scholarly journals STAT3 Inhibits CD103+ cDC1 Vaccine Efficacy in Murine Breast Cancer

Cancers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 128 ◽  
Author(s):  
Taylor T. Chrisikos ◽  
Yifan Zhou ◽  
Haiyan S. Li ◽  
Rachel L. Babcock ◽  
Xianxiu Wan ◽  
...  
Keyword(s):  
Breast Cancer ◽  
T Cells ◽  
Tumor Growth ◽  
Tumor Immunity ◽  
Intracellular Signaling ◽  
Similar Degree ◽  
Tumor Vaccination ◽  
Stat3 Signaling ◽  
Key Factor

Conventional dendritic cells (cDCs) are a critical immune population, composed of multiple subsets, and responsible for controlling adaptive immunity and tolerance. Although migratory type 1 cDCs (CD103+ cDC1s in mice) are necessary to mount CD8+ T cell-mediated anti-tumor immunity, whether and how tumors modulate CD103+ cDC1 function remain understudied. Signal Transducer and Activator of Transcription 3 (STAT3) mediates the intracellular signaling of tumor-associated immunosuppressive cytokines, such as interleukin (IL)-10; thus, we hypothesized that STAT3 restrained anti-tumor immune responses elicited by CD103+ cDC1s. Herein, we show that in vitro-derived STAT3-deficient (Stat3∆/∆) CD103+ cDC1s are refractory to the inhibitory effects of IL-10 on Toll-like receptor 3 (TLR3) agonist-induced maturation responses. In a tumor vaccination approach, we found Stat3∆/∆ CD103+ cDC1s restrained mammary gland tumor growth and increased mouse survival more effectively than STAT3-sufficient CD103+ cDC1s. In addition, vaccination with Stat3∆/∆ CD103+ cDC1s elicited increased amounts of tumor antigen-specific CD8+ T cells and IFN-γ+ CD4+ T cells in tumors and tumor-draining lymph nodes versus phosphate-buffered saline (PBS)-treated animals. Furthermore, IL-10 receptor-deficient CD103+ cDC1s controlled tumor growth to a similar degree as Stat3∆/∆ CD103+ cDC1s. Taken together, our data reveal an inhibitory role for STAT3 in CD103+ cDC1 maturation and regulation of anti-tumor immunity. Our results also suggest IL-10 is a key factor eliciting immunosuppressive STAT3 signaling in CD103+ cDC1s in breast cancer. Thus, inhibition of STAT3 in cDC1s may provide an important strategy to improve their efficacy in tumor vaccination approaches and cDC1-mediated control of anti-tumor immunity.

scholarly journals Progranulin induces immune escape in breast cancer via up-regulating PD-L1 expression on tumor-associated macrophages (TAMs) and promoting CD8+ T cell exclusion

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Wenli Fang ◽  
Ting Zhou ◽  
He Shi ◽  
Mengli Yao ◽  
Dian Zhang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Flow Cytometry ◽  
T Cells ◽  
Western Blot ◽  
Tumor Immunity ◽  
Immune Cells ◽  
Immune Escape ◽  
Stat3 Signaling ◽  
Stat3 Signaling Pathway ◽  
Programmed Death

Abstract Background Progranulin (PGRN), as a multifunctional growth factor, is overexpressed in multiple tumors, but the role of PGRN on tumor immunity is still unclear. Here, we studied the effect of PGRN on breast cancer tumor immunity and its possible molecular mechanism. Methods The changes of macrophage phenotypes after PGRN treatment were detected by western blot, quantitative polymerase chain reaction (PCR) and flow cytometry. Western blot was used to study the signal molecular mechanism of PGRN regulating this process. The number and localization of immune cells in Wild-type (WT) and PGRN−/− breast cancer tissues were analyzed by immunohistochemical staining and immunofluorescence techniques. The activation and proliferation of CD8+ T cells were measured by flow cytometry. Results After being treated with PGRN, the expressions of M2 markers and programmed death ligand 1 (PD-L1) on macrophages increased significantly. Signal transducer and activator of transcription 3 (STAT3) signaling pathway inhibitor Stattic significantly inhibited the expression of PD-L1 and M2 related markers induced by PGRN. In WT group, CD8 were co-localized with macrophages and PD-L1, but not tumor cells. The number of immune cells in PGRN−/− breast cancer tissue increased, and their infiltration into tumor parenchyma was also enhanced. Moreover, in the co-culture system, WT peritoneal macrophages not only reduced the ratio of activated CD8+ T cells but also reduced the proportion of proliferating CD8+ T cells. The addition of programmed death receptor 1 (PD-1) and PD-L1 neutralizing antibodies effectively reversed this effect and restored the immune function of CD8+ T cells. Conclusion These results demonstrate that PGRN promotes M2 polarization and PD-L1 expression by activating the STAT3 signaling pathway. Furthermore, through PD-1/PD-L1 interaction, PGRN can promote the breast tumor immune escape. Our research may provide new ideas and targets for clinical breast cancer immunotherapy.

Activated interferon signaling by down-regulation of CENP-N contributing to inhibited tumor growth in breast cancer

2019 ◽  
Author(s):  
Zhenhua Zhai ◽  
Ye Zhou ◽  
Xing Liu ◽  
Ying Wang ◽  
Yuyang Zhang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Tumor Growth ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Interferon Signaling ◽  
Breast Cancer Patients ◽  
Down Regulation ◽  
Key Factor

Abstract Background Centromere proteins (CENPs) are primary components for chromosomal segregation in the mitotic stage. CENP-N is a member of CENPs, and is a key factor for recruitment of other CENPs and formation of a link between the centromere and micro-tubules, which facilitate cell division. Methods In order to clarify the role of CENP-N in breast cancer, RNA sequences data were downloaded from TCGA online database and the CENP-N expression was knocked down in breast cancer cells. Results The results show that the expression of CENP-N was higher in breast cancer comparing with the paracancerous tissues. In breast cancer, patients with high expression of CENP-N have a short-term overall survival compared with low expression of CENP-N. Both in vitro and in vivo, the growth of breast cancer cells was inhibited by down-regulation of CENP-N. In the gene-chip analysis, it reveals that down-regulation of CENP-N is primarily associated with functions of immune response and anti-tumor ef-fects. Of these changed canonical pathways, the activated interferon signaling was the most significant in CENP-N down-regulated breast cancer cells. In the western blot as-say, up-regulated expressions of molecules involved in interferon signaling were also confirmed. Conclusions Our results suggest that CENP-N can be a potential therapeutic target in the treatment of breast cancer, and the involved interferon signaling needs to be mainly fo-cused on. Keywords: CENP-N, Breast cancer, interferon signaling, Tumor growth

scholarly journals PENTOXIFYLLINE ENHANCES IN VITRO T-CELL ANTITUMOR RESPONSE IN BREAST CANCER PATIENTS

2021 ◽  
Vol 23 (4) ◽  
pp. 785-790
Author(s):  
M. S. Kuznetsova ◽  
J. A. Shevchenko ◽  
J. N. Khantakova ◽  
A. A. Khristin ◽  
I. A. Obleukhova ◽  
...  
Keyword(s):  
Breast Cancer ◽  
T Cells ◽  
Metastatic Breast Cancer ◽  
Tumor Growth ◽  
Cancer Patients ◽  
Cell Activity ◽  
Metastatic Breast ◽  
Antitumor Response ◽  
Healthy Donors

The NF-κB transcription factor controls the expression of genes responsible for cell cycle, apoptosis, and other immunoregulatory functions. Some nonspecific NF-κB inhibitors were found after discovering the possibility of blocking tumor growth through suppression of NF-κB activity, but their use was complicated by multiple side effects, such as interleukin-1β-related systemic inflammation or non-immunerelated complications, which may be due to inhibition of the p65 NF-κB subunit that plays a central role in organogenesis and inflammation. Inhibition of the c-Rel subunit leads to tumor growth restriction by modulating the T-regulatory cell activity.In 2017, Grinberg-Bleyer and co-authors checked the hypothesis that selective inhibition of the c-Rel subunit can be performed using pentoxifylline and will effectively regulate Treg activity during tumor growth. The authors showed that pentoxphylline, an FDA-approved drug, could indeed induce selective degradation of c-Rel without affecting p65, and suggested that such an effect could be effective in suppressing tumor growth. In this regard, we aimed to investigate in vitro how pentoxifylline affect the functional activity and antitumor cytotoxic potential of T-cells in cancer patients.The objects of the study were peripheral blood mononuclear cells from 25 patients with primary breast cancer (no metastases), 15 patients with metastatic breast cancer, and 25 healthy women without breast pathology. Informed consent was obtained from all donors and patients. The study was approved by the local ethics committee.Here we showed that pentoxifylline treatment in vitro enhances the pro-apoptotic and cytotoxic antitumor response via increasing the expression of TRAIL on T-lymphocytes, mainly in healthy donors and patients with metastatic breast cancer, both on intact T-cells and in response to the cells of the tumor line of human breast carcinoma ZR-75-1. In healthy donors, in the presence of pentoxifylline, a population of highly expressing TRAIL CD4 and CD8 T-cells appears. 

scholarly journals Progranulin Induces Immune Escape in Breast Cancer Via Up-Regulating PD-L1 Expression on TAMS and Promoting CD8+T cell Exclusion

2020 ◽  
Author(s):  
Wenli Fang ◽  
Ting Zhou ◽  
He Shi ◽  
Mengli Yao ◽  
Dian Zhang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Flow Cytometry ◽  
T Cells ◽  
Western Blot ◽  
Molecular Mechanism ◽  
Tumor Immunity ◽  
Immune Cells ◽  
Immune Escape ◽  
Stat3 Signaling ◽  
Stat3 Signaling Pathway

Abstract Background: Progranulin (PGRN), as a multifunctional growth factor, is overexpressed in multiple tumors, but the role of PGRN on tumor immunity is still unclear. Here, we studied the effect of PGRN on breast cancer tumor immunity and its possible molecular mechanism.Methods: The changes of macrophage phenotypes after PGRN treatment were detected by western blot, quantitative PCR and flow cytometry. Western blot was used to study the signal molecular mechanism of PGRN regulating this process. The number and localization of immune cells in WT and PGRN-/- breast cancer tissues were analyzed by immunohistochemical staining and immunofluorescence techniques. The activation and proliferation of CD8+ T cells were measured by flow cytometry.Results: After being treated with PGRN, the expressions of M2 markers and PD-L1 on macrophages increased. STAT3 signaling pathway inhibitor Stattic could significantly inhibit PD-L1 expression and M2 related markers induced by PGRN. In WT group, CD8 were co-localized with macrophages and PD-L1, but not tumor cells. The number of immune cells in PGRN-/- breast cancer tissue increased, and the infiltration into tumor parenchyma also increased. Moreover, in the co-culture system, WT peritoneal macrophages not only reduced the ratio of activated CD8+T cells but also reduced the proportion of proliferating CD8+T cells. The addition of PD-1 and PD-L1 neutralizing antibodies could effectively reverse this effect and restore the immune function of CD8+T cells.Conclusion: The results show that PGRN can promote M2 polarization and PD-L1 expression by activating the STAT3 signaling pathway. Furthermore, through PD-1/PD-L1 interaction, PGRN can promote the breast tumor immune escape. Our research may provide new ideas and targets for clinical breast cancer immunotherapy.

scholarly journals P03.31 Skin dendritic cells in melanoma are key for successful checkpoint blockade therapy

2020 ◽  
Vol 8 (Suppl 2) ◽  
pp. A35.2-A36
Author(s):  
N Prokopi ◽  
CH Tripp ◽  
B Tummers ◽  
JC Crawford ◽  
M Efremova ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
T Cells ◽  
Tumor Microenvironment ◽  
Mouse Model ◽  
Tumor Growth ◽  
Tumor Immunity ◽  
Cd8 T Cells ◽  
Checkpoint Blockade ◽  
And Function

BackgroundImmunotherapy of cancer by checkpoint blockade has significantly improved the survival of melanoma patients. However, in patients with tumors that are poorly infiltrated by effector T cells the clinical results are not encouraging. Therefore, combination approaches that enhance pre-existing anti-tumor immunity and reset the patients‘ immunological status are urgently needed. In this study we used the tg(Grm1)EPv melanoma mouse model that reflects a non-immunogenic tumor microenvironment. In this mouse model, spontaneous melanoma development is driven by the ectopic expression of the metabotropic glutamate receptor-1 in melanocytes, which confers to them a hyperproliferative and anti-apoptotic phenotype. The same alteration has been shown to be present in 40% of melanoma patient samples. The aim of our study was to investigate whether enhancing dendritic cell (DC) numbers and function in the tg(Grm1)EPv mouse model could restore responsiveness to checkpoint blockade.Material and MethodsWe used multicolor flow cytometry, gene expression analysis by RNA-seq and microarray to analyze tumors and tumor-draining lymph nodes (tdLN). With various immunological in vitro and in vivo assays we determined the functional role of DC in tumor immunity.ResultsA loss of skin DC has previously been reported for primary melanoma lesions and we here show that melanoma progression in the tg(Grm1)EPv mouse model coincides with a gradual decrease in the skin cDC2 subset and an upregulation of the inhibitory ligands PD-L1 and galectin-9. Monotherapy with anti-PD-L1 could not delay tumor growth, suggesting that this is a good model to study resistance to checkpoint blockade. We hypothesized that by boosting DC numbers and function we would restore responsiveness to checkpoint blockade. By administering a treatment consisting of systemic Flt3L and intratumoral polyI:C/anti-CD40, we were able to rescue the numbers and function of skin cDC2. Analysis of the treated tumors by flow cytometry showed that the DC boost regimen led to an increased tumor infiltration of activated CD4+ and CD8+T cells. An in vitro T cell proliferation assay revealed that dermal cDC2 that had migrated to the tdLN, played a crucial role in this process, since these were able to cross-present endogenous gp100 antigen more efficiently than migratory Langerhans cells and dermal cDC1. CD4+ and CD8+T cells recruited in the tumors of the DC boost treated mice, expressed PD-1 and TIM-3. Therefore, combination therapy with checkpoint blockade of these molecules resulted in increased cytotoxic activity within the tumor and eventually delay of tumor growth.ConclusionsOur results demonstrate that skin DC shape the tumor microenvironment upon immunotherapy and thus, therapies that aim to enhance responsiveness to checkpoint blockade may well benefit from a component that boosts the numbers and the function of skin DC.Disclosure InformationN. Prokopi: None. C.H. Tripp: None. B. Tummers: None. J.C. Crawford: None. M. Efremova: None. K. Hutter: None. L. Bellmann: None. G. Cappellano: None. L. Boon: None. D. Ortner: None. Z. Trajanoski: None. S. Chen: None. T. de Gruijl: None. D.R. Green: None. P. Stoitzner: None.

scholarly journals AGI-134: a fully synthetic α-Gal glycolipid that converts tumors into in situ autologous vaccines, induces anti-tumor immunity and is synergistic with an anti-PD-1 antibody in mouse melanoma models

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Stephen M. Shaw ◽  
Jenny Middleton ◽  
Kim Wigglesworth ◽  
Amber Charlemagne ◽  
Oliver Schulz ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Growth ◽  
Tumor Cells ◽  
Tumor Immunity ◽  
Tumor Antigen ◽  
Tumor Regression ◽  
Antigen Uptake

Abstract Background Treatments that generate T cell-mediated immunity to a patient’s unique neoantigens are the current holy grail of cancer immunotherapy. In particular, treatments that do not require cumbersome and individualized ex vivo processing or manufacturing processes are especially sought after. Here we report that AGI-134, a glycolipid-like small molecule, can be used for coating tumor cells with the xenoantigen Galα1-3Galβ1-4GlcNAc (α-Gal) in situ leading to opsonization with pre-existing natural anti-α-Gal antibodies (in short anti-Gal), which triggers immune cascades resulting in T cell mediated anti-tumor immunity. Methods Various immunological effects of coating tumor cells with α-Gal via AGI-134 in vitro were measured by flow cytometry: (1) opsonization with anti-Gal and complement, (2) antibody-dependent cell-mediated cytotoxicity (ADCC) by NK cells, and (3) phagocytosis and antigen cross-presentation by antigen presenting cells (APCs). A viability kit was used to test AGI-134 mediated complement dependent cytotoxicity (CDC) in cancer cells. The anti-tumoral activity of AGI-134 alone or in combination with an anti-programmed death-1 (anti-PD-1) antibody was tested in melanoma models in anti-Gal expressing galactosyltransferase knockout (α1,3GT−/−) mice. CDC and phagocytosis data were analyzed by one-way ANOVA, ADCC results by paired t-test, distal tumor growth by Mantel–Cox test, C5a data by Mann–Whitney test, and single tumor regression by repeated measures analysis. Results In vitro, α-Gal labelling of tumor cells via AGI-134 incorporation into the cell membrane leads to anti-Gal binding and complement activation. Through the effects of complement and ADCC, tumor cells are lysed and tumor antigen uptake by APCs increased. Antigen associated with lysed cells is cross-presented by CD8α+ dendritic cells leading to activation of antigen-specific CD8+ T cells. In B16-F10 or JB/RH melanoma models in α1,3GT−/− mice, intratumoral AGI-134 administration leads to primary tumor regression and has a robust abscopal effect, i.e., it protects from the development of distal, uninjected lesions. Combinations of AGI-134 and anti-PD-1 antibody shows a synergistic benefit in protection from secondary tumor growth. Conclusions We have identified AGI-134 as an immunotherapeutic drug candidate, which could be an excellent combination partner for anti-PD-1 therapy, by facilitating tumor antigen processing and increasing the repertoire of tumor-specific T cells prior to anti-PD-1 treatment.

scholarly journals 845 A colony stimulating factor 1 receptor-blocking bifunctional protein simultaneously targets tumor-associated macrophages and exhausted T cells for the treatment of triple-negative breast cancer

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A886-A886
Author(s):  
Pandelakis Koni ◽  
Hung-Kai Chen ◽  
Yao-Wen Chang ◽  
Huey-Wen Hsiao ◽  
Chih-Lun Hsiao ◽  
...  
Keyword(s):  
Breast Cancer ◽  
T Cells ◽  
Fusion Protein ◽  
Tumor Immunity ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Tumor Model ◽  
Colony Stimulating Factor ◽  
Stimulating Factor

BackgroundTumor-associated macrophages (TAMs) are a significantly-poor prognostic factor for patients with triple-negative breast cancer (TNBC). The tumor microenvironment of TNBC features highly-infiltrating TAMs that contribute to tumor progression and metastasis. Therefore, TAM-targeted immunotherapies are recognized as a potential approach for treating TNBC. However, depleting TAMs alone by use of monoclonal antibodies against colony-stimulating factor 1 receptor (CSF1R) was insufficient to cause substantial tumor control. Recent studies revealed that interleukin-10 (IL-10) can directly activate terminally-exhausted CD8+ T cells to boost anti-tumor activity. We set forth to investigate whether a combination of anti-CSF1R antibody with a half-life-extended IL-10-Fc fusion protein (IL-10-Fc) may enhance anti-tumor immunity, and whether synergistic effects could be achieved with bifunctional antibody forms.MethodsAntibodies and recombinant proteins were produced in-house. In vitro CSF1R activity was evaluated by Western blot analysis of CSF1-mediated CSF1R phosphorylation and monocyte proliferation assays. In vitro IL10 activity was evaluated by MC/9 cell proliferation and CD8 T cell activation assays. 4T1 mouse breast tumor studies were performed at the National Yang Ming Chiao Tung University (Taiwan). Other tumor model studies employed the services of Crownbio (China). Methods of RNAseq analysis of 4T1 tumor masses included Cibersort, gene set enrichment analysis (GSEA) and immune gene signature score analysis.ResultsCo-treatment with a recombinant human IL-10-Fc protein significantly improved the anti-tumor efficacy of anti-mouse CSF1R antibody in a mouse CT26 colon tumor model. It was then hypothesized that a better synergistic effect could be achieved by a bifunctional anti-mouse CSF1R-IL-10 fusion protein (anti-mCSF1R-IL-10), to allow targeted-delivery of IL-10 to CSF1R-positive-TAM-rich tumor microenvironments. Indeed, anti-mCSF1R-IL-10 showed greatly increased anti-tumor efficacy in both EMT-6 and 4T1 mouse models of breast cancer. Consistent with the in vivo efficacy, gene expression profiling revealed an enhanced intratumoral interferon-gamma signature by treatment with anti-mCSF1R-IL-10 as compared to either anti-mCSF1R or IL-10-Fc alone. An anti-human CSF1R-IL-10 (hCSF1R-IL-10) was also constructed using a newly-produced anti-human CSF1R antibody and tested in cell-based functional assays, demonstrating that anti-hCSF1R-IL-10 could both inhibit CSF1-dependent cell growth and activate tumor-infiltrating T cells isolated from tumor biopsies of triple-negative breast cancer patients. Further validation of this bifunctional form will be presented.ConclusionsOur findings provide a potential strategy for simultaneously targeting TAM and exhausted T cells to potentiate anti-tumor immunity for treatment of triple-negative breast cancer.Ethics ApprovalThe studies were approved by the institutional animal care and use committee of National Yang Ming Chiao Tung University; approval numbers 1081025 and 109060.

Melatonin modifies tumor hypoxia and metabolism by inhibiting HIF-1α and energy metabolic pathway in the in vitro and in vivo models of breast cancer

2019 ◽  
Vol 2 (4) ◽  
pp. 83-98 ◽  
Author(s):  
André De Lima Mota ◽  
Bruna Vitorasso Jardim-Perassi ◽  
Tialfi Bergamin De Castro ◽  
Jucimara Colombo ◽  
Nathália Martins Sonehara ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Glucose Metabolism ◽  
Tumor Growth ◽  
Tumor Cells ◽  
Carbonic Anhydrases ◽  
In Vivo Models ◽  
Ca Ix ◽  
Gene And Protein Expression

Breast cancer is the most common cancer among women and has a high mortality rate. Adverse conditions in the tumor microenvironment, such as hypoxia and acidosis, may exert selective pressure on the tumor, selecting subpopulations of tumor cells with advantages for survival in this environment. In this context, therapeutic agents that can modify these conditions, and consequently the intratumoral heterogeneity need to be explored. Melatonin, in addition to its physiological effects, exhibits important anti-tumor actions which may associate with modification of hypoxia and Warburg effect. In this study, we have evaluated the action of melatonin on tumor growth and tumor metabolism by different markers of hypoxia and glucose metabolism (HIF-1α, glucose transporters GLUT1 and GLUT3 and carbonic anhydrases CA-IX and CA-XII) in triple negative breast cancer model. In an in vitro study, gene and protein expressions of these markers were evaluated by quantitative real-time PCR and immunocytochemistry, respectively. The effects of melatonin were also tested in a MDA-MB-231 xenograft animal model. Results showed that melatonin treatment reduced the viability of MDA-MB-231 cells and tumor growth in Balb/c nude mice (p <0.05). The treatment significantly decreased HIF-1α gene and protein expression concomitantly with the expression of GLUT1, GLUT3, CA-IX and CA-XII (p <0.05). These results strongly suggest that melatonin down-regulates HIF-1α expression and regulates glucose metabolism in breast tumor cells, therefore, controlling hypoxia and tumor progression. 

627 The DLL3-targeted half-life extended bispecific T cell engager (HLE BiTE®) immune-oncology therapy AMG 757 has potent antitumor activity in neuroendocrine cancer

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A663-A663
Author(s):  
Keegan Cooke ◽  
Juan Estrada ◽  
Jinghui Zhan ◽  
Jonathan Werner ◽  
Fei Lee ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Growth ◽  
Mouse Models ◽  
T Cell Activation ◽  
Phase 1 ◽  
Phase 1 Study ◽  
Human T Cells

BackgroundNeuroendocrine tumors (NET), including small cell lung cancer (SCLC), have poor prognosis and limited therapeutic options. AMG 757 is an HLE BiTE® immune therapy designed to redirect T cell cytotoxicity to NET cells by binding to Delta-like ligand 3 (DLL3) expressed on the tumor cell surface and CD3 on T cells.MethodsWe evaluated activity of AMG 757 in NET cells in vitro and in mouse models of neuroendocrine cancer in vivo. In vitro, co-cultures of NET cells and human T cells were treated with AMG 757 in a concentration range and T cell activation, cytokine production, and tumor cell killing were assessed. In vivo, AMG 757 antitumor efficacy was evaluated in xenograft NET and in orthotopic models designed to mimic primary and metastatic SCLC lesions. NSG mice bearing established NET were administered human T cells and then treated once weekly with AMG 757 or control HLE BiTE molecule; tumor growth inhibition was assessed. Pharmacodynamic effects of AMG 757 in tumors were also evaluated in SCLC models following a single administration of human T cells and AMG 757 or control HLE BiTE molecule.ResultsAMG 757 induced T cell activation, cytokine production, and potent T cell redirected killing of DLL3-expressing SCLC, neuroendocrine prostate cancer, and other DLL3-expressing NET cell lines in vitro. AMG 757-mediated redirected lysis was specific for DLL3-expressing cells. In patient-derived xenograft and orthotopic models of SCLC, single-dose AMG 757 effectively engaged human T cells administered systemically, leading to a significant increase in the number of human CD4+ and CD8+ T cells in primary and metastatic tumor lesions. Weekly administration of AMG 757 induced significant tumor growth inhibition of SCLC (figure 1) and other NET, including complete regression of established tumors and clearance of metastatic lesions. These findings warranted evaluation of AMG 757 (NCT03319940); the phase 1 study includes dose exploration (monotherapy and in combination with pembrolizumab) and dose expansion (monotherapy) in patients with SCLC (figure 2). A study of AMG 757 in patients with neuroendocrine prostate cancer is under development based on emerging data from the ongoing phase 1 study.Abstract 627 Figure 1AMG 757 Significantly reduced tumor growth in orthotopic SCLC mouse modelsAbstract 627 Figure 2AMG 757 Phase 1 study designConclusionsAMG 757 engages and activates T cells to kill DLL3-expressing SCLC and other NET cells in vitro and induces significant antitumor activity against established xenograft tumors in mouse models. These preclinical data support evaluation of AMG 757 in clinical studies of patients with NET.Ethics ApprovalAll in vivo work was conducted under IACUC-approved protocol #2009-00046.

scholarly journals 695 Oral delivery of a microbial extracellular vesicle induces potent anti-tumor immunity in mice

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A737-A737
Author(s):  
Loise Francisco-Anderson ◽  
Loise Francisco-Anderson ◽  
Mary Abdou ◽  
Michael Goldberg ◽  
Erin Troy ◽  
...  
Keyword(s):  
Tumor Microenvironment ◽  
Tumor Growth ◽  
Extracellular Vesicles ◽  
Tumor Immunity ◽  
Extracellular Vesicle ◽  
The Body ◽  
Checkpoint Inhibition ◽  
Small Intestinal ◽  
The Impact

BackgroundThe small intestinal axis (SINTAX) is a network of anatomic and functional connections between the small intestine and the rest of the body. It acts as an immunosurveillance system, integrating signals from the environment that affect physiological processes throughout the body. The impact of events in the gut in the control of tumor immunity is beginning to be appreciated. We have previously shown that an orally delivered single strain of commensal bacteria induces anti-tumor immunity preclinically via pattern recognition receptor-mediated activation of innate and adaptive immunity. Some bacteria produce extracellular vesicles (EVs) that share molecular content with the parent bacterium in a particle that is roughly 1/1000th the volume in a non-replicating form. We report here an orally-delivered and gut-restricted bacterial EV which potently attenuates tumor growth to a greater extent than whole bacteria or checkpoint inhibition.MethodsEDP1908 is a preparation of extracellular vesicles produced by a gram-stain negative strain of bacterium of the Oscillospiraceae family isolated from a human donor. EDP1908 was selected for its immunostimulatory profile in a screen of EVs from a range of distinct microbial strains. Its mechanism of action was determined by ex vivo analysis of the tumor microenvironment (TME) and by in vitro functional studies with murine and human cells.ResultsOral treatment of tumor-bearing mice with EDP1908 shows superior control of tumor growth compared to checkpoint inhibition (anti-PD-1) or an intact microbe. EDP1908 significantly increased the percentage of IFNγ and TNF producing CD8+ CTLs, NK cells, NKT cells and CD4+ cells in the tumor microenvironment (TME). EDP1908 also increased tumor-infiltrating dendritic cells (DC1 and DC2). Analysis of cytokines in the TME showed significant increases in IP-10 and IFNg production in mice treated with EDP1908, creating an environment conducive to the recruitment and activation of anti-tumor lymphocytes.ConclusionsThis is the first report of striking anti-tumor effects of an orally delivered microbial extracellular vesicle. These data point to oral EVs as a new class of immunotherapeutic drugs. They are particularly effective at harnessing the biology of the small intestinal axis, acting locally on host cells in the gut to control distal immune responses within the TME. EDP1908 is in preclinical development for the treatment of cancer.Ethics ApprovalPreclinical murine studies were conducted under the approval of the Avastus Preclinical Services’ Ethics Board. Human in vitro samples were attained by approval of the IntegReview Ethics Board; informed consent was obtained from all subjects.

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