TALL-104 Cells Research Articles

Cytotoxic immune cells do not affect TDP-43 and p62 sarcoplasmic aggregation but influence TDP-43 localisation

Sporadic inclusion body myositis (sIBM) is an idiopathic inflammatory myopathy with invasion of CD8 T cells in muscle and aggregation of proteins in the sarcoplasm. TDP-43 and p62 are two proteins that aggregate in affected muscle, and have been suggested as specific markers for sIBM over other inflammatory myopathies. TDP-43 is also mislocalised from the nucleus to the sarcoplasm in sIBM. It is not clear if inflammation precedes protein aggregation in sIBM. This study investigated if exposure to cytotoxic inflammatory cells caused TDP-43 and p62 aggregation or TDP-43 mislocalisation in cultured myotubes. TALL-104 coculture was highly cytotoxic to myotubes after 24 h. Secretion of IFNγ and TNFα were higher in cocultures compared to monocultured TALL-104 cells, indicating activation. TALL-104 cells attached to and infiltrated myotubes. There was no effect of TALL-104 coculture on TDP-43 or p62 sarcoplasmic aggregate size or frequency. However, there was decreased localisation of TDP-43 to the nucleus with TALL-104 coculture compared to control. In an in vitro setting, cytotoxic immune cells did not cause TDP-43 or p62 sarcoplasmic aggregation, suggesting cellular cytotoxicity may not trigger aggregation of these proteins. However TALL-104 coculture influenced TDP-43 localisation, suggesting cytotoxic immune cells may contribute to TDP-43 localisation shifts which is observed in sIBM.

Vascular Immune Evasion of Mesenchymal Glioblastoma Is Mediated by Interaction and Regulation of VE-Cadherin on PD-L1.

The mesenchymal subtype of glioblastoma (mGBM), which is characterized by rigorous vasculature, resists anti-tumor immune therapy. Here, we investigated the mechanistic link between tumor vascularization and the evasion of immune surveillance. Clinical datasets with GBM transcripts showed that the expression of the mesenchymal markers YKL-40 (CHI3L1) and Vimentin is correlated with elevated expression of PD-L1 and poor disease survival. Interestingly, the expression of PD-L1 was predominantly found in vascular endothelial cells. Orthotopic transplantation of glioma cells GL261 over-expressing YKL-40 in mice showed increased angiogenesis and decreased CD8+ T cell infiltration, resulting in a reduction in mouse survival. The exposure of recombinant YKL-40 protein induced PD-L1 and VE-cadherin (VE-cad) expression in endothelial cells and drove VE-cad-mediated nuclear translocation of β-catenin/LEF, where LEF upregulated PD-L1 expression. YKL-40 stimulated the dissociation of VE-cad from PD-L1, rendering PD-L1 available to interact with PD-1 from CD8+-positive TALL-104 lymphocytes and inhibit TALL-104 cytotoxicity. YKL-40 promoted TALL-104 cell migration and adhesion to endothelial cells via CCR5-dependent chemotaxis but blocked its anti-vascular immunity. Knockdown of VE-cad or the PD-L1 gene ablated the effects of YKL-40 and reinvigorated TALL-104 cell immunity against vessels. In summary, our study demonstrates a novel vascular immune escape mechanism by which mGBM promotes tumor vascularization and malignant transformation.

Abstract 3266: Classical chemotherapy modulates cytokine secretion in the MSS CRC immune microenvironment and enhances T cell killing

Abstract Metastatic colorectal cancer (mCRC) is the third deadliest cancer and has a five-year survival rate of 14%. Most patients receive chemotherapies 5-FU and folinic acid combined with oxaliplatin, irinotecan, or both. Immune checkpoint inhibitors (ICI) are effective for 3% of patients with microsatellite instable (MSI) tumors but 97% of patients have ICI-resistant microsatellite stable (MSS) tumors. Chemotherapy-mediated sensitization of MSS CRC to immune cell killing has been described in preclinical models and in the CheckMate 9X8 clinical trial. We hypothesize that chemotherapy modulates cytokine secretion within the MSS CRC tumor microenvironment and can enhance immune cell killing in certain contexts. SW480 and HT29 cells were pre-treated with chemotherapy (IC5072h, 24 hours), then co-cultured with TALL-104 cells -/+ pembrolizumab to measure immune cell-mediated killing. Using the Luminex 200 platform, the levels of 50+ cytokines were measured after chemotherapy treatment of SW480 and HT29 cells (IC5072h, 48 hours) and TALL-104 and NK-92 cells (1 µM or 10 µM, 36 hours). A humanized mouse model was established by injecting HCT 116 tumor-bearing nude mice with TALL-104 cells. Infiltration of injected TALL-104 cells was measured in mice that received either 5-FU + oxaliplatin or 5-FU + irinotecan. 5-FU + folinic acid + oxaliplatin -/+ pembrolizumab enhances TALL-104-mediated killing of SW480 and HT29 cells. In TALL-104 cells, soluble DcR3 increased significantly after low-dose 5-FU + oxaliplatin and the triple treatment but did not change with 5-FU + irinotecan. The triple treatment also slightly reduced GrB levels and MIF trended upward with all treatments. In NK-92 cells, B2M, CHI3L1, IL-10, IFN-γ, CCL3, CCL4, FasL, GrB, and IL-6 significantly decreased after all treatments and M-CSF increased with low-dose triple treatment. In SW480 cells, CHI3L1, IL-10, GrB, CCL2, and VEGF decreased after all treatments. GM-CSF increased only with 5-FU + oxaliplatin. In the humanized mouse model, there was a trend toward increased TALL-104 cell infiltration in chemotherapy pre-treated tumors. Chemotherapy tends to decrease cytokine secretion of TALL-104 and NK-92 cells. GM-CSF increases after 5-FU + oxaliplatin treatment in SW480 and HT29 cells, and pre-treatment with this regimen also enhances TALL-104-mediated killing of SW480 and HT29 cells -/+ ICI, pointing to 5-FU + oxaliplatin-induced GM-CSF as a mediator of chemotherapy-dependent enhancement of T cell killing. Chemotherapy pre-treatment may enhance TALL-104 cell infiltration in MSI tumors. Future directions include evaluation of concurrent vs. sequential chemotherapy + immunotherapy regimens using murine models of MSS colorectal cancer and isolation of circulating tumor cells from patients before and after chemotherapy treatment to measure effects on cytokine secretion and immune cell killing. Citation Format: Lindsey Carlsen, Kelsey E. Huntington, Wafik El-Deiry. Classical chemotherapy modulates cytokine secretion in the MSS CRC immune microenvironment and enhances T cell killing [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3266.

Abstract 3265: Temozolomide combined with ipilimumab + nivolumab enhances T cell killing of MGMT-expressing, MSS colorectal cancer cells

Abstract Colorectal cancer (CRC) is the third most frequently diagnosed cancer and third-deadliest cancer globally. Approximately 95% of patients with metastatic CRC have tumors that are microsatellite stable (MSS) and do not respond to immune checkpoint inhibitors (ICI). Results from the 2022 MAYA clinical trial suggest that the DNA-damaging agent temozolomide (TMZ), which is usually used to treat glioblastoma (GBM), sensitizes patients with MSS, MGMT-silenced CRC to ipilimumab + nivolumab ICI. The benefit of adding ipilimumab + nivolumab to TMZ and the impact of MGMT silencing remain unclear. Here, we aimed to determine in a controlled in vitro system if adding ICI to TMZ enhances T cell killing of MSS CRC cells. We also aimed to determine the role of MGMT in this response. MGMT protein expression was measured by western blot in CRC (n=4) and GBM (n=4) cell lines. Cell viability assays were conducted to measure sensitivity to TMZ. CRC and GBM cells were co-cultured with TALL-104 cells -/+ TMZ and -/+ ICI to measure TALL-104-mediated cell death. Western blot analysis indicated that CRC cells had significantly elevated MGMT expression as compared to GBM cells likely due to MGMT promoter methylation in GBM cells. In line with this, CRC cells were slightly more resistant to TMZ (IC50=100-150 µM) compared to GBM cells (IC50=10-90 µM) after five days of treatment. TMZ + ICI sensitized MGMT-expressing, MSS CRC cells to T cell killing. TMZ alone did not enhance T cell killing of MSS or MSI CRC cells but did enhance T cell killing of T98G GBM cells. Our results indicate that TMZ sensitizes MSS, MGMT-expressing CRC cells to ipilimumab + nivolumab ICI. Importantly, this suggests that TMZ-mediated sensitization to ipilimumab + nivolumab is independent of MGMT status and the patient cohort that may benefit TMZ + ipilimumab + nivolumab may be expanded to CRC patients with MGMT-expressing, MSS tumors. Citation Format: Zenovia Gonzalez, Lindsey J. Carlsen, Wafik S. El-Deiry. Temozolomide combined with ipilimumab + nivolumab enhances T cell killing of MGMT-expressing, MSS colorectal cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3265.

Abstract 1819: Integrin inhibitor GLPG-0187 promotes T-cell killing of mismatch repair-deficient colorectal cancer cells by suppression of SMAD/TGF-β signaling

Abstract Colorectal cancer is the third leading cause of cancer-related death and the third most common cause of cancer. As the five-year survival with advanced metastatic colorectal cancer (mCRC) is 14%, new treatment strategies are needed. Immune checkpoint blockade which takes advantage of an individual's immune system in order to fight cancer, is a promising future direction of research, although it is only effective and approved for the treatment of mismatch repair (MMR)-deficient CRCs. Long-term outcomes even in MMR-deficient mCRC suggest that most patients are not cured but eventually develop therapy resistance. We hypothesized that targeting TGF- β signaling may enhance immune-mediated T-cell killing by MMR-deficient CRC cells. Using GLPG-0187, an inhibitor of multiple integrin receptors and TGF- β, we demonstrate minimal cytotoxicity against MMR-deficient HCT116 or p53-null HCT116 human CRC cells. However, GLPG-0187 promoted significant immune cell killing of the CRC cells by TALL-104 T lymphoblast cells. GLPG-0187 reduced pSMAD2 in HCT116 p53-null cells either in the absence or presence of exogenous TGF- β. We observed a reduction in CCL20, CXCL5, prolactin, and TRAIL-R3 while GDF-15 was increased in TALL-104 cells treated with a T-cell activating dose of GLPG-0187 (4 μM). Our results suggest that TGF- signaling inhibition by a general integrin receptor inhibitor may boost T-cell killing of MMR-deficient colorectal cancer cells, and suggest that a combination of anti-GDF-15 in combination with TGF- β blockade should be further investigated in the treatment of MMR-deficient mCRC. Our results support the development of a novel immune-based therapeutic strategy to treat colorectal cancer by targeting the TGF-β signaling pathway through integrin receptor blockade. Citation Format: Brooke Verschleiser, William MacDonald, Lindsey Carlsen, Kelsey E. Huntington, Lanlan Zhou, Wafik El-Deiry. Integrin inhibitor GLPG-0187 promotes T-cell killing of mismatch repair-deficient colorectal cancer cells by suppression of SMAD/TGF-β signaling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1819.

Construction and stable gene expression of AGR2xPD1 bi-specific antibody that enhances attachment between T-Cells and lung tumor cells, suppress tumor cell migration and promoting CD8 expression in cytotoxic T-cells

There has been a substantial and consistent rise in the number of clinical trials to develop advanced and potent bispecific antibodies (BsAb) over the past two decades with multiple targets to improve the efficacy or tissue specificity of monoclonal antibodies (mAb) treatment for diseases with multiple determining factors or widely-expressed targets. In this study, we designed and synthesized BsAb AGR2xPD1 targeting extracellular AGR2, a paracrine signal, and PD1, an immune checkpoint protein. Our design is intended to use AGR2 binding to guide PD1 targeting for AGR2+cancer. We used this construction to produce AGR2xPD1 BsAb by generating clonally selected stable 293F cell line with high expression. Applying this BsAb in a T cell-Tumor cell co-culture system showed that targeting both PD1 and AGR2 with this BsAb induces the attachment of TALL-104 (CD8+T-lymphocytes) cells onto co-cultured H460 AGR2+ Lung tumor cells and significantly reduces migration of H460 cells. T-cell expression of CD8 and IFNγ is also synergistically enhanced by the AGR2xPD1 BsAb treatment in the AGR2+H460 co-culture system. These effects are significantly reduced with AGR2 expression negative WI38 cells. Our results demonstrate that the AGR2xPD1 BsAb could be a potential therapeutic agent to provide better solid tumor targeting and synergetic efficacy for treating AGR2+ cancer by blocking AGR2 paracrine signaling to reduce tumor survival, and redirecting cytotoxic T-cells into AGR2+ cancer cells.

2'-Hydroxy-4',5'-dimethoxyacetophenone Exhibit Collagenase, Aldose Reductase Inhibition, and Anticancer Activity Against Human Leukemic Cells: An In Vitro, and In Silico Study.

Diabetes is a serious growing concern that affects many parts of the body including the skin due to high sugar levels. Moreover, diabetic patients are at risk of developing cancer and are prone to a higher risk of hematological malignancies. In the present study, the inhibitory effect of 2'-Hydroxy-4',5'-dimethoxyacetophenone was investigated on aldose reductase and collagenase enzymes, along with docking and ADMET analysis. MTT assay was also conducted to investigate the anti-leukemic effect of 2'-Hydroxy-4',5'-dimethoxyacetophenone on human acute leukemia cells (32D-FLT3-ITD, Human HL-60/vcr, MOLT-3, and TALL-104 cell lines) and DPPH assay for establishing activity against oxidative stress. The 2'-Hydroxy-4',5'-dimethoxyacetophenone showed potent inhibition of both the above tested enzymes with numerous strong interactions with the key catalytic residues in the active site of the enzymes. The MTT assay showed strong anti-cancer activity against entire tested human acute leukemia cells and was found non-toxic to normal (HUVEC) at the tested concentration. In DPPH free radical scavenging assay, 2'-Hydroxy-4',5'-dimethoxyacetophenone showed strong inhibitory activity with IC50 of 157µg/mL, which found comparable to the standard BHT. Our study demonstrated prominent pharmacological benefit of 2'-Hydroxy-4',5'-dimethoxyacetophenone, against various leukemic cell lines, aldose reductase and collagenase enzymes, and free radical scavenging activity.

WIN Symposium 2022 - Abstract Poster Presentations.

WIN Symposium 2022 - Abstract Poster Presentations.

Senescence-Associated Molecules and Tumor-Immune-Interactions as Prognostic Biomarkers in Colorectal Cancer

Background and AimsThe initiation of cellular senescence in response to protumorigenic stimuli counteracts malignant progression in (pre)malignant cells. Besides arresting proliferation, cells entering this terminal differentiation state adopt a characteristic senescence-associated secretory phenotype (SASP) which initiates alterations to their microenvironment and effects immunosurveillance of tumorous lesions. However, some effects mediated by senescent cells contribute to disease progression. Currently, the exploration of senescent cells' impact on the tumor microenvironment and the evaluation of senescence as possible target in colorectal cancer (CRC) therapy demand reliable detection of cellular senescence in vivo. Therefore, specific immunohistochemical biomarkers are required. Our aim is to analyze the clinical implications of senescence detection in colorectal carcinoma and to investigate the interactions of senescent tumor cells and their immune microenvironment in vitro and in vivo.MethodsSenescence was induced in CRC cell lines by low-dose-etoposide treatment and confirmed by Senescence-associated β-galactosidase (SA-β-GAL) staining and fluorescence activated cell sorting (FACS) analysis. Co-cultures of senescent cells and immune cells were established. Multiple cell viability assays, electron microscopy and live cell imaging were conducted. Immunohistochemical (IHC) markers of senescence and immune cell subtypes were studied in a cohort of CRC patients by analyzing a tissue micro array (TMA) and performing digital image analysis. Results were compared to disease-specific survival (DSS) and progression-free survival (PFS).ResultsVarying expression of senescence markers in tumor cells was associated with in- or decreased survival of CRC patients. Proximity analysis of p21-positive senescent tumor cells and cytotoxic T cells revealed a significantly better prognosis for patients in which these cell types have the possibility to directly interact. In vitro, NK-92 cells (mimicking natural killer T cells) or TALL-104 cells (mimicking both cytotoxic T cells and natural killer T cells) led to dose-dependent specific cytotoxicity in >75 % of the senescent CRC cells but <20 % of the proliferating control CRC cells. This immune cell-mediated senolysis seems to be facilitated via direct cell-cell contact inducing apoptosis and granule exocytosis.ConclusionCounteracting tumorigenesis, cellular senescence is of significant relevance in CRC. We show the dual role of senescence bearing both beneficial and malignancy-promoting potential in vivo. Absence as well as exceeding expression of senescence markers are associated with bad prognosis in CRC. The antitumorigenic potential of senescence induction is determined by tumor micromilieu and immune cell-mediated elimination of senescent cells.

The fungal Clitocybe nebularis lectin binds distinct cell surface glycoprotein receptors to induce cell death selectively in Jurkat cells.

Clitocybe nebularis lectin (CNL) is a GalNAcβ1-4GlcNAc-binding lectin that exhibits an antiproliferative effect exclusively on the Jurkat leukemic T cell line by provoking homotypic aggregation and dose-dependent cell death. Cell death of Jurkat cells exhibited typical features of early apoptosis, but lacked the activation of initiating and executing caspases. None of the features of CNL-induced cell death were effectively blocked with the pan-caspase inhibitor or different cysteine peptidase inhibitors. Furthermore, CNL binding induced Jurkat cells to release the endogenous damage-associated molecular pattern molecule high-mobility group box 1 (HMGB1). A plant lectin with similar glycan-binding specificity, Wisteria floribunda agglutinin (WFA) showed less selective toxicity and induced cell death in Jurkat, Tall-104, and Hut-87 cell lines. HMGB1 release was also detected when Jurkat cells were treated with WFA. We identified the CD45 and CD43 cell surface glycoproteins on Jurkat cells as the main targets for CNL binding. However, the blockade of CD45 phosphatase activity failed to block either CNL-induced homotypic agglutination or cell death. Overall, our results indicate that CNL triggers atypical cell death selectively on Jurkat cells, suggesting the potential applicability of CNL in novel strategies for treating and/or detecting acute T cell leukemia.

Formulation, Characterization, Antioxidant, Cytotoxicity, and Anti-acute Leukemia Effects of Fe Nanoparticles.

In this study, iron nanoparticles were prepared and synthesized in aqueous medium using Cinnamomum verum as stabilizing and reducing agents. We determined the anti-acute leukemia potentials of FeNPs against acute T cell leukemia and acute lymphoblastic leukemia cell lines. FeNPs inhibited half of the DPPH molecules in the concentration of 139 µg/mL. MTT assay was used on J.RT3-T3.5 (Acute T cell leukemia cell line), Jurkat, Clone E6-1 (Acute T cell leukemia cell line), MOLT-3 (Acute lymphoblastic leukemia cell line), TALL-104 (Acute lymphoblastic leukemia cell line), and HUVEC (Normal cell line) for analyzing of cytotoxicity and anti-acute leukemia effects of FeNPs. These nanoparticles had high cell death and anti-acute leukemia effects against J.RT3-T3.5, Jurkat, Clone E6-1, MOLT-3, and TALL-104 cell lines. Among the above cell lines, the best result of anti-acute leukemia properties of composite was gained in the cell line of Jurkat, Clone E6-1. All result showed the iron nanoparticles may be used as a chemotherapeutic treatment drug of leukemia in humans.

Anti-human acute leukemia, cytotoxicity, antioxidant, and collagenase and aldose reductase inhibition effects of 2′-Hydroxy-4′,5′-dimethoxyacetophenone in the in vitro condition

IntroductionIn this study, it is recorded the inhibition effect of 2′-Hydroxy-4′,5′-dimethoxyacetophenone on aldose reductase and collagenase enzymes. Also, we have investigated that the in vitro inhibition effects of 2′-Hydroxy-4′,5′-dimethoxyacetophenone on aldose reductase and collagenase enzymes.Material and methodsTo investigate the antioxidant effects of 2′-Hydroxy-4′,5′-dimethoxyacetophenone, the DPPH test was used in the presence of butylated hydroxytoluene as the positive control. MTT test was used on normal (HUVEC) and human acute leukemia (32D-FLT3-ITD, Human HL-60/vcr, MOLT-3, and TALL-104) cell lines. 2′-Hydroxy-4′,5′-dimethoxyacetophenone had high cell death and anti-human acute leukemia effects against 32D-FLT3-ITD, Human HL-60/vcr, MOLT-3, and TALL-104 cell lines.ResultsThe 2′-Hydroxy-4′,5′-dimethoxyacetophenone inhibited half of the DPPH molecules in the concentration of 157 µg/mL. Among the above cell lines, the best result of anti-human acute leukemia properties of silver nanoparticles was gained in the cell line of UM-UC-3. The results of this study indicated the excellent anti-human acute leukemia potentials of 2′-Hydroxy-4′,5′-dimethoxyacetophenone in the in vitro condition.ConclusionsAfter confirming the above results in the clinical trial researches, this formulation may be administrated for the treatment of several types of acute leukemia in humans. After that, the comparison of the biological activities of the 2′-Hydroxy-4′,5′-dimethoxyacetophenone molecule against the studied enzymes was done by molecular docking method.

Abstract 2736: Decreasing colorectal cancer extracellular pH dampens immune cell killing and is partially ameliorated by treatment with NHE1 inhibitor Cariporide

Abstract Tumor cells upregulate a plethora of proteins that are important for pH regulation, resulting in the acidification of the extracellular tumor microenvironment. Abnormal pH is known to dampen immune function, resulting in a worsened anti-tumor immune response. Understanding how alterations in pH modulate the interactions between immune cells and tumors cells could help elucidate opportunities for new therapeutic approaches. To determine how pH modification impacts immune cell-mediated killing of tumor cells, co-culture experiments were conducted with GFP+ SW480 colorectal cancer cells and either NK-92 natural killer cells or TALL-104 T cells at various pHs in a 48-well plate. Manipulation of pH occurred using the compounds lactic acid and sodium bicarbonate. We observed that both NK-92 cells and TALL-104 cells exhibited decreasing amounts of cell killing in response to decreasing pH. Next, to determine if therapeutic manipulation of pH via alteration of pH pump activity could overcome the negative changes in immune cell activity associated with pH, we added Cariporide, a selective NHE1 inhibitor, to the co-culture experiments. Treatment with Cariporide bolstered T cell killing in a dose-dependent manner, however the doses used did not impact natural killer cell-mediated killing. Given the importance of cell signaling on immune function, and because we saw potentially significant changes in immune killing with Cariporide, we then evaluated how changes in pH using Cariporide affected these signaling molecules. Colorectal cancer cells (HCT116, HT29, KM12C) were treated with Cariporide at 5 µm and 10 µm doses and cancer cell culture supernatants were collected and frozen down at -80 °C. Cytokine, chemokine, and growth factor levels were analyzed using a Luminex 200 multiplexing instrument. Overall cytokine levels showed a decreasing trend in response to increasing doses of Cariporide. There were notable decreases in the levels of IL-8/CXCL8, VEGF, CCL3/MIP-1 alpha, and M-CSF with increasing doses of Cariporide. All of these factors, as well as extracellular acidosis, are known to promote epithelial mesenchymal transition (EMT), thus, promoting metastatic dissemination. A therapeutic that targets factors that lead to EMT could help prevent metastasis. Moreover, we saw that pH impacts the function of immune cells and this is relevant in the context of a highly acidic TME. Therapeutically modifying the pH of the TME using Cariporide treatment may be a way to improve immune response and prevent EMT. These experiments can help inform future investigations into how the pH of the tumor microenvironment may be extrinsically modulated to improve anti-tumor immune response. Citation Format: Kelsey E. Huntington, Aaron W. Maxwell, Anna Louie, Shengliang Zhang, Lanlan Zhou, Wafik S. El-Deiry. Decreasing colorectal cancer extracellular pH dampens immune cell killing and is partially ameliorated by treatment with NHE1 inhibitor Cariporide [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2736.

Cytotoxicity, anti-acute leukemia, and antioxidant properties of gold nanoparticles green-synthesized using Cannabis sativa L leaf aqueous extract

Metallic nanoparticles, especially gold nanoparticles, are used in the therapy of various diseases. Recently, many chemotherapeutic supplements or drugs have been formulated with gold nanoparticles. One option for synthesizing gold nanoparticles is to use herbs. Many previous studies have shown that medicinal herbs increase the antioxidant and cytotoxicity properties of gold nanoparticles against tumor cell lines. In this study, gold nanoparticles were prepared and synthesized in an aqueous medium using Cannabis sativa L leaf extract as stabilizing and reducing agents. In addition, we evaluated the anti-leukemia effects of gold nanoparticles against acute T-cell leukemia and lymphoblastic leukemia cell lines. Characterization of gold nanoparticles was done with FE - SEM, FT - IR, UV–Vis and TEM. The MTT test is used for anti-HAuCl4, C. sativa and C. Acute leukemia effects of AuNPs. To investigate the antioxidant potentials of HAuCl4, C. sativa aqueous extract and gold nanoparticles, the DPPH test was used in the presence of butylated hydroxytoluene as control. In UV–Vis, the clear peak at 538 nm wavelength showed the formation of gold nanoparticles. In the FT-IR, many antioxidant molecules with relevant bonds led to the perfect condition for gold reduction in gold nanoparticles. In addition, in TEM and FE-SEM images, gold nanoparticles were spherical, with an average size of 18.6 nm. The IC50 of gold nanoparticles were 329, 381, 275 and 218 µg / mL against MOLT-3, TALL-104, J.RT3-T3.5 and Clone E6-1 cell lines, and Jurkat, respectively. The best results of the anti-acute leukemia properties of gold nanoparticles were obtained in the Clone E6-1 cell line. Gold nanoparticles inhibited half of the DPPH at a concentration of 196 µg/mL. The above results confirm the excellent roles of the gold nanoparticles as new chemotherapeutic drugs in treating various types of acute leukemia.

Extracellular Cystatin F Is Internalised by Cytotoxic T Lymphocytes and Decreases Their Cytotoxicity.

Simple SummaryCytotoxic T lymphocytes kill cancer or virally infected cells by exocytosis of lytic granules. This leads to perforin-mediated granzyme entry into the target cell, consequently killing the target cell. Granzymes and perforin are activated by cysteine cathepsins whose activity is regulated by the protein inhibitor cystatin F. Since cystatin F can be secreted by a range of cancer and immune cells in tumour microenvironments, we here investigated whether extracellular cystatin F can be taken up by and affect the function of cytotoxic T lymphocytes. We demonstrated cystatin F uptake into cytotoxic T lymphocytes, down-regulation of target peptidases, and reduced target cell killing. Overall, our results indicate that cystatin F is an important mediator that can impair the killing efficiency of cytotoxic T lymphocytes and thus suggest that it is a possible target for cancer immunotherapy.Cystatin F is a protein inhibitor of cysteine cathepsins, peptidases involved in the activation of the effector molecules of the perforin/granzyme pathway. Cystatin F was previously shown to regulate natural killer cell cytotoxicity. Here, we show that extracellular cystatin F has a role in regulating the killing efficiency of cytotoxic T lymphocytes (CTLs). Extracellular cystatin F was internalised into TALL-104 cells, a cytotoxic T cell line, and decreased their cathepsin C and H activity. Correspondingly, granzyme A and B activity was also decreased and, most importantly, the killing efficiency of TALL-104 cells as well as primary human CTLs was reduced. The N-terminally truncated form of cystatin F, which can directly inhibit cathepsin C (unlike the full-length form), was more effective than the full-length inhibitor. Furthermore, cystatin F decreased cathepsin L activity, which, however, did not affect perforin processing. Cystatin F derived from K-562 target cells could also decrease the cytotoxicity of TALL-104 cells. These results clearly show that, by inhibiting cysteine cathepsin proteolytic activity, extracellular cystatin F can decrease the cytotoxicity of CTLs and thus compromise their function.

Chrysophanol suppresses growth and metastasis of T cell acute lymphoblastic leukemia via miR-9/PD-L1 axis.

T cell acute lymphoblastic leukemia (T-ALL) was a malignant lymphoma. Therefore, the development of novel therapeutic agents against T-ALL is imperative. Previous studies have shown that chrysophanol (CHL), an anthraquinone compound isolated from the Rheum palmatum L., exerts anti-proliferative and anti-metastatic effects in multiple malignant tumors. However, the effect of CHL on the progression of TALL is poorly understood. The aim of this study was to explore the role of CHL in the biological behavior of T-ALL cells and determine its underlying mechanism. Both T-ALL cell lines (Jurkat and TALL-104) were treated with CHL. The proliferation, apoptosis, migration, and invasion of T-ALL cells were determined by CCK-8, flow cytometry, wound healing, and Transwell assay, respectively. Western blot and RT-qPCR were applied to examine gene expression. The dual-luciferase reporter gene assay was employed to examine the regulation mechanism of miR-9 and PD-L1. A T-ALL xenograft model also was used to examine the effect of CHL on the tumor growth and metastasis in vivo. CHL treatment significantly inhibited the proliferation, migration, and invasion ability of both Jurkat and TALL-104 cells and induced cell apoptosis and the expression of miR-9. Moreover, miR-9 was proved to target PD-L1 by binding to its 3'-untranslated region (UTR). Mechanically, pretreated with PD-L1 inhibitor could augment the anti-proliferation and anti-metastatic effect of CHL, while miR-9-silenced alleviated this effect. Consistent with in vitro studies, CHL significantly suppressed the growth and metastasis of tumor in vivo. Our finding uncovers the antitumorigenic effect of CHL in T-ALL progression through upregulating the expression of miR-9 and suppressing PD-L1 expression, which may provide a new potential strategy for T-ALL clinical treatment.

Increased cystatin F levels correlate with decreased cytotoxicity of cytotoxic T cells.

BackgroundCystatin F is a protein inhibitor of cysteine peptidases, expressed predominantly in immune cells and localised in endosomal/lysosomal compartments. In cytotoxic immune cells cystatin F inhibits both the major pro-granzyme convertases, cathepsins C and H that activate granzymes, and cathepsin L, that acts as perforin activator. Since perforin and granzymes are crucial molecules for target cell killing by cytotoxic lymphocytes, defects in the activation of either granzymes or perforin can affect their cytotoxic potential.Materials and methodsLevels of cystatin F were assessed by western blot and interactions of cystatin F with cathepsins C, H and L were analysed by immunoprecipitation and confocal microscopy. In TALL-104 cells specific activities of the cathepsins and granzyme B were determined using peptide substrates.ResultsTwo models of reduced T cell cytotoxicity of TALL-104 cell line were established, either by treatment by ionomycin or by immunosuppressive transforming growth factor beta. Reduced cytotoxicity correlated with increased levels of cystatin F and with attenuated activities of cathepsins C, H and L and of granzyme B. Co-localisation of cystatin F and cathepsins C, H and L and interactions between cystatin F and cathepsins C and H were demonstrated.ConclusionsCystatin F is designated as a possible regulator of T cell cytotoxicity, similar to its role in natural killer cells.

MiR-196b/miR-1290 participate in the antitumor effect of resveratrol via regulation of IGFBP3 expression in acute lymphoblastic leukemia

MicroRNAs play critical roles in the progression of acute lymphoblastic leukemia (ALL). Previous studies have indicated that miR-196b and miR-1290 play critical roles in T-cell ALL (T-ALL) and B-cell ALL (B-ALL), respectively. Resveratrol, a natural edible polyphenolic phytoalexin, possesses certain anticancer activities. Nevertheless, the mechanism involved in the regulation of ALL by resveratrol is still poorly understood. The present study aimed to reveal the potential mechanism underlying the antitumor effect of resveratrol in ALL focusing on miRNAs. Research indicates that insulin-like growth factor binding protein3 (IGFBP3) plays a critical role in the aetiology of ALL. In the present study, we first demonstrated that the expression of IGFBP3 was decreased in ALL patients. We further identified that miR-196b and miR-1290 were overexpressed in T-ALL TALL-104 and B-ALL SUP-B15 cell lines, respectively. Moreover, resveratrol markedly decreased the overexpression of miR-196b/miR-1290 and elevated IGFBP3 expression in the ALL cell lines. As an miR-196b/miR-1290 inhibitor, resveratrol was further demonstrated to exert antitumor effects on ALL cells including antiproliferation, cell cycle arrest, apoptosis and inhibition of migration. Dual-luciferase reporter assay revealed that miR-196b/miR-1290 directly bound to the 3'-untranslated (3'-UTR) region of IGFBP3 mRNA. Moreover, we observed that IGFBP3 short interfering RNA reversed the antitumor activity of resveratrol against ALL cells. Taken together, the present study provides evidence that resveratrol targets miR-196b and miR-1290 for its antitumor activity in T-ALL and B-ALL, respectively. The present study also confirms that both miR‑196b and miR-1290 target the IGFBP3 3'-UTR and are potential therapeutic targets for ALL.

Abstract B182: IGN004 is an antibody-interferon-alpha fusion protein against a novel tumor-associated antigen with both direct anti-tumor and immunostimulatory effects

Abstract Background: Antibody-IFNα fusion proteins represent a cancer therapeutic with properties of an antibody-drug conjugate and an immunotherapeutic agent, having both direct anti-tumor and immune-activating effects. These powerful molecules have the potential to target the anti-tumor cytotoxic effects of IFN to the tumor and to change the immunosuppressive tumor microenvironment to activate anti-tumor immunity. We previously reported the activity of IGN002, a recombinant anti-CD20-IFNα fusion protein, against human non-Hodgkin B-cell lymphomas (Yamada et al, JCO 2013). We now report the in vitro and in vivo anti-tumor activity of IGN004, an antibody-IFNα fusion protein against a novel tumor associated antigen expressed by many solid and liquid tumors. Methods: IGN004 was evaluated against a panel of human non-small cell lung cancer (NSCLC), melanoma, multiple myeloma (MM), and acute myeloid leukemia (AML) cell lines. Antigen expression was assessed by flow cytometry and immunohistochemistry (IHC). Anti-proliferative activity was measured by MTS assay. MHC, costimulatory, and coinhibitory molecule expression was assessed by flow cytometry. T-cell killing of tumor cells by TALL-104 effector cells was assessed by MTS assay. Human tumor cell line and patient-derived xenografts were grown in immunodeficient mice. Results: IGN004 antibody bound to the majority of tumor cell lines investigated, including melanoma, NSCLC, AML, and MM. In addition, IGN004 antibody also bound to nearly 100% of the primary solid tumor samples tested by IHC. IGN004 induced stronger growth inhibition than the unfused antibody and IFNα. Incubation of tumor cells with IGN004 caused an increase in surface expression of MHC class I, PD-L1, and OX-40L. In an in vitro T-cell killing assay using TALL-104 cells as effectors and NSCLC cells as targets, treatment of tumor cells with IGN004 led to increased effector cell killing of tumor targets (69.2% killing without IGN004 vs. 100% killing with IGN004; p = 0.001). The enhanced T-cell killing was observed even with concentrations at the sub-picomolar level (EC50 = 0.87 pM). Importantly, IGN004 demonstrated robust in vivo efficacy against MM, AML, melanoma, and NSCLC xenografts, including patient-derived tumors. Against U266 MM xenografts, IGN004 fusion protein caused complete regression of all established tumors and achieved long-term survival in 62.5% of mice. IGN004 unfused antibody caused a significant delay in tumor progression (p=0.002 vs. vehicle) but did not achieve long-term survival (p=0003 vs. IGN004 fusion protein). When efficacy was tested against a panel of patient-derived NSCLC xenografts, IGN004 fusion protein demonstrated efficacy against 7/11 tumor models, including tumor regression in 3. Against a patient-derived xenograft model of melanoma, IGN004 unfused antibody was ineffective while IGN004 fusion protein inhibited the growth of the tumors. In a patient-derived xenograft model of AML, IGN004 treatment caused a reduction in the percentage of AML cells in the blood, spleen and bone marrow, compared to PBS treated animals. Conclusions: IGN004 demonstrated robust in vitro and in vivo anti-tumor activity against both solid and liquid tumors. Treatment of tumor cells with IGN004 caused an increase in surface expression of MHC class I, PD-L1, and OX-40L. IGN004 demonstrated the ability to enhance the effector T-cell-mediated killing of NSCLC cells in an in vitro assay using the TALL-104 cell line as effectors and NSCLC cell lines as targets. Against both cell line and patient-derived human xenograft tumors IGN004 had robust in vivo anti-tumor efficacy. These results support the further development of IGN004 as a potent targeted cancer immunotherapeutic agent that also has direct anti-tumor effects. Citation Format: Kristopher Steward, Michael Gresser, Raj Sachdev, Sanjay Khare. IGN004 is an antibody-interferon-alpha fusion protein against a novel tumor-associated antigen with both direct anti-tumor and immunostimulatory effects. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr B182.

31TiP - Phase II trial of intraperitoneal (IP) MHC unrestricted adoptive cell therapy with TALL-104 cells in patients with ovarian carcinoma (OC) with minimal or microscopic residual disease at second look laparotomy/laparoscopy

31TiP - Phase II trial of intraperitoneal (IP) MHC unrestricted adoptive cell therapy with TALL-104 cells in patients with ovarian carcinoma (OC) with minimal or microscopic residual disease at second look laparotomy/laparoscopy