR.
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| 6. |
- Christiansson, Lisa, et al.
(författare)
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The use of multiplex platforms for absolute and relative protein quantification of clinical material
- 2014
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Ingår i: EuPA Open Proteomics. - : Elsevier BV. - 2212-9685. ; 3, s. 37-47
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Tidskriftsartikel (refereegranskat)abstract
- When introducing multiplex platforms to measure protein content in precious clinical material there is an increased risk of cross reactivity, loss of sensitivity as well as accuracy. In this paper, four multiplex platforms and one singleplex platform were compared by running pre- and post-treatment plasma samples from CML patients. We found a variation of absolute protein concentrations between platforms. For some of the analytes and platforms, relative differences between pre- and post-treatment samples correlated. We conclude that absolute concentrations measured by different platforms should be compared with caution and comparing relative differences could be more accurate.
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- Eriksson, Emma, et al.
(författare)
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Activation of myeloid and endothelial cells by CD40L gene therapy supports T-cell expansion and migration into the tumor microenvironment
- 2017
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Ingår i: Gene Therapy. - : Springer Science and Business Media LLC. - 0969-7128 .- 1476-5462. ; 24:2, s. 92-103
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Tidskriftsartikel (refereegranskat)abstract
- CD40 is an interesting target in cancer immunotherapy due to its ability to stimulate T-helper 1 immunity via maturation of dendritic cells and to drive M2 to M1 macrophage differentiation. Pancreatic cancer has a high M2 content that has shown responsive to anti-CD40 agonist therapy and CD40 may thus be a suitable target for immune activation in these patients. In this study, a novel oncolytic adenovirus armed with a trimerized membrane-bound extracellular CD40L (TMZ-CD40L) was evaluated as a treatment of pancreatic cancer. Further, the CD40L mechanisms of action were elucidated in cancer models. The results demonstrated that the virus transferring TMZ-CD40L had oncolytic capacity in pancreatic cancer cells and could control tumor progression. TMZ-CD40L was a potent stimulator of human myeloid cells and T-cell responses. Further, CD40L-mediated stimulation increased tumor-infiltrating T cells in vivo, which may be due to a direct activation of endothelial cells to upregulate receptors for lymphocyte attachment and transmigration. In conclusion, CD40L-mediated gene therapy is an interesting concept for the treatment of tumors with high levels of M2 macrophages, such as pancreatic cancer, and an oncolytic virus as carrier of CD40L may further boost tumor killing and immune activation.
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- Lindqvist, Camilla A, et al.
(författare)
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FoxP3+ T-Cells in Patients with B-Cell Chronic Lymphocytic Leukemia Express Cytolytic Markers and Kill Autologous B-Cells
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Recent reports indicate that infiltration of FoxP3+ cells into the tumor area may be associated with better overall survival of patients with B-cell malignancies, which is in contrast to patients with non-hematopoetic tumors. Here, we demonstrate a possible mechanism to these findings. Since the tumor cell in lymphoma originates from the immune system we hypothesized that FoxP3+ T regulatory cells (Tregs) may have a suppressive role in tumor progression in patients with B-cell malignancies. Peripheral blood was collected from 14 patients with B-cell chronic lymphocytic leukemia (B-CLL) and their Tregs were evaluated for cytolytic markers such as FasL and CD107a. We found that both conventional Tregs (CD4+ FoxP3+CD127low T-cells) and FoxP3+CD127high T-cells were significantly increased in patients with B-CLL compared to healthy controls. Further, both groups of FoxP3+ cells displayed higher expression of the degranulation marker CD107a indicating perforin/granzyme release. A flow cytometry-based cytotoxicity assay demonstrated that purified Tregs from both patients and healthy controls could kill autologous B-cells in vitro. In conclusion, FoxP3+ T-cells in patients with CLL show effector phenotype and may be involved in tumor cell control by their natural capacity to kill B-cells.
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| 9. |
- Lindqvist, Camilla A, et al.
(författare)
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Peripheral T Lymphocytes, Including FoxP3+ T-Cells, Exhibit a Cytotoxic Phenotype in Patients with B-Cell Lymphoma
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Recent studies have shown that high levels of FoxP3+ cells within lymphoma-affected lymph nodes are associated with a better outcome of patients with B-cell lymphoma. This finding is opposite to what has been seen in patients with solid non-hematopoietic tumors. In an attempt to better understand the role of FoxP3+ cell in lymphoma, we collected peripheral blood from 17 patients and determined the level of T regulatory cells (CD3+CD4+FoxP3+CD127low lymphocytes) and FoxP3+CD127high T-cells (CD3+CD4+FoxP3+CD127high lymphocytes). The two subgroups of FoxP3+ T-cells, as well as conventional FoxP3- T-cells, were further analyzed for presence of cytotoxic markers such as FasL and CD107a. Patient plasma was analyzed for the immunosuppressive cytokines IL-10 and TGF-β. Finally, the proliferative capacity of T-cells was assessed using Alamar Blue assay. In lymphoma patients, both FoxP3+ T-cells and conventional T-cells had elevated levels of cytotoxic markers. No significant increase in IL-10 or TGF-β was detected and most patient T-cells had a normal proliferative capacity. This is the first, to our knowledge, study showing a cytotoxic phenotype of FoxP3+ T-cells in patients with B-cell lymphoma.
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| 10. |
- Lindqvist, Camilla A., et al.
(författare)
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T regulatory cells control T-cell proliferation partly by the release of soluble CD25 in patients with B-cell malignancies
- 2010
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Ingår i: Immunology. - : Wiley. - 0019-2805 .- 1365-2567. ; 131:3, s. 371-376
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Tidskriftsartikel (refereegranskat)abstract
- Interleukin-2 (IL-2) is one of the most studied cytokines driving T-cell proliferation, activation and survival. It binds to the IL-2 receptor consisting of three chains, the alpha (CD25), beta and common gamma (gammac). The binding of the CD25 chain to IL-2 is necessary to expose high-affinity binding sites for the beta and gammac chains, which, in turn, are responsible for downstream signalling. A high level of soluble CD25 (sCD25) has been associated with a poor prognosis in patients with non-Hodgkin's lymphoma. The function and source of origin of this soluble receptor is not well investigated. In the present study we hypothesized that T regulatory (Treg) cells may release CD25 to act as a decoy receptor for IL-2, thereby depriving T-effector cells of IL-2. Peripheral blood from patients with B-cell malignancies (n = 26) and healthy controls (n = 27) was investigated for the presence and function of FoxP3(+) Treg cells and sCD25 by multi-colour flow cytometry and enzyme-linked immunosorbent assay. Further, the proliferative capacity of T cells was evaluated with or without the presence of recombinant sCD25. The results demonstrate that Treg cells from patients had lower CD25 expression intensity and that they released CD25 in vitro. Further, high levels of Treg cells correlated with sCD25 plasma concentration. Recombinant sCD25 could suppress T-cell proliferation in vitro. In conclusion, the release of sCD25 by Treg cells may be a mechanism to deprive IL-2 and thereby inhibit anti-tumour T-cell responses.
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