Project description:Natural killer (NK) cells are immune cells that can kill certain types of cancer cells. Adoptive transfer of NK cells represents a promising immunotherapy for malignant tumours; however, there is a lack of methods to validate anti-tumour activity of NK cells in vivo. Herein, we report a new chemiluminescent probe to image in situ the granzyme B-mediated killing activity of NK cells against cancer cells. We have optimised a granzyme B-specific construct using an activatable phenoxydioxetane reporter so that enzymatic cleavage of the probe results in bright chemiluminescence. The probe shows high selectivity for active granzyme B over other proteases and higher signal-to-noise ratios than commercial fluorophores. Finally, we demonstrate that the probe can detect NK cell activity in mouse models, being the first chemiluminescent probe for in vivo imaging of NK cell activity in live tumours.
Project description:Natural killer (NK) cells are lymphocytes that play an important role in anti-tumour immunity. Their potential against brain cancer has been demonstrated in vitro and in vivo, both as a direct anti-tumour agent and in experimental therapies stimulating endogenous NK cell cytotoxicity. However, the clinical translation of these promising results requires detailed knowledge about the immune status of brain tumour patients, with focus on the NK cell population. In this report, we provide an overview of the studies investigating NK cell infiltration into the tumour, emphasizing the need of revision of the methodologies and further research in this field. We also discuss the potential of using autologous or allogeneic NK cells as effector cells in cellular therapy against brain cancer and developing immunotherapies stimulating endogenous NK cell-mediated anti-tumour response, such as blocking inhibitory killer immunoglobulin-like receptors. Combination of NK cell adoptive transfer with targeted therapies, such as anti-EGFR therapeutic antibody (CetuximAb) could also be a potent strategy.
Project description:The immune system plays a crucial role to prevent local growth and dissemination of cancer. Therapies based on activating the immune system can result in beneficial responses in patients with metastatic disease. Treatment with antibodies targeting the immunological checkpoint axis PD-1 / PD-L1 can result in the induction of anti-tumor T cell activation leading to meaningful long-lasting clinical responses. Still, many patients acquire resistance or develop dose-limiting toxicities to these therapies. Analysis of tumors from patients who progress on anti-PD-1 treatment reveal defective interferon-signaling and antigen presentation, resulting in immune escape from T cell-mediated attack. Natural killer (NK) cells are innate lymphocytes that can kill tumor cells without prior sensitization to antigens and can be activated to kill tumor cells that have an impaired antigen processing and presentation machinery. Thus, NK cells may serve as useful effectors against tumor cells that have become resistant to classical immune checkpoint therapy. Various approaches to activate NK cells are being increasingly explored in clinical trials against cancer. While clinical benefit has been demonstrated in patients with acute myeloid leukemia receiving haploidentical NK cells, responses in patients with solid tumors are so far less encouraging. Several hurdles need to be overcome to provide meaningful clinical responses in patients with solid tumors. Here we review the recent developments to augment NK cell responses against solid tumors with regards to cytokine therapy, adoptive infusion of NK cells, NK cell engagers, and NK cell immune checkpoints.
Project description:BackgroundRecently, allogeneic natural killer (NK) cells have gained considerable attention as promising immunotherapeutic tools due to their unique biological functions and characteristics. Although many NK expansion strategies have been reported previously, a deeper understanding of cryopreserved allogeneic NK cells is needed for specific therapeutic approaches.MethodsWe isolated CD3-CD56+ primary natural killer (pNK) cells from healthy donors and expanded them ex vivo using a GMP-compliant method without any feeder to generate large volumes of therapeutic pNK cells and cryopreserved stocks. After validation for high purity and activating phenotypes, we performed RNA sequencing of the expanded and cryopreserved pNK cells. The pNK cells were used against various cancer cell lines in 7-AAD/CFSE cytotoxicity assay. For in vivo efficacy study, NSG mice bearing subcutaneous cisplatin-resistant A2780cis xenografts were treated with our pNK cells or cisplatin. Antitumor efficacy was assessed by measuring tumor volume and weight.ResultsCompared to the pNK cells before expansion, pNK cells after expansion showed 2855 upregulated genes, including genes related to NK cell activation, cytotoxicity, chemokines, anti-apoptosis, and proliferation. Additionally, the pNK cells showed potent cytolytic activity against various cancer cell lines. Interestingly, our activated pNK cells showed a marked increase in NKp44 (1064-fold), CD40L (12,018-fold), and CCR5 (49-fold), and did not express the programmed cell death protein 1(PD-1). We also demonstrated the in vitro and in vivo efficacies of pNK cells against cisplatin-resistant A2780cis ovarian cancer cells having a high programmed death-ligand 1(PD-L1) and low HLA-C expression.ConclusionsTaken together, our study provides the first comprehensive genome wide analysis of ex vivo-expanded cryopreserved pNK cells. It also indicates the potential use of expanded and cryopreserved pNK cells as a highly promising immunotherapy for anti-cancer drug resistant patients.
Project description:Tissue oxygenation is a driving parameter of the tumor microenvironment, and hypoxia can be a prognostic indicator of aggressiveness, metastasis, and poor response to therapy. Here, we report a chemiluminescence imaging (CLI) agent based on the oxygen-dependent reduction of a nitroaromatic spiroadamantane 1,2-dioxetane scaffold. Hypoxia ChemiLuminescent Probe 2 (HyCL-2) responds to nitroreductase with ?170-fold increase in luminescence intensity and high selectivity for enzymatic reductase versus other small molecule reductants. HyCL-2 can image exogenous nitroreductase in vitro and in vivo in living mice, and total luminescent intensity is increased by ?5-fold under low oxygen conditions. HyCL-2 is demonstrated to report on tumor oxygenation during an oxygen challenge in H1299 lung tumor xenografts grown in a murine model as independently confirmed using multispectral optoacoustic tomography (MSOT) imaging of hemoglobin oxygenation.
Project description:Ex vivo-expanded, allogeneic natural killer (NK) cells can be used for the treatment of various types of cancer. In allogeneic NK cell therapy, NK cells from healthy donors must be expanded in order to obtain a sufficient number of highly purified, activated NK cells. In the present study, we established a simplified and efficient method for the large-scale expansion and activation of NK cells from healthy donors under good manufacturing practice (GMP) conditions. After a single step of magnetic depletion of CD3(+) T cells, the depleted peripheral blood mononuclear cells (PBMCs) were stimulated and expanded with irradiated autologous PBMCs in the presence of OKT3 and IL-2 for 14 days, resulting in a highly pure population of CD3(-)CD16(+)CD56(+) NK cells which is desired for allogeneic purpose. Compared with freshly isolated NK cells, these expanded NK cells showed robust cytokine production and potent cytolytic activity against various cancer cell lines. Of note, expanded NK cells selectively killed cancer cells without demonstrating cytotoxicity against allogeneic non-tumor cells in coculture assays. The anti-tumor activity of expanded human NK cells was examined in SCID mice injected with human lymphoma cells. In this model, expanded NK cells efficiently controlled lymphoma progression. In conclusion, allogeneic NK cells were efficiently expanded in a GMP-compliant facility and demonstrated potent anti-tumor activity both in vitro and in vivo.
Project description:In recent years, the use of natural killer (NK) cell-based immunotherapy has shown promise against various cancer types. To some extent therapeutic potential of NK cell-based immunotherapy depends on migration of NK cells towards tumors in animal models or human subjects and subsequent infiltration. Constant improvement in the pharmacological and therapeutic properties of NK cells is driving the performance and use of NK cell-based immunotherapies. In this review, we summarize the molecular imaging techniques used in monitoring the migration and infiltration of NK cells in vivo at preclinical and clinical levels. A review of pros and cons of each molecular imaging modality is done. Finally, we provide our perception of the usefulness of molecular imaging approaches for in vivo monitoring of NK cells in preclinical and clinical scenarios.
Project description:BackgroundHepatocellular carcinoma (HCC) is common, but remains difficult to treat. Natural killer (NK) cells are cells of the innate immune system that have potent anti-cancer activity. Recent work has shown that stimulation with IL-12/15/18 leads to the generation of NK cells with enhanced functional and putative "memory" properties. We have investigated the activity of these NK cells against HCC cell lines in vitro and in a mouse model.MethodsNK cells from healthy donors or individuals with HCC were activated with IL-12/15/18 in vitro and tested for cytotoxic activity against a panel of human HCC cell lines. IL-12/15/18 primed murine NK cells were then infused into a murine model of spontaneously arising HCC to test for anti-tumor activity.ResultsNK cells from patients and healthy controls had similar expression levels of activating and inhibitory NK cell receptors. However, proliferation of NK cells from HCC patients was weaker than healthy controls in response to IL-12/15/18 and IL-2 (p < 0.001 at day 9). In vitro, NK cells from both groups of individuals killed HCC targets to similar levels and this was unrelated to NKG2D expression. In a spontaneous model of HCC, IL-12/15/18 activated NK cells trafficked to the liver and resulted in lower levels of spontaneous HCC formation (p < 0.01).ConclusionCytokine-primed NK cells from patients with HCC have similar levels of activity against HCC cell lines as those from healthy controls. This type of activated NK cell has immunotherapeutic potential against hepatocellular carcinoma.
Project description:Integrins are a large family of heterodimeric proteins that are involved in cell adhesion, migration, and proliferation. Integrin diversity and function is regulated by alternative splicing. Membrane-bound and truncated β3-integrins were shown to be key players in cancer metastasis. However, the immunomodulatory functions of the soluble (s) β3-integrin have not been investigated yet. In this study, we described a novel form of sβ3-integrin in acute myeloid leukaemia (AML) patients. Furthermore, we assessed the role of the sβ3-integrin in the modulation of natural killer (NK)-cell activity. Levels of sβ3-integrin were analysed in plasma samples of 23 AML patients and 26 healthy donors by ELISA. The capacity of sβ3-integrin to regulate NK cell activity was investigated using proliferation, cytokine secretion, and cytotoxicity assays. Circulating sβ3-integrin was detected in the plasma of 8 AML patients. NK cells showed significantly higher proliferation rates after stimulation with sβ3-integrin and IL-2, IL-15 (73%). Significant increases in the NK cells' secreted levels of TNF-α, IFN-γ were measured in presence of sβ3-integrin. In addition, sβ3-integrin caused the upregulation of Granzyme B transcripts levels as well as FasL expression levels in NK cells. Most importantly, significantly higher K562 or AML blast target cell lysis rates were observed when NK cells were exposed to sβ3-integrin. This study reports the identification of a novel sβ3-integrin in AML patients and provides novel insights into its role in the immunomodulation of NK cell activity.
Project description:ObjectiveNatural killer (NK) cells have gained considerable attention due to their potential in treating "cold tumors," and are therefore considered as one of the new strategies for curing cancer, by using worldwide development of their new possibilities and interventions with NK cell-related therapeutic products.MethodsWe constructed a trispecific killer engager (TriKE) consisting of anti-CD16, IL-15, and anti-CD19. This TriKE was designed to attract CD19+ tumor cells to CD16+ NK cells, whereas IL-15 sustained the proliferation, development, and survival of NK cells.ResultsTreatment with 161519 TriKE in the presence of CD19+ targets upregulated expression of CD69, CD107a, TRAIL, IFN-γ, and TNF-α in NK cells, and significantly improved the proliferation and cytotoxicity of NK cells. NK cells "armed" with 161519 TriKE showed stronger cytolysis against CD19+ targets compared with that of "unarmed" NK cells. A preclinical model of B-cell lymphoma in human peripheral blood mononuclear cell-reconstituted xenograft mice showed significant inhibition of tumor growth and prolonged overall survival after treatment with 161519 TriKE, when compared with that in control mice or mice treated with 1619 BiKE. Combined use of IL-2 was a more effective treatment with 1619 BiKE, when compared with that using 161519 TriKE.ConclusionsThe newly generated 161519 TriKE enhanced the proliferation, activation, cytokine secretion, and cytotoxicity of NK cells in the presence of CD19+ tumor cells. The 161519 TriKE aided inhibition of tumor growth and prolonged the overall survival of murine xenografts, and could be used to treat CD19-positive cancers.