Advances In Cancer Immunotherapy Research Articles

Transforming growth factor beta (TGF-β) activity in immuno-oncology studies.

Transforming growth factor beta (TGF-β) is a potent pleiotropic polypeptide cytokine, with a complex and context dependent control of its activation, signaling and effector functions. This cytokine is pivotal in the regulation of immunological responses, tumor initiation and development, stromal homeostasis and all their intricate related interactions. Last decade advances in cancer immunotherapy have reactivated the clinical interest on potential drug with TGF-β inhibition effect, combined with immunomodulating enhancer drugs. The correct quantification of the in vitro and in vivo biological activity of this cytokine is essential to understand the intrinsic underlying biological mechanisms and TGF-β role in the immune system, tumor and stromal codevelopment, modulation and interactions. There is a wide variety of available procedures to quantify TGF-β activity, which includes different methodological approximations like ELISA, Bioassays including reporter gene assays, Flow cytometry (FC), Western blotting (WB), immunochemical/fluorescence microscopy, among others. Here, we detail available methods for TGF-β biological activity analysis, together with their applicability and suitability for each experimental setting, in order to get a complete analytical perspective and more comprehensive information along the development and design of combined antitumor immunotherapies, which include the inhibition of TGF-β biological activity.

CRISPR technology for immuno-oncology applications.

Emergency of the CRISPR technology, a new genome editing tool, revolutionized the biomedical research field in the past 6 years. At the same time, recent advances in cancer immunotherapy reinvigorated our hope to cure most if not all cancer patients with further development of various treatment options. A combination of the CRISPR technology with immuno-oncology research will undoubtedly accelerate the development of new cancer therapies. This review will focus on the CRISPR system and its applications in immune-oncology including identification of immune-oncology gene targets, generation of cancer animal models, and enabling better cell design and manufacture for adoptive cellular therapies.

Unleashing Tumour-Dendritic Cells to Fight Cancer by Tackling Their Three A's: Abundance, Activation and Antigen-Delivery.

Recent advances in cancer immunotherapy have mainly focused on re-activating T-cell responses against cancer cells. However, both priming and activation of effector T-cell responses against cancer-specific antigens require cross-talk with dendritic cells (DCs), which are responsible for the capturing, processing and presentation of tumour-(neo)antigens to T cells. DCs consequently constitute an essential target in efforts to generate therapeutic immunity against cancer. This review will discuss recent research that is unlocking the cancer-fighting potential of tumour-infiltrating DCs. First, the complexity of DCs in the tumour microenvironment regarding the different subsets and the difficulty of translating mouse data into equivalent human data will be briefly touched upon. Mainly, possible solutions to problems currently faced in DC-based cancer treatments will be discussed, including their infiltration into tumours, activation strategies, and antigen delivery methods. In this way, we hope to put together a broad picture of potential synergistic therapies that could be implemented to harness the full capacity of tumour-infiltrating DCs to stimulate anti-tumour immune responses in patients.

Emerging strategies in cancer therapy combining chemotherapy with immunotherapy.

Cancer immunotherapy holds great potential to battle cancer by exerting a durable immunity effect. However, this process might be limited by various constraints existing in the tumor microenvironment (TME), such as the lack of available neoantigen, insufficient T cells from the naive repertoire, or immunosuppressive networks in which immunogenic tissue is protected from immune attacks. Certain chemotherapeutic drugs could elicit immune-potentiating effects by either inducing immunogenicity or relieving tumor-induced immunosuppression. Some also leave tumors directly susceptible to cytotoxic T cell attacks. Mounting evidence accumulated from preclinical and clinical studies suggests that these two treatment modalities might be mutually reinforcing as an effective "chemo-immunotherapy" strategy. Herein, we reviewed the latest advances in cancer immunotherapy and related mechanisms involved in chemotherapeutic-mediated immune activation. The emerging combination strategies and synergistic effects in response to chemo-immunotherapy are highlighted. We also discuss the challenges and critical considerations in its future development.

Harnessing immune checkpoints in myeloid lineage cells for cancer immunotherapy.

Myeloid lineage immune cells, such as macrophages and dendritic cells, play important roles in the induction of antitumor immunity during the initial stage of the cancer-immunity cycle, eliciting antitumor adaptive immunity by phagocytosing cancer cells and processing cancer-specific antigens, and then presenting these antigens to T cells. During this process, cancer cell phagocytosis can be prevented by inhibitory signals, and the signaling cascades that elicit immune responses against cancer antigens can be inhibited by immunosuppressive myeloid cells in the tumor microenvironment. A number of therapeutic strategies for enhancing cancer cell phagocytosis and promoting antitumor immunity by targeting myeloid lineage cells have recently been developed. Here, we discuss recent advances in cancer immunotherapy that involve the targeting of myeloid lineage immune cells to induce effective antitumor immunity.

Abstract A101: IDO2 host genetic status influences progression and radiotherapy response in pancreatic ductal adenocarcinoma

Abstract Sporadic pancreatic ductal adenocarcinoma (PDAC) develops into a lethal disease that has remained refractory to different treatment approaches including recent advances in cancer immunotherapy. Variations in host genetic status affecting the inflammatory microenvironment can impact cancer susceptibility, malignant progression and clinical outcomes. In this study, we present genetic evidence from mouse and human genetic studies supporting a role for IDO2, an immunometabolic modifier of B cell-mediated autoimmune responses, in promoting pancreatic ductal adenocarcinoma (PDAC). In an established transgenic mouse model of KRAS-induced pancreatic cancer, IDO2 genetic inactivation markedly reduced malignant progression. In retrospective clinical analyses of PDAC patients (N=200), the biallelic occurrence of either of two inactivating polymorphisms in the IDO2 coding region trended with favorable disease-free survival. In PDAC tissues, an inactive IDO2 host genotype corresponded with changes in expression of genes involved in tryptophan catabolism and immune modulation, along with a reduced neutrophil to lymphocyte ratio. Notably, subset analysis revealed a striking association of inactive IDO2 status with improved disease-free survival in patients who had received adjuvant radiotherapy, a treatment modality that has been highly debated due to its variable efficacy in patients. Accordingly, our findings suggest that host IDO2 genetic status may offer a simple incisive marker to stratify PDAC patients who stand to gain the most from adjuvant radiotherapy, addressing the long-standing debate of its benefits. Citation Format: George C. Prendergast, Avinoam Nevler, Alexander J. Muller, Erika Sutanto-Ward, James B. DuHadaway, Kei Nagatomo, Eric Londin, Kevin O'Hayer, Joseph A. Cozzitorto, Harish Lavu, Theresa P. Yeo, Mark Curtis, Tatiana Villatoro, Benjamin E. Leiby, Jordan M. Winter, Charles J. Yeo, Jonathan R. Brody. IDO2 host genetic status influences progression and radiotherapy response in pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr A101.

Immunogenicity and Immune Silence in Human Cancer

Despite recent advances in cancer immunotherapy, the process of immunoediting early in tumorigenesis remains obscure. Here, we employ a mathematical model that utilizes the Cancer Genome Atlas (TCGA) data to elucidate the contribution of individual mutations and HLA alleles to the immunoediting process. We find that common cancer mutations including BRAF-V600E and KRAS-G12D are predicted to bind none of the common HLA alleles, and are thus “immunogenically silent” in the human population. We identify regions of proteins that are not presented by HLA at a population scale, coinciding with frequently mutated hotspots in cancer, and other protein regions broadly presented across the population in which few mutations occur. We also find that 9/29 common HLA alleles contribute disproportionately to the immunoediting of early oncogenic mutations. These data provide insights into immune evasion of common driver mutations and a molecular basis for the association of particular HLA genotypes with cancer susceptibility.

Adoptive therapy with TCR gene-modified T cells for hematological malignancies and solid tumors

Recent remarkable advancements in cancer immunotherapy have rendered adoptive T cell therapy an option of clinical treatment of patients with cancer following the success of immune checkpoint inhibitors. In 2017, the FDA approved adoptive cell therapy with chimeric antigen receptor (CAR) gene-modified T cells as a treatment for patients with acute lymphocytic leukemia and diffuse large cell lymphoma. In February this year, it was announced that this therapy will also be approved in Japan soon. Adoptive therapy with T-cell receptor (TCR) gene-modified T cells is a promising therapy for patients with hematological malignancy and solid tumors that follow the success of CAR-T cell therapy. This review aims to summarize the recent progress and issues of TCR gene-modified T-cell therapy with the introduction of our recent study.

Rational combination of cancer immunotherapy in melanoma.

The recent advances in cancer immunotherapy with unprecedented success in therapy of advanced melanoma represent a turning point in the landscape of melanoma treatment. Given the complexity of activation of immunological system and the physiologic multifactorial homeostatic mechanisms controlling immune responses, combinatorial strategies are eagerly needed in melanoma therapy. Nevertheless, rational selection of immunotherapy combinations should be more biomarker-guided, including not only the cancer immunogram, PD-L1 expression, interferon gene expression signature, mutational burden, and tumor infiltration by CD8+ T cells but also intratumoral T cell exhaustion and microbiota composition. In this review, we summarize the rationale to develop combination treatment strategies in melanoma and discuss biological background that could help to design new combinations in order to improve patients' outcome.

Enhanced Natural Killer Cell Immunotherapy by Rationally Assembling Fc Fragments of Antibodies onto Tumor Membranes.

Recent advances in cancer immunotherapy have exploited the efficient potential of natural killer (NK) cells to kill tumor cells through antibody-dependent cell-mediated cytotoxicity (ADCC). However, this therapeutic strategy is seriously limited by tumor antigen heterogeneity since antibodies can only recognize specific antigens. In this work, modified antibodies or their Fc fragments that can target solid tumors without the necessity of specific antigen presentation on tumors are developed. Briefly, Fc fragments or therapeutic monoclonal antibodies are conjugated with the N-terminus of pH low insertion peptide so that they will selectively assemble onto the membrane of solid tumor cells via the conformational transformation of the peptide by responding to the acidic tumor microenvironment. The inserted Fc fragments or antibodies can efficiently activate NK cells, initiating ADCC and killing multiple types of tumor cells, including antigen-negative cancer cells. In vivo therapeutic results also exhibit significant efficacy on both primary solid tumors and tumor metastasis. These modified Fc fragments and antibodies present strong potential to overcome the limitation of tumor antigen heterogeneity, broadening the applications of NK cell immunotherapy on solid tumor treatment.

Recent advances in cancer immunotherapy

Recent advances in cancer immunotherapy

The Era of Immune Checkpoint Therapy: From Cancer to Viral Infection-A Mini Comment on the 2018 Medicine Nobel Prize.

The 2018 Medicine Nobel Prize was awarded jointly to two immunologists, James P. Allison at the University of Texas MD Anderson Cancer Center in Houston and Tasuku Honjo at Kyoto University in Japan, who pioneered a new way to treat cancers ( Ledford et al. 2018 ). Both Laureates have shown how so called checkpoints on T cells can be used to manipulate the immune responses so that T cells can efficiently attack cancer cells. Using the immune system to fight cancers has been investigated for more than a 100 years. Recent advances in cancer immunotherapy, particularly immune checkpoint blockade therapy have dramatically changed the therapeutic strategy against advanced cancers. Through inhibiting negative immune regulation, these approaches have demonstrated improved overall survival for patients with advanced cancers. Importantly, for some of the patients treated with such strategies, their tumors seem to totally disappear.

Immunomodulatory Effects of Drugs for Effective Cancer Immunotherapy.

Recent advances in cancer immunotherapy, including immune checkpoint inhibitors or adoptive T cell therapies, have contributed to better outcomes in cancer patients. However, there are still many cancers with no cure. Therefore, combinations of several treatment strategies are being explored, and enhancing anticancer immunity will play an important role to combat the disease. There have been several reports on the immune-modulatory effects of commonly used drugs, namely, statin, metformin, and angiotensin receptor blockers (ARBs), which suggest that these drugs could enhance immunity against cancer cells. Other anticancer drugs, such as anthracyclines, thalidomides, lenalidomides, and hypomethylating drugs, could also strengthen the immune system to attack cancer cells at a relatively low dose. Hence, these drugs might contribute to better outcomes in cancer patients.

In situ administration of cytokine combinations induces tumor regression in mice.

BackgroundRecent advances in cancer immunotherapy suggest a possibility of harnessing the immune system to defeat malignant tumors, but the complex immunosuppressive microenvironment confines the therapeutic benefits to a minority of patients with solid tumors.MethodsA lentivector-based inducible system was established to evaluate the therapeutic effect of cytokines in established tumors. Intratumoral injection of certain cytokine combination in syngeneic tumor models was conducted to assess the therapeutic potentials.FindingsDoxycycline (Dox)-induced local expression of cytokine combinations exhibites a strong synergistic effect, leading to complete regression of tumors. Notably, IL12 + GMCSF+IL2 expression induces eradication of tumors in all mice tolerated with this treatment, including those bearing large tumors of ~15 mm in diameter, and generates intensive systemic antitumor immunity. Other combinations with similar immune regulatory roles also induce tumor elimination in most of mice. Moreover, intratumoral injection of chitosan/IL12 + GMCSF+IL2 solution induces a complete response in all the tested syngeneic tumor models, regardless of various tumor immunograms.InterpretationAdministration of certain cytokine combinations in tumor microenvironment induces a strong synergistic antitumor response, including the recruitment of large amount of immune cells and the generation of systemic antitumor immunity. It provides a versatile method for the immunotherapy of intractable malignant neoplasms.FundThere is no external funding supporting this study.

Urine-derived lymphocytes as a non-invasive measure of the bladder tumor immune microenvironment.

Despite the advances in cancer immunotherapy, only a fraction of patients with bladder cancer exhibit responses to checkpoint blockade, highlighting a need to better understand drug resistance and identify rational immunotherapy combinations. However, accessibility to the tumor prior and during therapy is a major limitation in understanding the immune tumor microenvironment (TME). Herein, we identified urine-derived lymphocytes (UDLs) as a readily accessible source of T cells in 32 patients with muscle invasive bladder cancer (MIBC). We observed that effector CD8+ and CD4+ cells and regulatory T cells within the urine accurately map the immune checkpoint landscape and T cell receptor repertoire of the TME. Finally, an increased UDL count, specifically high expression of PD-1 (PD-1hi) on CD8+ at the time of cystectomy, was associated with a shorter recurrence-free survival. UDL analysis represents a dynamic liquid biopsy that is representative of the bladder immune TME that may be used to identify actionable immuno-oncology (IO) targets with potential prognostic value in MIBC.

Acquired resistance to cancer immunotherapy.

In recent times, advances in cancer immunotherapy have yielded impressive, durable clinical responses in patients with varied subtypes of cancer. However, a significant proportion of patients who initially demonstrate encouraging tumor regression develop resistance and progress over time. The identification of novel therapeutic approaches to overcome resistance may result in significantly improved clinical outcomes and remains an area of high scientific priority. This review aims to summarize the current knowledge regarding the role of both tumor-intrinsic and tumor-extrinsic factors in the development of resistance to cancer immunotherapy and to discuss current and possible future therapeutic strategies targeting these mechanisms.

Induction of oligoclonal CD8 T cell responses against pulmonary metastatic cancer by a phospholipid-conjugated TLR7 agonist

Recent advances in cancer immunotherapy have improved patient survival. However, only a minority of patients with pulmonary metastatic disease respond to treatment with checkpoint inhibitors. As an alternate approach, we have tested the ability of systemically administered 1V270, a toll-like receptor 7 (TLR7) agonist conjugated to a phospholipid, to inhibit lung metastases in two variant murine 4T1 breast cancer models, as well as in B16 melanoma, and Lewis lung carcinoma models. In the 4T1 breast cancer models, 1V270 therapy inhibited lung metastases if given up to a week after primary tumor initiation. The treatment protocol was facilitated by the minimal toxic effects exerted by the phospholipid TLR7 agonist compared with the unconjugated agonist. 1V270 exhibited a wide therapeutic window and minimal off-target receptor binding. The 1V270 therapy inhibited colonization by tumor cells in the lungs in an NK cell dependent manner. Additional experiments revealed that single administration of 1V270 led to tumor-specific CD8+ cell-dependent adaptive immune responses that suppressed late-stage metastatic tumor growth in the lungs. T cell receptor (TCR) repertoire analyses showed that 1V270 therapy induced oligoclonal T cells in the lungs and mediastinal lymph nodes. Different animals displayed commonly shared TCR clones following 1V270 therapy. Intranasal administration of 1V270 also suppressed lung metastasis and induced tumor-specific adaptive immune responses. These results indicate that systemic 1V270 therapy can induce tumor-specific cytotoxic T cell responses to pulmonary metastatic cancers and that TCR repertoire analyses can be used to monitor, and to predict, the response to therapy.

Abstract 3323: Role of RNA methyltransferase METTL3 in melanoma

Abstract Melanoma is the sixth most common cancer in the USA. Introduction of BRAF inhibitors and advances in cancer immunotherapy has greatly improved treatment of melanoma, however, the problem of tumour relapse and therapy resistance persists. Better understanding of the mechanism of development of the diseases is urgently needed to improve therapeutic intervention. Role of DNA and histone modifications have been well established in several diseases, however, RNA modifications, specifically, N6 methyl adenosine (m6A), has only recently begun to be shown to play critical role in cancer. m6A plays crucial roles in mRNA stability, splicing, export, translation and decay and is regulated by: methyltransferase complex proteins METTL3, METTL14, and WTAP; the demethylases FTO and ALKBH5, and the m6A reader proteins. In the present study, we uncover the role of RNA methyltransferase METTL3 in human melanoma cells. METTL3 expression was assessed in 8 melanoma cell lines (A375, A375MA2, A2058, WM164, 451Lu, WM793, SKMEL2, WM3918). Western blotting data revealed METTL3 to be upregulated in seven melanoma cell lines (except A2058) relative to normal melanocytes. To uncover the role of METTL3 in melanoma, we knockdown METTL3 with lentiviral shRNA and studied the effect on melanoma cells tumorigenesis. The colony formation assay revealed reduced colony number in the METTL3 knockdown A375, A375MA2 and WM793 cells relative to the scrambled control cells. The main cause of melanoma associated fatality is its metastatic dissemination we therefore, next sought to investigate whether METTL3 could affect melanoma cells migration and invasiveness. We performed migration and invasion assays to detect the migratory potential of control or METTL3 knockdown A375, A375MA2 and WM793 cells. Interestingly, both migration and invasion was found to be reduced in METTL3 knockdown cells in all the three cell lines examined. RNA dot blot assay demonstrated a decreased m6A level in total RNA of the METTL3 knockdown cells relative to control cells. p16 and p53 mRNA were found to be enriched in m6A immunoprecipitated samples as compared to IgG control, pointing towards a potential role of m6A in regulating expression of melanoma associated genes. Ongoing effort is aimed at identifying what known or novel regulators of the migratory/invasive cascade is regulated by METTL3 and whether it is through m6A mediated or independent mechanisms. In summary, we have shown that METTL3 is overexpressed in human melanoma and play an important role in metastasis. Citation Format: Ujwal Dahal, Kang Le, Mamta Gupta. Role of RNA methyltransferase METTL3 in melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3323.

Understanding melanoma patients’ needs in the new era of treatment: A mixed-methods approach.

e22132Background: Advances in cancer immunotherapy and targeted therapy have improved clinical outcomes for patients with advanced melanoma. However, there is a lack of understanding of patients’ e...

Inhibition of autophagy potentiated the anti-tumor effects of VEGF and CD47 bispecific therapy in glioblastoma.

Glioblastoma, characterized by extensive microvascular proliferation and invasive tumor growth, is one of the most common and lethal malignancies in adults. Benefits of the conventional anti-angiogenic therapy were only observed in a subset of patients and limited by diverse relapse mechanism. Fortunately, recent advances in cancer immunotherapy have offered new hope for patients with glioblastoma. Herein, we reported a novel dual-targeting therapy for glioblastoma through simultaneous blockade of VEGF and CD47 signaling. Our results showed that VEGFR1D2-SIRPαD1, a VEGF and CD47 bispecific fusion protein, exerted potent anti-tumor effects via suppressing VEGF-induced angiogenesis and activating macrophage-mediated phagocytosis. Meanwhile, autophagy was activated by VEGFR1D2-SIRPαD1 through inactivating Akt/mTOR and Erk pathways in glioblastoma cells. Importantly, autophagy inhibitor or knockdown of autophagy-related protein 5 potentiated VEGFR1D2-SIRPαD1-induced macrophage phagocytosis and cytotoxicity against glioblastoma cells. Moreover, suppression of autophagy led to increased macrophage infiltration, angiogenesis inhibition, and tumor cell apoptosis triggered by VEGF and CD47 dual-targeting therapy, thus eliciting enhanced anti-tumor effects in glioblastoma. Our data revealed that VEGFR1D2-SIRPαD1 alone or in combination with autophagy inhibitor could effectively elicit potent anti-tumor effects, highlighting potential therapeutic strategies for glioblastoma through disrupting angiogenetic axis and CD47-SIRPα anti-phagocytic axis alone or in combination with autophagy inhibition.