Cancer cell-expressed BTNL2 facilitates tumour immune escape via engagement with IL-17A-producing γδ T cells

Therapeutic blockade of the immune checkpoint proteins programmed cell death protein 1 (PD-1) and cytotoxic T lymphocyte antigen 4 (CTLA4) has transformed cancer treatment. However, the overall response rate to these treatments is low, suggesting that immune checkpoint activation is not the only mechanism leading to dysfunctional anti-tumour immunity. Here we show that butyrophilin-like protein 2 (BTNL2) is a potent suppressor of the anti-tumour immune response. Antibody-mediated blockade of BTNL2 attenuates tumour progression in multiple in vivo murine tumour models, resulting in prolonged survival of tumour-bearing mice. Mechanistically, BTNL2 interacts with local γδ T cell populations to promote IL-17A production in the tumour microenvironment. Inhibition of BTNL2 reduces the number of tumour-infiltrating IL-17A-producing γδ T cells and myeloid-derived suppressor cells, while facilitating cytotoxic CD8+ T cell accumulation. Furthermore, we find high BTNL2 expression in several human tumour samples from highly prevalent cancer types, which negatively correlates with overall patient survival. Thus, our results suggest that BTNL2 is a negative regulator of anti-tumour immunity and a potential target for cancer immunotherapy.

A Novel Prognostic Risk Score Based on Ferroptosis-related LncRNAs Predicting Ovarian Cancer Patient Survival

Background: Long non-coding RNAs (lncRNAs) are thought to be associated with several processes during cancer development and have been shown to be involved in the regulation of ferroptosis. Ovarian cancer is highly malignant tumour with a poor prognosis. The identification biomarkers with prognostic value in ovarian cancer may improve patient outcomes and can help to elucidate potential future therapeutic targets.Results: We report differential expression of 187 ferroptosis-related lncRNAs in normal and ovarian cancer tissue. Using univariate and multivariable Cox regression analysis, we identified four lncRNAs that were strongly associated with prognosis. We constructed a prognostic risk score based on these four lncRNAs which was effectively able to distinguish between low- and high-risk OC patients based on survival time. Univariate and multivariable Cox regression analyses and time-related receiver operating characteristic curve analyses revealed that this risk score represented an independent prognostic factor in patients with ovarian cancer. For clinical implementation, we developed a nomogram based on the prognostic feature and patient age. Gene Ontology(GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that the four ferroptosis-related lncRNAs were related to tumour immunity.Conclusions: we identify four novel ferroptosis-related lncRNAs as predictors of ovarian cancer prognosis and potential future therapeutic targets for ovarian cancer.

Spontaneous Physical Activity in Obese Condition Favours Antitumour Immunity Leading to Decreased Tumour Growth in a Syngeneic Mouse Model of Carcinogenesis

Our goal was to evaluate the effect of spontaneous physical activity on tumour immunity during aging. Elderly (n = 10/group, 33 weeks) ovariectomized C57BL/6J mice fed a hyperlipidic diet were housed in standard (SE) or enriched (EE) environments. After 4 weeks, orthotopic implantation of syngeneic mammary cancer EO771 cells was performed to explore the immune phenotyping in the immune organs and the tumours, as well as the cytokines in the tumour and the plasma. EE lowered circulating myostatin, IL-6 and slowed down tumour growth. Spleen and inguinal lymph node weights reduced in relation to SE. Within the tumours, EE induced a lower content of lymphoid cells with a decrease in Th2, Treg and MDCS; and, conversely, a greater quantity of Tc and TAMs. While no change in tumour NKs cells occurred, granzyme A and B expression increased as did that of perforin 1. Spontaneous physical activity in obese conditions slowed tumour growth by decreasing low-grade inflammation, modulating immune recruitment and efficacy within the tumour.

Ionic Regulation of T-Cell Function and Anti-Tumour Immunity

The capacity of T cells to identify and kill cancer cells has become a central pillar of immune-based cancer therapies. However, T cells are characterized by a dysfunctional state in most tumours. A major obstacle for proper T-cell function is the metabolic constraints posed by the tumour microenvironment (TME). In the TME, T cells compete with cancer cells for macronutrients (sugar, proteins, and lipid) and micronutrients (vitamins and minerals/ions). While the role of macronutrients in T-cell activation and function is well characterized, the contribution of micronutrients and especially ions in anti-tumour T-cell activities is still under investigation. Notably, ions are important for most of the signalling pathways regulating T-cell anti-tumour function. In this review, we discuss the role of six biologically relevant ions in T-cell function and in anti-tumour immunity, elucidating potential strategies to adopt to improve immunotherapy via modulation of ion metabolism.

Manipulating Histone Acetylation Leads to Adverse Effects in Hemangiosarcoma Cells

Canine hemangiosarcoma (HSA) is a malignant tumour derived from endothelial cells. No effective treatment has yet been developed because of the lack of understanding of its pathogenesis. Histone acetylation, an epigenetic modification, is highly associated with cancer pathogenesis. Manipulating histone acetylation by histone deacetylase inhibitors (HDACi) or bromodomain and extraterminal domain inhibitors (BETi) is one approach to treat various cancers. However, the role of histone acetylation in HSA remains unknown. This study aimed to investigate how histone acetylation functions in HSA pathogenesis using two HDACi, suberanilohydroxamic acid (SAHA) and valproic acid (VPA), and one BETi, JQ1, in vitro and in vivo. Histone acetylation levels were high in cell lines and heterogeneous in clinical cases. SAHA and JQ1 induced apoptosis in HSA cell lines. SAHA and VPA treatment in HSA cell lines upregulated inflammatory-related genes, thereby attracting macrophages. This implies that SAHA and VPA can induce anti-tumour immunity. JQ1 stimulated autophagy and inhibited the cell cycle. Finally, JQ1 suppressed HSA tumour cell proliferation in vivo. These results suggest that HDACi and BETi can be alternative drugs for HSA treatment. Although further research is required, this study provides useful insights for developing new treatments for HSA.

Fascinating Dendritic Cells—Sentinel Cells of the Immune System a Review

Dendritic cells (DC) are specialized antigen presenting cells which have the unique ability to activate naive T-lymphocytes. Their role in the immune system is much more sophisticated than it seems, as they do not kill the pathogens directly, but provide a long-lasting antigen specific immune response thanks to that sufficiently bridging the innate and the adaptive immunity. In recent years, there has been a growing interest in studies of their role in immune regulation, autoimmune reactions, as well as in immune responses against pathogens and tumours. Processing and presentation capabilities of a highly specific and unique tumour antigen makes them an interesting tool for stimulating effective anti-tumour immunity. In vitro generations of DC represent a preferred model for more detailed studies of DC biology in other fields. The aim of this review was to discuss the main role of dendritic cells in the body as well as their current use as experimental models for further scientific studies.

Payload Delivery: Engineering Immune Cells to Disrupt the Tumour Microenvironment

Although chimeric antigen receptor (CAR) T cells have shown impressive clinical success against haematological malignancies such as B cell lymphoma and acute lymphoblastic leukaemia, their efficacy against non-haematological solid malignancies has been largely disappointing. Solid tumours pose many additional challenges for CAR T cells that have severely blunted their potency, including homing to the sites of disease, survival and persistence within the adverse conditions of the tumour microenvironment, and above all, the highly immunosuppressive nature of the tumour milieu. Gene engineering approaches for generating immune cells capable of overcoming these hurdles remain an unmet therapeutic need and ongoing area of research. Recent advances have involved gene constructs for membrane-bound and/or secretable proteins that provide added effector cell function over and above the benefits of classical CAR-mediated cytotoxicity, rendering immune cells not only as direct cytotoxic effectors against tumours, but also as vessels for payload delivery capable of both modulating the tumour microenvironment and orchestrating innate and adaptive anti-tumour immunity. We discuss here the novel concept of engineered immune cells as vessels for payload delivery into the tumour microenvironment, how these cells are better adapted to overcome the challenges faced in a solid tumour, and importantly, the novel gene engineering approaches required to deliver these more complex polycistronic gene constructs.

Directing the Future Breakthroughs in Immunotherapy: The Importance of a Holistic Approach to the Tumour Microenvironment

Immunotherapy has revolutionised the treatment of cancers by exploiting the immune system to eliminate tumour cells. Despite the impressive response in a proportion of patients, clinical benefit has been limited thus far. A significant focus to date has been the identification of specific markers associated with response to immunotherapy. Unfortunately, the heterogeneity between patients and cancer types means identifying markers of response to therapy is inherently complex. There is a growing appreciation for the role of the tumour microenvironment (TME) in directing response to immunotherapy. The TME is highly heterogeneous and contains immune, stromal, vascular and tumour cells that all communicate and interact with one another to form solid tumours. This review analyses major cell populations present within the TME with a focus on their diverse and often contradictory roles in cancer and how this informs our understanding of immunotherapy. Furthermore, we discuss the role of integrated omics in providing a comprehensive view of the TME and demonstrate the potential of leveraging multi-omics to decipher the underlying mechanisms of anti-tumour immunity for the development of novel immunotherapeutic strategies.

Improving immunotherapy for high grade glioma

<p>Glioblastoma multiforme (GBM) is a malignant primary brain tumour that is almost always fatal. Conventional treatment modalities are limited by toxicity. T cell-based immunotherapy is a promising alternative that has the potential to specifically target tumour cells. The author of this thesis was a principal investigator for a recently completed Phase I clinical trial in which patients with recurrent GBM were treated with surgery, dendritic cell-based immunotherapy and chemotherapy. In addition to conducting the trial in collaboration with others, the author used peripheral blood mononuclear cells from trial participants to assess anti-tumour immune responses before and after treatment. A broad correlation was observed between clinical outcome and anti-tumour immunity, with sustained progression-free survival occurring in two patients with baseline responses that persisted or increased after treatment. However, the overall clinical benefit was modest. For progress to be made, there is a need to develop a more potent vaccine. With this in mind, a novel “Glioma-Gal” vaccine was devised and tested in an orthotopic mouse model of glioma, This simple vaccine consisted of irradiated autologous tumour cells pulsed with the glycolipid alpha-galactosylceramide, an immunoadjuvant that induces invariant Natural Killer T cells to licence endogenous dendritic cells. The vaccine was shown to be effective in a therapeutic setting when accompanied by depletion of regulatory T cells. Mechanistically, vaccine efficacy was dependent on CD4 T cells and the mediastinal lymph node was shown to be an important site of T cell priming. It was further shown that components of the immune system necessary for the vaccine to work were present and competent in a cohort of GBM patients. The final chapters explore the idea of enhancing the therapeutic benefit of this vaccine by targeting certain tumour cell subsets or phenotypes. Cancer stem cells (CSC) are proposed to be a subset of tumour cells with a unique capacity for initiating and maintaining tumours. Eliminating these cells may therefore be both necessary and sufficient to achieve cure. Using the same mouse model, a variety of methods were assessed for their ability to isolate or enrich for a CSC subset. Of these, culture in serum-free medium in the presence of certain growth factors was shown to enrich for a more stem cell-like phenotype. However, a vaccine constructed from these stem cell-like cells was not more effective than the standard vaccine. Next, the author tested the hypothesis that a vaccine manipulated to target chemoresistant cells would be more effective than standard vaccine when used in combination with chemotherapy. However, the modified vaccine showed no advantage over standard vaccine in this model. In the course of these experiments, synergy was observed between the vaccine and the chemotherapy agent doxorubicin. The mechanism responsible for this supra-additive effect remains undetermined but is most likely due to an immunomodulatory effect of low dose doxorubicin. The Glioma-Gal vaccine design holds promise but more studies are needed to realise the full potential of this approach. The data presented in the thesis did not support targeting CSC or chemoresistant cells as ways of achieving this. In contrast, combining the vaccine with immunomodulation was effective and merits further exploration.</p>