Sleep-deprivation reduces NK cell number and function mediated by β-adrenergic signalling

Pre-existing sleep disturbances and risk of COVID-19: a meta-analysis

Background

Sleep disturbances are widespread but usually overlooked health risk factors for coronavirus disease 2019 (COVID-19). We aimed to investigate the influence of pre-existing sleep disturbances on the susceptibility, severity, and long-term effects of COVID-19.

Methods

We searched PubMed, Web of Science, and Embase for relevant articles from inception to October 27, 2023 and updated at May 8, 2024. Sleep disturbances included obstructive sleep apnea (OSA), insomnia, abnormal sleep duration, night-shift work, and any other sleep disturbances. Outcomes were COVID-19 susceptibility, hospitalization, mortality, and long COVID. The effect sizes were pooled odds ratios (ORs) and 95% confidence intervals (95% CIs). This study is registered with PROSPERO (CRD42024503518).

Findings

A total of 48 observational studies (n = 8,664,026) were included. Pre-existing sleep disturbances increased the risk of COVID-19 susceptibility (OR = 1.12, 95% CI 1.07-1.18), hospitalization (OR = 1.25, 95% CI 1.15-1.36), mortality (OR = 1.45, 95% CI 1.19-1.78), and long COVID (OR = 1.36 95% CI 1.17-1.57). Subgroup analysis showed that younger individuals with sleep disturbances were associated with higher susceptibility and hospitalization and a lower risk of mortality than older individuals. Males with sleep disturbances were associated with higher mortality. For specific sleep disturbances, the susceptibility and hospitalization of COVID-19 were associated with OSA, abnormal sleep duration, and night-shift work; mortality of COVID-19 was linked to OSA; risk of long COVID was related to OSA, abnormal sleep duration and insomnia.

Interpretation

Pre-existing sleep disturbances, especially OSA, increased the risk of COVID-19 susceptibility, hospitalization, mortality, and long COVID. Age and sex played important roles in the effect of sleep disturbances on COVID-19.

Funding

The National Natural Science Foundation of China and the Key Laboratory of Respiratory Diseases of Liaoning Province.

Surgical stress induced tumor immune suppressive environment

Despite significant advances in cancer treatment over the decades, surgical resection remains a prominent management approach for solid neoplasms. Unfortunately, accumulating evidence suggests that surgical stress caused by tumor resection may potentially trigger postoperative metastatic niche formation. Surgical stress not only activates the sympathetic-adrenomedullary axis and hypothalamic-pituitary-adrenocortical axis but also induces hypoxia and hypercoagulable state. These adverse factors can negatively impact the immune system by downregulating immune effector cells and upregulating immune suppressor cells, which contribute to the colonization and progression of postoperative tumor metastatic niche. This review summarizes the effects of surgical stress on four types of immune effector cells (neutrophils, macrophages, natural killer cells and cytotoxic T lymphocytes) and two types of immunosuppressive cells (regulatory T cells and myeloid-derived suppressor cells), and discusses the immune mechanisms of postoperative tumor relapse and progression. Additionally, relevant therapeutic strategies to minimize the pro-tumorigenic effects of surgical stress are elucidated.

The Function of the Immune System, Beyond Strategies Based on Cell-Autonomous Mechanisms, Determines Cancer Development: Immune Response and Cancer Development

Although cancer remains a challenging disease to treat, early detection and removal of primary tumors through surgery or chemotherapy/radiotherapy can offer hope for patients. The privilege paradigm in cancer biology suggests that cell-autonomous mechanisms play a central role in tumorigenesis. According to this paradigm, these cellular mechanisms are the primary focus for the prevention and treatment of cancers. However, this point of view does not present a comprehensive theory for the initiation of cancer and an effective therapeutic strategy. Having an incomplete understanding of the etiology of cancer, it is essential to re-examine previous assumptions about carcinogenesis and develop new, practical theories that can account for all available clinical and experimental evidence. This will not only help to gain a better understanding of the disease, but also offer new avenues for treatment. This review provides evidence suggesting a shift in focus from a cell-autonomous mechanism to systemic mechanisms, particularly the immune system, that are involved in cancer formation.

Natural killer cells immunosenescence and the impact of lifestyle management

Natural killer cells (NKs) are lymphocytes of the innate immune system that quickly respond to viruses, infections, and tumors during their short cell life cycle. However, it was recently found that NKs undergo quantitative, distributional, structural, and functional phenotypic changes during aging that suppress immune responses, which is known as immunosenescence. The aging host environment, cytokine regulation, cytomegalovirus status, and hypothalamic‒pituitary‒adrenal axis have significant effects on NK function. Different lifestyle management interventions modulate the number and cytotoxic activity of NKs, which are essential for rebuilding the immune barrier against pathogens in elderly individuals. Based on recent studies, we review the phenotypic changes of and potential threats of NKs during aging and explore the underlying mechanisms. By summarizing the effects of lifestyle management on NKs and their application prospects, we aim to provide evidence for enhancing immune system function against immune diseases in elderly individuals.

Targeting adrenergic receptors to mitigate invariant natural killer T cells-induced acute liver injury

Invariant Natural Killer T (iNKT) cell activation by α-galactosylceramide (αGC) potentiates cytotoxic immune responses against tumors. However, αGC-induced liver injury is a limiting factor for iNKT-based immunotherapy. Although adrenergic receptor stimulation is an important immunosuppressive signal that curbs tissue damage induced by inflammation, its effect on the antitumor activity of invariant Natural Killer T (iNKT) cells remains unclear. We use mouse models and pharmacological tools to show that the stimulation of the sympathetic nervous system (SNS) inhibits αGC-induced liver injury without impairing iNKT cells' antitumoral functions. Mechanistically, SNS stimulation prevents the collateral effect of TNF-α production by iNKT cells and neutrophil accumulation in hepatic parenchyma. Our results suggest that the modulation of the adrenergic signaling can be a complementary approach to αGC-based immunotherapy to mitigate iNKT-induced liver injury without compromising its antitumoral activity.

The need to promote sleep health in public health agendas across the globe

Healthy sleep is essential for physical and mental health, and social wellbeing; however, across the globe, and particularly in developing countries, national public health agendas rarely consider sleep health. Sleep should be promoted as an essential pillar of health, equivalent to nutrition and physical activity. To improve sleep health across the globe, a focus on education and awareness, research, and targeted public health policies are needed. We recommend developing sleep health educational programmes and awareness campaigns; increasing, standardising, and centralising data on sleep quantity and quality in every country across the globe; and developing and implementing sleep health policies across sectors of society. Efforts are needed to ensure equity and inclusivity for all people, particularly those who are most socially and economically vulnerable, and historically excluded.

Circadian disruption: from mouse models to molecular mechanisms and cancer therapeutic targets

The circadian clock is a timekeeping system for numerous biological rhythms that contribute to the regulation of numerous homeostatic processes in humans. Disruption of circadian rhythms influences physiology and behavior and is associated with adverse health outcomes, especially cancer. However, the underlying molecular mechanisms of circadian disruption-associated cancer initiation and development remain unclear. It is essential to construct good circadian disruption models to uncover and validate the detailed molecular clock framework of circadian disruption in cancer development and progression. Mouse models are the most widely used in circadian studies due to their relatively small size, fast reproduction cycle, easy genome manipulation, and economic practicality. Here, we reviewed the current mouse models of circadian disruption, including suprachiasmatic nuclei destruction, genetic engineering, light disruption, sleep deprivation, and other lifestyle factors in our understanding of the crosstalk between circadian rhythms and oncogenic signaling, as well as the molecular mechanisms of circadian disruption that promotes cancer growth. We focused on the discoveries made with the nocturnal mouse, diurnal human being, and cell culture and provided several circadian rhythm-based cancer therapeutic strategies.

Sleep disturbance is associated with perturbations in immune-inflammatory pathways in oncology outpatients undergoing chemotherapy

OBJECTIVE/BACKGROUND

Sleep disturbance is a common problem in patients receiving chemotherapy. Purpose was to evaluate for perturbations in immune-inflammatory pathways between oncology patients with low versus very high levels of sleep disturbance.

PATIENTS/METHODS

Sleep disturbance was evaluated using the General Sleep Disturbance Scale six times over two cycles of chemotherapy. Latent profile analysis was used to identify subgroups of patients with distinct sleep disturbance profiles. Pathway impact analyses were performed in two independent samples using gene expression data obtained from RNA sequencing (n = 198) and microarray (n = 162) technologies. Fisher's combined probability test was used to identify significantly perturbed pathways between Low versus Very High sleep disturbance classes.

RESULTS

In the RNA sequencing and microarray samples, 59.1% and 51.9% of patients were in the Very High sleep disturbance class, respectively. Thirteen perturbed pathways were related to immune-inflammatory mechanisms (i.e., endocytosis, phagosome, antigen processing and presentation, natural killer cell mediated cytotoxicity, cytokine-cytokine receptor interaction, apoptosis, neutrophil extracellular trap formation, nucleotide-binding and oligomerization domain-like receptor signaling, Th17 cell differentiation, intestinal immune network for immunoglobulin A production, T-cell receptor signaling, complement and coagulation cascades, and tumor necrosis factor signaling).

CONCLUSIONS

First study to identify perturbations in immune-inflammatory pathways associated with very high levels of sleep disturbance in oncology outpatients. Findings suggest that complex immune-inflammatory interactions underlie sleep disturbance.

Impact of sleep restriction in B-1 cells activation and differentiation

B-1 lymphocytes are a subtype of B cells with functional and phenotypic features that differ from conventional B lymphocytes. These cells are mainly located in mice's pleural and peritoneal cavities and express unconventional B cell surface markers. B-1 cells participate in immunity by producing antibodies, cytokines, and chemokines and physically interacting with other immune cells. In addition, B-1 cells can differentiate into mononuclear phagocyte-like cells and phagocytize several pathogens. However, the activation and differentiation of B-1 cells are not entirely understood. It is known that several factors can influence B-1 cells, such as pathogens components and the immune response. This work aimed to evaluate the influence of chronic stress on B-1 cell activation and differentiation into phagocytes. The experimental sleep restriction was used as a stress model since the sleep alteration alters several immune cells' functions. Thus, mice were submitted to sleep restriction for 21 consecutive days, and the activation and differentiation of B-1 cells were analyzed. Our results demonstrated that B-1 cells initiated the differentiation process into mononuclear phagocytes after the period of sleep restriction. In addition, we detected a significant decrease in lymphoid lineage commitment factors (EBF, E2A, Blnk) (*P < 0.05) and an increase in the G-CSFR gene (related to the myeloid lineage commitment factor) (****P < 0.0001), as compared to control mice no submitted to sleep restriction. An increase in the co-stimulatory molecules CD80 and CD86 (**P < 0.01 and *P < 0.05, respectively) and a higher production of nitric oxide (NO) (*P < 0.05) and reactive oxygen species (ROS) (*P < 0.05) were also observed in B-1 cells from mice submitted to sleep restriction. Nevertheless, B-1 cells from sleep-restricted mice showed a significant reduction in the Toll-like receptors (TLR)-2, -6, and -9, and interleukine-10 (IL-10) cytokine expression (***P < 0.001) as compared to control. Sleep-restricted mice intraperitoneally infected withL. amazonensispromastigotes showed a reduction in the average internalized parasites (*P < 0.05) by B-1 cells. These findings suggest that sleep restriction interferes with B-1 lymphocyte activation and differentiation. In addition, b-1 cells assumed a more myeloid profile but with a lower phagocytic capacity in this stress condition.

The Nervous System as a Regulator of Cancer Hallmarks: Insights into Therapeutic Implications

Simple Summary

The nervous system communicates with the whole organism, regulating several physiological pathways. The modification of nerve activity could deregulate the state of cellular and tissue homeostasis which could drive cancer development. This paper provides the current state of knowledge, in an evidence-oriented manner, that the nervous system is able to participate in the carcinogenesis process by inducing biochemical, physiological, and cellular modifications involved in the hallmarks of cancer.

Abstract

The involvement of the nervous system in the development of cancer is controversial. Several authors have shown opinions and conflicting evidence that support the early effect of the nervous system on the carcinogenic process. For about a century, research has not been enough, questions remain open, ideas are not discarded, and although more research is still needed to answer all the questions, there is now enough evidence to support the theories and give hope of finding one more possible form of treatment. It is clear that malignant neoplasms have endogenous characteristics that allow them to establish and progress. Some of these characteristics known as hallmarks of cancer, are damage mechanisms in the pathology but necessary during other physiological processes which show some nerve dependence. The nervous system communicates with the whole organism, regulating physiological processes necessary to respond to external stimuli and for the maintenance of homeostasis. The modification of nerve activity could generate an overload and deregulate the state of cellular and tissue homeostasis; this could drive cancer development. In this review, we will address the issue in an evidence-oriented manner that supports that the nervous system is able to participate in the initial and progressive process of carcinogenesis by inducing biochemical, physiological, and cellular modifications involved in the hallmarks of cancer.

Sleep disruption induces activation of inflammation and heightens risk for infectious disease: Role of impairments in thermoregulation and elevated ambient temperature

Thermoregulation and sleep are tightly coordinated, with evidence that impairments in thermoregulation as well as increases in ambient temperature increase the risk of sleep disturbance. As a period of rest and low demand for metabolic resources, sleep functions to support host responses to prior immunological challenges. In addition by priming the innate immune response, sleep prepares the body for injury or infection which might occur the following day. However when sleep is disrupted, this phasic organization between nocturnal sleep and the immune system becomes misaligned, cellular and genomic markers of inflammation are activated, and increases of proinflammatory cytokines shift from the nighttime to the day. Moreover, when sleep disturbance is perpetuated due to thermal factors such as elevated ambient temperature, the beneficial crosstalk between sleep and immune system becomes further imbalanced. Elevations in proinflammatory cytokines have reciprocal effects and induce sleep fragmentation with decreases in sleep efficiency, decreases in deep sleep, and increases in rapid eye movement sleep, further fomenting inflammation and inflammatory disease risk. Under these conditions, sleep disturbance has additional potent effects to decrease adaptive immune response, impair vaccine responses, and increase vulnerability to infectious disease. Behavioral interventions effectively treat insomnia and reverse systemic and cellular inflammation. Further, insomnia treatment redirects the misaligned inflammatory- and adaptive immune transcriptional profiles with the potential to mitigate risk of inflammation-related cardiovascular, neurodegenerative, and mental health diseases, as well as susceptibility to infectious disease.

Control of lymph node activity by direct local innervation

The nervous system detects environmental and internal stimuli and relays this information to immune cells via neurotransmitters and neuropeptides. This is essential to respond appropriately to immunogenic threats and to support system homeostasis. Lymph nodes (LNs) act as sentinels where adaptive immune responses are generated. They are richly innervated by peripheral sympathetic and sensory nerves, which are responsible for the local secretion of neurotransmitters by sympathetic fibers, such as norepinephrine, and neuropeptides by sensory fibers, including calcitonin gene-related peptide (CGRP) and substance P. Additionally, time-of-day-dependent oscillations in nerve activity are associated with differential immune responses, suggesting a potential role for neuroimmune interactions in coordinating immunity in a circadian fashion. Here, we discuss how LN activity is controlled by local innervation.

Sleep Disruption and Cancer: Chicken or the Egg?

Sleep is a nearly ubiquitous phenomenon across the phylogenetic tree, highlighting its essential role in ensuring fitness across evolutionary time. Consequently, chronic disruption of the duration, timing, or structure of sleep can cause widespread problems in multiple physiological systems, including those that regulate energy balance, immune function, and cognitive capacity, among others. Many, if not all these systems, become altered throughout the course of cancer initiation, growth, metastatic spread, treatment, and recurrence. Recent work has demonstrated how changes in sleep influence the development of chronic diseases, including cancer, in both humans and animal models. A common finding is that for some cancers (e.g., breast), chronic disruption of sleep/wake states prior to disease onset is associated with an increased risk for cancer development. Additionally, sleep disruption after cancer initiation is often associated with worse outcomes. Recently, evidence suggesting that cancer itself can affect neuronal circuits controlling sleep and wakefulness has accumulated. Patients with cancer often report difficulty falling asleep, difficulty staying asleep, and severe fatigue, during and even years after treatment. In addition to the psychological stress associated with cancer, cancer itself may alter sleep homeostasis through changes to host physiology and via currently undefined mechanisms. Moreover, cancer treatments (e.g., chemotherapy, radiation, hormonal, and surgical) may further worsen sleep problems through complex biological processes yet to be fully understood. This results in a "chicken or the egg" phenomenon, where it is unclear whether sleep disruption promotes cancer or cancer reciprocally disrupts sleep. This review will discuss existing evidence for both hypotheses and present a framework through which the interactions between sleep and cancer can be dissociated and causally investigated.

Sleep During Oncological Treatment - A Systematic Review and Meta-Analysis of Associations With Treatment Response, Time to Progression and Survival

Introduction

Disrupted sleep and sleep-wake activity are frequently observed in cancer patients undergoing oncological treatment. These disruptions are often associated with aggravated symptom burden and diminished health-related quality of life that in turn may compromise treatment adherence and, thus, effectiveness. In addition, disrupted sleep has been linked to carcinogenic processes, which ultimately could result in worse prognostic outcomes.

Aims

Our aim was to systematically review and conduct a meta-analysis of studies examining the associations between sleep and sleep-wake activity and prognostic outcomes in cancer patients undergoing oncological treatment.

Methods

A comprehensive systematic search of English language papers was undertaken in June 2020 using PubMed, The Cochrane Library, and CINAHL. Two reviewers independently screened 4,879 abstracts. A total of 26 papers were included in the narrative review. Thirteen papers reporting hazard ratios reflecting associations between a dichotomized predictor variable (sleep) and prognostic outcomes were subjected to meta-analysis.

Results

Nineteen of the 26 eligible studies on a total of 7,092 cancer patients reported associations between poorer sleep and poorer response to treatment, shorter time to progression, and/or reduced overall survival, but were highly heterogeneous with respect to the sleep and outcome parameters investigated. Meta-analysis revealed statistically significant associations between poor self-reported sleep and reduced overall survival (HR = 1.33 [95% CI 1.09-1.62], k = 11), and shorter time to progression (HR = 1.40 [95% CI 1.23-1.59], k = 3) and between poor objectively assessed sleep and reduced overall survival (HR = 1.74 [95% CI 1.05-2.88], k = 4).

Conclusion

The current findings indicate that disturbed sleep during treatment may be a relevant behavioral marker of poor cancer prognosis. The limited number of studies, the common use of single item sleep measures, and potential publication bias highlight the need for further high quality and longitudinal studies.

Aging of the Immune System: Focus on Natural Killer Cells Phenotype and Functions

Aging is the greatest risk factor for nearly all major chronic diseases, including cardiovascular diseases, cancer, Alzheimer’s and other neurodegenerative diseases of aging. Age-related impairment of immune function (immunosenescence) is one important cause of age-related morbidity and mortality, which may extend beyond its role in infectious disease. One aspect of immunosenescence that has received less attention is age-related natural killer (NK) cell dysfunction, characterized by reduced cytokine secretion and decreased target cell cytotoxicity, accompanied by and despite an increase in NK cell numbers with age. Moreover, recent studies have revealed that NK cells are the central actors in the immunosurveillance of senescent cells, whose age-related accumulation is itself a probable contributor to the chronic sterile low-grade inflammation developed with aging (“inflammaging”). NK cell dysfunction is therefore implicated in the increasing burden of infection, malignancy, inflammatory disorders, and senescent cells with age. This review will focus on recent advances and open questions in understanding the interplay between systemic inflammation, senescence burden, and NK cell dysfunction in the context of aging. Understanding the factors driving and enforcing NK cell aging may potentially lead to therapies countering age-related diseases and underlying drivers of the biological aging process itself.

Glucocorticoids and natural killer cells: A suppressive relationship

Glucocorticoids exert their pharmacological actions by mimicking and amplifying the function of the endogenous glucocorticoid system's canonical physiological stress response. They affect the immune system at the levels of inflammation and adaptive and innate immunity. These effects are the basis for therapeutic use of glucocorticoids. Innate immunity is the body's first line of defense against disease conditions. It is relatively nonspecific and, among its mediators, natural killer(NK) cells link innate and acquired immunity. NK cell numbers are altered in patients with auto immune diseases, and research suggests that interactions between glucocorticoids and natural killer cells arecritical for successful glucocorticoid therapy. The aim of this review is to summarize these interactions while highlighting the latest and most important developments in this field. Production and release in theblood of endogenous glucocorticoids are strictly regulated by the hypothalamus-pituitary-adrenal axis. Aself-regulatory mechanism prevents excessive plasma levels of these hormones. However, exogenousstimuli such as stress, inflammation, infections, cancer, and autoimmune disease can trigger thehypothalamus-pituitary-adrenal axis response and lead to excessive systemic release of glucocorticoids.Thus, stress stimuli, such as sleep deprivation, intense exercise, depression, viral infections, andcancer, can result in release of glucocorticoids and associated immunosuppressant effects. Among theseeffects are decreases in the numbers and activities of NK cells in inflammatory and autoimmune diseases(e.g., giant cell arteritis, polymyalgia rheumatica, and familial hypogammaglobulinemia).

Potential effects of shift work on skin autoimmune diseases

Shift work is associated with systemic chronic inflammation, impaired host and tumor defense and dysregulated immune responses to harmless antigens such as allergens or auto-antigens. Thus, shift workers are at higher risk to develop a systemic autoimmune disease and circadian disruption with sleep impairment seem to be the key underlying mechanisms. Presumably, disturbances of the sleep-wake cycle also drive skin-specific autoimmune diseases, but epidemiological and experimental evidence so far is scarce. This review summarizes the effects of shift work, circadian misalignment, poor sleep, and the effect of potential hormonal mediators such as stress mediators or melatonin on skin barrier functions and on innate and adaptive skin immunity. Human studies as well as animal models were considered. We will also address advantages and potential pitfalls in animal models of shift work, and possible confounders that could drive skin autoimmune diseases in shift workers such as adverse lifestyle habits and psychosocial influences. Finally, we will outline feasible countermeasures that may reduce the risk of systemic and skin autoimmunity in shift workers, as well as treatment options and highlight outstanding questions that should be addressed in future studies.

Role of sleep deprivation in immune-related disease risk and outcomes

Modern societies are experiencing an increasing trend of reduced sleep duration, with nocturnal sleeping time below the recommended ranges for health. Epidemiological and laboratory studies have demonstrated detrimental effects of sleep deprivation on health. Sleep exerts an immune-supportive function, promoting host defense against infection and inflammatory insults. Sleep deprivation has been associated with alterations of innate and adaptive immune parameters, leading to a chronic inflammatory state and an increased risk for infectious/inflammatory pathologies, including cardiometabolic, neoplastic, autoimmune and neurodegenerative diseases. Here, we review recent advancements on the immune responses to sleep deprivation as evidenced by experimental and epidemiological studies, the pathophysiology, and the role for the sleep deprivation-induced immune changes in increasing the risk for chronic diseases. Gaps in knowledge and methodological pitfalls still remain. Further understanding of the causal relationship between sleep deprivation and immune deregulation would help to identify individuals at risk for disease and to prevent adverse health outcomes.

Non-immune Cell Components in the Gastrointestinal Tumor Microenvironment Influencing Tumor Immunotherapy

Interactions of genetic susceptibility factors, immune microenvironment, and microbial factors contribute to gastrointestinal tumorigenesis. The suppressive immune microenvironment reshaped by the tumors during gastrointestinal tumorigenesis directly contributes to T-cell depletion in tumor immunotherapy. Soluble factors secreted by tumor cells or stromal cells collectively shape the suppressive immune environment. Here, we reviewed the key factors in the gastrointestinal tumor microenvironment that influence tumor immunotherapy, focusing on the effects of fibroblasts, neuronal cells, soluble cytokines, exosomes, and the microbiome in tumor microenvironment. Research in this field has helped to identify more precise and effective biomarkers and therapeutic targets in the era of tumor immunotherapy.

The Role of Psychologic Stress in Cancer Initiation: Clinical Relevance and Potential Molecular Mechanisms

The hypothesis that the physiologic response to psychologic stress influences the initiation of cancer is highly controversial. The link between initiating stressors, the psychologic stress response, and disease is plausible, considering that the stress response is associated with defined physiologic outcomes and molecular mechanisms. In light of this, we review the clinical relevance of psychologic stress on the risk of cancer, and we propose potential molecular pathways that may link the stress response to early stages of malignant cell transformation.

Sleep Deprivation Disturbs Immune Surveillance and Promotes the Progression of Hepatocellular Carcinoma

Sleep disturbance is common in patients with cancer and is associated with poor prognosis. However, the effects of sleep deprivation (SD) on immune surveillance during the development of hepatocellular carcinoma (HC) and the underlying mechanisms are not known. This was investigated in the present study using mouse models of SD and tumorigenesis. We determined that acute and chronic sleep deprivation (CSD) altered the relative proportions of various immune cell types in blood and peripheral organs. CSD increased tumor volume and weight, an effect that was enhanced with increasing CSD time. Expression of the cell proliferation marker Ki-67 was elevated in tumor tissues, and tumor cell infiltration into adjacent muscles was enhanced by CSD. Multicolor flow cytometry analysis revealed that CSD significantly reduced the numbers of antitumor CD3+ T cells and natural killer (NK) cells and increased that of immunosuppressive CD11b+ cells infiltrating into the tumor microenvironment from the spleen via the peripheral blood. These results indicate that CSD impairs immune surveillance mechanisms and promotes immunosuppression in the tumor microenvironment to accelerate tumor growth, underscoring the importance of alleviating sleep disturbance in HC patients in order to prevent HC progression.

Cardiovascular Complications of Sleep Disorders: A Better Night's Sleep for a Healthier Heart / From Bench to Bedside

Sleep is essential to and an integral part of life and when lacking or disrupted, a multitude of mental and physical pathologies ensue, including cardiovascular (CV) disease, which increases health care costs. Several prospective studies and meta-analyses show that insomnia, short (<7h) or long (>9h) sleep and other sleep disorders are associated with an increased risk of hypertension, metabolic syndrome, myocardial infarction, heart failure, arrhythmias, CV disease risk and/or mortality. The mechanisms by which insomnia and other sleep disorders lead to increased CV risk may encompass inflammatory, immunological, neuro-autonomic, endocrinological, genetic and microbiome perturbations. Guidelines are emerging that recommend a target of >7 h of sleep for all adults >18 years for optimal CV health. Treatment of sleep disorders includes cognitive-behavioral therapy considered the mainstay of non-pharmacologic management of chronic insomnia, and drug treatment with benzodiazepine receptor agonists binding to gamma aminobutyric acid type A (benzodiazepine and non-benzodiazepine agents) and some antidepressants. However, observational studies and meta-analyses indicate an increased mortality risk of anxiolytics and hypnotics, although bias may be involved due to confounding and high heterogeneity in these studies. Nevertheless, it seems that the risk incurred by the non-benzodiazepine hypnotic agents (Z drugs) may be relatively less than the risk of anxiolytics, with evidence indicating that at least one of these agents, zolpidem, may even confer a lower risk of mortality in adjusted models. All these issues are herein reviewed.

Very-Short-Term Sleep Deprivation Slows Early Recovery of Lymphocytes in Septic Patients

Sleep plays an important role in immune function. However, the effects of very-short-term sleep deprivation on the early recovery of immune function after sepsis remain unclear. This study was conducted in the intensive care unit to investigate the effects of 2 consecutive days of sleep deprivation (SD) on lymphocyte recovery over the following few days in septic patients who were recovering from a critical illness. The patients' self-reports of sleep quality was assessed using the Richards–Campbell Sleep Questionnaire at 0 and 24 h after inclusion. The demographic, clinical, laboratory, treatment, and outcome data were collected and compared between the good sleep group and poor sleep group. We found that 2 consecutive days of SD decreased the absolute lymphocyte count (ALC) and ALC recovery at 3 days after SD. Furthermore, post-septic poor sleep decreased the plasma levels of atrial natriuretic peptide (ANP) immediately after 2 consecutive days of SD. The ANP levels at 24 h after inclusion were positively correlated with ALC recovery, the number of CD3⁺ T cells, or the number of CD3⁺ CD4⁺ cells in the peripheral blood on day 5 after inclusion. Our data suggested that very-short-term poor sleep quality could slow down lymphocyte recovery over the following few days in septic patients who were recovering from a critical illness. Our results underscore the significance of very-short-term SD on serious negative effects on the immune function. Therefore, it is suggested that continuous SD or several short-term SD with short intervals should be avoided in septic patients.

Immunosurveillance of Cancer and Viral Infections with Regard to Alterations of Human NK Cells Originating from Lifestyle and Aging

Natural killer (NK) cells are cytotoxic immune cells with an innate capacity for eliminating cancer cells and virus- infected cells. NK cells are critical effector cells in the immunosurveillance of cancer and viral infections. Patients with low NK cell activity or NK cell deficiencies are predisposed to increased risks of cancer and severe viral infections. However, functional alterations of human NK cells are associated with lifestyles and aging. Personal lifestyles, such as cigarette smoking, alcohol consumption, stress, obesity, and aging are correlated with NK cell dysfunction, whereas adequate sleep, moderate exercise, forest bathing, and listening to music are associated with functional healthy NK cells. Therefore, adherence to a healthy lifestyle is essential and will be favorable for immunosurveillance of cancer and viral infections with healthy NK cells.

Neuroimmune Interactions and Rhythmic Regulation of Innate Lymphoid Cells

The Earth’s rotation around its axis, is one of the parameters that never changed since life emerged. Therefore, most of the organisms from the cyanobacteria to humans have conserved natural oscillations to regulate their physiology. These daily oscillations define the circadian rhythms that set the biological clock for almost all physiological processes of an organism. They allow the organisms to anticipate and respond behaviorally and physiologically to changes imposed by the day/night cycle. As other physiological systems, the immune system is also regulated by circadian rhythms and while diurnal variation in host immune responses to lethal infection have been observed for many decades, the underlying mechanisms that affect immune function and health have only just started to emerge. These oscillations are generated by the central clock in our brain, but neuroendocrine signals allow the synchronization of the clocks in peripheral tissues. In this review, we discuss how the neuroimmune interactions create a rhythmic activity of the innate lymphoid cells. We highlight how the disruption of these rhythmic regulations of immune cells can disturb homeostasis and lead to the development of chronic inflammation in murine models.

Psychosocial stress and immunosuppression in cancer: what can we learn from new research?

It is generally believed that the physiological consequences of stress could contribute to poor outcomes for patients being treated for cancer. However, despite preclinical and clinical evidence suggesting that stress promotes increased cancer-related mortality, a comprehensive understanding of the mechanisms involved in mediating these effects does not yet exist. We reviewed 47 clinical studies published between 2007 and 2020 to determine whether psychosocial stress affects clinical outcomes in cancer: 6.4% of studies showed a protective effect; 44.6% showed a harmful effect; 48.9% showed no association. These data suggest that psychosocial stress could affect cancer incidence and/or mortality, but the association is unclear. To shed light on this potentially important relationship, objective biomarkers of stress are needed to more accurately evaluate levels of stress and its downstream effects. As a potential candidate, the neuroendocrine signalling pathways initiated by stress are known to affect anti-tumour immune cells, and here we summarise how this may promote an immunosuppressive, pro-tumour microenvironment. Further research must be done to understand the relationships between stress and immunity to more accurately measure how stress affects cancer progression and outcome.

The Effect of the Clenbuterol-β2-Adrenergic Receptor Agonist on the Peripheral Blood Mononuclear Cells Proliferation, Phenotype, Functions, and Reactive Oxygen Species Production in Race Horses In Vitro

Clenbuterol, the β2-adrenoceptor agonist, is gaining growing popularity because of its effects on weight loss (i.e., chemical liposuction). It is also popular in bodybuilding and professional sports, due to its effects that are similar to anabolic steroids. However, it is prohibited by anti-doping control. On the other hand, it is suggested that clenbuterol can inhibit the inflammatory process. The cells from 14 untrained and 14 well-trained race horses were collected after acute exercise and cultured with clenbuterol. The expressions of CD4, CD8, FoxP3, CD14, MHCII, and CD5 in PBMC, and reactive oxygen species (ROS) production, as well as cell proliferation, were evaluated by flow cytometry. In addition, IL-1β, IL-4, IL-6, IL-10, IL-17, INF-γ and TNF-α concentrations were evaluated by ELISA. β2-adrenoceptor stimulation leads to enhanced anti-inflammatory properties in well-trained horses, as do low doses in untrained animals. In contrast, higher clenbuterol doses create a pro-inflammatory environment in inexperienced horses. In conclusion, β2-adrenoceptor stimulation leads to a biphasic response. In addition, the immune cells are more sensitive to drug abuse in inexperienced individuals under physical training.

Grain-sized moxibustion promotes NK cell antitumour immunity by inhibiting adrenergic signalling in non-small cell lung cancer

Lung cancer is the leading cause of cancer‐related death worldwide, and non–small cell lung cancer (NSCLC) accounts for 85% of lung cancer diagnoses. As an ancient therapy, moxibustion has been used to treat cancer‐related symptoms in clinical practice. However, its antitumour effect on NSCLC remains largely unexplored. In the present study, a Lewis lung cancer (LLC) xenograft tumour model was established, and grain‐sized moxibustion (gMoxi) was performed at the acupoint of Zusanli (ST36). Flow cytometry and RNA sequencing (RNA‐Seq) were used to access the immune cell phenotype, cytotoxicity and gene expression. PK136, propranolol and epinephrine were used for natural killer (NK) cell depletion, β‐adrenoceptor blockade and activation, respectively. Results showed that gMoxi significantly inhibited LLC tumour growth. Moreover, gMoxi significantly increased the proportion, infiltration and activation of NK cells, whereas it did not affect CD4⁺ and CD8⁺ T cells. NK cell depletion reversed gMoxi‐mediated tumour regression. LLC tumour RNA‐Seq indicated that these effects might be related to the inhibition of adrenergic signalling. Surely, β‐blocker propranolol clearly inhibited LLC tumour growth and promoted NK cells, and gMoxi no longer increased tumour regression and promoted NK cells after propranolol treatment. Epinephrine could inhibit NK cell activity, and gMoxi significantly inhibited tumour growth and promoted NK cells after epinephrine treatment. These results demonstrated that gMoxi could promote NK cell antitumour immunity by inhibiting adrenergic signalling, suggesting that gMoxi could be used as a promising therapeutic regimen for the treatment of NSCLC, and it had a great potential in NK cell–based cancer immunotherapy.

Nerves in the Tumor Microenvironment: Origin and Effects

Studies have reported the vital role of nerves in tumorigenesis and cancer progression. Nerves infiltrate the tumor microenvironment thereby enhancing cancer growth and metastasis. Perineural invasion, a process by which cancer cells invade the surrounding nerves, provides an alternative route for metastasis and generation of tumor-related pain. Moreover, central and sympathetic nervous system dysfunctions and psychological stress-induced hormone network disorders may influence the malignant progression of cancer through multiple mechanisms. This reciprocal interaction between nerves and cancer cells provides novel insights into the cellular and molecular bases of tumorigenesis. In addition, they point to the potential utility of anti-neurogenic therapies. This review describes the evolving cross-talk between nerves and cancer cells, thus uncovers potential therapeutic targets for cancer.

β2-adrenergic signals downregulate the innate immune response and reduce host resistance to viral infection

In humans, psychological stress has been associated with a higher risk of infectious illness. However, the mechanisms by which the stress pathway interferes with host response to pathogens remain unclear. We demonstrate here a role for the β2-adrenergic receptor (β2-AR), which binds the stress mediators adrenaline and noradrenaline, in modulating host response to mouse cytomegalovirus (MCMV) infection. Mice treated with a β2-AR agonist were more susceptible to MCMV infection. By contrast, β2-AR deficiency resulted in a better clearance of the virus, less tissue damage, and greater resistance to MCMV. Mechanistically, we found a correlation between higher levels of IFN-γ production by liver natural killer (NK) cells and stronger resistance to MCMV. However, the control of NK cell IFN-γ production was not cell intrinsic, revealing a cell-extrinsic downregulation of the antiviral NK cell response by adrenergic neuroendocrine signals. This pathway reduces host immune defense, suggesting that the blockade of the β2-AR signaling could be used to increase resistance to infectious diseases.

Invariant Natural Killer T cells resilience to paradoxical sleep deprivation-associated stress

Although several studies demonstrate that stressful situations, such as sleep disturbances, negatively impact the innate and adaptive arms of the immune system, their influence on invariant Natural Killer T (iNKT) cells remains unclear. iNKT cells are CD1d-restricted innate T cells that recognize glycolipid antigens and rapidly produce polarizing cytokines being key players in several immune responses, and a potential target for immunotherapy. iNKT cells differ in several aspects from conventional T lymphocytes, including a unique dependence on CD1d-expressing double-positive (DP) thymocytes for intrathymic maturation. As a consequence of stress, DP thymocytes undergo glucocorticoid-induced apoptosis, which might compromise iNKT developmental pathway. Therefore, we used a paradoxical sleep deprivation (SD) model to determine the impact of sleep disturbance on iNKT cell biology. After 72 h of SD, C57Bl/6 mice exhibited a significant increase in systemic glucocorticoid levels and thymus atrophy. Despite marked decrease in the number of DP thymocytes, the ratio CD1d⁺/CD1d^- was higher in SD mice, and the number of thymic iNKT cells remained unaltered, suggesting that SD did not compromise the iNKT developmental pathway. In contrast, SD reduced hepatic IFN-γ, but not, IL-4-producing iNKT cells, without further effect in the spleen. Despite this fact, SD did not affect stimulation of IFN-γ production by iNKT cells, or cytokine release, in response to α-galactosylceramide, a specific antigen. Furthermore, although SD impaired splenic NK cells activity against tumor cells, it did not affect iNKT cell-specific cytotoxicity. Thus, our study shows that SD-induced stress did not impair the iNKT cells' responses to a cognate antigen.

Sex differences in the hypothalamic-pituitary-adrenal axis response following a single or multiple days of sleep restriction

One in three adults reports experiencing inadequate or disrupted sleep throughout the night, with the incidence being higher in women than in men. Disturbances in nightly sleep result in physiological alterations that contribute to a number of disorders. Poor sleep quality is believed to contribute to the pathogenesis of these disorders through interactions with the hypothalamic-pituitary-adrenal (HPA) axis. The present study investigated the effect of one and three days of restricted sleep on HPA axis reactivity. Male and female C57BL/6J (n = 8/group) mice were sleep-deprived for a 20 h period for one day or three consecutive days using the modified multiple platform method, and then subjected to acute restraint stress. In response to sleep restriction, males showed blunted restraint-induced rises in CORT relative to controls. After three days of restricted sleep, females showed a similar attenuation in restraint-induced CORT. However, this effect was ablated after a single day of sleep restriction. Analyses of gene expression revealed significant elevations in the expression of pituitary HPA axis regulatory genes proopiomelanocortin and corticotropin releasing factor receptor 1 in both sexes following sleep restriction. In males, but not females, adrenal mRNA expression of 11β-hydroxylase and melanocortin receptor 2 were also increased. Altogether, these data suggest several possible mechanisms are involved in the HPA axis dysregulation following sleep restriction, and that there are sex differences in how the HPA axis responds to sleep loss.Lay summarySleep restriction alters the stress response differently in males and females following varying nights of sleep restriction. These alterations are accompanied by changes in gene expression in the pituitary and adrenal glands.

Propranolol Suppresses the Growth of Colorectal Cancer Through Simultaneously Activating Autologous CD8+ T Cells and Inhibiting Tumor AKT/MAPK Pathway

Propranolol suppresses tumor growth in a variety of preclinical solid tumor models, with a number of proposed cell signaling and immunological mechanisms. We want to confirm the potential mechanisms, including reduced phosphorylation of AKT/MAPK pathways, as well as enhanced CD8⁺ T-cell-mediated antitumor immune response. To clarify the mechanism of propranolol activity in colorectal cancer, the therapeutic activity of propranolol was then assessed in CT26WT tumors engrafted in BALB/C mice. Then the effect of propranolol treatment was also examined by randomizing patients undergoing surgical resection of a previously untreated colorectal cancer to propranolol or placebo group and treated for 1 week prior to surgery. CT26WT tumor size was smaller after propranolol than vehicle control. Propranolol downregulated the expression of p-AKT/p-ERK/p-MEK in tumor tissue. The frequency of tumor CD8⁺ T cells was significantly elevated in propranolol-treated mice. The expression of GzmB/IFN-γ/T-bet in the CD8⁺ T-cell population was significantly increased in propranolol treated mice tumor tissue. In propranolol-treated surgical specimens, the expression of p-ERK was decreased and the frequency of CD8⁺ was significantly elevated. The expression of GzmB in the CD8⁺ T-cell population was significantly increased in propranolol-treated subjects. Together, these data show propranolol simultaneously activating autologous CD8⁺ T cells and decreasing the expression of p-AKT/p-ERK/p-MEK in mouse tumor models, while inhibiting the expression of p-ERK in clinical colorectal cancer. Effort is now needed to further dissect whether both pathways are required for antitumor effect, as the activity of this old drug is moved forward.

Sleep deprivation and stress: a reciprocal relationship

Sleep is highly conserved across evolution, suggesting vital biological functions that are yet to be fully understood. Animals and humans experiencing partial sleep restriction usually exhibit detrimental physiological responses, while total and prolonged sleep loss could lead to death. The perturbation of sleep homeostasis is usually accompanied by an increase in hypothalamic–pituitary–adrenal (HPA) axis activity, leading to a rise in circulating levels of stress hormones (e.g. cortisol in humans, corticosterone in rodents). Such hormones follow a circadian release pattern under undisturbed conditions and participate in the regulation of sleep. The investigation of the consequences of sleep deprivation, from molecular changes to behavioural alterations, has been used to study the fundamental functions of sleep. However, the reciprocal relationship between sleep and the activity of the HPA axis is problematic when investigating sleep using traditional sleep-deprivation protocols that can induce stress per se. This is especially true in studies using rodents in which sleep deprivation is achieved by exogenous, and potentially stressful, sensory–motor stimulations that can undoubtedly confuse their conclusions. While more research is needed to explore the mechanisms underlying sleep loss and health, avoiding stress as a confounding factor in sleep-deprivation studies is therefore crucial. This review examines the evidence of the intricate links between sleep and stress in the context of experimental sleep deprivation, and proposes a more sophisticated research framework for sleep-deprivation procedures that could benefit from recent progress in biotechnological tools for precise neuromodulation, such as chemogenetics and optogenetics, as well as improved automated real-time sleep-scoring algorithms.

Relationship between rosacea and sleep

Rosacea is a chronic facial skin disease involved in neurovascular dysregulation and neurogenic inflammation. Behavioral factors such as stress, anxiety, depression and sleep were identified to be associated with other inflammatory skin diseases. Few studies have reported sleep status in rosacea. Aiming to investigate the relationship between rosacea and sleep, a case-control survey was conducted, enrolling 608 rosacea patients and 608 sex- and age-matched healthy controls. Sleep quality was assessed through the Pittsburgh Sleep Quality Index (PSQI) questionnaire. Diagnosis and severity grading of rosacea were evaluated under the standard guidelines of the National Rosacea Society. More rosacea patients (52.3%, n = 318) suffered poor sleep quality (PSQI, >5) than the healthy controls (24.0%, n = 146), displaying a much higher PSQI score (rosacea vs control, 6.20 vs 3.95). There was a strong association between sleep quality and rosacea (odds ratio [OR], 3.525; 95% confidence interval [CI], 2.759-4.519). Moreover, the severity of rosacea was also associated with sleep quality (OR, 1.847; 95% CI, 1.332-2.570). Single nucleotide polymorphisms in hydroxytryptamine receptor 2A and adrenoceptor-β1 genes, which are associated with sleep behaviour, were detected and revealed to be associated with rosacea. Furthermore, the LL-37-induced rosacea-like phenotype and sleep-deprivation mice models were applied, revealing that sleep deprivation aggravated the rosacea-like phenotype in mice, with higher expression of matrix metallopeptidase 9, Toll-like receptor 2, cathelicidin antimicrobial peptide and vascular endothelial growth factor. In conclusion, rosacea patients presented poorer sleep quality, as well as a higher propability of genetic background with sleep disturbance. In addition, poor sleep might aggravate rosacea through regulating inflammatory factors, contributing to a vicious cycle in the progression of disease.

Sleep and inflammation: partners in sickness and in health

The discovery of reciprocal connections between the central nervous system, sleep and the immune system has shown that sleep enhances immune defences and that afferent signals from immune cells promote sleep. One mechanism by which sleep is proposed to provide a survival advantage is in terms of supporting a neurally integrated immune system that might anticipate injury and infectious threats. However, in modern times, chronic social threats can drive the development of sleep disturbances in humans, which can contribute to the dysregulation of inflammatory and antiviral responses. In this Review, I describe our current understanding of the relationship between sleep dynamics and host defence mechanisms, with a focus on cytokine responses, the neuroendocrine and autonomic pathways that connect sleep with the immune system and the role of inflammatory peptides in the homeostatic regulation of sleep. Furthermore, I discuss the therapeutic potential of harnessing these reciprocal mechanisms of sleep-immune regulation to mitigate the risk of inflammatory and infectious diseases.

Transportation and Routine Veterinary Interventions Alter Immune Function in the Dog

Rapid activation of the hypothalamic pituitary adrenal axis and the sympathetic nervous system are hallmarks of the acute stress response and these systems interact with the immune system by signaling though glucocorticoid and adrenergic receptors on immune cells. There is limited information about the effect of these physiologic responses on immunologic parameters of pet dogs enrolled in clinical studies. The objective of this study was to evaluate how travel, instrumentation, and hospitalization alter immunologic parameters in pet dogs. Blood was collected from healthy dogs in a home environment and from healthy dogs at the time of presentation to the hospital and after instrumentation and 24 hours of hospitalization. We found that lipopolysaccharide (LPS)-induced downregulation of toll like receptor 4 (TLR4) was blunted in dogs exposed to stress. Neutrophil and monocyte major histocompatibility complex class II (MHCII) expression increased after transportation to the veterinary hospital but then became similar to that of the control dogs at the end of hospitalization. Peripheral blood mononuclear cell cytotoxicity function was blunted in dogs exposed to the stress of transportation as well as hospitalization. Neutrophil apoptosis was greater in dogs exposed to stress compared to controls although this effect significantly decreased after hospitalization stress. Conversely, stress did not alter induced or spontaneous cytokine production from leukocytes, neutrophil or monocyte expression of TLR4, LPS-induced downregulation of monocyte TLR4, LPS-induced neutrophil and monocyte expression of MHCII or peripheral blood lymphocyte phenotype. Transportation and instrumentation/hospitalization stress should be considered when interpreting immunologic studies in pet dogs.

The Sleep-Immune Crosstalk in Health and Disease

Sleep and immunity are bidirectionally linked. Immune system activation alters sleep, and sleep in turn affects the innate and adaptive arm of our body's defense system. Stimulation of the immune system by microbial challenges triggers an inflammatory response, which, depending on its magnitude and time course, can induce an increase in sleep duration and intensity, but also a disruption of sleep. Enhancement of sleep during an infection is assumed to feedback to the immune system to promote host defense. Indeed, sleep affects various immune parameters, is associated with a reduced infection risk, and can improve infection outcome and vaccination responses. The induction of a hormonal constellation that supports immune functions is one likely mechanism underlying the immune-supporting effects of sleep. In the absence of an infectious challenge, sleep appears to promote inflammatory homeostasis through effects on several inflammatory mediators, such as cytokines. This notion is supported by findings that prolonged sleep deficiency (e.g., short sleep duration, sleep disturbance) can lead to chronic, systemic low-grade inflammation and is associated with various diseases that have an inflammatory component, like diabetes, atherosclerosis, and neurodegeneration. Here, we review available data on this regulatory sleep-immune crosstalk, point out methodological challenges, and suggest questions open for future research.

Translation of cancer immunotherapy from the bench to the bedside

The tremendous success of immune checkpoint blockades has revolutionized cancer management. Our increased understanding of the cell types that compose the tumor microenvironment (TME), including those of the innate and adaptive immune system, has helped to shape additional immune modulatory strategies in cancer care. Pre-clinical and clinical investigations targeting novel checkpoint interactions and key pathways that regulate cancer immunity continue to increase rapidly. Various combinatorial drug regimens are being tested in attempt to achieve durable response and survival rates of patients with cancer. This review provides an overview of specific components of the TME, an introduction to novel immune checkpoints, followed by a survey of present day and future combination immune modulatory therapies. The idea that the immune system can recognize and destroy tumor cells was first described in the cancer immunosurveillance hypothesis of Burnet and Thomas. However, early experimental evidence failed to support the concept. It was not until the late 1990s when seminal papers clearly showed the existence of cancer immunosurveillance, leading to the cancer immunoediting hypothesis. In this century, progress in the understanding of negative regulators of the immune response led to the discovery that inhibition of these regulators in patients with cancer could lead to dramatic and durable remissions. Drs. Tasuku Honjo and James P. Allison were awarded the Nobel Prize in 2018 for their pioneering work in this field. We now see rapid advances in cancer immunology and emerging effective therapies revolutionizing cancer care across tumor types in the clinic, while pre-clinical research is moving from a focus on the malignant cells themselves to dissect the highly heterogenic and complex multi-cellular tumor microenvironment (TME).

Physiological Regulation of Innate Lymphoid Cells

Discovery of innate lymphoid cells (ILCs) have provoked a paradigm shift in our understanding of the immune protection. Their constitutive presence and activity at the body's barrier surfaces ensure the maintenance of the tissue homeostasis and immune protection. This complex family has distinct and non-redundant functions that can have both beneficial and detrimental effects on disease outcome. The capacity of ILCs to perform their function effectively relies on their ability to sense and integrate intrinsic and extrinsic signals. Recent studies have shown that ILCs are not only sensitive to pathogen-derived stimuli but are also very well equipped to sense host-derived signals such as neuropeptides, hormones, and metabolites. The integration of these signals represents a complex and constant cross-talk between the immune system and the physiological systems of the body, including the nervous, endocrine, digestive, and reproductive systems. The physiological regulation of ILCs constitutes an important step in our understanding of the events leading to the protective and pathological properties of these cells. This review summarizes the recent advances in the understanding of the regulation of ILCs by physiological signals and their consequences on the maintenance of tissue homeostasis.

Sensing of physiological regulators by innate lymphoid cells

Maintenance of homeostasis and immune protection rely  on the coordinated action of different physiological systems. Bidirectional communication between the immune system and physiological systems is required to sense and restore any disruption of equilibrium. Recent transcriptomic analyses of innate lymphoid cells (ILCs) from different tissues have revealed that ILCs express a large array of receptors involved in the recognition of neuropeptides, hormones and metabolic signals. ILCs rapidly secrete effector cytokines that are central in the development and activation of early immune responses, but they also constitutively secrete mediators that are important for tissue homeostasis. To achieve these functions effectively, ILCs integrate intrinsic and extrinsic signals that modulate their constitutive and induced activity. Disruption of the regulation of ILCs by physiological regulators leads to altered immune responses with harmful consequences for the organism. An understanding of these complex interactions between the immune system and physiological mediators is crucial to decipher the events leading to the protective versus pathological effects of these cells.

Roles of sleep deprivation in cardiovascular dysfunctions

It is widely recognized that inadequate sleep is associated with multiple acute and chronic diseases and results in increased mortality and morbidity for cardiovascular diseases. In recent years, there has been increasing interest in sleep related investigations. Emerging evidence indicates that sleep deprivation changes the biological phenotypes of DNA, RNA and protein levels, but the underlying mechanisms are not clear. We summarized the current research on the detrimental roles of sleep deprivation on the heart and elucidated the underlying mechanisms of sleep deficiency to improve our understanding of sleep deprivation and the emerging strategies to target this process for therapeutic benefit.

Sleep Deprivation Alters the Pituitary Stress Transcriptome in Male and Female Mice

Poor sleep hygiene is a growing problem, with detrimental effects on many biological systems. The pituitary gland plays a crucial role in the regulation of sleep and the stress response, and its dysfunction leads to sleep-related disorders. However, the interaction between these critical functions remains unclear. Thus, we performed a comparative, whole-transcriptome, analysis to identify stress-induced genes and relevant pathways that may be affected by sleep deprivation. One day following 12 h of Paradoxical Sleep Deprivation (PSD), mice were restrained for 20 min. Gene expression changes in the pituitary were assessed via RNA-Seq and Gene Ontology in PSD and/or restrained groups compared to controls. We show that restraint triggers transcriptional responses involved in hormone secretion, the glucocorticoid response, and apoptosis in both sexes, with 285 differentially expressed genes in females and 93 in males. When PSD preceded restraint stress, the numbers of differentially expressed genes increased to 613 in females and 580 in males. The pituitary transcriptome of restraint+PSD animals was enriched for microglia and macrophage proliferation, cellular response to corticosteroids, and apoptosis, among others. Finally, we identify sex-specific differences in restraint-induced genes following PSD. These findings provide genetic targets to consider when studying sleep and the response to stress.

Bidirectional Role of β2-Adrenergic Receptor in Autoimmune Diseases

Disorder of the sympathetic nervous system (SNS) is closely related to the pathogenesis of various autoimmune diseases (ADs). Catecholamine triggered beta2-adrenergic receptor (β2-AR) signaling is important in creating a bidirectional response in the progression of ADs due to factors including diverse expression patterns, single nucleotide polymorphisms (SNPs), biased signals, and desensitization of β2-AR, as well as different subtypes of Gα binding to β2-AR. In this review, we summarize the actions of β2-AR signaling in regulating the functions of immunocytes and in the pathogenesis of ADs, and the application of β2-AR agonists or antagonists in treating major types of ADs is also discussed. We suggest that restoring the immune balance via a soft regulation of the expression or activation of β2-AR is one of the promising therapeutic strategies for systematic ADs.

Adrenergic Signaling: A Targetable Checkpoint Limiting Development of the Antitumor Immune Response

An immune response must be tightly controlled so that it will be commensurate with the level of response needed to protect the organism without damaging normal tissue. The roles of cytokines and chemokines in orchestrating these processes are well known, but although stress has long been thought to also affect immune responses, the underlying mechanisms were not as well understood. Recently, the role of nerves and, specifically, the sympathetic nervous system, in regulating immune responses is being revealed. Generally, an acute stress response is beneficial but chronic stress is detrimental because it suppresses the activities of effector immune cells while increasing the activities of immunosuppressive cells. In this review, we first discuss the underlying biology of adrenergic signaling in cells of both the innate and adaptive immune system. We then focus on the effects of chronic adrenergic stress in promoting tumor growth, giving examples of effects on tumor cells and immune cells, explaining the methods commonly used to induce stress in preclinical mouse models. We highlight how this relates to our observations that mandated housing conditions impose baseline chronic stress on mouse models, which is sufficient to cause chronic immunosuppression. This problem is not commonly recognized, but it has been shown to impact conclusions of several studies of mouse physiology and mouse models of disease. Moreover, the fact that preclinical mouse models are chronically immunosuppressed has critical ramifications for analysis of any experiments with an immune component. Our group has found that reducing adrenergic stress by housing mice at thermoneutrality or treating mice housed at cooler temperatures with β-blockers reverses immunosuppression and significantly improves responses to checkpoint inhibitor immunotherapy. These observations are clinically relevant because there are numerous retrospective epidemiological studies concluding that cancer patients who were taking β-blockers have better outcomes. Clinical trials testing whether β-blockers can be repurposed to improve the efficacy of traditional and immunotherapies in patients are on the horizon.

Natural killer cell metabolism

Natural killer (NK) cells are a critical component in the innate immune response against disease. NK cell function is tightly regulated by specific cytokine and activation/inhibitory receptor signalling, leading to diverse effector responses. Like all living cells, energy metabolism is a fundamental requirement for NK cell activation and survival. There is growing evidence that distinct functional profiles of NK cells are determined by alterations to cellular metabolic pathways. In this review, we summarise current literature that has explored NK cell metabolism to provide insight into how metabolic regulation controls NK cell function. We focus on metabolism pathways induced by different NK cell stimuli, metabolic regulatory proteins, and nutrient and hormonal levels in health and disease which impact on NK cell metabolic and functional activity.