Costimulation Endows Immunotherapeutic CD8 T Cells with IL-36 Responsiveness during Aerobic Glycolysis

Extracellular CIRP co-stimulated T cells through IL6R/STAT3 in pediatric IgA vasculitis

Immunoglobulin A vasculitis (IgAV) is the most common vasculitis of childhood. Disordered immune responses play important roles in its pathogenesis, but the comprehensive immune profile of the disease and the underlying mechanisms are still largely unknown. Here we found a potential disease biomarker cold inducible RNA binding protein (CIRP) in our pediatric IgAV cohort. Serum CIRP level in these patients were elevated and positively correlated with the increased early memory (CD45RA+CD62L+CD95+) T cells revealed using multicolor flow cytometry. Immune phenotyping of the patients showed they had more activated T cells with higher IL6Ra expression. T cell culture experiment showed CIRP further activated both human CD4+ and CD8+ T cells as indicated by increased perforin secretion and phosphorylation of STAT3. Blockade of IL6Rα attenuated CIRP-induced T cell toxicity in vitro. RNA-sequencing data further supported CIRP stimulation promoted human T cell activation and migration, fueled inflammation through the JAK-STAT signaling pathway. Therefore, IL6Ra-mediated T cell activation by extracellular CIRP may contribute to pathogenesis of IgAV in children, both CIRP and IL6Ra could be new therapeutic targets for IgAV.

Floxed Il1rl2 Locus with mCherry Reporter Element Reveals Distinct Expression Patterns of the IL-36 Receptor in Barrier Tissues

IL-36 cytokines are emerging as beneficial in immunity against pathogens and cancers but can also be detrimental when dysregulated in autoimmune and autoinflammatory conditions. Interest in targeting IL-36 activity for therapeutic purposes is rapidly growing, yet many unknowns about the functions of these cytokines remain. Thus, the availability of robust research tools is essential for both fundamental basic science and pre-clinical studies to fully access outcomes of any manipulation of the system. For this purpose, a floxed Il1rl2, the gene encoding the IL-36 receptor, mouse strain was developed to facilitate the generation of conditional knockout mice. The targeted locus was engineered to contain an inverted mCherry reporter sequence that upon Cre-mediated recombination will be flipped and expressed under the control of the endogenous Il1rl2 promoter. This feature can be used to confirm knockout in individual cells but also as a reporter to determine which cells express the IL-36 receptor IL-1RL2. The locus was confirmed to function as intended and further used to demonstrate the expression of IL-1RL2 in barrier tissues. Il1rl2 expression was detected in leukocytes in all barrier tissues. Interestingly, strong expression was observed in epithelial cells at locations in direct contact with the environment such as the skin, oral mucosa, the esophagus, and the upper airways, but almost absent from epithelial cells at more inward facing sites, including lung alveoli, the small intestine, and the colon. These findings suggest specialized functions of IL-1RL2 in outward facing epithelial tissues and cells. The generated mouse model should prove valuable in defining such functions and may also facilitate basic and translational research.

Modulating Glycolysis to Improve Cancer Therapy

Cancer cells undergo metabolic reprogramming and switch to a 'glycolysis-dominant' metabolic profile to promote their survival and meet their requirements for energy and macromolecules. This phenomenon, also known as the 'Warburg effect,' provides a survival advantage to the cancer cells and make the tumor environment more pro-cancerous. Additionally, the increased glycolytic dependence also promotes chemo/radio resistance. A similar switch to a glycolytic metabolic profile is also shown by the immune cells in the tumor microenvironment, inducing a competition between the cancer cells and the tumor-infiltrating cells over nutrients. Several recent studies have shown that targeting the enhanced glycolysis in cancer cells is a promising strategy to make them more susceptible to treatment with other conventional treatment modalities, including chemotherapy, radiotherapy, hormonal therapy, immunotherapy, and photodynamic therapy. Although several targeting strategies have been developed and several of them are in different stages of pre-clinical and clinical evaluation, there is still a lack of effective strategies to specifically target cancer cell glycolysis to improve treatment efficacy. Herein, we have reviewed our current understanding of the role of metabolic reprogramming in cancer cells and how targeting this phenomenon could be a potential strategy to improve the efficacy of conventional cancer therapy.

The signaling and the metabolic differences of various CAR T cell designs

Chimeric antigen receptor (CAR) T cell therapy is introduced as an effective, rapidly evolving therapeutic to treat cancer, especially cancers derived from hematological cells, such as B cells. CAR T cell gene constructs combine a tumor-targeting device coupled to the T cell receptor (TCR) zeta chain domain with different signaling domains such as domains derived from CD28 or 4-1BB (CD137). The incorporation of each specific co-stimulatory domain targets the immunometabolic pathways of CAR T cells as well as other signaling pathways. Defining the immunometabolic and signaling pathways by which CAR T cells become and remain active, survive, and eliminate their targets may represent a huge step forward in this relatively young research field as the CAR gene can be tailored to gain optimal function also for solid tumors with elaborate immunosuppression and protective stroma. There is a close relationship between different signaling domains applied in CAR T cells, and difficult to evaluate the benefit from different tested CAR gene constructs. In this review, we attempt to collect the latest findings regarding the CAR T cell signaling pathways that affect immunometabolic pathways.

Rapid Progression of COVID-19-Associated Fatal Capillary Leak Syndrome

Several cases of capillary leak syndrome (CLS) related to COVID-19 or vaccination against SARS-CoV-2 have been described in the literature. We present a case of a 42-year-old, previously healthy male, presenting with a mild form of COVID-19, who suddenly developed severe shock with hypotension and severe hemoconcentration within hours of admission to the hospital. Volume resuscitation was not effective, increasing hemoglobin (198 g/L on admission, 222 g/L 9 h later) suggested fluid leak into peripheral tissues. After cardiac arrest, the patient was resuscitated and connected to extracorporeal membrane oxygenation, but died shortly afterwards due to refractory heart failure. Retrospective investigation of blood samples confirmed diagnosis of CLS by progressive hypoalbuminemia (40 g/L on admission, 14 g/L 19 h later) and monoclonal gammopathy kappa (4.7 g/L). Patient's CLS was triggered by COVID-19, either a first attack of idiopathic CLS called Clarkson's disease or a COVID-19-induced secondary CLS.

Metabolic modulation of immune checkpoints and novel therapeutic strategies in cancer

Cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) or programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1)-based immune checkpoint inhibitors (ICIs) have led to significant improvements in the overall survival of patients with certain cancers and are expected to benefit patients by achieving complete, long-lasting remissions and cure. However, some patients who receive ICIs either fail treatment or eventually develop immunotherapy resistance. The existence of such patients necessitates a deeper understanding of cancer progression, specifically nutrient regulation in the tumor microenvironment (TME), which includes both metabolic cross-talk between metabolites and tumor cells, and intracellular metabolism in immune and cancer cells. Here we review the features and behaviors of the TME and discuss the recently identified major immune checkpoints. We comprehensively and systematically summarize the metabolic modulation of tumor immunity and immune checkpoints in the TME, including glycolysis, amino acid metabolism, lipid metabolism, and other metabolic pathways, and further discuss the potential metabolism-based therapeutic strategies tested in preclinical and clinical settings. These findings will help to determine the existence of a link or crosstalk between tumor metabolism and immunotherapy, which will provide an important insight into cancer treatment and cancer research.

Evaluating the glycolytic potential of mouse costimulated effector CD8+ T cells ex vivo

Studying the metabolic fitness of T cells is fundamental to understand how immune responses are regulated. Here, we describe a step-by-step protocol optimized to efficiently generate and isolate effector antigen-specific CD8+ T cells ex vivo using costimulation. We also detail steps to evaluate their metabolic activity using Seahorse technology. This protocol can be used to measure the glycolytic potential of effector murine T cells in response to different manipulations, such as infections, adjuvant studies, gene editing, or metabolite supplementation. For complete details on the use and execution of this protocol, please refer to Agliano et al. (2022).

Systemic capillary leak syndrome following granulocyte colony-stimulating factor therapy in a T-lymphoblastic leukemia/lymphoma patient: a case report

Introduction

Systemic capillary leak syndrome (SCLS) is a rare and often fatal clinical entity used to describe a generalized increase in vascular permeability leading to fluid extravasation toward the interstitial compartment. SCLS could be an idiopathic disease or secondary to infections, malignancies or drugs.

Case

We present a case of presumably granulocyte colony-stimulating factor (G-CSF)-induced SCLS in a 21-year-old man diagnosed with T‑lymphoblastic leukemia/lymphoma. He received the 6th cycle (part B) of the hyper-CVAD chemotherapeutic regimen followed by the initiation of neutropenic fever prophylaxis protocol which included antibiotics and G‑CSF. In a course of hours, the patient became dyspneic, hypotensive, and edematous which required intensive care unit admission and was stabilized accordingly. In the following days the patient's anasarca progressively increased which was associated with hypoalbuminemia, hypotension and anemia with pericardial and bilateral plural effusions. As a diagnosis of exclusion augmented by the acuity of such clinical event, observed concomitantly with the administration of the prophylaxis protocol, the suspicion of G‑CSF-induced SCLS was established. Consequently, G‑CSF was discontinued and treatment with dexamethasone and intravenous immunoglobulins (IVIG) was started. The patient's condition improved significantly illustrated by hemodynamic stability in addition to improvement regarding the anasarca, hypoalbuminemia, and anemia. Follow-up scans suggest resolution of the pericardial and plural effusions.

Conclusion

SCLS remains a serios and potentially fatal complication of G‑CSF administration which should be taken into consideration, since such medication is widely utilized in oncology wards.

Interleukin-36α inhibits colorectal cancer metastasis by enhancing the infiltration and activity of CD8+ T lymphocytes

Colorectal cancer is one of the deadliest cancers, and the discovery of new diagnostic biomarkers and therapeutic targets is vital. Interleukin-36α (IL-36α) is a proinflammatory factor that can initiate the inflammatory response and promote the systemic T helper-1 (Th1) immune response. In this study, we investigated the immunological role of IL-36α in CRC. We found that IL-36α was downregulated in human CRC tissues. Patients with high IL-36α levels showed better survival and low IL-36α expression was significantly associated with greater tumor distal metastasis and TNM stage. We constructed two cell lines overexpressing IL-36α (CT26-IL-36α and HT29-IL-36α cells). In vitro assays revealed that IL-36α overexpression reduced the proliferation, migration, and invasion of CT26-IL-36α, and HT29-IL-36α cells. Using CT26-vector and CT26-IL-36α tumor mouse model and lung metastasis models, we found that IL-36α overexpression elicited a significant antitumor effect and inhibited lung metastasis in vivo. These inhibitory effects were associated with an increase in the number of CD3+CD8+ T lymphocytes within the tumor tissue as well as increased cytokine production in CD8+ T lymphocytes present in the tumor, spleen, and draining lymph nodes. Furthermore, we revealed that CT26-IL-36α cells enhanced the secretion of CXCL10 and CXCL11 from chemotactic CD8+ T lymphocytes, as compared with CT26-vector cells. Taken together, these results suggest that IL-36α is a promising therapeutic agent for targeting CRC by promoting the activation, proliferation, and tumor infiltration of T lymphocytes.

Leukemic progenitor cells enable immunosuppression and post-chemotherapy relapse via IL-36-inflammatory monocyte axis

Chemotherapy can effectively reduce the leukemic burden and restore immune cell production in most acute myeloid leukemia (AML) cases. Nevertheless, endogenous immunosurveillance usually fails to recover after chemotherapy, permitting relapse. The underlying mechanisms of this therapeutic failure have remained poorly understood. Here, we show that abnormal IL-36 production activated by NF-κB is an essential feature of mouse and human leukemic progenitor cells (LPs). Mechanistically, IL-36 directly activates inflammatory monocytes (IMs) in bone marrow, which then precludes clearance of leukemia mediated by CD8⁺ T cells and facilitates LP growth. While sparing IMs, common chemotherapeutic agents stimulate IL-36 production from residual LPs via caspase-1 activation, thereby enabling the persistence of this immunosuppressive IL-36–IM axis after chemotherapy. Furthermore, IM depletion by trabectedin, with chemotherapy and PD-1 blockade, can synergistically restrict AML progression and relapse. Collectively, these results suggest inhibition of the IL-36–IM axis as a potential strategy for improving AML treatment.

The Complex Integration of T-cell Metabolism and Immunotherapy

Immune oncology approaches of adoptive cell therapy and immune checkpoint blockade aim to activate T cells to eliminate tumors. Normal stimulation of resting T cells induces metabolic reprogramming from catabolic and oxidative metabolism to aerobic glycolysis in effector T cells, and back to oxidative metabolism in long-lived memory cells. These metabolic reprogramming events are now appreciated to be essential aspects of T-cell function and fate. Here, we review these transitions, how they are disrupted by T-cell interactions with tumors and the tumor microenvironment, and how they can inform immune oncology to enhance T-cell function against tumors. SIGNIFICANCE: T-cell metabolism plays a central role in T-cell fate yet is altered in cancer in ways that can suppress antitumor immunity. Here, we discuss challenges and opportunities to stimulate effector T-cell metabolism and improve cancer immunotherapy.

The Role of IL-36 in Infectious Diseases: Potential Target for COVID-19?

IL-36 is a member of the interleukin 1 cytokine family, which is currently experiencing a renaissance due to the growing understanding of its context-dependent roles and advances in our understanding of the inflammatory response. The immunological role of IL-36 has revealed its profound and indispensable functional roles in psoriasis, as well as in several inflammatory diseases, including inflammatory bowel disease (IBD), systemic lupus erythematosus, rheumatoid arthritis (RA) and cancer. More recently, an increasing body of evidence suggests that IL-36 plays a crucial role in viral, bacterial and fungal infections. There is a growing interest as to whether IL-36 contributes to host protective immune responses against infection as well as the potential implications of IL-36 for the development of new therapeutic strategies. In this review, we summarize the recent progress in understanding cellular expression, regulatory mechanisms and biological roles of IL-36 in infectious diseases, which suggest more specific strategies to maneuver IL-36 as a diagnostic or therapeutic target, especially in COVID-19.

Manipulating the Metabolism to Improve the Efficacy of CAR T-Cell Immunotherapy

The adoptive transfer of the chimeric antigen receptor (CAR) expressing T-cells has produced unprecedented successful results in the treatment of B-cell malignancies. However, the use of this technology in other malignancies remains less effective. In the setting of solid neoplasms, CAR T-cell metabolic fitness needs to be optimal to reach the tumor and execute their cytolytic function in an environment often hostile. It is now well established that both tumor and T cell metabolisms play critical roles in controlling the immune response by conditioning the tumor microenvironment and the fate and activity of the T cells. In this review, after a brief description of the tumoral and T cell metabolic reprogramming, we summarize the latest advances and new strategies that have been developed to improve the metabolic fitness and efficacy of CAR T-cell products.

Costimulation Induces CD4 T Cell Antitumor Immunity via an Innate-like Mechanism

Chronic exposure to tumor-associated antigens inactivates cognate T cells, restricting the repertoire of tumor-specific effector T cells. This problem was studied here by transferring TCR transgenic CD4 T cells into recipient mice that constitutively express a cognate self-antigen linked to MHC II on CD11c-bearing cells. Immunotherapeutic agonists to CD134 plus CD137, "dual costimulation," induces specific CD4 T cell expansion and expression of the receptor for the Th2-associated IL-1 family cytokine IL-33. Rather than producing IL-4, however, they express the tumoricidal Th1 cytokine IFNγ when stimulated with IL-33 or IL-36 (a related IL-1 family member) plus IL-12 or IL-2. IL-36, which is induced within B16-F10 melanomas by dual costimulation, reduces tumor growth when injected intratumorally as a monotherapy and boosts the efficacy of tumor-nonspecific dual costimulated CD4 T cells. Dual costimulation thus enables chronic antigen-exposed CD4 T cells, regardless of tumor specificity, to elaborate tumoricidal function in response to tumor-associated cytokines.

IL36 Cooperates With Anti-CTLA-4 mAbs to Facilitate Antitumor Immune Responses

Despite the great impact on long-term survival of some cancer patients, the immune checkpoint blockade (ICB) therapy is limited by its low response rates for most cancers. There is a pressing need for novel combination immunotherapies that overcome the resistance to current ICB therapies. Cytokines play a pivotal role in tumor immunotherapy by helping initiating and driving antitumor immune responses. Here, we demonstrated that, besides conventional CD4⁺ and CD8⁺ T cells, IL36 surprisingly increased the number of tumor-infiltrating regulatory T (Treg) cells in vivo and enhanced proliferation of Tregs in vitro. Administration of CTLA-4 monoclonal antibodies (mAbs) strongly enhanced IL36-stimulated antitumor activities through depletion of Tregs. In addition, a cancer gene therapy using the IL36-loaded nanoparticles in combination with CTLA-4 mAbs additively reduced lung metastasis of breast tumor cells. We further showed that the combined therapy of CTLA-4 mAbs and IL36 led to an increase in proliferation and IFN-γ production by CD4⁺ and CD8⁺ T cells when compared to single therapy with CTLA-4 mAbs or IL36. Collectively, our findings demonstrated a new combination therapy that could improve the clinical response to ICB immunotherapy for cancer.

Cell Intrinsic and Systemic Metabolism in Tumor Immunity and Immunotherapy

Immune checkpoint inhibitor (ICI) therapy has shown extraordinary promise at treating cancers otherwise resistant to treatment. However, for ICI therapy to be effective, it must overcome the metabolic limitations of the tumor microenvironment. Tumor metabolism has long been understood to be highly dysregulated, with potent immunosuppressive effects. Moreover, T cell activation and longevity within the tumor microenvironment are intimately tied to T cell metabolism and are required for the long-term efficacy of ICI therapy. We discuss in this review the intersection of metabolic competition in the tumor microenvironment, T cell activation and metabolism, the roles of tumor cell metabolism in immune evasion, and the impact of host metabolism in determining immune surveillance and ICI therapy outcomes. We also discussed the effects of obesity and calorie restriction—two important systemic metabolic perturbations that impact intrinsic metabolic pathways in T cells as well as cancer cells.

GRK2 enforces androgen receptor dependence in the prostate and prostate tumors

Metastatic tumors that have become resistant to androgen deprivation therapy represent the major challenge in treating prostate cancer. Although these recurrent tumors typically remain dependent on the androgen receptor (AR), non-AR-driven tumors that also emerge are particularly deadly and becoming more prevalent. Here, we present a new genetically engineered mouse model for non-AR-driven prostate cancer that centers on a negative regulator of G protein-coupled receptors that is downregulated in aggressive human prostate tumors. Thus, prostate-specific expression of a dominant-negative G protein-coupled receptor kinase 2 (GRK2-DN) transgene diminishes AR and AR target gene expression in the prostate, and confers resistance to castration-induced involution. Further, the GRK2-DN transgene dramatically accelerates oncogene-initiated prostate tumorigenesis by increasing primary tumor size, potentiating visceral organ metastasis, suppressing AR, and inducing neuroendocrine marker mRNAs. In summary, GRK2 enforces AR-dependence in the prostate, and the loss of GRK2 function in prostate tumors accelerates disease progression towards the deadliest stage.

IL-36 Signaling in the Tumor Microenvironment

The ability of the immune system to prevent or control the growth of tumor cells is critically dependent on inflammatory processes that lead to the activation, expansion, and recruitment of antitumor effector cells into the tumor microenvironment (TME). These processes are orchestrated by soluble cytokines produced in tissues that alarm local immune surveillance cells (such as dendritic cells, DCs) to mobilize protective antitumor immune populations (B cells, T cells). The interleukin (IL)-36 family of pro-inflammatory cytokines plays an important role in multiple disease processes, ranging from an instigator of autoimmune psoriasis to an initiator of therapeutic immune responses against tumor cells. This chapter will focus on the biologic role of immunomodulatory IL-36 family cytokines in the cancer setting and their potential utility in the design of effective interventional therapies. (127 words).

IL-36β Promotes CD8+ T Cell Activation and Antitumor Immune Responses by Activating mTORC1

Cytokine-amplified functional CD8⁺ T cells ensure effective eradication of tumors. Interleukin 36α (IL-36α), IL-36β, and IL-36γ share the same receptor complex, composed of the IL-36 receptor (IL-36R), and IL-1RAcP. Recently, we revealed that IL-36γ greatly promoted CD8⁺ T cell activation, contributing to antitumor immune responses. However, the underlying mechanism of IL-36-mediated CD8⁺ T cell activation remains understood. In the current study, we proved that IL-36β had the same effect on CD8⁺ T cell as IL-36γ, and uncovered that IL-36β significantly activated mammalian target of rapamycin complex 1 (mTORC1) of CD8⁺ T cells. When mTORC1 was inhibited by rapamycin, IL-36β-stimulated CD8⁺ T cell activation and expansion was drastically downregulated. Further, we elucidated that IL-36β-mediated mTORC1 activation was dependent on the pathway of phosphatidylinositol 3 kinase (PI3K)/Akt, IκB kinase (IKK) and myeloid differentiation factor 88 (MyD88). Inhibition of PI3K or IKK by inhibitor, or deficiency of MyD88, respectively, suppressed mTORC1 signal, causing arrest of CD8⁺ T cell activation. Additionally, it was validated that IL-36β significantly promoted mTORC1 activation and antitumor function of CD8⁺ tumor-infiltrating lymphocytes (TILs) in vivo, resulting in inhibition of tumor growth and prolongation of survival of tumor-bearing mice. Taken together, we substantiated that IL-36β could promote CD8⁺ T cell activation through activating mTORC1 dependent on PI3K/Akt, IKK and MyD88 pathways, leading to enhancement of antitumor immune responses, which laid the foundations for applying IL-36β into tumor immunotherapy.

A mathematical model of combined CD8 T cell costimulation by 4-1BB (CD137) and OX40 (CD134) receptors

Combined agonist stimulation of the TNFR costimulatory receptors 4-1BB (CD137) and OX40(CD134) has been shown to generate supereffector CD8 T cells that clonally expand to greater levels, survive longer, and produce a greater quantity of cytokines compared to T cells stimulated with an agonist of either costimulatory receptor individually. In order to understand the mechanisms for this effect, we have created a mathematical model for the activation of the CD8 T cell intracellular signaling network by mono- or dual-costimulation. We show that supereffector status is generated via downstream interacting pathways that are activated upon engagement of both receptors, and in silico simulations of the model are supported by published experimental results. The model can thus be used to identify critical molecular targets of T cell dual-costimulation in the context of cancer immunotherapy.

Activated T-effector seeds: cultivating atherosclerotic plaque through alternative activation

Atherosclerosis is a chronic inflammatory pathology that precipitates substantial morbidity and mortality. Although initiated by physiological patterns of low and disturbed flow that differentially prime endothelial cells at sites of vessel branch points and curvature, the chronic, smoldering inflammation of atherosclerosis is accelerated by comorbidities involving inappropriate activation of the adaptive immune system, such as autoimmunity. The innate contributions to atherosclerosis, especially in the transition of monocyte to lipid-laden macrophage, are well established, but the mechanisms underpinning the infiltration, persistence, and effector dynamics of CD8 T cells in particular are not well understood. Adaptive immunity is centered on a classical cascade of antigen recognition and activation, costimulation, and effector cytokine secretion upon recall of antigen. However, chronic inflammation can generate alternative cues that supplant this behavior pattern and promote the retention and activation of peripherally activated T cells. Furthermore, the atherogenic foci that activated immune cell infiltrate are unique lipid-laden environments that offer a diverse array of stimuli, including those of survival, antigen hyporesponsiveness, and inflammatory cytokine expression. This review will focus on how known cardiovascular comorbidities may be influencing CD8 T-cell activation and how, once infiltrated within atherogenic foci, these T cells face a multitude of cues that skew the classical cascade of T-cell behavior, highlighting alternative modes of activation that may help contextualize associations of autoimmunity, viral infection, and immunotherapy with cardiovascular morbidity.

Direct CD137 costimulation of CD8 T cells promotes retention and innate-like function within nascent atherogenic foci

Effector CD8 T cells infiltrate atherosclerotic lesions and are correlated with cardiovascular events, but the mechanisms regulating their recruitment and retention are not well understood. CD137 (4-1BB) is a costimulatory receptor induced on immune cells and expressed at sites of human atherosclerotic plaque. Genetic variants associated with decreased CD137 expression correlate with carotid-intimal thickness and its deficiency in animal models attenuates atherosclerosis. These effects have been attributed in part to endothelial responses to low and disturbed flow (LDF), but CD137 also generates robust effector CD8 T cells as a costimulatory signal. Thus, we asked whether CD8 T cell-specific CD137 stimulation contributes to their infiltration, retention, and IFNγ production in early atherogenesis. We tested this through adoptive transfer of CD8 T cells into recipient C57BL/6J mice that were then antigen primed and CD137 costimulated. We analyzed atherogenic LDF vessels in normolipidemic and PCSK9-mediated hyperlipidemic models and utilized a digestion protocol that allowed for lesional T-cell characterization via flow cytometry and in vitro stimulation. We found that CD137 activation, specifically of effector CD8 T cells, triggers their intimal infiltration into LDF vessels and promotes a persistent innate-like proinflammatory program. Residence of CD137⁺ effector CD8 T cells further promoted infiltration of endogenous CD8 T cells with IFNγ-producing potential, whereas CD137-deficient CD8 T cells exhibited impaired vessel infiltration, minimal IFNγ production, and reduced infiltration of endogenous CD8 T cells. Our studies thus provide novel insight into how CD137 costimulation of effector T cells, independent of plaque-antigen recognition, instigates their retention and promotes innate-like responses from immune infiltrates within atherogenic foci. NEW & NOTEWORTHY Our studies identify CD137 costimulation as a stimulus for effector CD8 T-cell infiltration and persistence within atherogenic foci, regardless of atherosclerotic-antigen recognition. These costimulated effector cells, which are generated in pathological states such as viral infection and autoimmunity, have innate-like proinflammatory programs in circulation and within the atherosclerotic microenvironment, providing mechanistic context for clinical correlations of cardiovascular morbidity with increased CD8 T-cell infiltration and markers of activation in the absence of established antigen specificity.

Immunometabolism of T cells and NK cells: metabolic control of effector and regulatory function

Metabolic flux can dictate cell fate, including immune cell effector and regulatory function. The metabolic regulation of cell function is well characterized with respect to effector, memory, and regulatory T cells. This knowledge may allow for manipulation of T cell metabolic pathways that set the stage for more effective T cell therapy. Natural Killer (NK) and T-lymphocytes have complementary roles in the defense against pathogens. However, studies of NK cell metabolism are only beginning to emerge and there is comparatively little knowledge on the metabolic regulation of NK-cell activation and effector function. Given their common lymphoid lineage, effector functions and cellular memory potential our current knowledge on T cell metabolism could inform investigation of metabolic reprogramming in NK cells. In this review, we compare the current knowledge of metabolic regulation in T cell and NK cell development, activation, effector and memory function. Commonalties in glucose transport, hypoxia-inducible factors and mTOR highlight metabolic control points in both cells types. Contrasting the glycolytic and oxidative nodes of metabolic regulation in T cells versus NK cells may provide insight into the contribution of specific immune responses to disease and promote the development of immunotherapeutic approaches targeting both innate and adaptive immune responses.

A Guide to IL-1 family cytokines in adjuvanticity

Growing awareness of the multiplicity of roles for the IL-1 family in immune regulation has prompted research exploring these cytokines in the context of vaccine-induced immunity. While tightly regulated, cytokines of the IL-1 family are normally released in response to cellular stress and in combination with other danger-/damage-associated molecular patterns (DAMPs), triggering potent local and systemic immune responses. In the context of infection or autoimmunity, engagement of IL-1 family receptors links robust innate responses to adaptive immunity. Clinical and experimental evidence has revealed that many vaccine adjuvants induce the release of one or multiple IL-1 family cytokines. The coordinated release of IL-1 family members in response to adjuvant-induced damage or cell death may be a determining factor in the transition from local inflammation to the induction of an adaptive response. Here, we analyse the effects of IL-1 family cytokines on innate and adaptive immunity with a particular emphasis on activation of antigen-presenting cells and induction of T cell-mediated immunity, and we address in detail the contribution of these cytokines to the modes of action of vaccine adjuvants including those currently approved for human use.

An Immunotherapeutic CD137 Agonist Releases Eomesodermin from ThPOK Repression in CD4 T Cells

Agonists to the TNF/TNFR costimulatory receptors CD134 (OX40) and CD137 (4-1BB) elicit antitumor immunity. Dual costimulation with anti-CD134 plus anti-CD137 is particularly potent because it programs cytotoxic potential in CD8⁺ and CD4⁺ T cells. Cytotoxicity in dual-costimulated CD4 T cells depends on the T-box transcription factor eomesodermin (Eomes), which we report is induced via a mechanism that does not rely on IL-2, in contrast to CD8⁺ CTL, but rather depends on the CD8 T cell lineage commitment transcription factor Runx3, which supports Eomes expression in mature CD8⁺ CTLs. Further, Eomes and Runx3 were indispensable for dual-costimulated CD4 T cells to mediate antitumor activity in an aggressive melanoma model. Runx3 is also known to be expressed in standard CD4 Th1 cells where it fosters IFN-γ expression; however, the CD4 T cell lineage commitment factor ThPOK represses transcription of Eomes and other CD8 lineage genes, such as Cd8a Hence, CD4 T cells can differentiate into Eomes⁺ cytotoxic CD4⁺CD8⁺ double-positive T cells by terminating ThPOK expression. In contrast, dual-costimulated CD4 T cells express Eomes, despite the continued expression of ThPOK and the absence of CD8α, indicating that Eomes is selectively released from ThPOK repression. Finally, although Eomes was induced by CD137 agonist, but not CD134 agonist, administered individually, CD137 agonist failed to induce CD134^-/- CD4 T cells to express Eomes or Runx3, indicating that both costimulatory pathways are required for cytotoxic Th1 programming, even when only CD137 is intentionally engaged with a therapeutic agonist.

Anti-inflammatory effects of octadecylamine-functionalized nanodiamond on primary human macrophages

Chronic inflammatory disorders such as rheumatoid arthritis are characterized by excessive pro-inflammatory or "M1" activation of macrophages, the primary cells of the innate immune system. Current treatments include delivery of glucocorticoids (e.g. dexamethasone - Dex), which reduce pro-inflammatory M1 behaviour in macrophages. However, these treatments have many off-target effects on cells other than macrophages, resulting in broad immunosuppression. To limit such side effects, drug-incorporated nano- and microparticles may be used to selectively target macrophages via phagocytosis, because of their roles as highly effective phagocytes in the body. In this study, surface-modified nanodiamond (ND) was explored as a platform for the delivery of dexamethasone to macrophages because of ND's rich surface chemistry, which contributes to ND's high potential as a versatile drug delivery platform. After finding that octadecylamine-functionalized nanodiamond (ND-ODA) enhanced adsorption of Dex compared to carboxylated ND, the effects of Dex, ND-ODA, and Dex-adsorbed ND-ODA on primary human macrophage gene expression were characterized. Surprisingly, even in the absence of Dex, ND-ODA had strong anti-inflammatory effects, as determined by multiplex gene expression via NanoString and by protein secretion analysis via ELISA. ND-ODA also inhibited expression of M2a markers yet increased the expression of M2c markers and phagocytic receptors. Interestingly, the adsorption of Dex to ND-ODA further increased some anti-inflammatory effects, but abrogated the effect on phagocytic receptors, compared to its individual components. Overall, the ability of ND-ODA to promote anti-inflammatory and pro-phagocytic behaviour in macrophages, even in the absence of loaded drugs, suggests its potential for use as an anti-inflammatory therapeutic to directly target macrophages through phagocytosis.

Clinical implications of the novel cytokine IL-38 expressed in lung adenocarcinoma: Possible association with PD-L1 expression

Interleukin (IL)-38, a novel member of the IL-1 cytokine family, is homologous to IL-1 receptor antagonist (IL-1Ra) and IL-36Ra, and has been reported to act as an antagonist. IL-38 expression is found in tonsil, placenta, and spleen, and recent studies suggest an association between IL-38 and autoimmune diseases. However, whether IL-38 plays a role in carcinogenesis or cancer growth is unclear. In the present study, we identified increases in IL-38 expression by immunohistochemistry in multiple types of cancer cells. In the examination of 417 surgically resected primary lung adenocarcinomas, Fisher's exact tests showed significant associations between high IL-38 expression and high tumor grades, an advanced T status, advanced N status, advanced stage, and the presence of pleural and vessel invasions. Survival analyses by the Kaplan-Meier method showed that patients with high expression of IL-38 had significantly shorter disease-free survival and shorter overall survival after surgery than patients with low expression of IL-38 (log-rank test: P = 0.0021 and P = 0.0035, respectively). Moreover, programmed cell death-ligand 1 (PD-L1)-positive cases showed higher expression of IL-38 than PD-L1-negative cases (Wilcoxon rank-sum test: P < 0.0001). In conclusion, IL-38 was expressed in tumor cells of various cancers, and IL-38 expression was associated with poor survival of lung adenocarcinoma patients. IL-38 may affect host immunity or the tumor microenvironment, and contribute to the progression of lung adenocarcinoma.

Cytokines and metabolic factors regulate tumoricidal T-cell function during cancer immunotherapy

Recent advances in cancer biology and genetics have fostered precision therapies targeting tumor-specific attributes. Immune-based therapies that elicit cytolytic T cells (CTL) specific for tumor antigens can provide therapeutic benefit to cancer patients, however, cure rates are typically low. This largely results from immunosuppressive mechanisms operating within the tumor microenvironment, many of which inflict metabolic stresses upon CTL. Conversely, immunotherapies can mitigate specific metabolic stressors. For instance, dual costimulation immunotherapy with CD134 (OX40) plus CD137 (4-1BB) agonists appears to mediate tumor control in part by engaging cytokine networks that enable infiltrating CTL to compete for limiting supplies of glucose. Future efforts combining modalities that endow CTL with complimentary metabolic advantages should improve therapeutic efficacies.

Tbet and IL-36γ cooperate in therapeutic DC-mediated promotion of ectopic lymphoid organogenesis in the tumor microenvironment

We have previously reported that direct injection of dendritic cells (DC) engineered to express the Type-1 transactivator Tbet (i.e., DC.Tbet) into murine tumors results in antitumor efficacy in association with the development of structures resembling tertiary lymphoid organs (TLO) in the tumor microenvironment (TME). These TLO contained robust infiltrates of B cells, DC, NK cells, and T cells in proximity to PNAd⁺ blood vessels; however, they were considered incomplete, since the recruited B cells failed to organize into classic germinal center-like structures. We now report that antitumor efficacy and TLO-inducing capacity of DC.Tbet-based i.t. therapy is operational in peripheral lymph node-deficient LTA^-/- mice, and that it is highly dependent upon a direct Tbet target gene product, IL-36γ/IL-1F9. Intratumoral DC.Tbet fails to provide protection to tumor-bearing IL-36R^-/- hosts, or to tumor-bearing wild-type recipient mice co-administered rmIL-1F5/IL-36RN, a natural IL-36R antagonist. Remarkably, the injection of tumors with DC engineered to secrete a bioactive form of mIL-36γ (DC.IL36γ) also initiated therapeutic TLO and slowed tumor progression in vivo. Furthermore, DC.IL36γ cells strongly upregulated their expression of Tbet, suggesting that Tbet and IL-36γ cooperate to reinforce each other's expression in DC, rendering them competent to promote TLO formation in an "immunologically normalized," therapeutic TME.

Optimal CD4 T cell priming after LPS-based adjuvanticity with CD134 costimulation relies on CXCL9 production

LPS is a powerful adjuvant, and although LPS-mediated TLR4 signaling has been exquisitely delineated, the in vivo mechanism of how TLR4 responses impact T cell priming is far less clear. Besides costimulation, TNF and type 1 IFN are dominant cytokines released after TLR4 activation and can shape T cell responses, but other downstream factors have not been examined extensively. Depending on context, we show that IFNαR1 blockade resulted in minor to major effects on specific CD4 T cell clonal expansion. To help explain these differences, it was hypothesized that IFNαR1 blockade would inhibit specific T cell migration by reducing chemokine receptor signaling, but specific CD4 T cells from IFNαR1-blocked mice were readily able to migrate in response to specific chemokines. Next, we examined downstream factors and found that type 1 IFN signaling was necessary for chemokine production, even when mice were immunized with specific Ag with LPS and CD134 costimulation. IFNαR1 signaling promoted CXCL9 and CXCL10 synthesis, suggesting that these chemokines might be involved in the LPS and CD134 costimulation response. After immunization, we show that CXCL9 blockade inhibited CD4 T cell accumulation in the liver but also in LNs, even in the presence of elevated serum IFN-β levels. Thus, whereas type 1 IFN might have direct effects on primed CD4 T cells, the downstream chemokines that play a role during migration also impact accumulation. In sum, CXCL9 production is a key benchmark for productive CD4 T cell vaccination strategies.

Unveil the mysterious mask of cytokine-based immunotherapy for melanoma

Melanoma is the leading cause of death among all skin cancers and its incidence continues to rise rapidly worldwide in the past decades. The available treatment options for melanoma remain limited despite extensive clinical research. Melanoma is an immunogenic tumor and great advances in immunology in recent decades allow for the development of immunotherapeutic agents against melanoma. In recent years, immunotherapy utilizing cytokines has been particularly successful in certain cancers and holds promise for patients with advanced melanoma. In this review, an overview of the current status and emerging perspectives on cytokine immunotherapy for melanoma are discussed in details. Such a study will be helpful to unveil the mysterious mask of cytokine-based immunotherapy for melanoma.