bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract A076: Cutaneous microbiota drive the accumulation of IL-17A-producing T cells within the lungs
Authors: Constantinides Michael G. , Ridaura Vanessa K. , Belkaid Yasmine
Published: November 2016

Infectious agents are estimated to cause approximately 18% of cancers worldwide, supporting a link between microbial products and carcinogenesis. The microbiome consists of a diverse array of commensal microorganisms that reside at barrier sites of the human body and promote local immune homeostasis, but also provide the primary source of constitutive microbial stimulation. While recent work has demonstrated that intestinal commensals can influence immunity throughout the body, the distal effects of other microbial communities have not been fully explored. Here we show that application of distinct human commensals to the skin of mice induces the accumulation of IL-17A-producing T cells in the lungs. The induction of these cells occurs in a manner that is partially dependent on both antigen presentation and IL-23 signaling. Response kinetics and adoptive transfer experiments suggest that the T cells migrate from the skin-draining lymph nodes, while transcriptional analysis has identified specific chemokine receptors that facilitate trafficking to the lungs. Furthermore, in the context of a pulmonary challenge, cutaneous application of commensals promotes the production of IL-17A and recruitment of neutrophils to the lungs. This work demonstrates that the skin microbiome can enhance pulmonary immunity, but also has the potential to cause pro-oncogenic inflammation. Since IL-17A promotes tumor vascularization and neutrophils can contribute to the establishment of metastases, specific microbes at distal sites such as the skin may exacerbate the progression of lung cancer.

Citation Format: Michael G. Constantinides, Vanessa K. Ridaura, Yasmine Belkaid. Cutaneous microbiota drive the accumulation of IL-17A-producing T cells within the lungs [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr A076.
Abstract A090: Identify molecular mechanisms that regulate the GMP-AMP synthase (cGAS) activity
Authors: Li Tuo , Chen Zhijian J.
Published: November 2016

While checkpoint inhibitors are achieving stunning success in cancer treatment, one possible approach to improve the response rate is to enhance the initiation of anti-tumor immune response. Recently studies showed that the cytosolic DNA sensing pathway is essential for the innate immune response in dendritic cells to radiation treated tumor cells. Cytosolic DNA, as a danger signal, is sensed by the cyclic GMP-AMP synthase (cGAS), which produces the second messenger, 2'3'-cyclic AMP-GMP (cGAMP) to activate STING-mediated Type I interferon response. Despite the critical role of cGAS in anti-tumor immunity, how its activity is regulated remains poorly understood. To explore cGAS-regulating mechanisms in cells, we used mass spectrometry to study cGAS and its interacting partners during the course of DNA sensing. The results indicate that cGAS is phosphorylated at multiple serine and threonine residues. Mutagenesis experiments showed that the phosphorylation at Serine305 can potently inhibit the cGAMP-synthesis activity. Structural analysis illustrated that this phosphorylation site locates at the entrance of the active site, therefore the negatively charged phosphate group may sterically block the access of substrates, ATP and GTP. This serine is highly conserved in mammalian species, and locates within a cyclin kinase motif. Indeed, purified human CDK1-cyclin B complex, the dominant mitosis driver, can specifically phosphorylate this serine in vitro. The results suggest that the cGAS activity may coordinate with the cell cycle, and implies that the phosphorylation may limit the immunogenicity of tumor radiation therapy.

Note: This abstract was not presented at the conference.

Citation Format: Tuo Li, Zhijian J. Chen. Identify molecular mechanisms that regulate the GMP-AMP synthase (cGAS) activity [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr A090.
Abstract A095: Immunosuppressive plasmocytes regulate the development of NASH-induced HCC
Authors: Shalapour Shabnam , Karin Michael
Published: November 2016

Hepatocellular carcinoma (HCC), a rather common and lethal malignancy, is the prevalent common form of liver cancer, associated with chronic tissue damage caused by fat accumulation, environmental toxicants, viral infections, inflammation and stress. Although at present, hepatitis virus infections are the primary HCC risk factors, they will soon be replaced by hypernutrition and ethanol consumption, both of which cause hepatic steatosis. According to a recent CDC report the incidence of HCC continues to grow at an alarming yearly rate, in part due to the obesity epidemic. This has sparked a considerable effort to understand how non-alcoholic fatty liver disease (NAFLD) and its more aggressive manifestation, non-alcoholic steatohepatitis (NASH), drive HCC development. Although, many studies have confirmed that NASH to HCC progression is inflammation dependent, the role of adaptive immune responses in NASH-promoted HCC is largely unknown. We recently identified a type of B cells in both mouse and human prostate cancer (PC), that have potent immunosuppressive properties. Ablation of these immunosuppressive plasmocytes (ISP), enables nearly complete elimination of large and advanced PC tumors upon treatment with the immunogenic chemotherapeutic oxaliplatin. ISP are IgA-producing plasmocytes that express the immunosuppressive molecules IL-10 and PD-L1. In PCa, generation of ISP is driven by TGFβ, which is produced in large amounts by αSMA+ CAF, which also produce the B cell chemoattractant CXCL13. We therefore examined whether ISP are present in other tumors that are rich in TGFβ (and CXCL13)-producing αSMA+ myofibroblasts and confirmed their presence in two mouse models of liver cancers that develop in the context of chronic inflammation and fibrosis. Meanwhile, a strong correlation between circulating IgA and the degree of liver fibrosis was observed in patients suffering from NASH. Interestingly, accumulation of IgA and IL-10 expressing plasmocytes precedes HCC development and is not seen in mice that develop simple steatosis. The depletion of IL-10 and PD-L1-expressing ISP in livers of NASH-afflicted mice resulted in at least a 50% decrease in tumor burden accompanied by CTL activation and infiltration. Thus, a combination of anti-PD-L1 or other ISP-depleting treatment with a suitable immunogenic chemotherapeutic agent may result in more extensive HCC regression.

Citation Format: Shabnam Shalapour, Michael Karin. Immunosuppressive plasmocytes regulate the development of NASH-induced HCC [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr A095.
Abstract A096: Myeloid cells are required for pancreatic carcinogenesis and PD-1/PD-L1 checkpoint activation
Authors: Zhang Yaqing , Velez-Delgado Ashley , Mathew Esha , Li Dongjun , Mendez Flor M. , Flannagan Kevin , Rhim Andrew D. , Simeone Diane M. , Beatty Gregory L. , Magliano Marina Pasca di
Published: November 2016

Myeloid cells, including both macrophages and immature myeloid cells/myeloid derived suppressor cells (MDSCs), accumulate during the progression of pancreatic cancer. The goal of this study was to determine the effect of myeloid cell depletion on the onset and progression of pancreatic cancer, and to understand the relationship between myeloid cells and T cell-mediated immunity within the pancreatic cancer microenvironment.

Primary mouse pancreatic cancer cells were transplanted into CD11b-DTR mice. Alternatively, the iKras* mouse model of pancreatic cancer was crossed into CD11b-DTR mice. CD11b+ cells were depleted by Diphtheria Toxin treatment during tumor initiation or in established tumors. Depletion of myeloid cells prevented KrasG12D driven pancreatic cancer initiation.

Myeloid cells are required for sustained MAPK signaling in pancreatic epithelial cells during the onset of carcinogenesis, notwithstanding the expression of oncogenic Kras. In pre-established tumors, myeloid cell depletion arrested tumor growth and in some cases, induced tumor regressions that were dependent on CD8+ T cells. We found that myeloid cells inhibited CD8+ T cell anti-tumor activity by inducing the expression of Programmed cell death-ligand 1 (PD-L1) in tumor cells in an EGFR/MAPK dependent manner. Treatment with MEK inhibitors lowers the intratumoral expression of PD-L1 and renders the tumor susceptible to PD-1 blockade.

Our results show that myeloid cells support immune evasion in pancreatic cancer through EGFR/MAPK dependent regulation of PD-L1 expression on tumor cells. Derailing this cross-talk between myeloid cells and tumor cells is sufficient to restore anti-tumor immunity mediated by CD8+ T cells, a finding with implications for the design of immune therapies for pancreatic cancer.

Note: This abstract was not presented at the conference.

Citation Format: Yaqing Zhang, Ashley Velez-Delgado, Esha Mathew, Dongjun Li, Flor M. Mendez, Kevin Flannagan, Andrew D. Rhim, Diane M. Simeone, Gregory L. Beatty, Marina Pasca di Magliano. Myeloid cells are required for pancreatic carcinogenesis and PD-1/PD-L1 checkpoint activation [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr A096.
Abstract A105: Characterization of adenosine producing B cells in patients with head and neck cancer as well as of the influence of adenosine on B cell function
Authors: Jäkle Sandra S. , Brunner Cornelia , Hoffmann Thomas K. , Schuler Patrick J.
Published: November 2016

Introduction: Recently, we have shown that human regulatory B cells (Breg) and regulatory T cells (Treg) are the main producers of exogenous immune-suppressive adenosine (ADO) with the ectonucleotidases, CD39 and CD73, being the functional enzymes. Immune suppression in the tumor environment may cause increased tumor growth and metastasis. But the role of intracellular components of Breg and in response to ADO are not completely understood.

Methods: Peripheral blood mononuclear cells (PBMC) and tumor infiltrating lymphocytes (TIL) were isolated from patients with head and neck cancer (n = 20). Phenotypes, intracellular expression of phosphor-proteins of the B cell-receptor (BCR)-mediated signaling pathway and ADO production were determined by multicolor flow cytometry and luminescence. The influence of exogenous ADO on intracellular signaling pathways was determined by flow cytometry, western blot and PCR on healthy volunteers.

Results: In comparison to healthy donors, the frequency of Treg is increased while the frequency of Breg remains stable in the peripheral blood of cancer patients. For the Treg this effect is pronounced in the tumor microenvironment, while the B cells showed new phenotypic characteristics. The phosphorylation of the proteins of the intracellular BCR-pathway in healthy B cells are inhibited by treatment with ADO. In contrast, after BCR-specific stimulation, the secretion of inflammatory cytokines by B cells is increased in the presence of ADO.

Conclusion: Adenosine producing immune cells contribute to immune suppression in the tumor microenvironment and may promote tumor growth. Intracellular key regulators of ADO-production in Breg may serve as a therapeutic target in cancer patients.

Citation Format: Sandra S. Jäkle, Cornelia Brunner, Thomas K. Hoffmann, Patrick J. Schuler. Characterization of adenosine producing B cells in patients with head and neck cancer as well as of the influence of adenosine on B cell function [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr A105.
Abstract A124: Protumoral effects of TLR7 in lung tumors
Authors: Dajon Marion , Iribarren Kristina , Cremer Isabelle
Published: November 2016

TLR7 agonists are currently under investigations for their ability to enhance anti-tumor immune responses. However, in some tumor models, these agonists can also stimulate tumor cells, which express high levels of TLR7. In Non-Small-Cell Lung Carcinoma (NSCLC), we have demonstrated that high expression of TLR7 conferred poor clinical outcome and was strongly associated with resistance to chemotherapy. This protumorigenic effect of TLR7 has been validated in murine models in which the injection of TLR7 agonists in NOD/SCID mice, in C57BL/6 wild-type or in TLR7-deficient mice grafted with lung adenocarcinoma tumor cells led to increased tumor progression and chemotherapeutic resistance. TLR7 stimulation resulted in a significant increase of Myeloid-Derived Suppressor Cells (MDSC) in the tumor microenvironment. Depletion experiments of MDSC indicated that these cells appeared to be responsible to the in vivo pro-tumoral effect induced upon TLR7 stimulation. Finally, we have demonstrated that the pro-tumoral effect of TLR7 stimulation, mediated by the MDSC recruitment, was independent of stimulation of TLR7 of immune cells.

Our results reveal the mechanism by which TLR7 stimulation induce the pro-tumoral effect in mice, and open the way to the development of novel cancer therapeutics including TLR7 inhibitors, for NSCLC patients.

Citation Format: Marion Dajon, Kristina Iribarren, Isabelle Cremer. Protumoral effects of TLR7 in lung tumors [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr A124.
Abstract A134: Identification of novel Treg-specific molecule targets
Authors: Kim Jung-Ho , Moon Jae-Seung , Lee Sang-Kyou
Published: November 2016

Regulatory T cells (Treg cells) play as a specialized cell lineage that has an essential role in the immunological tolerance and maintenance of immune homeostasis, and it has been reported that Treg cells are enriched within the tumor microenvironment for immune evasion due to their immunosuppressive functions. Currently studies have revealed the heterogeneity or developmental plasticity in the Treg cells lineage, acquisition of alternative effector or hybrid fates. In this study, we conducted next generation sequencing (NGS) to identify the molecular interaction of Treg cells and Th17 cells genetic programs in response to cytokine regulation. We found that 41 differential expression genes (DEGs) are related common TGF-β signaling, 129 DEGs are involved specific Treg cells fate determination and maintenance and 144 DEGs are linked pro-inflammatory Th17 cells response. Also we identified Treg cell-specific molecular targets such as TregP1, TregL1, TregG, and TregAP2 by systemic and classical biologic approaches. These genes highly expressed in Treg cells independently of Foxp3 expression, and conferred unique role on Treg cells. Thus, we propose that these genes targeting have potential therapeutic applications in cancer, and other conditions which Foxp3+Treg cells limit protective host immune responses.

Note: This abstract was not presented at the conference.

Citation Format: Jung-Ho Kim, Jae-Seung Moon, Sang-Kyou Lee. Identification of novel Treg-specific molecule targets [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr A134.
Abstract A147: Differential transcriptional profiling of tumor cell populations
Authors: Duttke Sascha H. , Glass Christopher K.
Published: November 2016

Tumors compass remarkably diverse cell populations as a result of genetic and environmental influences. Macrophages are a type of white blood cell with pivotal roles in immunity and tissue homeostasis that were reported to constitute up to 50% of the tumor mass. Macrophages also present a central line of defense against cancer by preventing inflammation as well as specific elimination of tumor cells. However, tumors can manipulate macrophages to switch their function from tumor-suppressing to tumor-supporting. Tumor-supporting macrophages are pro-angiogenic, immunosuppressive and aid the neoplastic progression. My aim is to characterize the core transcriptional network of “supporting” or “repressing” tumor associated macrophages in mice and humans. At phase 1 of the project, I am testing methods to differentially analyze cell populations from tumors with minimal perturbations as well as ways to reduce input for GROseq and RNAseq analysis.

Citation Format: Sascha H. Duttke, Christopher K. Glass. Differential transcriptional profiling of tumor cell populations [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr A147.
Abstract B022: Intratumoral CD40 activation and checkpoint blockade induces systemic anti-melanoma immunity that eradicates disseminated tumors
Authors: Singh Manisha , Vianden Christina , Diab Adi , Hwu Patrick , Overwijk Willem W.
Published: November 2016

Although surgical resection is a reliable treatment for localized melanoma, treatment options for metastatic melanoma are limited. Melanoma Brain metastasis (MBM) is a major clinical problem in patients with advanced melanoma, and the incidence of brain metastasis is increasing every year. Thus, there is a significant unmet need for effective therapies for metastatic melanoma and MBM patients. Agonistic CD40 antibodies generate strong tumor specific CD8 T cell response and anti-tumor activity; however systemic anti-CD40 therapy has been associated with cytokine release syndrome and liver toxicity. We studied the anti-melanoma activity and mechanism of action of a non-replicating adenovirus encoding a CD40-targeting chimeric immunostimulatory protein (ISF35) by local intratumoral delivery approach to treat local and distant melanoma. Mice bearing established B16 melanomas on both right and left flanks or on right flank and in brain were treated intratumorally with ISF35 or rAd.empty to the right flank tumor and received anti-PD1 plus anti-CTLA-4 systemically. Anti-tumor effects of mono or combination therapies were determined by mice survival and tumor growth measurement. The mechanistic contribution of immune cells to this therapy was determined by using antibody blockades. Immune cell infiltrates in tumor and expression of activation markers on these cells were analyzed by flow cytometry. Intratumoral administration of ISF35 generates systemic anti-tumor immunity mediates by CD8 T cells and suppress both injected and distant uninjected wild-type B16.F10 melanomas. However, tumors did not completely regress after therapy. When combined with checkpoint inhibitors, ISF35 generates synergistic systemic anti-melanoma immunity that eradicates both injected and uninjected distant subcutaneous melanoma and uninjected brain melanoma with 40% of mice cured. The systemic anti-tumor activity of ISF35/anti-PD-1/anti-CTLA-4 was associated with greater production of melanoma-specific CD8 T cells with an activated phenotype. Immunotherapy based on intratumoral CD40 activation is potentiated by PD-1 and CTLA-4 blockade and this combination generates functional and long-lasting anti-tumor CD8 T cell immunity that systemically suppresses melanoma metastases. This approach will be a better option for treatment of patients with metastatic melanoma that does not respond to checkpoint blockage monotherapy.

Citation Format: Manisha Singh, Christina Vianden, Adi Diab, Patrick Hwu, Willem W. Overwijk. Intratumoral CD40 activation and checkpoint blockade induces systemic anti-melanoma immunity that eradicates disseminated tumors [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr B022.
Abstract B033: A novel IL-2 and IL-15 antagonist shifting the immune balance towards tolerance: Potential therapeutic applications
Authors: Dihia Meghnem , Morisseau Sebastien , Trillet Kilian , Frutoso Marie , Barbieux Isabelle , Quemener Agnes , Jacques Yannick , Mortier Erwan
Published: November 2016

Interleukin-15 and interleukin-2 are two hematopoietic cytokines belonging to γc family and both share the IL2/15Rβ chain and the common γ chain. The IL-15Rα and IL-2Rα chains confer specific binding and signalling for IL-15 and IL-2 respectively. IL-15 and IL-2 induce T-cell proliferation, effector T-cell differentiation and memory T-cell survival. Unlike IL-15, IL-2 plays a crucial role, in development and activation of regulatory T cells, which constitutively express specific IL-2Rα chain. In order to inhibit IL-2 and IL-15 dependent effector functions, we developed an original antagonist called BinhG which target the shared IL-2/15Rβγ receptor. To characterize BinhG's mechanism and therapeutic potential, we first studied its effect in vitro on IL-15 and IL-2-induced proliferation on cell lines and peripheral blood mononuclear cells. We found that BinhG was able to inhibit IL-15 and IL-2-dependent proliferation of effector NK and CD8 T cells expressing the IL-2/15Rβγ dimeric receptor, whereas it was unable to inhibit IL-2 induced-T-reg cells due to ILtheirs IL-2Rα expression. These results were confirmed in vivo, by inhibition of IL-2 or IL-15 induced activation in mice. Moreover, after PolyIC stimulation in vivo, BinhG was able to reduce IFNγ secretion by NK cells and activation marker CD69 surface expression by CD4 T and CD8 T lymphocytes, but has no effect on T-reg cells. In the light of these observations, BinhG was evaluated in order to induce tolerance. Thus, we set up a murine model of skin graft rejection, and we observed that BinhG prolonged the skin graft survival. The use of the BinhG antagonist appears to have much promise, as it is able to shift immune response towards the tolerance side of the balance. However, further studies are needed to maximize the therapeutic outcome, by improving BinhG in vivo half-life. Moreover, it would be of interest to evaluate BinhG's effect in autoimmune contexts.

Citation Format: Meghnem Dihia, Sebastien Morisseau, Kilian Trillet, Marie Frutoso, Isabelle Barbieux, Agnes Quemener, Yannick Jacques, Erwan Mortier. A novel IL-2 and IL-15 antagonist shifting the immune balance towards tolerance: Potential therapeutic applications [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr B033.
Abstract B042: Potent and selective small molecule USP7 inhibitors for cancer immunotherapy
Authors: Kumar Suresh , Wu Jian , Wang Liqing , Wang Jack , Sokirniy Ivan , Wang Hui , Fegley Glen , Weinstock Joseph , Mattern Michael , Hancock Wayne W.
Published: November 2016

Immunotherapy using biological agents such as anti-PD1 antibody has revolutionized cancer treatment. Nevertheless, patient response has been highly variable, with many patients showing no response. Although the precise mechanism of resistance is unknown, the complex immunosuppressive tumor milieu necessitates development of additional therapeutic agents to potentiate active drugs and expand the scope of the revolutionary cancer immunotherapy. Regulatory T cells (Tregs) present in tumors dampen the anti-tumor activities of effector T cells and are correlated with poor prognosis. Therefore, depletion of Tregs or impairment of Treg function is considered an attractive therapeutic approach. USP7, a deubiquitylase (DUB) implicated as a critical node in several cancer signaling pathways, is essential for maintaining Treg function, and Treg specific deletion of USP7 results in impaired Treg functions and lethal autoimmunity. Progenra has identified selective small molecule USP7 inhibitors that were subsequently lead optimized and evaluated in ADME/PK studies. Potent, selective and irreversible USP7 inhibitors have been shown to impair Treg functions and exhibit powerful anti-tumor activity against syngeneic lung tumor models in immunocompetent mice. In addition, Progenra's USP7 inhibitors synergize with anti-PD1 antibody and cancer vaccines. These studies suggest that USP7 inhibitors alone or in combination can improve the efficacy and expand the scope of cancer immunotherapy

Citation Format: Suresh Kumar, Jian Wu, Liqing Wang, Jack Wang, Ivan Sokirniy, Hui Wang, Glen Fegley, Joseph Weinstock, Michael Mattern, Wayne W. Hancock. Potent and selective small molecule USP7 inhibitors for cancer immunotherapy [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr B042.
Abstract B043: Systems pharmacology modeling of anti-CD20/CD3 T-cell dependent bispecific antibody and its application to clinical trial design
Authors: Hosseini Iraj , Gadkar Kapil , Stefanich Eric , Li Chi-Chung , Sun Laura , Chu Yu-Waye , Ramanujan Saroja
Published: November 2016

Objectives: To develop and apply a quantitative systems pharmacology (QSP) model to support clinical trial design for anti-CD20/CD3 T-cell dependent bispecific antibody in non-Hodgkin lymphoma (NHL).

Methods: We developed a mechanistic model to describe the dynamics of B- and T-lymphocytes and their interactions in multiple physiological compartments (peripheral blood, tumor, and lymphoid tissues including the spleen, lymph nodes, and bone marrow) in the presence of an anti-CD20/CD3 T-cell dependent bispecific antibody (CD20-TDB) and the CD19-targeting bispecifc T-cell engager blinatumomab (a molecule with a similar mechanism of action, approved for ALL). The model is based on physiological, mechanistic, pharmacokinetic, and pharmacodynamic data and includes: 1) multiple activation states of CD8+ T-cells; 2) CD19+CD20- (pro-B), and CD19+CD20+ (pre- to mature-B) B-lymphocytes; and 3) the pharmacokinetics of CD20-TDB and blinatumomab and their mechanistic effects (activation of CD8+ T-lymphocytes and consequent killing of CD20+ and CD19+ B-lymphocytes, respectively).

Results: The model was calibrated using in vitro potency data and circulating cell measurements in cynomolgous monkeys treated with CD20-TDB [1]. Preclinical and translational validation was performed using additional CD20-TDB preclinical data and blinatumomab clinical data [2, 3]. The model replicated the effects of CD20-TDB on cell dynamics in circulation, and predicted CD20-TDB preclinical data at lower doses and in tissues, and blinatumomab clinical data in patients with ALL and NHL. The model will be used to evaluate and propose dosing strategies for CD20-TDB in patients with NHL and to inform other clinical development considerations.

Conclusions: The mechanism-based systems model accurately captures and predicts the pharmacodynamics of CD20-TDB in cynomolgous monkeys and in patients with ALL and NHL. The model provides a novel approach for evaluation of clinical dosing strategies for CD20-TDB and can be extended to related molecules and/or other B cell malignancies.

References: [1] Sun LL, et al. Sci Transl Med. 2015; 7(287): 1-10. [2] Klinger M, et al. Blood. 2012;119(26):6226-3. [3] Hijazi Y, et al. Abstract: 3051. ASCO; May 31-June 4, 2013.

Citation Format: Iraj Hosseini, Kapil Gadkar, Eric Stefanich, Chi-Chung Li, Laura Sun, Yu-Waye Chu, Saroja Ramanujan. Systems pharmacology modeling of anti-CD20/CD3 T-cell dependent bispecific antibody and its application to clinical trial design [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr B043.
Abstract B047: Combining natural killer T cell immunotherapy with chemotherapy induced immunogenic cell death to target post-surgical breast cancer metastasis
Authors: Gebremeskel Simon , Tanner Kaitlyn , Lobert Lynnea , Johnston Brent
Published: November 2016

Breast cancer is the most common cancer in Canadian women and the second leading cause of cancer deaths. Given that most mammary tumors are surgically resectable and over 90% of breast cancer-associated deaths are due to metastasis, new therapeutic strategies targeting metastasis are required. Natural killer T (NKT) cells are a rare population of immune cells that have been shown to limit primary tumor growth and target distant metastatic disease in various animal models. We have shown that NKT cell activation improves survival in a model of post-surgical metastatic breast cancer. We are now expanding this work to determine whether NKT cell activation can be combined with chemotherapies to improve outcomes. In our model, 4T1 mammary carcinoma cells were injected into the mammary fatpad of syngeneic BALB/c mice. Tumors were resected at day 12, and mice were treated with cyclophosphamide or gemcitabine. On day 17, NKT cells were activated by transfer of dendritic cells loaded with the glycolipid antigen α-GalCer. We also examined whether Gemcitabine or mafosphamide (active component of cyclophosphamide) would induce immunogenic cell death of 4T1 cells in culture. Chemotherapeutics did not affect NKT cell activation as measured by serum IFNγ levels. Treatment with cyclophosphamide, gemcitabine, or α-GalCer-loaded dendritic cells alone reduced metastasis and prolonged survival. Combined treatments significantly enhanced survival. NKT cell activation decreased the frequency and immunosuppressive function of myeloid derived suppressor cells (MDSCs). Treatments resulted in enhanced tumor specific immunity as surviving mice exhibited slower tumor growth following secondary tumor challenge. Gemcitabine and mafosphamide also increase the immunogenicity of cancer cells in vitro by increasing the exposure/release of MHCI, MHCII, CD1d, Calreticulin, HMGB1 and ATP. NKT cell activation therapy can successfully be combined with low doses of Gemcitabine or cyclophosphamide to enhance protection against tumor metastasis and recurrence. This work provides a clear rationale for combining chemotherapy with NKT cell immunotherapy to target metastatic disease in the clinical setting.

Citation Format: Simon Gebremeskel, Kaitlyn Tanner, Lynnea Lobert, Brent Johnston. Combining natural killer T cell immunotherapy with chemotherapy induced immunogenic cell death to target post-surgical breast cancer metastasis [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr B047.
Abstract B055: Augmentation of OX40-dependent NK mediated antitumor activity is dependent on antibody cross-linking
Authors: Lim Sean H. , Turaj Anna H. , Willoughby Jane , Chan Claude H.T. , Penfold Christine A. , Johnson Peter W.M. , Glennie Martin J. , Cragg Mark S. , Levy Ronald
Published: November 2016

Introduction: The TNF superfamily (TNFSF) member OX40 (CD134) has been shown to enhance T cell function but its role on NK cells is poorly understood. CD137, another TNFSF member has been shown to enhance the anti-tumor activity of NK cells in various malignancies. This study examines the expression and function of OX40 on human and murine NK cells, and assesses its therapeutic efficacy as a target in murine B-cell lymphoma models.

Methods: In vitro flow cytometry-based assays using primary NK cells from healthy volunteers and syngeneic lymphoma mouse models were used.

Results: OX40 was transiently upregulated upon NK activation. In contrast to CD137, the induction of OX40 on human NK cells was dependent on cell-to-cell contact with either monocytes or T cells. Stimulation with agonistic anti-OX40 mAb, but not multimeric OX40 ligand, induced IFNγ and TNFα production by human NK cells, suggesting that the OX40 effects are dependent on antibody:FcγR mediated clustering. Whilst we observed increased human NK degranulation, there was no evidence of increased antibody-dependent cellular cytotoxicity (ADCC). In complementary murine studies, intravenous inoculation with BCL1 lymphoma into immunocompetent syngeneic mice resulted in transient upregulation of OX40 on murine NK cells. Combination treatment with anti-CD20 and anti-OX40 mAb produced a synergistic effect with more durable remissions.

Conclusion: The upregulation of OX40 on NK cells is more complex than CD137 and conditional upon interaction with other cell types. Anti-OX40 agonists may enhance NK-mediated anti-tumor activity in a cytokine-dependent manner instead of conventional ADCC, through antibody:FcγR-mediated receptor clustering.

Citation Format: Sean H. Lim, Anna H. Turaj, Jane Willoughby, Claude H.T. Chan, Christine A. Penfold, Peter W.M. Johnson, Martin J. Glennie, Mark S. Cragg, Ronald Levy. Augmentation of OX40-dependent NK mediated antitumor activity is dependent on antibody cross-linking [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr B055.
Abstract B058: Development of AVID200, a novel and highly potent TGF-beta neutralizing immunotherapy
Authors: O'Connor-McCourt Maureen D. , Lenferink Anne E.G. , Zwaagstra John , Sulea Traian , Baardsnes Jason , Collins Catherine , Cantin Christiane , Couture Lucie , Tao Limei , Durocher Yves , Singh Renu , Koropatnick James
Published: November 2016

Introduction: Elevated TGF-beta ligand markedly augments cancer progression primarily by suppressing the immune system in the tumor microenvironment, in particular by suppressing T-cell recruitment and/or activation. We developed AVID200, a novel decoy receptor trap that potently blocks TGF-beta and induces T-cell infiltration into tumors. This promotes the “T-cell-inflamed” tumor state, which is expected to render tumors sensitive to immune checkpoint inhibitors and other immunotherapeutics.

Experimental Procedures: AVID200 is a computationally designed novel class of avidity-enhanced receptor-ectodomain-based trap that binds and neutralizes TGF-beta 1 and 3 with low pM potency. Several trap formats have been produced and tested, with each format exhibiting varying characteristics, including differing circulating half-lives and in vitro blocking potencies. AVID200 was evaluated for efficacy in in vivo studies using the syngeneic 4T1 triple negative breast cancer (TNBC) tumor model. Additionally, ex vivo studies were performed on CD4+ and CD8+ T-cells harvested from the draining lymph nodes of treated animals.

Results: In efficacy studies using the syngeneic 4T1 TNBC model, novel TGF-beta traps were shown to promote significant T-cell infiltration into tumors. This infiltration resulted in reduced primary tumor growth as well as significant reductions in metastatic lesions. Additionally, ex vivo studies revealed that trap treatment decreased T-cell apoptosis, promoted T-cell proliferation in response to tumor cell lysates in the presence of dendritic cells, as well as increased the capacity of T-cells to specifically lyse 4T1 tumor cells.

Conclusion: AVID200 is a novel computationally-designed TGF-beta trap that neutralizes TGF-beta 1 and 3 with pM potency and markedly promotes the “T-cell-inflamed” tumor state. Combination studies with immune checkpoint inhibitors are ongoing.

Citation Format: Maureen D. O'Connor-McCourt, Anne E.G. Lenferink, John Zwaagstra, Traian Sulea, Jason Baardsnes, Catherine Collins, Christiane Cantin, Lucie Couture, Limei Tao, Yves Durocher, Renu Singh, James Koropatnick. Development of AVID200, a novel and highly potent TGF-beta neutralizing immunotherapy [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr B058.
Abstract B068: Hydrocortisone, prednisolone, methylprednisolone, and dexamethasone inhibit CetuGEX™-mediated ADCC in vitro
Authors: Goletz Christoph , Rühmann Johanna , Habel Beate , Danielczyk Antje , Goletz Steffen
Published: November 2016

Introduction: Antibody dependent cellular cytotoxicity is a key mode of action of therapeutic antibodies. ADCC enhancement as well as a broader coverage of F/V allotypes leads to maximal utilization of the anti-tumor effect. Glycooptimization provides the best available opportunity to maximize ADCC activity of monoclonal antibodies. Utilizing the GEX™ platform allows the combination of minimizing fucosylation, maximizing galactosylation and branching, which maximally increases the ADCC activity. The GEX™ platform comprises a comprehensive portfolio of proprietary glycoengineered human suspension cell lines, which allow for the high yield production of proteins with tailored glycosylation patterns. Productivities of 22g/L perfusion bioreactor volume have been achieved for ADCC optimized monoclonal antibodies. Cancer therapies with monoclonal antibodies including CetuGEX™ are often accompanied by treatment with glucocorticoids in order to prevent or counteract side effects like infusion reactions. However, the immunosuppressive character of glucocorticoids may also have the potential to inhibit the ADCC effect and immune cells mediating ADCC, respectively. In this study, we analyzed the influence of different glucocorticoids on ADCC mediated by CetuGEX™.

Methods: By using a europium release assay with an EGFR-expressing cancer cell line and PBMCs as effector cells we tested the ability of hydrocortisone, prednisolone, methylprednisolone and dexamethasone to inhibit ADCC mediated by CetuGEX™. In addition, we analyzed the direct effect of glucocorticoids on effector and target cells using flow cytometry.

Results: All tested glucocorticoids inhibited the CetuGEX™-mediated ADCC. This effect was not caused by a decreased expression of EGFR on the target cells. NK cells which are key effector cells mediating ADCC were found to be less activated in presence of glucocorticoids and CetuGEX™ compared to CetuGEX™ alone.

Conclusions: Glucocorticoids have a negative influence on ADCC mediated by NK cells which is one of the key modes of actions of CetuGEX™ and other ADCC enhanced antibodies. Therefore, the use of glucocorticoids during may impair clinical the efficacy ADCC-enhanced antibodies and should be avoided or at least minimized.

Citation Format: Christoph Goletz, Johanna Rühmann, Beate Habel, Antje Danielczyk, Steffen Goletz. Hydrocortisone, prednisolone, methylprednisolone, and dexamethasone inhibit CetuGEX™-mediated ADCC in vitro [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr B068.
Abstract B084: Transparent tumor tomography (T3): Spatial analysis for PD-L1 checkpoint blockade immunotherapy
Authors: Lee Seung-Young
Published: November 2016

Untangling the complexity of programmed death-ligand 1 (PD-L1) expression within a heterogeneous tumor microenvironment is an urgent challenge in PD-1/PD-L1 immune checkpoint blockade therapy. Here, we address this challenge with a method, termed transparent tumor tomography (T3), facilitating three-dimensional (3D) visualization and spatial analysis of distributions of multiple biomarkers including Her2, CD45, Ki-67, CD31, and PD-L1 throughout transgenic mouse mammary tumors. Based on our T3 imaging, we reveal that PD-L1 expression within the tumor microenvironment is highly adaptable to tumor status for efficiently preventing immune cell infiltration into the tumor. We also determine spatial pharmacokinetics of anti-PD-L1 antibody in the whole mouse mammary tumor in the context of hypoxia, CD31+ blood vessels, and target PD-L1+ cells. Finally, we demonstrate broad distribution of tumor infiltrating CD3+CD8+ cytotoxic T cells following radiation and anti-PD-L1 antibody therapy. These results provide unique spatial insights into PD-L1 cloaking and PD-L1 blockade therapy.

Citation Format: Steve Seung-Young Lee. Transparent tumor tomography (T3): Spatial analysis for PD-L1 checkpoint blockade immunotherapy [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr B084.
Abstract B098: A panel of well characterized syngeneic models for in vivo screening analysis: MuScreenTM
Authors: Jin Ying , Zhang Lan , Zhang Juan , Murphy Eric , Li Zhongliang , Qiao Meng , Shi Qian
Published: November 2016

Background: Syngeneic tumor models have proven to be one of the most robust model systems for cancer immunotherapy. However, in vitro screens that are frequently used in oncology to quickly identify cells, models, and PD effects for further study often fail in immuno-oncology, due to immunotherapeutics targeting the complex host immune system. Alternatively, an in vivo screen with a panel of models addresses many of these questions, e.g. PD and efficacy, but may be cost prohibitive. Material and methods: Leveraging in-house detailed profiling data on our syngeneic models, including efficacy benchmarking with aPD-1, aPD-L1 and aCTLA-4 antibodies, RNAseq data on tumor samples, and FACS analysis on both baseline and treatment response tumor samples, CrownBio recently launched a new service platform: MuScreen. MuScreen includes up to 20 well-characterized syngeneic models in a 3 month screening run. Both PD and efficacy may be determined in the run, allowing researchers to make decisions based on results observed from a large dataset. To address the cost issue, test agents from multiple clients are pooled together for each run (sharing vehicle and other common groups) providing a significant reduction in the number of animals used and the associated costs. Results: CrownBio has established the largest collection of syngeneic models with well-characterized immunotherapy data. In the first MuScreen run, we have generated new data on common IO agents, e.g. aPD-1 antibodies, with FACS analysis, IHC, and efficacy data. The first complete set of MuScreen data will be shown. Design parameters, such as starting tumor size, group size, of the MuScreen studies will be discussed. Conclusions: MuScreen is the first in vivo screening tool for cancer immunotherapeutics. It provides detailed response data on a panel of syngeneic models, therefore enabling decision making in a cost and time efficient manner.

Citation Format: Ying Jin, Lan Zhang, Juan Zhang, Eric Murphy, Zhongliang Li, Meng Qiao, Qian Shi. A panel of well characterized syngeneic models for in vivo screening analysis: MuScreenTM [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr B098.
Abstract B104: Impact of PD-1 blockade on epigenetic and transcriptional reprogramming of exhausted T cells
Authors: Pauken Kristen E. , Sammons Morgan A. , Odorizzi Pamela M. , Manne Sasi K. , Godec Jernej , Khan Omar , Sen Debattama , Kurachi Makoto , Barnitz R. Anthony , Bengsch Bertram , Huang Alexander C. , Schenkel Jason M. , Vahedi Golnaz , Haining W. Nicholas , Berger Shelley L. , Wherry E. John
Published: November 2016

Blocking PD-1 can reinvigorate exhausted CD8 T cells and improve control of chronic infections and cancer. One potential advantage of this immunotherapy is durable protection if immune memory can be established. It is unclear, however, whether blocking PD-1 can reprogram exhausted CD8 T cells into effector or durable memory CD8 T cells. Here, we found reinvigoration of exhausted T cells by PD-L1 blockade caused re-acquisition of some features of effector T cells, but minimal memory development. Indeed, after checkpoint blockade, reinvigorated T cells became re-exhausted if antigen remained high, and failed to become memory T cells upon antigen clearance. Exhausted T cells acquired an epigenetic profile distinct from effector and memory T cells that was minimally altered by blocking PD-L1. Nevertheless, modest enhancer changes resulted in transcriptional network rewiring that may provide opportunities to enhance checkpoint blockade. These data indicate that epigenetic fate inflexibility may limit current immunotherapies and suggest that improving (re)differentiation to memory following PD-1 pathway blockade could enhance clinical outcomes.

Citation Format: Kristen E. Pauken, Morgan A. Sammons, Pamela M. Odorizzi, Sasi K. Manne, Jernej Godec, Omar Khan, Debattama Sen, Makoto Kurachi, R. Anthony Barnitz, Bertram Bengsch, Alexander C. Huang, Jason M. Schenkel, Golnaz Vahedi, W. Nicholas Haining, Shelley L. Berger, E. John Wherry. Impact of PD-1 blockade on epigenetic and transcriptional reprogramming of exhausted T cells [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr B104.
Abstract B115: Improved efficacy of neoadjuvant compared to adjuvant immunotherapy to eradicate metastatic disease
Authors: Liu Jing , Blake Stephen , Yong Michelle , Harjunpaa Heidi , Ngiow Shin Foong , Takeda Kazuyoshi , Young Arabella , Allen Stacey , Smyth Mark J. , Teng Michele WL
Published: November 2016

Immunotherapy has recently entered a renaissance phase with the approval of multiple agents for the treatment of cancer. Immunotherapy stands ready to join traditional modalities, including surgery, chemotherapy, radiation, and hormone therapy, as a pillar of cancer treatment. Although immunotherapy has begun to have success in advanced cancer treatment, its scheduling and efficacy with surgery to treat earlier stages of cancer and prevent distant metastases has not been systematically examined. Here, we have used two models of spontaneously metastatic breast cancers in mice, to illustrate the significantly greater therapeutic power of neoadjuvant, compared with adjuvant immunotherapies in the context of primary tumor resection. Elevated and sustained peripheral tumor-specific immune responses underpinned the outcome, and blood sampling of tumor-specific CD8+ T cells immediately prior and post surgery may provide a predictor of outcome. These data now provide strong rationale to extensively test and compare neoadjuvant immunotherapy in humans.

Citation Format: Jing Liu, Stephen Blake, Michelle Yong, Heidi Harjunpaa, Shin Foong Ngiow, Kazuyoshi Takeda, Arabella Young, Stacey Allen, Mark J. Smyth, Michele WL Teng. Improved efficacy of neoadjuvant compared to adjuvant immunotherapy to eradicate metastatic disease [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr B115.