1. |
- Foord, Emelie, et al.
(author)
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Profound Functional Suppression of Tumor-Infiltrating T-Cells in Ovarian Cancer Patients Can Be Reversed Using PD-1-Blocking Antibodies or DARPin (R) Proteins
- 2020
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In: Journal of Immunology Research. - : Hindawi Limited. - 2314-8861 .- 2314-7156. ; 2020
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Journal article (peer-reviewed)abstract
- PD-1/PD-L1 blockade has revolutionized the field of immunooncology. Despite the relative success, the response rate to anti-PD-1 therapy requires further improvements. Our aim was to explore the enhancement of T-cell function by using novel PD-1-blocking proteins and compare with clinically approved monoclonal antibodies (mAbs). We isolated T-cells from the ascites and tumor of 17 patients with advanced epithelial ovarian cancer (EOC) and analyzed the effects using the mAbs nivolumab and pembrolizumab and two novel engineered ankyrin repeat proteins (DARPin (R) proteins). PD-1 blockade with either mAb or DARPin (R) molecule significantly increased the release of IFN-gamma, granzyme B, IL-2, and TNF-alpha, demonstrating successful reinvigoration. The monovalent DARPin (R) protein was less effective compared to its bivalent equivalent, demonstrating that bivalency brings an additional benefit to PD-1 blockade. Overall, we found a higher fold increase of lymphokine secretion in response to the PD-1 blockade by tumor-derived T-cells; however, the absolute amounts were significantly lower compared to the release from ascites-derived T-cells. Our results demonstrate that PD-1 blockade can only partially reinvigorate functionally suppressed T-cells from EOC patients. This warrants further investigation preferably in combination with other therapeutics. The study provides an early pilot proof-of-concept for the potential use of DARPin (R) proteins as eligible alternative scaffold proteins to block PD-1.
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2. |
- Norström, Melissa M., et al.
(author)
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Progression of benign prostatic hyperplasia is associated with pro-inflammatory mediators and chronic activation of prostate-infiltrating lymphocytes
- 2016
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In: Oncotarget. - : Impact Journals LLC. - 1949-2553. ; 7:17, s. 23581-23593
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Journal article (peer-reviewed)abstract
- Benign prostatic hyperplasia (BPH) is a common chronic non-malignant condition whose prevalence substantially increases with age. Immune cell infiltration and pro-inflammatory mediators have been implicated in the pathogenesis. Here, we characterized 21 extracellular markers on prostate-infiltrating lymphocytes (PILs) and analyzed expression of 26 soluble proteins in prostate tissue obtained from BPH patients (n = 31). These data were correlated with clinical parameters and compared with peripheral blood mononuclear cells (PBMCs) (n = 10). Increased frequencies of T cells expressing co-inhibitory receptors LAG-3, PD-1, TIM-3 or CTLA-4, and co-stimulatory receptors CD28, OX40 or 4-1BB were observed in BPH tissue compared to PBMCs. These findings are consistent with chronic activation and possible functional exhaustion of PILs that may be further augmented by several identified pro-inflammatory factors, such as IL-8 and MCP-1, promoting inflammation and chemotaxis of immune cells to the prostate. Prostate size and plasma prostate-specific antigen levels positively correlated with IL-8 and MCP-1 concentrations, and frequencies of T cells expressing CTLA-4 and TIM-3. It remains to be established whether the link between inflammation and BPH progression supported by our findings reflects a progressive failure of the immune system leading to decreased immune surveillance and development of prostate cancer.
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3. |
- Rasmusson, Ida, et al.
(author)
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Mesenchymal stem cells fail to trigger effector functions of cytotoxic T lymphocytes
- 2007
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In: Journal of Leukocyte Biology. - : Oxford University Press (OUP). - 0741-5400 .- 1938-3673. ; 82:4, s. 887-893
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Journal article (peer-reviewed)abstract
- Mesenchymal stem cells (MSCs), isolated from adult human bone marrow, have immunomodulatory properties. The functional outcomes of MSCs-CTL interactions remain poorly characterized. In this study, we demonstrate that MSCs remain resistant to CTL lysis, even after pulsing with the specific synthetic peptide at high concentrations, in spite of surface expression of the relevant MHC class I allele. MSCs were also much less sensitive to lysis by an allo-specific CTL clone as compared with HLA-matched lymphoblastoid cell lines. MSCs induced CD25 up-regulation, albeit at relatively low levels, and were unable to induce CD3 or CD8 down-regulation at the surface of CTLs. MSCs also failed to induce IFN-γ and TNF-α production by the CTLs. Furthermore, peptide-pulsed MSCs were inefficient in stimulating tyrosine phosphorylation in specific CTLs. Our results demonstrate that MSCs induce only an abortive activation program in fully differentiated, effector CTLs, which does not involve activation of major CTL effector functions. These data may have important implications for the development of therapeutic strategies based on administration of in vitro-expanded MSCs.
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4. |
- Sabri, Farideh, et al.
(author)
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Soluble factors released by virus specific activated cytotoxicT-lymphocytes induce apoptotic death of astroglioma cell lines
- 2003
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In: Brain Pathology. - : Wiley. - 1015-6305 .- 1750-3639. ; 13:2, s. 165-175
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Journal article (peer-reviewed)abstract
- Astrocytomas and astrogliomas represent the most common types of primary tumors in human central nervous system and are associated with high mortality due to the absence of efficient therapy. Here we demonstrate that, upon antigen-specific activation, cytotoxic T-lymphocytes (CTLs) secrete products that inhibit proliferation and induce apoptosis in a significant proportion of astroglioma cell lines. This effect is tumor specific in that normal cultured astrocytes do not develop apoptotic changes upon exposure to supernatant of activated CTLs. Experiments with purified lymphokines and lymphokine specific blocking antibodies indicate that synergistic activities of tumor necrosis factor (TNF)-alpha and interferon (INF)-gamma are required for the apoptosis inducing effect on some astroglioma cell lines. However, this effect appears to be dependent on additional factors produced by activated CTLs. Our results suggest that local application of factors released by activated CTLs or induction of CTL migration and activation in the tumor site may have a therapeutic effect in patients with astrogliomas.
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