scholarly journals B7 immune-checkpoints as targets for the treatment of neuroendocrine tumors

2021 ◽  
Author(s):  
Ziqiang Yuan ◽  
Juliet C Gardiner ◽  
Elaine C Maggi ◽  
Shuyu Huang ◽  
Asha Adem ◽  
...  

The B7 family, and their receptors, the CD28 family, are major immune checkpoints that regulate T-cell activation and function. In the present study, we explore the role of two B7 immune-checkpoints: HERV-H LTR-Associating Protein 2 (HHLA2) and B7 Family Member, H4 (B7x), in the progression of gastrointestinal and pancreatic neuroendocrine tumors (GINETs and PNETs). We demonstrated that both HHLA2 and B7x were expressed to a high degree in human GINETs and PNETs. We determined that the expression of B7x and HHLA2 correlates with higher grade and higher incidence of nodal and distant spread. Furthermore, we confirmed that HIF-1 overexpression is associated with the upregulation of B7x both in our in vivo (animal model) and in vitro (cell culture) models. When grown in vitro, islet tumor β-cells lack B7x expression, unless cultured under hypoxic conditions, which results in both hypoxia inducible factor 1 subunit alpha (HIF-1α) and B7x upregulation. In vivo, we demonstrated that Men1/B7x double knockout (KO) mice (with loss of B7x expression) exhibited decreased islet β-cell proliferation and tumor transformation accompanied by increased T-cell infiltration compared with Men1 single knockout mice. We have also shown that systemic administration of a B7x mAb to our Men1 KO mice with PNETs promotes an antitumor response mediated by increased T-cell infiltration. These findings suggest that B7x may be a critical mediator of tumor immunity in the tumor microenvironment of NETs. Therefore, targeting B7x offers an attractive strategy for the immunotherapy of patients suffering from NETs.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e14532-e14532
Author(s):  
Joerg Wischhusen ◽  
Markus Haake ◽  
Neha Vashist ◽  
Sabrina Genßler ◽  
Kilian Wistuba-Hamprecht ◽  
...  

e14532 Background: Growth and differentiation factor 15 (GDF-15) is a divergent member of the TGF-β superfamily with low to absent expression in healthy tissue. GDF-15 has been linked to feto-maternal immune tolerance, to prevention of excessive immune cell infiltration during tissue damage, and to anorexia. Various major tumor types secrete high levels of GDF-15. In cancer patients, elevated GDF-15 serum levels correlate with poor prognosis and reduced overall survival (OS). Methods: Impact of a proprietary GDF-15 neutralizing antibody (CTL-002) regarding T cell trafficking was analyzed by whole blood adhesion assays, a HV18-MK melanoma-bearing humanized mouse model and a GDF-15-transgenic MC38 model. Additionally, patient GDF-15 serum levels were correlated with clinical response and overall survival in oropharyngeal squamous cell carcinoma (OPSCC) and melanoma brain metastases. Results: In whole blood cell adhesion assays GDF-15 impairs adhesion of T and NK cells to activated endothelial cells. Neutralization of GDF-15 by CTL-002 rescued T cell adhesion. In HV18-MK-bearing humanized mice CTL-002 induced a strong increase in TIL numbers. Subset analysis revealed an overproportional enrichment of T cells, in particular CD8+ T cells. As immune cell exclusion is detrimental for checkpoint inhibitor (CPI) therapy, a GDF-15-transgenic MC38 model was tested for anti-PD-1 therapy efficacy. In GDF-15 overexpressing MC38 tumors response to anti PD-1 therapy was reduced by 90% compared to wtMC38 tumors. Combining aPD-1 with CTL-002 resulted in 50% of the mice rejecting their GDF-15 overexpressing tumors. Clinically, inverse correlations of GDF-15 levels with CD8+ T cell infiltration were shown for HPV+ OPSCC and for melanoma brain metastases. GDF-15 serum levels were significantly higher in HPV- than in HPV+ OPSCC patient (p < 0.0001). Low GDF-15 levels corresponded to longer OS in both HPV- and HPV+ OPSCC. In two independent melanoma patient cohorts treated with nivolumab or pembrolizumab low baseline serum GDF-15 levels were predictive for clinical response to anti-PD1 treatment and superior OS. Bivariate analysis including LDH indicates that GDF-15 independently predicts poor survival in aPD-1 treated melanoma patients. Conclusions: Taken together our in vitro and in vivo data show that elevated GDF-15 levels block T-cell infiltration into tumor tissues. Neutralizing GDF-15 with CTL-002 restores the ability of T cells to extravasate blood vessels and enter tumor tissue both in vitro and in vivo. In melanoma, patients with higher GDF-15 levels have significantly shorter survival and are less likely to respond to anti-PD1 therapy. GDF-15 may thus serve as a new predictive biomarker for anti-PD1 response, but most importantly also represents a novel target for cancer immunotherapy to improve tumor immune cell infiltration and response to anti-PD1 therapy.


Author(s):  
Qun Chen ◽  
Jing Jin ◽  
Xin Huang ◽  
Fan Wu ◽  
Hongguang Huang ◽  
...  

Abstract Background The immunosuppressive tumour microenvironment is a critical factor in the initiation and progression of glioblastoma (GBM), which is characterized by an abundance of tumour-associated macrophages (TAMs) but a paucity of infiltrating T cells. In this research, we studied whether epithelial membrane protein 3 (EMP3) plays a crucial role in immune modulation in GBM. Methods TCGA and CGGA transcriptomic profiles of wild-type IDH1 GBM were used for bioinformatic analysis. The role of EMP3 in GBM was validated through in vivo and in vitro experiments. Human GBM specimens were collected and evaluated using immunofluorescence analysis. Results EMP3 was associated with immunosuppression in GBM. Elevated EMP3 in GBM areas was accompanied by high expression of PD-L1 and abundant M2 TAM recruitment but a lake of T cell infiltration. We found that EMP3 was a potent protein in M2 TAM polarization and recruitment that impaired the ability of GBM cells to secrete CCL2 and TGF-β1. Furthermore, EMP3 suppressed T cell infiltration into GBM tumours by inhibiting the secretion of CXCL9 and CXCL10 by macrophages and led to an effective response to anti-PD1 therapy. Conclusions EMP3 is thus a critical immunosuppressive factor for recruiting TAMs in GBM and suppressing intratumoural T cell infiltration to facilitate tumour progression and is a potential therapeutic target.


2021 ◽  
Vol 10 (4) ◽  
pp. 832
Author(s):  
Ida Aringer ◽  
Katharina Artinger ◽  
Corinna Schabhüttl ◽  
Thomas Bärnthaler ◽  
Agnes A. Mooslechner ◽  
...  

Selectively targeting the E-type prostanoid receptor 4 (EP4) might be a new therapeutic option in the treatment of glomerulonephritis (GN), since the EP4 receptor is expressed on different immune cells, resident kidney cells, and endothelial cells, which are all involved in the pathogenesis of immune-complex GN. This study aimed to evaluate the therapeutic potential and to understand the mode of action of EP4 agonist in immune-complex GN using the murine model of nephrotoxic serum nephritis (NTS). In vivo, NTS mice were treated two times daily with two different doses of an EP4 agonist ONO AE1-329 or vehicle for 14 days total. The effect of PGE2 and EP4 agonism and antagonism was tested on murine distal convoluted tubular epithelial cells (DCT) in vitro. In vivo, the higher dose of the EP4 agonist led to an improved NTS phenotype, including a reduced tubular injury score and reduced neutrophil gelatinase-associated lipocalin (NGAL) and blood urea nitrogen (BUN) levels. EP4 agonist treatment caused decreased CD4+ T cell infiltration into the kidney and increased proliferative capacity of tubular cells. Injection of the EP4 agonist resulted in dose-dependent vasodilation and hypotensive episodes. The low-dose EP4 agonist treatment resulted in less pronounced episodes of hypotension. In vitro, EP4 agonism resulted in cAMP production and increased distal convoluted tubular (DCT) proliferation. Taken together, EP4 agonism improved the NTS phenotype by various mechanisms, including reduced blood pressure, decreased CD4+ T cell infiltration, and a direct effect on tubular cells leading to increased proliferation probably by increasing cAMP levels.


2011 ◽  
Vol 208 (3) ◽  
pp. 577-592 ◽  
Author(s):  
Li Wang ◽  
Rotem Rubinstein ◽  
Janet L. Lines ◽  
Anna Wasiuk ◽  
Cory Ahonen ◽  
...  

The immunoglobulin (Ig) superfamily consists of many critical immune regulators, including the B7 family ligands and receptors. In this study, we identify a novel and structurally distinct Ig superfamily inhibitory ligand, whose extracellular domain bears homology to the B7 family ligand PD-L1. This molecule is designated V-domain Ig suppressor of T cell activation (VISTA). VISTA is primarily expressed on hematopoietic cells, and VISTA expression is highly regulated on myeloid antigen-presenting cells (APCs) and T cells. A soluble VISTA-Ig fusion protein or VISTA expression on APCs inhibits T cell proliferation and cytokine production in vitro. A VISTA-specific monoclonal antibody interferes with VISTA-induced suppression of T cell responses by VISTA-expressing APCs in vitro. Furthermore, anti-VISTA treatment exacerbates the development of the T cell–mediated autoimmune disease experimental autoimmune encephalomyelitis in mice. Finally, VISTA overexpression on tumor cells interferes with protective antitumor immunity in vivo in mice. These findings show that VISTA, a novel immunoregulatory molecule, has functional activities that are nonredundant with other Ig superfamily members and may play a role in the development of autoimmunity and immune surveillance in cancer.


Author(s):  
Jing Chen ◽  
Yan Hu ◽  
Yincheng Teng ◽  
BiKang Yang

Background: Importin 7 (IPO7), a karyopherin-β protein, is involved in various tumorigenesis and progression abilities by mediating the nuclear import of oncoproteins. However, the exact biological functions of IPO7 remain to be further elucidated.Materials and Methods: TCGA and GEO datasets were used to identify dysregulated expression of IPO7 in various cancers. Gain-of-function and loss-of-function analyses were used to identify the oncogenic functions of IPO7 in vitro and in vivo. Moreover, LC-MS/MS and parallel reaction monitoring analysis were used to comparatively profiled IPO7-related proteomics and potential molecular machinery.Results: Our works demonstrated that the expression of IPO7 was upregulated and was correlated with a poor prognosis in cervical cancer. In vitro and in vivo experiments demonstrated that knockdown of IPO7 inhibited the proliferation of HeLa and C-4 I cells. LC-MS/MS analysis showed that IPO7-related cargo proteins mainly were enriched in gene transcription regulation. Then independent PRM analysis for the first time demonstrated that 32 novel IPO7 cargo proteins, such as GTF2I, RORC1, PSPC1, and RBM25. Moreover, IPO7 contributed to activating the PI3K/AKT-mTOR pathway by mediating the nuclear import of GTF2I in cervical cancer cells. Intriguingly, we found that the IPO7 expression was negatively correlated with CD8 T cell infiltration via regulating the expression of CD276 in cervical cancer.Conclusion: This study enhances our understanding of IPO7 nuclear-cytoplasmic translocation and might reveal novel potential therapeutic targets. The results of a negative correlation between the IPO7 and CD8 T cell infiltration indicate that the IPO7 might play an important impact on the immune microenvironment of cervical cancer.


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A663-A663
Author(s):  
Keegan Cooke ◽  
Juan Estrada ◽  
Jinghui Zhan ◽  
Jonathan Werner ◽  
Fei Lee ◽  
...  

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.


Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 817
Author(s):  
Mehreen Ishfaq ◽  
Timothy Pham ◽  
Cooper Beaman ◽  
Pablo Tamayo ◽  
Alice L. Yu ◽  
...  

MDSCs are immune cells of myeloid lineage that plays a key role in promoting tumor growth. The expansion of MDSCs in tumor-bearing hosts reduces the efficacy of checkpoint inhibitors and CAR-T therapies, and hence strategies that deplete or block the recruitment of MDSCs have shown benefit in improving responses to immunotherapy in various cancers, including NB. Ibrutinib, an irreversible molecular inhibitor of BTK, has been widely studied in B cell malignancies, and recently, this drug is repurposed for the treatment of solid tumors. Herein we report that BTK is highly expressed in both granulocytic and monocytic murine MDSCs isolated from mice bearing NB tumors, and its increased expression correlates with a poor relapse-free survival probability of NB patients. Moreover, in vitro treatment of murine MDSCs with ibrutinib altered NO production, decreased mRNA expression of Ido, Arg, Tgfβ, and displayed defects in T-cell suppression. Consistent with these findings, in vivo inhibition of BTK with ibrutinib resulted in reduced MDSC-mediated immune suppression, increased CD8+ T cell infiltration, decreased tumor growth, and improved response to anti-PDL1 checkpoint inhibitor therapy in a murine model of NB. These results demonstrate that ibrutinib modulates immunosuppressive functions of MDSC and can be used either alone or in combination with immunotherapy for augmenting antitumor immune responses in NB.


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Annemarie Noordeloos ◽  
Elza van Deel ◽  
Denise Hermes ◽  
Maarten L Simoons ◽  
Dirk J Duncker ◽  
...  

Introduction: Although expression of heme oxygenase-1 (HO1) attenuates transplantation arteriosclerosis, the mechanism by which HO1 exerts its protective effect remains unclear. We studied the effect of HO1-deficient vs. wildtype (WT) dendritic cells (DCs) on the T-cell priming response and outcome in a murine transplant arteriosclerosis model. Methods: At day 0 C57bl6 mice received either WT (n=6) or HO1-knockout DCs (n=6) pre-sensitized with Balb/c splenocytes lysate to accelerate the development of arteriosclerosis. At day 10 an aorta segment from Balb/c mice was transplanted into the carotid artery position of C57Bl6 mice.14 days after transplantation allografts were excised and processed for immunohistochemical analysis. Results: HO1-deficient DCs significantly increased neointimal hyperplasia as compared to WT DCs (116995 vs. 46114μm 2 P<0.05) and incidence of intima formation (83 vs. 50% in WT DC). HO1 deficient DCs also increased medial thickeness (15936 vs.12034 μm 2 P<0.05) and intimal VSMCs content (76 vs. 46% P<0.05) and resulted in more prominent medial cell infiltration (461μm 2 vs. 232μm 2 P<0.05). Although HO1 deficient and WT DCs could be detected in allografts, HO1-nullizygous DCs induced an increase in CD4+ T-cell infiltration (9.5 vs. 0.1% in WT P<0.05) concomitant to a decrease of CD8+ T cell infiltration (8 vs.14%, P<0.05). In line with these observations Affymetrix microarray analysis confirmed that HO1 deletion in DCs was associated with a significant downregulation of MHCII-H2A expression (associated with CD4+T-cell activation) and induction of inhibitors of MHCII expression (including IK protein) whereas MHC I expression remained unchanged. Conclusions: HO1 expression in dendritic cells increases vascular cell infiltration with a higher CD8+/CD4+ T-cell ratio by stabilizing MHCII expression in vascular allografts resulting in inhibition of neointima formation and hence improved allograft survival.


2012 ◽  
Vol 209 (6) ◽  
pp. 1201-1217 ◽  
Author(s):  
Tadashi Yokosuka ◽  
Masako Takamatsu ◽  
Wakana Kobayashi-Imanishi ◽  
Akiko Hashimoto-Tane ◽  
Miyuki Azuma ◽  
...  

Programmed cell death 1 (PD-1) is a negative costimulatory receptor critical for the suppression of T cell activation in vitro and in vivo. Single cell imaging elucidated a molecular mechanism of PD-1–mediated suppression. PD-1 becomes clustered with T cell receptors (TCRs) upon binding to its ligand PD-L1 and is transiently associated with the phosphatase SHP2 (Src homology 2 domain–containing tyrosine phosphatase 2). These negative costimulatory microclusters induce the dephosphorylation of the proximal TCR signaling molecules. This results in the suppression of T cell activation and blockade of the TCR-induced stop signal. In addition to PD-1 clustering, PD-1–TCR colocalization within microclusters is required for efficient PD-1–mediated suppression. This inhibitory mechanism also functions in PD-1hi T cells generated in vivo and can be overridden by a neutralizing anti–PD-L1 antibody. Therefore, PD-1 microcluster formation is important for regulation of T cell activation.


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