The dietary sweetener sucralose is a negative modulator of T cell-mediated responses.

Artificial sweeteners are used as calorie-free sugar substitutes in many food products and their consumption has increased substantially over the past years1. Although generally regarded as safe, some concerns have been raised about the long-term safety of the consumption of certain sweeteners2-5. In this study, we show that the intake of high doses of sucralose in mice results in immunomodulatory effects by limiting T cell proliferation and T cell differentiation. Mechanistically, sucralose affects the membrane order of T cells, accompanied by a reduced efficiency of T cell receptor signalling and intracellular calcium mobilization. Mice given sucralose show decreased CD8+ T cell antigen-specific responses in subcutaneous cancer models and bacterial infection models, and reduced T cell function in models of T cell-mediated autoimmunity. Overall, these findings suggest that a high intake of sucralose can dampen T cell-mediated responses, an effect that could be used in therapy to mitigate T cell-dependent autoimmune disorders.

Programmable DNA-augmented hydrogels for controlled activation of human lymphocytes.

Contractile forces within the planar interface between T cell and antigen-presenting surface mechanically stimulate T cell receptors (TCR) in the mature immune synapses. However, the origin of mechanical stimulation during the initial, i.e., presynaptic, microvilli-based TCR activation in the course of immune surveillance remains unknown and new tools to help address this problem are needed. In this work, we develop nucleic acid nanoassembly (NAN)-based technology for functionalization of hydrogels using isothermal toehold-mediated reassociation of RNA/DNA heteroduplexes. Resulting platform allows for regulation with NAN linkers of 3D force momentum along the TCR mechanical axis, whereas hydrogels contribute to modulation of 2D shear modulus. By utilizing different lengths of NAN linkers conjugated to polyacrylamide gels of different shear moduli, we demonstrate an efficient capture of human T lymphocytes and tunable activation of TCR, as confirmed by T-cell spreading and pY foci.

Dasatinib Is an Effective Treatment for Angioimmunoblastic T-cell Lymphoma.

Recurrent hotspot (p.Gly17Val) mutations in RHOA encoding a small GTPase, together with loss-of-function mutations in TET2 encoding an epigenetic regulator, are genetic hallmarks of angioimmunoblastic T-cell lymphoma (AITL). Mice expressing the p.Gly17Val RHOA mutant on a Tet2-null background succumbed to AITL-like T-cell lymphomas due to deregulated T-cell receptor (TCR) signaling. Using these mice to investigate therapeutics for AITL, we found that dasatinib, a multikinase inhibitor prolonged their survival through inhibition of hyperactivated TCR signaling. A phase I clinical trial study of dasatinib monotherapy in 5 patients with relapsed/refractory AITL was performed. Dasatinib was started at a dose of 100 mg/body once a day and continued until days 10-78 (median day 58). All the evaluable patients achieved partial responses. Our findings suggest that AITL is highly dependent on TCR signaling and that dasatinib could be a promising candidate drug for AITL treatment. SIGNIFICANCE: Deregulated T-cell receptor signaling is a critical molecular event in angioimmunoblastic T-cell lymphoma and can be targeted with dasatinib.

Utilization of CAR T Cell Therapy in Pediatric Patients.

OBJECTIVE: To provide an overview of chimeric antigen receptor (CAR) T cell therapy for pediatric patients with relapsed or refractory malignancy and the associated toxicities. DATA SOURCES: Research articles, reviews, clinical trial information. CONCLUSION: The key to the successful application of CAR T cell immunotherapy is (1) identifying patients with malignancies that are eligible for immunotherapy, (2) coordinating T-cell collection, (3) safe infusion of CAR T cells, and (4) managing/preventing toxicities following infusion. IMPLICATIONS FOR NURSING PRACTICE: As the use of targeted therapy with tumor-specific T cells becomes more prevalent, it is essential that the nursing staff stay abreast of these current therapies.

Utilization of Chimeric Antigen Receptor T-cell Therapy in Adults.

OBJECTIVE: To discuss the mechanism of action and nursing care of adults receiving chimeric antigen receptor (CAR) T-cell therapy. DATA SOURCE: Peer reviewed articles and pharmaceutical drug labels. CONCLUSION: CAR T-cell therapy is among the most exciting therapies in the evolution of cancer treatment. The efficacy of research with CAR T-cell therapy has shown promising results in hematologic malignancies as well as in solid tumors. IMPLICATIONS FOR NURSING PRACTICE: Understanding the complexity of care for these patients from the bedside to the outpatient setting is vital for their survival and quality of care.

Tyrosine kinase inhibition to improve anthracycline-based chemotherapy efficacy in T-cell lymphoma.

BACKGROUND: Anthracycline-containing regimens, namely cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP) or CHOEP (CHOP + etoposide), represent the current standard of care for patients with newly diagnosed peripheral T-cell lymphomas (PTCLs), although responses are unsatisfactory. In this study, we investigated the pathways able to mitigate the sensitivity to CHOP-based regimens in preclinical models of T-cell lymphoma (TCL) to select agents for the development of CHOP-based drug combinations. METHODS: We performed gene expression profiling of malignant T-cell lines exposed to CHOEP; flow cytometry was employed to study the effects of drug combinations on cell viability, cell cycle distribution, apoptosis and mitochondrial membrane depolarisation. Western blot analyses were performed to study cell signalling downstream of the T-cell receptor and apoptosis. The in vivo effect of the drug combination was tested in xenograft models. RESULTS: We highlighted a modulation of tyrosine kinases belonging to the T-cell receptor pathway upon chemotherapy that provided the rationale for combining the tyrosine kinase inhibitor dasatinib with CHOEP. Dasatinib improves CHOEP activity and reduces viability in vitro. Furthermore, combination treatment results in tumour growth inhibition in in vivo xenograft mouse models. CONCLUSIONS: Our data provide the rationale for clinical testing of the dasatinib-CHOEP combination in patients with T-cell lymphoma.

Management Principles Associated With Cytokine Release Syndrome.

OBJECTIVE: To discuss current recommendations and resources for nurses to ensure they advocate for patients with cytokine release syndrome (CRS). DATA SOURCES: A literature search using key terms: cytokine release syndrome, neurotoxicity, CAR T, adverse events. CONCLUSION: Chimeric antigen receptor (CAR) T-cell immunotherapy is a growing and rapidly changing field of research. Prompt recognition and management of the side effects of CAR T-cell therapy is pivotal to the safe outcomes of patients. As patients are treated with these novel therapies, additional recommendations and standards for treating CRS and neurotoxicity will occur. IMPLICATION FOR NURSING PRACTICE: Nursing plays a pivotal role in the CAR T patients' treatment course because they are the first line of defense in the care of these patients. Providers and patients both rely on nursing knowledge and training to recognize symptoms of CRS and neurotoxicity. With the early recognition of the signs and symptoms of CRS and neurotoxicity, nursing will help improve the outcomes of the patients receiving CAR T-cell therapy.

Individual Patient Data Meta-Analysis from 16 Trials for Safety Factors in Cytokine Release Syndrome After CAR-T Therapy in Patients with Non-Hodgkin Lymphoma (NHL) and Acute Lymphoblastic Leukemia.

INTRODUCTION: Chimeric antigen receptor T cells (CAR-T) with anti-CD19 have shown great promise in the treatment of relapsed and refractory non-Hodgkin lymphoma (NHL) and acute lymphoblastic leukemia (ALL). Cytokine release syndrome (CRS) is the most significant and life-threatening side effect. This individual patient data (IPD) meta-analysis is to investigate the association of severe CRS with CAR-T dose and baseline factors. METHODS: We collected the individual patient-level data of 237 patients with NHL or ALL from 16 published papers. A logistic model was used to analyze the association of severe CRS incidence with CAR-T dose and baseline factors including age and baseline tumor burden. A generalized additive model (GAM) with logit link function was used to estimate the nonlinear response for severe CRS incidence with CAR-T dose and baseline factors. RESULTS: Severe CRS incidence was positively associated with current proposed CAR-T treatment infusion dose at a range of 0.2 × 106-5.0 × 106 T cells per kg of body weight in patients less than or equal to 25 years old. For patients over 25 years old the association was not significant. Significant association between severe CRS incidence and baseline tumor burden was also shown in this study. CONCLUSIONS: Our results provide novel insights that association between CAR-T treatment dose and severe CRS incidence only exists in patients less than or equal to 25 years old. Severe CRS incidence is associated with baseline tumor burden which indicates that tumor burden needs to be controlled with induced chemotherapy before CAR-T treatment.

NEW STRATEGIES TO PREDICT AND PREVENT SERIOUS IMMUNOLOGICALLY MEDIATED ADVERSE DRUG REACTIONS.

Preventive efforts for serious immunologically mediated adverse drug reactions (IM-ADRs) have been fueled by discovery of strong class I human leukocyte antigen (HLA) associations; however, the low positive predictive value of HLA for IM-ADRs has limited translation. Studies were undertaken to explain why most patients carrying an HLA risk allele do not develop IM-ADR on exposure to the risk drug. Tissue-specific approaches defined the T-cell receptor (TCR) repertoire and phenotype of the pathogenic T cells found in the skin and blister fluid of IM-ADRs. Dominant CD8+ T cell clonotypes representing >50% of total TCRαß sequences among CD8+ CD137+ T cells were identified in tissue to identify the pathogenic activated T cells. Identification of the specific molecular and cellular signatures of the antigen-driven pathogenic T cells will facilitate more specific mechanisms to determine the small percentage of individuals carrying an HLA risk allele who are likely to develop an IM-ADR before drug exposure.

An overview of the toxicities of checkpoint inhibitors in older patients with cancer.

Checkpoint inhibitors offer an exciting new option for treatment of a wide variety of cancers. By binding to surface receptors or their associated ligands on T cells, this class of drugs enhances immune activation and response to cancer cells. In available studies, the drugs are well tolerated, although toxicity involving skin, gastrointestinal tract, liver, lungs, and endocrine organs has been observed. Unfortunately, few studies to date have included patients older than 70 years of age. Since aging has been linked to changes in immune function, there are theoretical concerns that this patient population might experience a different profile of adverse events. This article reviews the tolerability of checkpoint inhibitors in older patients with cancer in clinical practice.

Delayed Terminal Ileal Perforation in a Relapsed/Refractory B-Cell Lymphoma Patient with Rapid Remission Following Chimeric Antigen Receptor T-Cell Therapy.

Chimeric antigen receptor T-cell strategy targeting CD19 (CART19) has prominent anti-tumor effect for relapsed/refractory B-cell lymphomas. CART19-associated complications have been gradually recognized, however, late-onset complications have not been extensively studied. Herein, for the first time we report a diffuse large B-cell lymphoma patient with terminal ileum involvement obtained rapid remission and developed spontaneous terminal ileal perforation 38 days following CART19 infusion. The late-onset perforation reminds us that, for the safety of CART treatment, more cautions are warranted for the management of delayed GI complications.

Case report for recurrent and new-onset SLE patients treated by high-dose glucocorticoid therapy: Characteristics of peripheral TCR beta chain CDR3 repertoires.

RATIONALE: High-dose glucocorticoid therapy has been widely applied in clinical practice in systemic lupus erythematosus (SLE)patients, but less is known about the changes of T cells, especially the T cell receptor (TCR) repertoires, during the treatment. The aim of this paper is to describe the changes of TCR that recurrent and new-onset SLE patients treated by high-dose glucocorticoid therapy. PATIENT CONCERNS: Drugs of clinical treatment of SLE mainly include glucocorticoid, immunosuppressive agents, nonsteroidal anti-inflammatory drugs and B cell targeted drugs, etc, but the clinical symptoms were in remission and recurrent of onset patients with SLE. DIAGNOSES: Refer to the diagnostic criteria for SLE in 2011 by the American society of rheumatology. INTERVENTIONS: All patients were treated with High-dose glucocorticoid therapy and surveyed the TCR repertoires at 3 monitoring moments (before treatment, one month after treatment, and 3 months after treatment) to analyze the relationship between the characteristics of TCR repertoire and the highdose glucocorticoid therapy. OUTCOMES: We found that high-dose glucocorticoid therapy resulted in clinical symptom remission, as well as change of diversity, highly expanded clones (HEC), usage of TCR beta chain variable gene (TRBV)/TCR beta chain joining gene (TRBJ), and overlapped sequences of TCR beta chain complementarity determining region 3 (CDR3) repertoires. This suggests that the effect of high-dose glucocorticoids on TCR repertoires is closely related to individual autoimmune T cells. LESSONS: In this study, we have shown that we could evaluate the effect of therapy, the pathogenesis, and the prognosis for the patients with SLE by monitoring the TCR CDR3 repertoires. It could afford a new method to find the therapeutic target of SLE.

Peptides Against Autoimmune Neurodegeneration.

The mammalian immune system is a nearly perfect defensive system polished by a hundred million years of evolution. Unique flexibility and adaptivity have created a virtually impenetrable barrier to numerous exogenous pathogens that are assaulting us every moment. Unfortunately, triggers that remain mostly enigmatic will sometimes persuade the immune system to retarget against self-antigens. This civil war remains underway, showing no mercy and taking no captives, eventually leading to irreversible pathological changes in the human body. Research that has emerged during the last two decades has given us hope that we may have a chance to overcome autoimmune diseases using a variety of techniques to "reset" the immune system. In this report, we summarize recent advances in utilizing short polypeptides - mostly fragments of autoantigens - in the treatment of autoimmune neurodegeneration.

Transgenic Expression of IL15 Improves Antiglioma Activity of IL13Rα2-CAR T Cells but Results in Antigen Loss Variants.

Glioblastoma (GBM) is the most aggressive primary brain tumor in adults and is virtually incurable with conventional therapies. Immunotherapy with T cells expressing GBM-specific chimeric antigen receptors (CAR) is an attractive approach to improve outcomes. Although CAR T cells targeting GBM antigens, such as IL13 receptor subunit α2 (IL13Rα2), HER2, and EGFR variant III (EGFRvIII), have had antitumor activity in preclinical models, early-phase clinical testing has demonstrated limited antiglioma activity. Transgenic expression of IL15 is an appealing strategy to enhance CAR T-cell effector function. We tested this approach in our IL13Rα2-positive glioma model in which limited IL13Rα2-CAR T-cell persistence results in recurrence of antigen-positive gliomas. T cells were genetically modified with retroviral vectors encoding IL13Rα2-CARs or IL15 (IL13Rα2-CAR.IL15 T cells). IL13Rα2-CAR.IL15 T cells recognized glioma cells in an antigen-dependent fashion, had greater proliferative capacity, and produced more cytokines after repeated stimulations in comparison with IL13Rα2-CAR T cells. No autonomous IL13Rα2-CAR.IL15 T-cell proliferation was observed; however, IL15 expression increased IL13Rα2-CAR T-cell viability in the absence of exogenous cytokines or antigen. In vivo, IL13Rα2-CAR.IL15 T cells persisted longer and had greater antiglioma activity than IL13Rα2-CAR T cells, resulting in a survival advantage. Gliomas recurring after 40 days after T-cell injection had downregulated IL13Rα2 expression, indicating that antigen loss variants occur in the setting of improved T-cell persistence. Thus, CAR T cells for GBM should not only be genetically modified to improve their proliferation and persistence, but also to target multiple antigens.Summary: Glioblastoma responds imperfectly to immunotherapy. Transgenic expression of IL15 in T cells expressing CARs improved their proliferative capacity, persistence, and cytokine production. The emergence of antigen loss variants highlights the need to target multiple tumor antigens. Cancer Immunol Res; 5(7); 571-81. ©2017 AACR.

CD8(+) T-cell pathogenicity in Rasmussen encephalitis elucidated by large-scale T-cell receptor sequencing.

Rasmussen encephalitis (RE) is a rare paediatric epilepsy with uni-hemispheric inflammation and progressive neurological deficits. To elucidate RE immunopathology, we applied T-cell receptor (TCR) sequencing to blood (n=23), cerebrospinal fluid (n=2) and brain biopsies (n=5) of RE patients, and paediatric controls. RE patients present with peripheral CD8(+) T-cell expansion and its strength correlates with disease severity. In addition, RE is the only paediatric epilepsy with prominent T-cell expansions in the CNS. Consistently, common clones are shared between RE patients, who also share MHC-I alleles. Public RE clones share Vß genes and length of the CDR3. Rituximab/natalizumab/basiliximab treatment does not change TCR diversity, stem cell transplantation replaces the TCR repertoire with minimal overlap between donor and recipient, as observed in individual cases. Our study supports the hypothesis of an antigen-specific attack of peripherally expanded CD8(+) lymphocytes against CNS structures in RE, which might be ameliorated by restricting access to the CNS.

Current status of immunotherapy.

The successful use of immune checkpoint inhibitors has been big breakthrough in the development of cancer immunotherapy. Anti-CTLA-4 monoclonal antibody, ipilimumab, is the first-approved immune checkpoint inhibitor and has shown durable objective responses for advanced melanoma beyond the effect of dacarbazine. Anti-PD-1 monoclonal antibodies, nivolumab and pembrolizumab, are other immune checkpoint inhibitors that have demonstrated more effective results than conventional drugs in clinical trials for a variety of advanced solid tumors including melanoma, non-small cell lung carcinoma and renal carcinoma. These studies have indicated that the enhancement of anti-cancer immunity by controlling the immune suppressive environment in cancer tissues is an important issue for the development of cancer immune-therapy. Accordingly, in recent years, the enthusiasm for research of cancer immunology has shifted to studies regarding the formation of the immune suppressive environment, immune suppression mechanisms in cancer tissues and the molecules and cells involved in these pathways. Novel findings from these studies might lead to the development of cancer immunotherapy based on control of the immune suppressive environment.

Immune Therapies in Multiple Myeloma.

Treatment paradigms have changed rapidly for multiple myeloma, and immune therapies have taken center stage. Advances in therapies for myeloma have led to a dramatic improvement in the survival of patients with this incurable malignancy. The immune system is significantly impaired in patients with myeloma as a result of the disease leading to suppression of normal plasma cells as well the negative effects on cellular immunity. Given this scenario, immune approaches have not been successful until recently. Monoclonal antibodies directed against CD38 (daratumumab) and SLAMF7 (elotuzumab) are already in the clinic, and several other antibodies directed against different plasma cell antigens are under evaluation. Although immune checkpoint inhibition with PD-1 inhibitors had no clinical efficacy when the inhibitors were used as single agents, it has led to some dramatic results when the inhibitors are combined with immunomodulatory drugs such as lenalidomide and pomalidomide. Vaccination strategies have shown in vivo immune responses but no clear clinical efficacy. Newer approaches to vaccination with multiple antigens, used in combinations with immunomodulatory drugs and in the setting of minimal residual disease, have all increased possibility of this approach succeeding. Ex vivo effector cell expansion also appears to be promising and is in clinical trials. Finally, a chimeric antigen receptor T-cell approach appears to have some promise based on isolated reports of success and remains an area of intense investigation. Immune-based approaches can potentially augment or even supplant some of the current approaches and, given the low toxicity profile, may hold great potential in the early treatment of precursor-stage diseases. Clin Cancer Res; 22(22); 5453-60. ©2016 AACR SEE ALL ARTICLES IN THIS CCR FOCUS SECTION, "MULTIPLE MYELOMA MULTIPLYING THERAPIES".

Third-generation CD28/4-1BB chimeric antigen receptor T cells for chemotherapy relapsed or refractory acute lymphoblastic leukaemia: a non-randomised, open-label phase I trial protocol.

INTRODUCTION: There is no curative treatment available for patients with chemotherapy relapsed or refractory CD19+ B cells-derived acute lymphoblastic leukaemia (r/r B-ALL). Although CD19-targeting second-generation (2nd-G) chimeric antigen receptor (CAR)-modified T cells carrying CD28 or 4-1BB domains have demonstrated potency in patients with advanced B-ALL, these 2 signalling domains endow CAR-T cells with different and complementary functional properties. Preclinical results have shown that third-generation (3rd-G) CAR-T cells combining 4-1BB and CD28 signalling domains have superior activation and proliferation capacity compared with 2nd-G CAR-T cells carrying CD28 domain. The aim of the current study is therefore to investigate the safety and efficacy of 3rd-G CAR-T cells in adults with r/r B-ALL. METHODS AND ANALYSIS: This study is a phase I clinical trial for patients with r/r B-ALL to test the safety and preliminary efficacy of 3rd-G CAR-T cells. Before receiving lymphodepleting conditioning regimen, the peripheral blood mononuclear cells from eligible patients will be leukapheresed, and the T cells will be purified, activated, transduced and expanded ex vivo. On day 6 in the protocol, a single dose of 1 million CAR-T cells per kg will be administrated intravenously. The phenotypes of infused CAR-T cells, copy number of CAR transgene and plasma cytokines will be assayed for 2 years after CAR-T infusion using flow cytometry, real-time quantitative PCR and cytometric bead array, respectively. Moreover, several predictive plasma cytokines including interferon-γ, interleukin (IL)-6, IL-8, Soluble Interleukin (sIL)-2R-α, solubleglycoprotein (sgp)130, sIL-6R, Monocyte chemoattractant protein (MCP1), Macrophage inflammatory protein (MIP1)-α, MIP1-ß and Granulocyte-macrophage colony-stimulating factor (GM-CSF), which are highly associated with severe cytokine release syndrome (CRS), will be used to forecast CRS to allow doing earlier intervention, and CRS will be managed based on a revised CRS grading system. In addition, patients with grade 3 or 4 neurotoxicities or persistent B-cell aplasia will be treated with dexamethasone (10 mg intravenously every 6 hours) or IgG, respectively. Descriptive and analytical analyses will be performed. ETHICS AND DISSEMINATION: Ethical approval for the study was granted on 10 July 2014 (YLJS-2014-7-10). Written informed consent will be taken from all participants. The results of the study will be reported, through peer-reviewed journals, conference presentations and an internal organisational report. TRIAL REGISTRATION NUMBER: NCT02186860.

In vivo immunotoxicity of perfluorooctane sulfonate in BALB/c mice: Identification of T-cell receptor and calcium-mediated signaling pathway disruption through gene expression profiling of the spleen.

Perfluorooctane sulfonate (PFOS) is a persistent organic pollutant that is used worldwide and is continuously being detected in biota and the environment, thus presenting potential threats to the ecosystem and human health. Although PFOS is highly immunotoxic, its underlying molecular mechanisms remain largely unknown. The present study examined PFOS-induced immunotoxicity in the mouse spleen and explored its underlying mechanisms by gene expression profiling. Oral exposure of male BALB/c mice for three weeks followed by one-week recovery showed that a 10 mg/kg/day PFOS exposure damaged the splenic architecture, inhibited T-cell proliferation in response to mitogen, and increased the percentages of T helper (CD3(+)CD4(+)) and cytotoxic T (CD3(+)CD8(+)) cells, despite the decrease in the absolute number of these cells. A delayed type of PFOS immunotoxicity was observed, which mainly occurred during the recovery period. Global gene expression profiling of mouse spleens and QRT-PCR analyses suggest that PFOS inhibited the expression of genes involved in cell cycle regulation and NRF2-mediated oxidative stress response, and upregulated those in TCR signaling, calcium signaling, and p38/MAPK signaling pathways. Western blot analysis confirmed that the expressions of CAMK4, THEMIS, and CD3G, which were involved in the upregulated pathways, were induced upon PFOS exposure. Acute PFOS exposure modulated calcium homoeostasis in splenocytes. These results indicate that PFOS exposure can activate TCR signaling and calcium ion influx, which provides a clue for the potential mechanism of PFOS immunotoxicity. The altered signaling pathways by PFOS treatment as revealed in the present study might facilitate in better understanding PFOS immunotoxicity and explain the association between immune disease and PFOS exposure.

Radiation and dual checkpoint blockade activate non-redundant immune mechanisms in cancer.

Immune checkpoint inhibitors result in impressive clinical responses, but optimal results will require combination with each other and other therapies. This raises fundamental questions about mechanisms of non-redundancy and resistance. Here we report major tumour regressions in a subset of patients with metastatic melanoma treated with an anti-CTLA4 antibody (anti-CTLA4) and radiation, and reproduced this effect in mouse models. Although combined treatment improved responses in irradiated and unirradiated tumours, resistance was common. Unbiased analyses of mice revealed that resistance was due to upregulation of PD-L1 on melanoma cells and associated with T-cell exhaustion. Accordingly, optimal response in melanoma and other cancer types requires radiation, anti-CTLA4 and anti-PD-L1/PD-1. Anti-CTLA4 predominantly inhibits T-regulatory cells (Treg cells), thereby increasing the CD8 T-cell to Treg (CD8/Treg) ratio. Radiation enhances the diversity of the T-cell receptor (TCR) repertoire of intratumoral T cells. Together, anti-CTLA4 promotes expansion of T cells, while radiation shapes the TCR repertoire of the expanded peripheral clones. Addition of PD-L1 blockade reverses T-cell exhaustion to mitigate depression in the CD8/Treg ratio and further encourages oligoclonal T-cell expansion. Similarly to results from mice, patients on our clinical trial with melanoma showing high PD-L1 did not respond to radiation plus anti-CTLA4, demonstrated persistent T-cell exhaustion, and rapidly progressed. Thus, PD-L1 on melanoma cells allows tumours to escape anti-CTLA4-based therapy, and the combination of radiation, anti-CTLA4 and anti-PD-L1 promotes response and immunity through distinct mechanisms.