159 METFORMIN DOWNREGULATES PD-L1 EXPRESSION IN ESOPHAGEAL SQUAMOUS CELL CARCINOMA BY INHIBITING IL-6 SIGNALING PATHWAY

2021 ◽  
Vol 34 (Supplement_1) ◽  
Author(s):  
Feng Wang ◽  
Dao Xin ◽  
Xiangrui Meng ◽  
Qingxia Fan

Abstract   ESCC is an aggressive cancer with poor prognosis in China. Metformin with low cost and toxicity have proved to have anti-cancer effects in many kinds of cancers, while its role in combination of immune checkpoint blockade and mechanism in ESCC has seldom been studied. This study was designed to evaluate the potential role of combinatorial anti-tumor effect with metformin and immunomodulatory monoclonal antibodies (mAbs) targeting programmed cell death protein-1 (PD-1) in vitro and in vivo. Methods Reverse transcription-quantitative polymerase chain reaction, western blot and immunohistochemistry (IHC) assays were used to study the effects of metformin on the expression levels of PD-L1. In addition, T cell activation and killing assay were performed in the co-culture system of ESCC cell and peripheral blood mononuclear cells (PBMCs) treated with metformin or IL-6 to evaluate the function of inhibiting PD-L1 expression. In vivo assay, we used NPIdKOTM mice model, which was re-constructed replaced immune system by transplanting PBMCs through intravenously injecting. Mice were treated with metformin alone as well as in combination with anti-PD-1 mAbs. Results PD-L1 expression were downregulated by metformin via JAK2 and STAT3 signaling pathway. The results showed that metformin promoted CD3/CD28 induced ERK phosphorylation at a dose dependent measure. And IL-2 was increased in the supernatant of KYSE-450/PBMC coculture system after metformin treatment. Both of which are indicators of T cell activation. T cell mediated tumor killing assay showed that metformin inducing PD-L1 downregulation could protect T cell function, and it could be reversed by IL-6. It showed that metformin enhanced its efficacy in TE-7 cells-harboring mice in the combination treatment group, reflected by tumor sizes assay, and in vivo imaging system. Conclusion Various approaches are under way to expand the benefits and improve the efficacy of these immune checkpoint inhibitors. Another approach is combining immunotherapy with existing anticancer therapies. In this regard, we have evaluated the mechanism of metformin inhibiting PD-L1 expression in ESCC. This finding indicated that metformin significantly improved the antitumor effects by anti-PD-1 blockade without detectable toxicity and suggested that metformin has strong potential to be used in combination with immunotherapy.

2021 ◽  
Vol 9 (5) ◽  
pp. e001925
Author(s):  
Shujuan Zhou ◽  
Fanyan Meng ◽  
Shiyao Du ◽  
Hanqing Qian ◽  
Naiqing Ding ◽  
...  

BackgroundPoor infiltration and limited activation of transferred T cells are fundamental factors impeding the development of adoptive cell immunotherapy in solid tumors. A tumor-penetrating peptide iRGD has been widely used to deliver drugs deep into tumor tissues. CD3-targeting bispecific antibodies represent a promising immunotherapy which recruits and activates T cells.MethodsT-cell penetration was demonstrated in tumor spheroids using confocal microscope, and in xenografted tumors by histology and in vivo real-time fluorescence imaging. Activation and cytotoxicity of T cells were assessed by flow cytometry and confocal microscope. Bioluminescence imaging was used to evaluate in vivo antitumor effects, and transmission electron microscopy was used for mechanistic studies.ResultsWe generated a novel bifunctional agent iRGD-anti-CD3 which could immobilize iRGD on the surface of T cells through CD3 engaging. We found that iRGD-anti-CD3 modification not only facilitated T-cell infiltration in 3D tumor spheroids and xenografted tumor nodules but also induced T-cell activation and cytotoxicity against target cancer cells. T cells modified with iRGD-anti-CD3 significantly inhibited tumor growth and prolonged survival in several xenograft mouse models, which was further enhanced by the combination of programmed cell death protein 1 (PD-1) blockade. Mechanistic studies revealed that iRGD-anti-CD3 initiated a transport pathway called vesiculovacuolar organelles in the endothelial cytoplasm to promote T-cell extravasation.ConclusionAltogether, we show that iRGD-anti-CD3 modification is an innovative and bifunctional strategy to overcome major bottlenecks in adoptive cell therapy. Moreover, we demonstrate that combination with PD-1 blockade can further improve antitumor efficacy of iRGD-anti-CD3-modified T cells.


Author(s):  
Juan Yang ◽  
Xianzhi Yang ◽  
Wenfeng Pan ◽  
Mingshuo Wang ◽  
Yuxiong Lu ◽  
...  

Immune checkpoint blockade (ICB) therapies such as PD-1 antibodies have produced significant clinical responses in treating a variety of human malignancies, yet only a subset of cancer patients benefit from such therapy. To improve the ICB efficacy, combinations with additional therapeutics were under intensive investigation. Recently, special dietary compositions that can lower the cancer risk or inhibit cancer progression have drawn significant attention, although few were reported to show synergistic effects with ICB therapies. Interestingly, Fucoidan is naturally derived from edible brown algae and exhibits antitumor and immunomodulatory activities. Here we discover that fucoidan-supplemented diet significantly improves the antitumor activities of PD-1 antibodies in vivo. Specifically, fucoidan as a dietary ingredient strongly inhibits tumor growth when co-administrated with PD-1 antibodies, which effects can be further strengthened when fucoidan is applied before PD-1 treatments. Immune analysis revealed that fucoidan consistently promotes the activation of tumor-infiltrating CD8+ T cells, which support the evident synergies with ICB therapies. RNAseq analysis suggested that the JAK-STAT pathway is critical for fucoidan to enhance the effector function of CD8+ T cells, which could be otherwise attenuated by disruption of the T-cell receptor (TCR)/CD3 complex on the cell surface. Mechanistically, fucoidan interacts with this complex and augments TCR-mediated signaling that cooperate with the JAK-STAT pathway to stimulate T cell activation. Taken together, we demonstrated that fucoidan is a promising dietary supplement combined with ICB therapies to treat malignancies, and dissected an underappreciated mechanism for fucoidan-elicited immunomodulatory effects in cancer.


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A831-A831
Author(s):  
Tienan Wang ◽  
Qing Lin ◽  
Jie Zhang

BackgroundCancer immunotherapies, including immune checkpoint inhibitors, CAR-T, cancer vaccines and bispecific antibodies, have been brought to spot light in recent years as several therapeutic strategies targeting the immune system have produced exciting clinical results. Bispecific antibody typically play dual roles in blocking the immune checkpoint and redirecting/re-boosting the function of the immune effector cells. Blinatumomab belongs to CD3 bispecific T cell engager (CD3 BiTE), which was engineered to harbor two arms binding with CD3 and CD19 simultaneously and direct CD8+ T cells to specifically recognize CD19 positive lymphoma cells to execute cytotoxicity. Approval of Blinatumomab for patients with relapse/refractory B cell acute lymphoblastic leukemia (ALL) has driven remarkable increase in combination studies of Blinatumomab with other immunotherapies such as checkpoint inhibitors.MethodsIn this study, we developed CD8+ T cytotoxic system targeting different B lymphoma cell line and fully validated the function of Blinatumomab in promoting target tumor cell lysis by primary CD8+ T cells (figure 1). In addition, we established a mixed lymphocyte and tumor system to mimic physiological TME to dissect the combinational role of Nivolumab and Blinatumomab (figure 2).ResultsThe result suggest that combinatory therapy is highly depend on the dosage of Blinatumomab and also T cell number in the TME, which might give an instruction for ongoing clinical trial design. Finally, we have employed humanized mouse models bearing Raji or Daudi tumor cells to further validate this combination treatment in vivo. Both In-vivo and In-vitro data support that Blinatumomab is dominant in activing T cell and Nivolumab can only exhibit synergistic effect under suboptimal dosage of Blinatumomab.Abstract 781 Figure 1Establishment of In vitro co-culture system for CD3 BiTEestablish in vitro human PBMC based system to validate CD3 BiTE functionAbstract 781 Figure 2Opdivo and CD3 BiTE CombinationOpdivo could further promote T cell activation under the treatment of CD3 BiTEConclusionsSuccessfully establish in vitro system to evaluate the function of CD3 BiTE and also take advantage of MLR/tumor co-culture system to demonstrate PD1 antibody could further promote T cell activation under appropriate dosage of CD3 BiTE.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Emily Lee ◽  
Sarah Szvetecz ◽  
Ryan Polli ◽  
Angelo Grauel ◽  
Jayson Chen ◽  
...  

AbstractHigh-grade serous ovarian cancers (HGSOC) represent the most common subtype of ovarian malignancies. Due to the frequency of late-stage diagnosis and high rates of recurrence following standard of care treatments, novel therapies are needed to promote durable responses. We investigated the anti-tumor activity of CD3 T cell engaging bispecific antibodies (TCBs) directed against the PAX8 lineage-driven HGSOC tumor antigen LYPD1 and demonstrated that anti-LYPD1 TCBs induce T cell activation and promote in vivo tumor growth inhibition in LYPD1-expressing HGSOC. To selectively target LYPD1-expressing tumor cells with high expression while sparing cells with low expression, we coupled bivalent low-affinity anti-LYPD1 antigen-binding fragments (Fabs) with the anti-CD3 scFv. In contrast to the monovalent anti-LYPD1 high-affinity TCB (VHP354), the bivalent low-affinity anti-LYPD1 TCB (QZC131) demonstrated antigen density-dependent selectivity and showed tolerability in cynomolgus monkeys at the maximum dose tested of 3 mg/kg. Collectively, these data demonstrate that bivalent TCBs directed against LYPD1 have compelling efficacy and safety profiles to support its use as a treatment for high-grade serous ovarian cancers.


Blood ◽  
2011 ◽  
Vol 118 (3) ◽  
pp. 795-803 ◽  
Author(s):  
Katia Urso ◽  
Arantzazu Alfranca ◽  
Sara Martínez-Martínez ◽  
Amelia Escolano ◽  
Inmaculada Ortega ◽  
...  

Abstract The nuclear factor of activated T cells (NFAT) family of transcription factors plays important roles in many biologic processes, including the development and function of the immune and vascular systems. Cells usually express more than one NFAT member, raising the question of whether NFATs play overlapping roles or if each member has selective functions. Using mRNA knock-down, we show that NFATc3 is specifically required for IL2 and cyclooxygenase-2 (COX2) gene expression in transformed and primary T cells and for T-cell proliferation. We also show that NFATc3 regulates COX2 in endothelial cells, where it is required for COX2, dependent migration and angiogenesis in vivo. These results indicate that individual NFAT members mediate specific functions through the differential regulation of the transcription of target genes. These effects, observed on short-term suppression by mRNA knock-down, are likely to have been masked by compensatory effects in gene-knockout studies.


2004 ◽  
Vol 72 (7) ◽  
pp. 4233-4239 ◽  
Author(s):  
Andrew L. Leisewitz ◽  
Kirk A. Rockett ◽  
Bonginkosi Gumede ◽  
Margaret Jones ◽  
Britta Urban ◽  
...  

ABSTRACT Dendritic cells, particularly those residing in the spleen, are thought to orchestrate acquired immunity to malaria, but it is not known how the splenic dendritic cell population responds to malaria infection and how this response compares with the responses of other antigen-presenting cells. We investigated this question for Plasmodium chabaudi AS infection in C57BL/6 mice. We found that dendritic cells, defined here by the CD11c marker, migrated from the marginal zone of the spleen into the CD4+ T-cell area within 5 days after parasites entered the bloodstream. This contrasted with the results observed for the macrophage and B-cell populations, which expanded greatly but did not show any comparable migration. Over the same time period dendritic cells showed upregulation of CD40, CD54, and CD86 costimulatory molecules that are required for successful T-cell activation. In dendritic cells, the peak intracellular gamma interferon expression (as shown by fluorescence-activated cell sorting) was on day 5, 2 days earlier than the peak expression in B-cells or macrophages. These findings show that splenic dendritic cells are actively engaged in the earliest phase of malarial infection in vivo and are likely to be critical in shaping the subsequent immune response.


2021 ◽  
Author(s):  
Alessia Furgiuele ◽  
Massimilano Legnaro ◽  
Alessandra Luini ◽  
Marco Ferrari ◽  
Emanuela Rasini ◽  
...  

This protocol was designed to activate the lymphocytes T of a population of peripheral blood mononuclear cells (PBMCs), simulating their physiological response to antigen/MHC complex acting on T Cell Receptors-TCR , in order to test their functional responses including cell proliferation and cytokine production. The co-stimulation protocol include: i)anti-CD3 antibody a polyclonal activator specific for invariant framework epitopes on TCR complex (in particular, we use UCHT1 clone an anti-human CD3 antibody that recognizes the ε-chain of CD3 which is used for immobilized option of activation) (http://static.bdbiosciences.com/documents/BD_Tcell_Human_CD3_Activation_Protocol.pdf) ii) anti-CD28 antibody used to cooperate with TCR signals promoting activation of T cells The procedure has been reproduced following the indications contained in the protocol of "EBiooscience" (https://tools.thermofisher.com/content/sfs/manuals/t-cell-activation-in-vitro.pdf). Pilot experiments on PBMC were carried out to determine the best concentrations of anti-CD3 and anti-CD28 to induce optimal proliferation of PBMC and production of cytokines TNF-α and IFN-γ. We found a dose dependent correlation between immobilized anti-CD3 and cells functional responses. The selected amount was 2 µg/mL for both anti-CD3 and anti-CD28 that was the concentration below the maximum response which allows also to test possible modulations by therapeutic agents. References http://static.bdbiosciences.com/documents/BD_Tcell_Human_CD3_Activation_Protocol.pdf https://tools.thermofisher.com/content/sfs/manuals/t-cell-activation-in-vitro.pdf https://www.bdbiosciences.com/ds/pm/tds/555330.pdf https://www.bdbiosciences.com/ds/pm/tds/555726.pdf BEFORE STARTING with this procedure Moreover, work under laminar flow hood when you are processing samples from the beginning to the end of the culture. Make sure you are using,sterile culture mediumand sterile plastic disposable as well.


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