bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract A062: The effects of cellular context on miR-155 mediated regulation of gene expression
Authors: Hsin Jing-Ping , Lu Yuheng , Leslie Christina S. , Rudensky Alexander Y.
Published: November 2016

MicroRNA-155 (miR-155) is involved in differentiation and regulation of responses of multiple haematopoietic cell types. Its dysregulation is implicated in many human malignancies, e.g. Hodgkin, diffuse large B lymphomas, and breast cancer. Many microRNAs and their target mRNAs are co-expressed in diverse types of cells and tissues. To what extent the interaction between a specific microRNA and its target mRNAs is preserved in different cellular context is largely unknown. We employed genome-wide approaches to investigate whether regulation of commonly expressed mRNA by miR-155 operates in a cell type-specific manner in analogy to cell-context dependent regulation by transcription factors. We first performed RNA-Seq to quantitatively measure mRNA expression levels in primary B cells, dendritic cells, macrophages, and CD4+ T cells from wild type and miR-155 knockout mice. We found many miR-155 target mRNAs that contain seed matches in 3' untranslated regions (3'UTRs) were differentially repressed between four types of primary immune cells. Next, we performed iCLIP (individual-nucleotide resolution UV crosslinking and immunoprecipitation) to precisely map Argonaute 2 binding. Quantitative analysis of iCLIP in both wild type and miR-155 KO primary cells uncovered hundreds of miR-155 bound genes, a large number of which overlapped the cohorts of genes that were identified by RNA-Seq as differentially regulated by miR-155. Most mRNAs are alternatively polyadenylated, and through alternative polyadenylation (ApA) mRNAs can acquire or lose microRNA sites. To account for ApA, we carried out PolyA-Seq to measure polyadenylation site usage, and found that ApA contributed to differential miR-155 regulation of a number of genes. However, in many cases the same target 3'UTR isoforms were differentially regulated between cell types, suggesting ApA-independent mechanisms of miR-155 specificity, and cellular context dependent miR-155-mediated regulation of gene expression. This research will elucidate mechanistic underpinning of cell-context dependent microRNA function, and help understand miR-155 functions in disease, specifically in lymphomas and other cancers.

Citation Format: Jing-Ping Hsin, Yuheng Lu, Christina S. Leslie, Alexander Y. Rudensky. The effects of cellular context on miR-155 mediated regulation of gene expression [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 A062.
Abstract A102: The fat in ovarian cancer: Immune-dependent tumor-promoting effects
Authors: Suarez-Carmona Meggy , Heinzelmann Anita , Valous Nektarios A. , Hampel Mareike , Berthel Anna , Schott Sarah , Zörnig Inka , Jäger Dirk , Halama Niels
Published: November 2016

Because of the particular anatomy of ovaries, which are in close contact with the adipocyte-rich omentum, ovarian cancer frequently presents itself with established metastasis-like disseminated tumor islets along the omentum.

The tropism of ovarian cancer cells for fat is well described. Indeed, adipocyte-derived free fatty acids have been causatively linked to cancer cell proliferation and invasive properties. Obesity is additionally linked to increased risk of ovarian cancer onset and, in ovarian cancer patients, to worse outcome. However, there is to our knowledge no clear association between omentum-anchored dissemination and the anti-tumor immune response.

Here we describe an unsuspected association between the presence peritoneal fat in ovarian tumors and massive tumor infiltration by T cells. Still, this massive T cell influx seems to fail in its anti-tumor activity since (1) tumor-infiltrating T cells seem to be hijacked away from tumor cells and accumulate around fatty areas and (2) tumor-infiltrating T cells display an exhausted phenotype.

In this presentation, we also describe a new model of tissue culture of explants from primary human tumors that are treated with various drugs in an attempt to circumvent this fat-derived immune exhaustion and restore an efficient anti-tumor immune response.

Citation Format: Meggy Suarez-Carmona, Anita Heinzelmann, Nektarios A. Valous, Mareike Hampel, Anna Berthel, Sarah Schott, Inka Zörnig, Dirk Jäger, Niels Halama. The fat in ovarian cancer: Immune-dependent tumor-promoting effects [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 A102.
Abstract A114: Effect of different standard of care chemotherapeutics on anti-PD-L1 responses in syngeneic mouse tumor models
Authors: Cubas Rafael , Moskalenko Marina , Cheung Jeanne , Luoh Shiuh-Ming , McNamara Erin , Belvin Marcia , Kim Jeong , Gould Stephen
Published: November 2016

Immunotherapy with checkpoint inhibitors has proven to be highly effective, with durable responses in a subset of patients. In an effort to broaden the number of responding individuals, overcome resistance to single-agent therapy and extend the duration of responses, combination of immunotherapy with other treatments such as chemotherapy is currently being tested in multiple clinical trials. Importantly, combination of immunotherapy with standard of care chemotherapy could bring the benefits of immunotherapy into earlier lines of treatment.

Here, we have evaluated the effects of different classes of chemotherapeutic agents alone or in combination with anti-PD-L1 treatment in syngeneic murine tumor models. We have found that combination of anti-PD-L1 with various alkylating agents, taxanes and platins caused differential changes on the frequency and number of intratumoral immune cell subsets, but did not antagonize the functional changes mediated by anti-PD-L1 treatment. Importantly, by comparing the effects of these chemotherapies in different tumor models, we have observed that their effects are model-specific. These differences may be due to tumor-specific immune composition and tumor intrinsic responses to different chemotherapies.

Our results demonstrate that in the models we have tested, chemotherapeutic agents do not appear to directly antagonize the activity of anti-PD-L1 as measured by pharmacodynamic changes in immune cell activation although some differences can be observed in the frequency and number of certain intratumoral immune cell subsets. Additionally, our findings also reveal that tumor models might respond differently to the same chemotherapeutic treatment adding complexity to how we evaluate the effect of combination treatments with chemotherapy. Nonetheless, our results suggest a rationale for combining immunotherapy with chemotherapy in the clinic, although consideration should be taken when generalizing results from mouse tumor models.

Citation Format: Rafael Cubas, Marina Moskalenko, Jeanne Cheung, Shiuh-Ming Luoh, Erin McNamara, Marcia Belvin, Jeong Kim, Stephen Gould. Effect of different standard of care chemotherapeutics on anti-PD-L1 responses in syngeneic mouse tumor models [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 A114.
Abstract A116: IgG antibody switching and clonal expansion in melanoma and normal skin microenvironments
Authors: Saul Louise , Ilieva Kristina M. , Bax Heather J. , Karagiannis Panagiotis , Correa Isabel , Rodriguez-Hernandez Irene , Josephs Debra H. , Tosi Isabella , Egbuniwe Isioma U. , Lombardi Sara , Crescioli Silvia , Hobbs Carl , Villanova Federica , Cheung Anthony , Geh Jenny LC , Healy Ciaran , Harries Mark , Sanz-Moreno Victoria , Fear David , Spicer James F. , Lacy Katie E. , Nestle Frank O. , Karagiannis Sophia N.
Published: November 2016

Antibodies have been detected against known melanoma-associated antigens in patients with malignant disease. While much is known about cancer-specific T cell responses, the nature of cancer-specific B cells and their antibody repertoires are less well understood. We investigated circulating skin-homing B cells (CD19+CD22+CLA+) in healthy volunteers (n = 24) and melanoma patients (n = 49) and examined the presence of CD22+ B cells in melanoma lesions (n = 173) and normal skins tissue (n = 16). We detected mature IgG mRNA in 13 of 27 normal skin and 9 of 21 cutaneous melanoma samples and we detected mRNA for the enzyme Activation-induced cytidine deaminase (AID). IgG variable heavy chain sequences from melanomas (n = 51) and normal skins (n = 29) featured lower IgG1/IgGtotal subclass representation compared with circulating B cell antibody sequences (n = 36). The presence of affinity-matured cutaneous antibody repertoires in malignant skin was supported by evidence of somatic hypermutation, class-switching and B cell clonal family trees in melanoma lesions and a subset of melanoma-associated clones featuring shorter CDR3 region lengths relative to circulating B cell sequences. Homology modelling also indicated differential putative binding site patterns in melanoma compared to normal skin-resident antibodies, suggesting distinct melanoma-associated repertoires and potentially, antigen recognition profiles. These findings support the presence of a mature tumor-resident B cell compartment with characteristics distinct to that of B cells in normal skin and the circulation.

Citation Format: Louise Saul, Kristina M. Ilieva, Heather J. Bax, Panagiotis Karagiannis, Isabel Correa, Irene Rodriguez-Hernandez, Debra H. Josephs, Isabella Tosi, Isioma U. Egbuniwe, Sara Lombardi, Silvia Crescioli, Carl Hobbs, Federica Villanova, Anthony Cheung, Jenny LC Geh, Ciaran Healy, Mark Harries, Victoria Sanz-Moreno, David Fear, James F. Spicer, Katie E. Lacy, Frank O. Nestle, Sophia N. Karagiannis. IgG antibody switching and clonal expansion in melanoma and normal skin microenvironments [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 A116.
Abstract A127: The role of macrophages in tissue homeostasis
Authors: Franklin Ruth A. , Pope Scott D. , Medzhitov Ruslan
Published: November 2016

Organisms maintain homeostasis at the cellular, tissue, and systemic levels in order to survive changing physiological and environmental conditions. While maintenance mechanisms at the cellular and systemic levels are well characterized, the key cell types and signaling components controlling homeostasis in tissue compartments are undefined. Perturbations in homeostasis activate stress response pathways and result in both cell-intrinsic and cell-extrinsic responses, the latter of which can result in tissue level adaptations. Macrophages are found in almost all tissues and are known to orchestrate tissue level responses to infection and damage. Furthermore, recent evidence suggests that these innate immune cells may also perceive more general and subtle changes within the surrounding environment. We hypothesize that macrophages regulate tissue level changes to maintain homeostasis and that this feature may become dysregulated during chronic inflammatory conditions, including cancer. In order to model disrupted homeostasis, we applied a number of diverse stressors to bone marrow-derived macrophages (BMDMs) in vitro: osmotic stress, endoplasmic reticulum (ER) stress, amino acid deprivation, glucose deprivation, hypoxia, and heat shock. Next, RNA sequencing at early and late time points was performed to compare gene expression patterns between different stress conditions. We found that each stressor induces a unique transcriptional program in BMDMs, as well as a set of genes shared amongst several stress conditions. To identify potential paracrine signals originating from macrophages and acting on surrounding tissues, we focused on genes encoding secreted proteins, upregulated early after stimulation under multiple conditions, and containing known stress-associated motifs in their promoters. We found that many of the genes fitting these criteria are associated with tissue remodeling, including extracellular matrix components, cell adhesion molecules, factors involved in angiogenesis, and chemokines/cytokines. We are currently developing both in vitro and in vivo models of tissue stress to investigate these molecules as potential regulators of tissue level homeostasis.

Citation Format: Ruth A. Franklin, Scott D. Pope, Ruslan Medzhitov. The role of macrophages in tissue homeostasis [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 A127.
Abstract A132: Multi-parametric profiling of non-small cell lung cancers reveals distinct immunophenotypes
Authors: Lizotte Patrick , Ivanova Elena , Bittinger Mark , Wong Kwok-Kin
Published: November 2016

Immune checkpoint blockade improves survival in a subset of patients with non-small cell lung cancer (NSCLC), but robust biomarkers that predict response to PD-1 pathway inhibitors are lacking. Furthermore, our understanding of the diversity of the NSCLC tumor immune microenvironment remains limited. To develop a more comprehensive knowledge of the NSCLC tumor immune landscape, we performed comprehensive flow-cytometric immunoprofiling on both tumor and immune cells from 51 NSCLCs and integrated this analysis with clinical and histopathologic characteristics, next generation sequencing, mRNA expression, and PD-L1 immunohistochemistry (IHC). Cytometric profiling identified two main tumor immunophenotypes: an immunologically “hot” cluster with high abundance of CD8+ T cells expressing high levels of the inhibitory receptors PD-1 and TIM-3, and an immunologically “cold” cluster with lower relative abundance of CD8+ T cells and expression of inhibitory markers. The “hot” cluster was highly enriched for expression of genes associated with T cell trafficking and cytotoxic function by mRNA analysis, and high PD-L1 expression by IHC. Within the “hot” cluster there was a small subgroup with high granulocytic infiltrates and lower relative T cell abundance, but with high expression of inhibitory receptors by T cells. There was no correlation between immunophenotype and KRAS or EGFR mutation status, or patient smoking history, but we did observe an enrichment of squamous subtype and tumors with higher mutation burden in the “hot” cluster. Additionally, ∼20% of cases had high B cell infiltrates and we demonstrate that a subset of these cells display characteristics of immunosuppressive IL-10-producing cells. Our results support the use of immune-based metrics to study response and resistance to immunotherapy in lung cancer.

Citation Format: Patrick Lizotte, Elena Ivanova, Mark Bittinger, Kwok-Kin Wong. Multi-parametric profiling of non-small cell lung cancers reveals distinct immunophenotypes [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 A132.
Abstract A137: PD-L1 antibodies induce macrophage phenotypic and functional activation
Authors: Hartley Genevieve , Wheat William , Coy Jonathan , Dow Steven
Published: November 2016

Background: The ability of PD-L1 signaling to alter tumor metabolism and stem cell properties has been previously established. However, the effects of PD-L1 signaling on other cells that express PD-L1, including tumor-associated macrophages, has not been previously investigated. It is also unknown how treatment with PD-L1 targeted antibodies may affect macrophage function.

Purpose: These studies were designed to investigate the effects of PD-L1 antibodies on macrophage phenotype and function. Studies were done using in vitro assays of murine bone marrow-derived macrophages, as well as human monocyte-derived macrophages.

Experimental Methods: Murine bone marrow-derived macrophages were generated by non-adherent culture in M-CSF. The cells were then plated in tissue culture plates and incubated with anti-murine PD-L1 antibodies (or with isotype-matched antibodies), and the effects on macrophage phenotype, proliferation, activation, antigen presentation, and tumor killing were assessed.

Study Results: Following incubation with PD-l1 antibodies, we observed remarkable phenotypic changes in bone marrow-derived macrophages. These included physical changes including increased cell size and spreading, and increased proliferation and survival as measured by EdU incorporation and MTT assay. Macrophages incubated with PD-L1 antibodies spontaneously upregulated production of inflammatory cytokines and upregulated co-stimulatory molecule expression, as assessed by flow cytometry. Increased functional activation was revealed by upregulated expression of iNOS and decreased antigen uptake.

Conclusions: Our findings indicate that PD-L1 antibodies induce strong activation of macrophages in vitro. These findings suggest that some of the observed immunological activities of PD-L1 therapeutic antibodies may be mediated by macrophage activation.

Citation Format: Genevieve Hartley, William Wheat, Jonathan Coy, Steven Dow. PD-L1 antibodies induce macrophage phenotypic and functional 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 A137.
Abstract A139: Antitumor effects of improved DC vaccine with ALA-PDT induced immunogenic apoptotic cells for skin squamous cell carcinoma in mice
Authors: Zhang Haiyan , Zhang Guolong , Fan Zhixia , Wang Xiaojie , Shi Lei , Yang Degang , Bahavar Cody F. , Zhou Feifan , Chen Wei R. , Wang Xiuli
Published: November 2016

Targeted immunotherapy using dendritic cell (DC) vaccine has been employed for the treatment of solid tumors. Topical 5-aminolevulinic acid mediated photodynamic therapy (ALA-PDT), an established approach for topical cancers, can induce an effective antitumor immune response.We have previously shown that ALA-PDT-induced tumor lysates could considerably enhance antigen-presenting capacity of ex vivo-generated DCs.The current study further demonstrates that ALA-PDT-DC vaccine can induce immune responses against cancers.DC cells pulsed by PDT-treated cutaneous squamous cell carcinoma (cSCC) cells inhibited SCC to a greater extent than tumor lysates treated by PDT alone or DCs pulsed by freeze/thawed treated tumor cells (FT-DC).Immunohistochemistry showed that PDT-DC vaccine could increase the activity of CD4+ and CD8+ T cells in the tumor implantation sites.Flow cytometry assays showed that CD4+ and CD8+ T cells in the spleens of PDT-DC vaccine immunized mice increased significantly.Furthermore, we observed increased amounts of IL-12 and IFN-γ and decreased amounts of IL-10 in the splenocytes and peripheral blood of PDT-DC vaccine immunized mice by ELISA.Taken together, our findings suggest that PDT-DC vaccination is an effective prophylactic therapy for cSCC.

Note: This abstract was not presented at the conference.

Citation Format: Haiyan Zhang, Guolong Zhang, Zhixia Fan, Xiaojie Wang, Lei Shi, Degang Yang, Cody F. Bahavar, Feifan Zhou, Wei R. Chen, Xiuli Wang. Antitumor effects of improved DC vaccine with ALA-PDT induced immunogenic apoptotic cells for skin squamous cell carcinoma in mice [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 A139.
Abstract B006: Large scale microarray profiling reveals four stages of immune escape in Non Hodgkin lymphomas
Authors: Fournie Jean-Jacques
Published: November 2016

Non-Hodgkin B-cell lymphoma (B-NHL) are aggressive lymphoid malignancies that develop in patients due to oncogenic activation, chemo-resistance and immune evasion. Tumor biopsies show that B-NHL frequently use several immune escape strategies, which has hindered the development of checkpoint blockade immunotherapies in these diseases. To gain a better understanding of B-NHL immune editing, we hypothesized that the transcriptional hallmarks of immune escape associated with these diseases could be identified from the meta-analysis of large series of microarrays from B-NHL biopsies. Thus, 1446 transcriptome microarrays from seven types of B-NHL were downloaded and assembled from 33 public Gene Expression Omnibus (GEO) datasets, and a method for scoring the transcriptional hallmarks in single samples was developed. This approach was validated by matching scores to phenotypic hallmarks of B-NHL such as proliferation, signaling, metabolic activity and leucocyte infiltration. Through this method, we observed a significant enrichment of 33 immune escape genes in most diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL) samples, with fewer in mantle cell lymphoma (MCL) and marginal zone lymphoma (MZL) samples. Comparing these gene expression patterns with overall survival data evidenced four stages of cancer immune editing in B-NHL: non-immunogenic tumors (stage 1), immunogenic tumors without immune escape (stage 2), immunogenic tumors with immune escape (stage 3), and fully immuno-edited tumors (stage 4). This model complements the standard international prognostic indices for B-NHL and proposes that immune escape stages 3 and 4 (76% of the FL and DLBCL samples in this dataset) identify patients relevant for checkpoint blockade immunotherapies.

Note: This abstract was not presented at the conference.

Citation Format: Jean-Jacques Fournie. Large scale microarray profiling reveals four stages of immune escape in Non Hodgkin lymphomas [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 B006.
Abstract B009: Phase I clinical trial of a PSA, IL-2, GM-CSF containing prostate cancer vaccine in PSA defined biochemical recurrent prostate cancer patients
Authors: Head Jonathan F. , Daniels Gregory A. , McKinney Michelle , Ongkeko Weg , Sakamoto Kyoko , Wang-Rodriguez Jessica
Published: November 2016

Immunotherapy for cancer has had two main approaches that have led to clinical applications. The first is stimulating immune responses to tumor cells with cytokines or cellular immunotherapy and the second is blocking tumor immune evasion and the associated inhibition of T-cell activation with antibodies to the CTLA-4 receptor, PD-1 receptor or PD-L1. We have taken a different approach and have developed therapeutic cancer vaccines that are a combination of tumor antigens (proteins overexpressed by tumors) with biological adjuvants (the cytokines IL-2 and GM-CSF). This study is a Phase 1a/1b clinical trial of a PSA/IL-2/GM-CSF vaccine in recurrent prostate cancer in hormone-naïve and hormone-independent patients. Major inclusion criteria include adenocarcinoma of the prostate, rising serum PSA and no measurable disease. Phase 1a examines the rate of dose limiting adverse events (DLAEs) in an initial course of 6 vaccinations (“induction vaccination”). Twenty patients will receive intradermal injections of the PSA/IL-2/GM-CSF vaccine at weeks 0, 1, 2, 6, 10 and 14. To date, twelve patients in the Phase 1a portion of the trial have received all 6 vaccines. Eight of the 11 patients who have received all 6 vaccines had increased immune responses to PSA in a lymphocyte blastogenesis assay by week 19. Six of 10 of the patients had an increase in the doubling time of their serum PSA, suggesting a slowing of the progression of the cancer. Median follow up after the first vaccine is 23 months (range: 4-32 months). None of the patients vaccinated in the Phase 1a portion have had a DLAE and enrollment continues in the Phase 1a.

Citation Format: Jonathan F. Head, Gregory A. Daniels, Michelle McKinney, Weg Ongkeko, Kyoko Sakamoto, Jessica Wang-Rodriguez. Phase I clinical trial of a PSA, IL-2, GM-CSF containing prostate cancer vaccine in PSA defined biochemical recurrent prostate cancer patients [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 B009.
Abstract B012: Preclinical study of Kiatomab, a novel monoclonal antibody to the cancer stem cell surface marker KIAA1114, for anti-cancer therapy in colorectal carcinoma
Authors: Kim Young Min , Kim Sae Won , Lee Seungwon , Kim Hyekang , Kim Ji-Hae , Park Han Wook , Sung Young Chul , Lee Seung-Woo
Published: November 2016

Most targeted therapy drugs block the growth of cancer cells by targeting specific molecules needed for tumor growth. Among targeted therapy drugs, cetuximab, the monoclonal antibody which binds to epidermal growth factor receptor (EGFR) and inhibits downstream signaling of EGFR, has greatly improved the median survival of patients with metastatic colorectal cancer (CRC). Yet, cetuximab showed limited therapeutic effect in CRC patients who carry certain mutation in the KRAS, which emphasizes the necessity of developing new targeted therapy drugs for CRC. KIA1114 is a full-length protein of the trophinin gene and is localized on the cell surface. In our previous research, we identified the role of KIA1114 as a novel surface marker of tumor initiating cells of hepatocellular carcinoma (HCC) by developing Kiatomab, KIA1114-specific monoclonal antibody. Here, we show that KIA1114 is also highly expressed in various CRC cells with mouse or human origin. Kiatomab treatment inhibits tumor growth in a syngeneic graft CRC mouse model in antibody-dependent cell-mediated cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) dependent manner. In the metastatic CRC model, Kiatomab therapy suppresses metastasis, with a significant increase of survival. Of note, the anticancer efficacy of Kiatomab is further improved by combinatorial treatment with the standard chemotherapeutic agent cyclophosphamide (CTX), in both metastatic and solid tumor models. In summary, our findings suggest that KIAA1114 is a new target for CRC and its monoclonal antibody Kiatomab might have a potential for anticancer therapy.

Citation Format: Young Min Kim, Sae Won Kim, Seungwon Lee, Hyekang Kim, Ji-Hae Kim, Han Wook Park, Young Chul Sung, Seung-Woo Lee. Preclinical study of Kiatomab, a novel monoclonal antibody to the cancer stem cell surface marker KIAA1114, for anti-cancer therapy in colorectal carcinoma [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 B012.
Abstract B015: Expansion and activation of CD103+ dendritic cell progenitors at the tumor site transform tumor response to PD-L1 and BRAF inhibition
Authors: Salmon Hélène , Idoyaga Juliana , Rahman Adeeb , Remark Romain , Gnjatic Sacha , Bhardwaj Nina , Brody Joshua , Palucka Anna Karolina , Ginhoux Florent , Merad Miriam
Published: November 2016

High numbers of melanoma lesions develop resistance to BRAF blockade or fail to respond to checkpoint inhibition therapy. Here we explored whether modulation of intratumoral antigen presenting cells (APCs) can help increase response to BRAF and checkpoint blockade in tamoxifen-induced Braf-mutant and B16 melanoma lesions. In both models, we found that CD103+ dendritic cells (DCs) were the only APCs that transported intact antigens to the lymph nodes and primed tumor-specific CD8+ T cells.

CD103+ DC expressed high PD-L1 levels in the tumor and were required to promote anti-tumoral effects upon blockade of the checkpoint ligand PD-L1; however, PD-L1 inhibition only led to partial responses and minimal accumulation of intratumoral CD8+ T cells. Strikingly, systemic administration of fms-like tyrosine kinase 3 ligand (Flt3L) followed by intratumoral poly I:C injections expanded and activated CD103+ DC progenitors in the tumor, enhancing responses to BRAF and PD-L1 blockade and protecting mice from tumor rechallenge in a T cell dependent manner. Thus, the paucity of activated CD103+ DCs in tumors limits checkpoint blockade efficacy and Flt3L-poly I:C therapy can transform clinical responses to checkpoint and BRAF blockade.

Salmon et al, 2016. Immunity, 44(4):924-38.

Citation Format: Hélène Salmon, Juliana Idoyaga, Adeeb Rahman, Romain Remark, Sacha Gnjatic, Nina Bhardwaj, Joshua Brody, Anna Karolina Palucka, Florent Ginhoux, Miriam Merad. Expansion and activation of CD103+ dendritic cell progenitors at the tumor site transform tumor response to PD-L1 and BRAF inhibition [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 B015.
Abstract B021: Single domain antibodies targeting CTLA-4 demonstrate a critical role for Fc in the antitumor response
Authors: Dougan Michael , Ingram Jessica , Blomberg Olga , Rashidian Mohammad , Keliher Edmund , Weissleder Ralph , Almo Steven , Ploegh Hidde
Published: November 2016

Monoclonal antibodies targeting CTLA-4 are now a central part of the standard of care for metastatic melanoma, and have shown efficacy against diverse tumor types. However, the extent to which direct blockade of CTLA-4 contributes to the efficacy of these antibodies remains incompletely understood. Mice lacking FcγRIV fail to respond to αCTLA-4 therapy, and maintain robust tumor infiltrating Treg populations. These findings suggest that anti-CTLA-4 antibody therapy enhances antitumor responses through Treg depletion, though a requirement for FcγR in other aspects of the antitumor response has not been excluded, and the importance of CTLA-4 blockade alone has not be directly assessed. We have developed an alpaca-derived single domain antibody (H11) that binds CTLA-4 with high affinity, occluding the B7 binding motif as determined by x-ray crystallography. We are able to use this single domain antibody in 18F immuno-PET to produce a comprehensive image of CTLA-4 expression in a tumor-bearing live mouse, confirming penetration of H11 into the tumor microenvironment. Therapeutically, we find that H11 potently blocks CTLA-4 co-inhibition in vitro, but fails to elicit protective immunity in vivo. Therapeutic activity is restored when H11 is attached to the Fc region of murine IgG2a, but not when half-life alone is increased through H11 dimerization or conjugation to PEG, confirming a central role for Fc-dependent function in αCTLA-4 responses, as well as the minimal efficacy of CTLA-4 blockade alone. We further find that the efficacy of αCTLA-4 therapy can be enhanced through blockade of CD47, consistent with an important role for Treg depletion by myeloid cells in the activity of this therapy. These findings have implications for the development of combinations immune therapies.

Citation Format: Michael Dougan, Jessica Ingram, Olga Blomberg, Mohammad Rashidian, Edmund Keliher, Ralph Weissleder, Steven Almo, Hidde Ploegh. Single domain antibodies targeting CTLA-4 demonstrate a critical role for Fc in the antitumor response [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 B021.
Abstract B031: FAK/PYK2 inhibition enhances antitumor efficacy of anti-PD-1 and anti-4-1BB antibodies
Authors: Pachter Jonathan A. , Weaver David T.
Published: November 2016

Although durable responses to single agent immune checkpoint inhibitors have been reported, additional approaches are needed to extend this therapeutic benefit to a greater proportion of patients. Combination of immunotherapy agents with tumor microenvironment modulators has the potential to overcome barriers that tumor cells develop to evade the immune system, and provide benefit to a greater proportion of patients. Focal Adhesion Kinase (FAK) and the family member PYK2 are potentially valuable targets due to their roles in regulating key cellular populations in the tumor microenvironment. The FAK/PYK2 dual inhibitors, VS-6063 and VS-4718, have previously been shown to inhibit monocyte-derived macrophages, reduce tumor-associated macrophages in xenograft models, and promote a CD8+ T cell-mediated anti-tumor response in squamous cell carcinoma models.

We now report the combination of VS-4718 with an anti-PD-1 mAb shows substantially improved efficacy over anti-PD-1 mAb alone in MC38 syngeneic tumor-bearing animals. Analysis of MC38 tumors at day 12 of treatment revealed a significant increase in the CD8+ T cell/Treg ratio in tumors in the VS-4718 + anti-PD-1 combination group, providing a mechanistic understanding for the enhanced efficacy of this combination.

To explore additional combination options, we tested the combination of VS-4718 with anti-4-1BB in the MC38 model. Consistent with what was observed with the anti-PD-1 combination, addition of VS-4718 also enhanced the efficacy of an anti-4-1BB mAb inducing full tumor regression.

To further delineate the effect of FAK inhibition, an in vitro T cell proliferation assay was conducted. VS-6063 and VS-4718 dose-dependently stimulated proliferation of CD8+ cytotoxic T cells isolated from healthy donors. This is in distinct contrast to other protein kinase inhibitors, such as the SRC inhibitor dasatinib which potently impaired the proliferation of CD8+ cytotoxic T cells. In addition, both VS-4718 and VS-6063 decreased CD8+ T cell exhaustion markers (LAG3 and PD-1), and increased T cell-mediated tumor cell killing in vitro.

These data provide additional rationale for ongoing clinical trials testing the FAK/PYK2 inhibitor VS-6063 in combination with pembrolizumab (anti-PD-1) plus gemcitabine in pancreatic cancer or in combination with avelumab (anti-PD-L1) in ovarian cancer.

Citation Format: Jonathan A. Pachter, David T. Weaver. FAK/PYK2 inhibition enhances antitumor efficacy of anti-PD-1 and anti-4-1BB antibodies [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 B031.
Abstract B037: Macrophage repolarization therapy in metastatic colorectal cancer: CCR5 inhibition
Authors: Halama Niels , Zoernig Inka , Berthel Anna , Kahlert Christoph , Klupp Fee , Suarez-Carmona Meggy , Krauss Juergen , Brand Karsten , Lasitschka Felix , Lerchl Tina , Luckner-Minden Claudia , Ulrich Alexis , Weitz Juergen , Schneider Martin , Buechler Markus W. , Zitvogel Laurence , Herrmann Thomas , Benner Axel , Kunz Christina , Luecke Stephan , Springfeld Christoph , Falk Christine , Jaeger Dirk
Published: November 2016

The influence of the local immune response on the clinical course of colorectal cancer (CRC) has been analyzed extensively. Analyzing the invasive margin of human CRC liver metastases, we identified a protumoral mechanism of T-cell-derived CCL5 that leads to immune cell exploitation by tumor cells. Two distinct subsets of myeloid cells produce CXCL9/CXCL10, which induce an influx of T cells into the invasive margin. CCL5 is produced by these exhausted T cells and stimulates tumor cell proliferation and invasive behavior via CCR5 on tumor cells and macrophages. CCR5 inhibition in patient-derived functional in vitro organotypic culture models induced macrophage repolarization with anti-tumoral effects. These immunomodulatory and anti-tumoral effects of CCR5 blockade then could be confirmed in a phase I trial with a CCR5 antagonist in advanced refractory CRC patients with liver metastases. Amelioration of tumor-promoting inflammation on the tumor tissue level and objective tumor responses in advanced metastatic CRC patients were observed.

Citation Format: Niels Halama, Inka Zoernig, Anna Berthel, Christoph Kahlert, Fee Klupp, Meggy Suarez-Carmona, Juergen Krauss, Karsten Brand, Felix Lasitschka, Tina Lerchl, Claudia Luckner-Minden, Alexis Ulrich, Juergen Weitz, Martin Schneider, Markus W. Buechler, Laurence Zitvogel, Thomas Herrmann, Axel Benner, Christina Kunz, Stephan Luecke, Christoph Springfeld, Christine Falk, Dirk Jaeger. Macrophage repolarization therapy in metastatic colorectal cancer: CCR5 inhibition [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 B037.
Abstract B038: Class IIa HDAC inhibition promotes an antitumor macrophage phenotype that induces breast tumor regression and inhibits metastasis
Authors: Guerriero Jennifer L. , Sotayo Alaba , Ponichtera Holly , Pourzia Alexandra , Schad Sara , Carrasco Ruben , Lazo Suzan , Bronson Roderick , Letai Anthony
Published: November 2016

While tumor-associated macrophages (TAMs) often have net pro-tumor effects, their embedded location and their untapped potential provide impetus to the discovery of strategies to turn them against tumors. We recently reported that a first in class selective class IIa HDAC inhibitor (TMP195) influenced human monocyte responses to colony stimulating factors CSF-1 and CSF-2 in vitro. Here, we utilize a macrophage-dependent autochthonous mouse model of breast cancer to demonstrate that in vivo TMP195 treatment alters the tumor microenvironment and reduces tumor burden and pulmonary metastases through macrophage modulation. TMP195 induces recruitment and differentiation of highly phagocytic and stimulatory macrophages within tumors. Furthermore, combining TMP195 with chemotherapy regimens or T-cell checkpoint blockade in this model significantly enhances the durability of tumor reduction. These data introduce class IIa HDAC inhibition as a novel means to harness the antitumor potential of macrophages to enhance cancer therapy.

Citation Format: Jennifer L. Guerriero, Alaba Sotayo, Holly Ponichtera, Alexandra Pourzia, Sara Schad, Ruben Carrasco, Suzan Lazo, Roderick Bronson, Anthony Letai. Class IIa HDAC inhibition promotes an antitumor macrophage phenotype that induces breast tumor regression and inhibits 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 B038.
Abstract B052: Peroxisome proliferator-activated receptor delta agonist GW501516 enhances the efficacy of adoptive cell therapy
Authors: Saibil Samuel , St. Paul Michael , Ohahsi Pamela
Published: November 2016

Adoptive cell therapy (ACT) has demonstrated tremendous promise for the treatment of metastatic melanoma. Emerging evidence has indicated that memory CD8+ T cells (Tcm) are superior mediators of ACT than are effector CD8+ T cells (Teff) due to a superior ability to persist in vivo. Underpinning the survival advantage of Tcm is a shift in cellular metabolism away from aerobic glycolysis to instead favor fatty acid oxidation (FAO). This switch to FAO in Tcm requires the expression of carnitine palmitoyl transferase 1a (CPT1a), the rate-limiting enzyme of FAO. Here, we investigated the impact of the peroxisome proliferator-activated receptor (PPAR)δ/β agonist GW501516 (GW), an agent known to boost CPT1a expression and promote FAO in other tissues, on CD8+ T cell metabolism, function and performance in the murine B16-GP33 melanoma model. Via the activation of both PPARα and PPARδ/β we found that GW treatment increased CPT1a expression in activated CD8+ T cells. Using a metabolomics approach, we demonstrated that GW treatment increased the abundance of multiple different acylcarnitines, consistent with enhanced FAO. Unexpectedly, we also found that T cells activated in the presence of GW as well as inflammatory signals, either LPS-matured dendritic cells (DCs) or IL-12, demonstrated enhanced production of interferon-γ. This increase in interferon-γ correlated with increased expression of the transcription factor T-bet. Despite the high T-bet expression, a characteristic of short-lived effector cells, GW-treated CD8+ T cells activated by LPS-treated DCs demonstrated an enhanced ability to persist in vivo. They also demonstrated improved performance in our murine model of ACT. Thus, our data indicates that combined treatment of CD8+ T cells with GW and inflammatory signals can result in in Teff cell with improved ability to produce cytokines but that have also shifted their metabolism to increase FAO akin to Tcm, allowing for enhanced in vivo persistence. These data identify GW501516, and potentially other combined PPARα and PPARδ/β agonists currently being developed, as attractive candidates for further studies and rapid translation into clinical trials of ACT.

Citation Format: Samuel Saibil, Michael St. Paul, Pamela Ohahsi. Peroxisome proliferator-activated receptor delta agonist GW501516 enhances the efficacy of adoptive cell therapy [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 B052.
Abstract B061: CD81: A new target for therapy of B cell lymphoma
Authors: Vences-Catalán Felipe , Kuo Chiung-Chi , Rajapaksa Ranjani , Levy Ronald , Levy Shoshana
Published: November 2016

CD81 belongs to an evolutionary conserved family of proteins named tetraspanins and it was originally described as a B cell target. Tetraspanins associate in multi-molecular complexes in tetraspanin-enriched microdomains (TEMS). Indeed, in B cells CD81 associates with CD19 and CD21, and together function as co-receptor to lower the cell activation threshold initiated by the BCR. Recently, we have demonstrated the importance of CD81 in tumor growth and metastasis of solid tumors1. However, the role of CD81 in B cell malignancies has not been explored. Previously, we have shown that anti-CD81 antibodies had anti-proliferative effects on human B cell lymphoma cell lines in vitro2. Here we tested the therapeutic effect of a mouse anti-human CD81 antibody in vivo against Raji and SUP-B8 B cell lymphomas using a xenograft model in SCID mice. Our studies demonstrated that our anti-CD81 antibody had therapeutic effect comparable to rituximab. Moreover, we found ADCC as one of the mechanism of action. Furthermore, to enhance the anti-CD81-mediated ADCC we engineered chimeric antibodies containing human IgG1ADCC-HIGH and human IgG4 ADCC-LOW Fc constant regions. Indeed, the chimeric human IgG1 anti-CD81 mAb showed a remarkable increase in NK cell-mediated ADCC compared to Rituximab in vitro. These results suggest that CD81 can be a potential therapeutic target on B cell lymphomas by virtue of both its direct cytotoxic effect and as a mediator of ADCC. The Human IgG1 version is being developed as a therapeutic candidate.

1. Vences-Catalan, F., et al. Cancer Res 75, 4517-4526 (2015).

2. Oren, R., Takahashi, S., Doss, C., Levy, R. & Levy, S. Mol Cell Biol 10, 4007-4015 (1990).

Citation Format: Felipe Vences-Catalán, Chiung-Chi Kuo, Ranjani Rajapaksa, Ronald Levy, Shoshana Levy. CD81: A new target for therapy of B cell lymphoma [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 B061.
Abstract B075: Conversion of extracellular signals to programmable genome manipulation via CRISPRouter
Authors: Dingal P C Dave P. , Kipniss Nathan , Gao Yuchen , Qi Lei S.
Published: November 2016

Molecular engineering and synthetic biology approaches have been applied (1) to replace the intracellular domain (NICD) of Notch with synthetic transcription factors1 that bind to genes other than natural Notch targets; (2) to replace human Notch extracellular domain (NECD) with recognition motifs against novel targets (e.g. cognate receptor ligands such as Delta versus single-chain variable fragments raised against a specific antigen). The project aims to interrogate and engineer the fate of a receiver cell to surface-receptor levels of a sender cell by harnessing contact-mediated Notch-Delta signaling and RNA-guided CRISPR genome engineering. We have developed Notch1-Cas9 chimeric receptors that, upon binding Delta ligand to the extra-cellular Notch domain, cleave and release Cas9 to manipulate gene expression of transgenic reporter constructs - and - of endogenous targets in mammalian cells. First, we describe the challenges and solutions in the construction of Notch-Cas9, which led to the discovery of a naturally occurring sequence in bacterial Cas9 that is being co-opted as a nuclear localization signal (NLS) when expressed in mammalian cells. To our knowledge, this is the first reported evidence of a cognate NLS in bacterial Cas9. Second, we expand the toolkit with not only Delta-dependent gene activation, but also with gene editing in two Cas9 orthologs (Streptococcus pyogenes and Staphylococcus aureus Cas9). The toolkit performs well in reporter-gene activation and editing assays. Finally, we demonstrate activation of and phenotypic changes associated with endogenous genes encoding for regulators of the cell-division cycle, CDKN1B and CASP8; and editing of CXCR4 and CD47, receptors relevant to immune trafficking and tolerance. This Notch-Cas9 fusion technology opens up novel biological behaviors in response to cell-cell contact and can be utilized to interrogate or manipulate existing signaling pathways.

Citation Format: P C Dave P. Dingal, Nathan Kipniss, Yuchen Gao, Lei S. Qi. Conversion of extracellular signals to programmable genome manipulation via CRISPRouter [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 B075.