The effect of sex on immune cells in healthy aging: Elderly women have more robust natural killer lymphocytes than do elderly men

Expression of human Interferon Regulatory Factor 3 (IRF-3) in alveolar macrophages relates to clinical and functional traits in COPD

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is a frequent cause of morbidity and mortality. Dysregulated and enhanced immune-inflammatory responses have been described in COPD. Recent data showed impaired immune responses and, in particular, of interferon (IFNs) signaling pathway in these patients.

AIM

To evaluate in peripheral lung of COPD patients, the expression of some of the less investigated key components of the innate immune responses leading to IFN productions including: IFN-receptors (IFNAR1/IFNAR2), IRF-3 and MDA-5. Correlations with clinical traits and with the inflammatory cell profile have been assessed.

METHODS

Lung specimens were collected from 58 subjects undergoing thoracic surgery: 22 COPD patients, 21 smokers with normal lung function (SC) and 15 non-smoker controls (nSC). The expression of IFNAR1, IFNAR2, IRF-3 and MDA-5, of eosinophils and activated NK cells (NKp46+) were quantified in the peripheral lung by immunohistochemistry.

RESULTS

A significant increase of IRF-3 + alveolar macrophages were observed in COPD and SC compared with nSC subjects. However, in COPD patients, the lower the levels of IRF-3 + alveolar macrophages the lower the FEV1 and the higher the exacerbation rate. The presence of chronic bronchitis (CB) was also associated with low levels of IRF-3 + alveolar macrophages. NKp46 + cells, but not eosinophils, were increased in COPD patients compared to nSC patients (p < 0.0001).

CONCLUSIONS

Smoking is associated with higher levels of innate immune response as showed by higher levels of IRF-3 + alveolar macrophages and NKp46 + cells. In COPD, exacerbation rates, severe airflow obstruction and CB were associated with lower levels of IRF-3 expression, suggesting that innate immune responses characterize specific clinical traits of the disease.

Immunoengineering Biomaterials for Musculoskeletal Tissue Repair across Lifespan

Musculoskeletal diseases and injuries are among the leading causes of pain and morbidity worldwide. Broad efforts have focused on developing pro-regenerative biomaterials to treat musculoskeletal conditions; however, these approaches have yet to make a significant clinical impact. Recent studies have demonstrated that the immune system is central in orchestrating tissue repair and that targeting pro-regenerative immune responses can improve biomaterial therapeutic outcomes. However, aging is a critical factor negatively affecting musculoskeletal tissue repair and immune function. Hence, understanding how age affects the response to biomaterials is essential for improving musculoskeletal biomaterial therapies. This review focuses on the intersection of the immune system and aging in response to biomaterials for musculoskeletal tissue repair. The article introduces the general impacts of aging on tissue physiology, the immune system, and the response to biomaterials. Then, it explains how the adaptive immune system guides the response to injury and biomaterial implants in cartilage, muscle, and bone and discusses how aging impacts these processes in each tissue type. The review concludes by highlighting future directions for the development and translation of personalized immunomodulatory biomaterials for musculoskeletal tissue repair.

Hallmarks of sex bias in immuno-oncology: mechanisms and therapeutic implications

Sex differences are present across multiple non-reproductive organ cancers, with male individuals generally experiencing higher incidence of cancer with poorer outcomes. Although some mechanisms underlying these differences are emerging, the immunological basis is not well understood. Observations from clinical trials also suggest a sex bias in conventional immunotherapies with male individuals experiencing a more favourable response and female individuals experiencing more severe adverse events to immune checkpoint blockade. In this Perspective article, we summarize the major biological hallmarks underlying sex bias in immuno-oncology. We focus on signalling from sex hormones and chromosome-encoded gene products, along with sex hormone-independent and chromosome-independent epigenetic mechanisms in tumour and immune cells such as myeloid cells and T cells. Finally, we highlight opportunities for future studies on sex differences that integrate sex hormones and chromosomes and other emerging cancer hallmarks such as ageing and the microbiome to provide a more comprehensive view of how sex differences underlie the response in cancer that can be leveraged for more effective immuno-oncology approaches.

Sex-dependent differences in type I IFN-induced natural killer cell activation

Natural killer (NK) cells are important antiviral effector cells and also involved in tumor clearance. NK cells express IFNAR, rendering them responsive to Type I IFNs. To evaluate Type I IFN-mediated modulation of NK cell functions, individual Type I IFNs subtypes were assessed for their ability to activate NK cells. Different Type I IFN subtypes displayed a broad range in the capacity to induce and modulate NK cell activation and degranulation, measured by CD69 and CD107a expression in response to leukemia cell line K562. When including biological sex as a variable in the analysis, transwell co-cultures of NK cells with either male- or female-derived PBMCs or pDCs stimulated with the TLR7/8 agonist CL097 showed that NK cells were more activated by CL097-stimulated cells derived from females. These sex-specific differences were linked to higher CL097-induced IFNα production by pDCs derived from females, indicating an extrinsic sex-specific effect of Type I IFNs on NK cell function. Interestingly, in addition to the extrinsic effect, we also observed NK cell-intrinsic sex differences, as female NK cells displayed higher activation levels after IFNα-stimulation and after co-culture with CL097-stimulated pDCs, suggesting higher activation of IFNα-signaling transduction in female NK cells. Taken together, the results from these studies identify both extrinsic and intrinsic sex-specific differences in Type I IFN-dependent NK cell functions, contributing to a better understanding of sex-specific differences in innate immunity.

The inter-link of ageing, cancer and immunity: findings from real-world retrospective study

BACKGROUND

Although the concept of declined immune function associated with cancer has been accepted extensively, real-world clinical studies focusing on analysis of the peripheral blood immune changes underlying ageing, immunity and cancer are scarce.

METHODS

In this case-control study, we retrospectively analysed 1375 cancer patients and enrolled 275 age and gender matched healthy individuals. Flow cytometry was conducted to assess the immune changes. Further analysis was examined by SPSS 17.0 and GraphPad Prism 9 software.

RESULTS

Cancer patients showed obviously decreased CD3+ T, CD3+CD4+ Th, CD3+CD8+ CTL, CD19+ B, CD16+CD56+ NK cell counts and lower percentage of PD-1 (programmed cell death protein-1, PD-1) positive cells than healthy control (P < 0.0001). For cancer patients, the reference range of circulating percentage of PD-1+CD45+ cells, PD-1+CD3+ T cells, PD-1+CD3+CD4+ Th cells and PD-1+CD3+CD8+ CTL (Cytotoxic T Lymphocyte, CTL) were 11.2% (95% CI 10.8%-11.6%), 15.5% (95% CI 14.7%-16.0%), 15.4% (95% CI 14.9%-16.0%) and 14.5% (95% CI 14.0%-15.5%), respectively. Moreover, the reduction of CD3+ T, CD3+CD4+ Th, CD3+CD8+ CTL, CD19+ B cell counts accompanied with age and stage advancing (P < 0.05). CD16+CD56+ NK cells decreased with stage, but elevated in aged and male cancer patients (P < 0.05). Additionally, the percentage of PD-1 positive cells varied across cancer types, raised with age and stage. Head and neck, pancreatic, gynaecological and lung demonstrated a higher level of the percentage of PD-1 positive cells than melanoma, prostate, and breast cancer (P < 0.05).

CONCLUSIONS

This study provides the reference range of the percentage of PD-1 positive cells on peripheral blood, confirms the decreased immune cells and a series of immune changes accompanying with cancer, expands our real world evidence to better understand the interactions of ageing, cancer and immunity. Moreover, the circulating percentage of PD-1 positive cells shows similar tumor type distribution with tumor mutational burden (TMB), supports that it maybe a potential predictive biomarker for immune checkpoint inhibitor therapy.

Natural killer cells and BNT162b2 mRNA vaccine reactogenicity and durability

Introduction

Natural killer (NK) cells can both amplify and regulate immune responses to vaccination. Studies in humans and animals have observed NK cell activation within days after mRNA vaccination. In this study, we sought to determine if baseline NK cell frequencies, phenotype, or function correlate with antibody responses or inflammatory side effects induced by the Pfizer-BioNTech COVID-19 vaccine (BNT162b2).

Methods

We analyzed serum and peripheral blood mononuclear cells (PBMCs) from 188 participants in the Prospective Assessment of SARS-CoV-2 Seroconversion study, an observational study evaluating immune responses in healthcare workers. Baseline serum samples and PBMCs were collected from all participants prior to any SARS-CoV-2 infection or vaccination. Spike-specific IgG antibodies were quantified at one and six months post-vaccination by microsphere-based multiplex immunoassay. NK cell frequencies and phenotypes were assessed on pre-vaccination PBMCs from all participants by multi-color flow cytometry, and on a subset of participants at time points after the 1st and 2nd doses of BNT162b2. Inflammatory side effects were assessed by structured symptom questionnaires, and baseline NK cell functionality was quantified by an in vitro killing assay on participants that reported high or low post-vaccination symptom scores.

Results

Key observations include: 1) circulating NK cells exhibit evidence of activation in the week following vaccination, 2) individuals with high symptom scores after 1st vaccination had higher pre-vaccination NK cytotoxicity indices, 3) high pre-vaccination NK cell numbers were associated with lower spike-specific IgG levels six months after two BNT162b2 doses, and 4) expression of the inhibitory marker NKG2A on immature NK cells was associated with higher antibody responses 1 and 6 months post-vaccination.

Discussion

These results suggest that NK cell activation by BNT162b2 vaccination may contribute to vaccine-induced inflammatory symptoms and reduce durability of vaccine-induced antibody responses.

Sex/gender-related differences in inflammaging

Geroscience puts mechanisms of aging as a driver of the most common age-related diseases and dysfunctions. Under this perspective, addressing the basic mechanisms of aging will produce a better understanding than addressing each disease pathophysiology individually. Worldwide, despite greater functional impairment, life expectancy is higher in women than in men. Gender differences in the prevalence of multimorbidity lead mandatory to the understanding of the mechanisms underlying gender-related differences in multimorbidity patterns and disability-free life expectancy. Extensive literature suggested that inflammaging is at the crossroad of aging and age-related diseases. In this review, we highlight the main evidence on sex/gender differences in the mechanisms that foster inflammaging, i.e. the age-dependent triggering of innate immunity, modifications of adaptive immunity, and accrual of senescent cells, underpinning some biomarkers of inflammaging that show sex-related differences. In the framework of the "gender medicine perspective", we will also discuss how sex/gender differences in inflammaging can affect sex differences in COVID-19 severe outcomes.

Use of Antiandrogens as Therapeutic Agents in COVID-19 Patients

COVID-19, caused by the severe acute respiratory syndrome coronavirus 2 (SARS CoV-2), is estimated to have caused over 6.5 million deaths worldwide. The emergence of fast-evolving SARS-CoV-2 variants of concern alongside increased transmissibility and/or virulence, as well as immune and vaccine escape capabilities, highlight the urgent need for more effective antivirals to combat the disease in the long run along with regularly updated vaccine boosters. One of the early risk factors identified during the COVID-19 pandemic was that men are more likely to become infected by the virus, more likely to develop severe disease and exhibit a higher likelihood of hospitalisation and mortality rates compared to women. An association exists between SARS-CoV-2 infectiveness and disease severity with sex steroid hormones and, in particular, androgens. Several studies underlined the importance of the androgen-mediated regulation of the host protease TMPRSS2 and the cell entry protein ACE2, as well as the key role of these factors in the entry of the virus into target cells. In this context, modulating androgen signalling is a promising strategy to block viral infection, and antiandrogens could be used as a preventative measure at the pre- or early hospitalisation stage of COVID-19 disease. Different antiandrogens, including commercial drugs used to treat metastatic castration-sensitive prostate cancer and other conditions, have been tested as antivirals with varying success. In this review, we summarise the most recent updates concerning the use of antiandrogens as prophylactic and therapeutic options for COVID-19.

Consequences of sex differences in Type I IFN responses for the regulation of antiviral immunity

The immune system protects us from pathogens, such as viruses. Antiviral immune mechanisms aim to limit viral replication, and must maintain immunological homeostasis to avoid excessive inflammation and damage to the host. Sex differences in the manifestation and progression of immune-mediated disease point to sex-specific factors modulating antiviral immunity. The exact mechanisms regulating these immunological differences between females and males are still insufficiently understood. Females are known to display stronger Type I IFN responses and are less susceptible to viral infections compared to males, indicating that Type I IFN responses might contribute to the sexual dimorphisms observed in antiviral responses. Here, we review the impact of sex hormones and X chromosome-encoded genes on differences in Type I IFN responses between females and males; and discuss the consequences of sex differences in Type I IFN responses for the regulation of antiviral immune responses.

Low-Dose Acetylsalicylic Acid Treatment in Non-Skull-Base Meningiomas: Impact on Tumor Proliferation and Seizure Burden

MIB-1 index is an important predictor of meningioma progression and was found to be correlated with COX-2 expression. However, the impact of low-dose acetylsalicylic acid (ASA) on MIB-1 index and clinical symptoms is unclear. Between 2009 and 2022, 710 patients with clinical data, tumor-imaging data, inflammatory laboratory (plasma fibrinogen, serum C-reactive protein) data, and neuropathological reports underwent surgery for primary cranial WHO grade 1 and 2 meningioma. ASA intake was found to be significantly associated with a low MIB-1 labeling index in female patients ≥ 60 years. Multivariable analysis demonstrated that female patients ≥ 60 years with a non-skull-base meningioma taking ASA had a significantly lower MIB-1 index (OR: 2.6, 95%: 1.0–6.6, p = 0.04). Furthermore, the intake of ASA was independently associated with a reduced burden of symptomatic epilepsy at presentation in non-skull-base meningiomas in both genders (OR: 3.8, 95%CI: 1.3–10.6, p = 0.03). ASA intake might have an anti-proliferative effect in the subgroup of elderly female patients with non-skull-base meningiomas. Furthermore, anti-inflammatory therapy seems to reduce the burden of symptomatic epilepsy in non-skull-base meningiomas. Further research is needed to investigate the role of anti-inflammatory therapy in non-skull-base meningiomas.

Immunosenescence, aging and successful aging

Aging induces a series of immune related changes, which is called immunosenescence, playing important roles in many age-related diseases, especially neurodegenerative diseases, tumors, cardiovascular diseases, autoimmune diseases and coronavirus disease 2019(COVID-19). However, the mechanism of immunosenescence, the association with aging and successful aging, and the effects on diseases are not revealed obviously. In order to provide theoretical basis for preventing or controlling diseases effectively and achieve successful aging, we conducted the review and found that changes of aging-related phenotypes, deterioration of immune organ function and alterations of immune cell subsets participated in the process of immunosenescence, which had great effects on the occurrence and development of age-related diseases.

Gender Differences in Urothelial Bladder Cancer: Effects of Natural Killer Lymphocyte Immunity

Men are more likely to develop cancer than women. In fact, male predominance is one of the most consistent cancer epidemiology findings. Additionally, men have a poorer prognosis and an increased risk of secondary malignancies compared to women. These differences have been investigated in order to better understand cancer and to better treat both men and women. In this review, we discuss factors that may cause this gender difference, focusing on urothelial bladder cancer (UBC) pathogenesis. We consider physiological factors that may cause higher male cancer rates, including differences in X chromosome gene expression. We discuss how androgens may promote bladder cancer development directly by stimulating bladder urothelium and indirectly by suppressing immunity. We are particularly interested in the role of natural killer (NK) cells in anti-cancer immunity.

Influence of Exercise on Exhausted and Senescent T Cells: A Systematic Review

The impaired effector function of exhausted and senescent T cells is implicated in cancer progression and inadequate vaccine responses. Exercise has been shown to improve cancer therapy and vaccine efficacy, most likely by improving immune function. However, given inconsistent terminology and definitions, the interactions between exercise and exhausted and senescent T cells remain unclear. We therefore performed a systematic review to investigate the effect of exercise on senescent and exhausted CD8⁺ T cell populations clearly defined by protein surface markers. Thirty articles were included, with the majority (n = 24) reporting senescent T cell populations defined according to a variety of surface markers. Repeated exercise was shown to be beneficial through limiting the accumulation of senescent and exhausted CD8⁺ T cells. This outcome is likely related to exercise-induced preferential mobilization of senescent T cells promoting apoptosis in the peripheral blood compartment. Future studies need to determine the clinical relevance of this effect in cancer prevention and vaccine efficacy. Data regarding exercise and exhausted T cells are limited due to a lack of available high-quality studies. Future studies require the control of confounding variables such as sex and cytomegalovirus (CMV) status, and consistent definitions of exhausted and senescent T cell populations to improve comparisons between studies and interventions.

Noninvasive Analysis Using Data-Independent Acquisition Mass Spectrometry: New Epidermal Proteins That Reveal Sex Differences in the Aging Process

The development of mass spectrometry has provided a method with extremely high sensitivity and selectivity that can be used to identify protein biomarkers. Epidermal proteins, lipids, and cornified envelopes are involved in the formation of the skin epidermal barrier. The epidermal protein composition changes with age. Therefore, quantitative proteomic changes may be indicative of skin aging. We sought to utilize data-independent acquisition mass spectrometry for noninvasive analysis of epidermal proteins in healthy Chinese individuals of different age groups and sexes. In our study, we completed high-throughput protein detection, analyzed protein differences with MaxQuant software, and performed statistical analyses of the proteome. We obtained interesting findings regarding ceruloplasmin (CP), which exhibited significant differences and is involved in ferroptosis, a signaling pathway significantly associated with aging. There were also several proteins that differed between sexes in the younger group, but the sex differences disappeared with aging. These proteins, which were associated with both aging processes and sex differences, are involved in signaling pathways such as apoptosis, oxidative stress, and genomic stability and can serve as candidate biomarkers for sex differences during aging. Our approach for noninvasive detection of epidermal proteins and its application to accurately quantify protein expression can provide ideas for future epidermal proteomics studies.

Sex-Related Differences in Drugs with Anti-Inflammatory Properties

There is increasing evidence of sex differences in the action of anti-inflammatory drugs, with women being at significantly higher risk of adverse effects. Nevertheless, clinicians' awareness of the implications of these sex differences on dosing and adverse event monitoring in routine practice is still in need of improvement. We reviewed the literature evaluating sex differences in terms of pharmacokinetics and pharmacodynamics of anti-inflammatory drugs. The anti-thrombotic activity of selective and non-selective COX-inhibitors tends to be stronger in men than women. Side effect profiles differ with regards to gastro-intestinal, renal and hepatic complications. Glucocorticosteroids were found to be more effective in men; women were more sensitive to corticosteroids when their oestradiol levels were high, a finding important for women taking hormonal contraception. TNF-alpha inhibitors have a longer half-life in men, leading to stronger immunosuppression and this a higher incidence of infections as side effects. Although research on sex differences in the effectiveness and safety of drugs is increasing, findings are often anecdotal and controversial. There is no systematic sex-differentiated reporting from clinical trials, and women are often under-represented. As personalized medicine is gaining in importance, sex, and gender aspects need to become integral parts of future research and policy making.

Macrophage function in the elderly and impact on injury repair and cancer

Older age is associated with deteriorating health, including escalating risk of diseases such as cancer, and a diminished ability to repair following injury. This rise in age-related diseases/co-morbidities is associated with changes to immune function, including in myeloid cells, and is related to immunosenescence. Immunosenescence reflects age-related changes associated with immune dysfunction and is accompanied by low-grade chronic inflammation or inflammageing. This is characterised by increased levels of circulating pro-inflammatory cytokines such as tumor necrosis factor (TNF), interleukin (IL)-1β and IL-6. However, in healthy ageing, there is a concomitant age-related escalation in anti-inflammatory cytokines such as transforming growth factor-β1 (TGF-β1) and IL-10, which may overcompensate to regulate the pro-inflammatory state. Key inflammatory cells, macrophages, play a role in cancer development and injury repair in young hosts, and we propose that their role in ageing in these scenarios may be more profound. Imbalanced pro- and anti-inflammatory factors during ageing may also have a significant influence on macrophage function and further impact the severity of age-related diseases in which macrophages are known to play a key role. In this brief review we summarise studies describing changes to inflammatory function of macrophages (from various tissues and across sexes) during healthy ageing. We also describe age-related diseases/co-morbidities where macrophages are known to play a key role, focussed on injury repair processes and cancer, plus comment briefly on strategies to correct for these age-related changes.

Age-Specific Differences in the Severity of COVID-19 Between Children and Adults: Reality and Reasons

In severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections, children experience mild symptoms compared to adults. However, the precise explanations for this disparity are not clear. Thus, we attempted to identify rational explanations about age-related differences as reported in different studies. Given the incomplete data on SARS-CoV-2, some information has been gathered from other studies of earlier coronavirus or influenza outbreaks. Age-related differences in disease severity are important with regard to diagnosis, prognosis, and treatment of SARS-CoV-2 infections. In addition, these differences impact social distancing needs, since pediatric patients with mild or asymptomatic are likely to play a significant role in disease transmission.

Sexual dimorphism in aging hematopoiesis: an earlier decline of hematopoietic stem and progenitor cells in male than female mice

Adult hematopoietic stem and progenitor cells (HSPCs) reside in the bone marrow (BM) ensuring homeostasis of blood production and immune response throughout life. Sex differences in immunocompetence and mortality are well-documented in humans. However, whether HSPCs behave dimorphically between sexes during aging remains unknown. Here, we show that a significant expansion of BM-derived HSPCs occurs in the middle age of female but in the old age of male mice. We then show that a decline of HSPCs in male mice, as indicated by the expression levels of select hematopoietic genes, occurs much earlier in the aging process than that in female mice. Sex-mismatched heterochronic BM transplantations indicate that the middle-aged female BM microenvironment plays a pivotal role in sustaining hematopoietic gene expression during aging. Furthermore, a higher concentration of the pituitary sex hormone follicle-stimulating hormone (FSH) in the serum and a concomitant higher expression of its receptor on HSPCs in the middle-aged and old female mice than age-matched male mice, suggests that FSH may contribute to the sexual dimorphism in aging hematopoiesis. Our study reveals that HSPCs in the BM niches are possibly regulated in a sex-specific manner and influenced differently by sex hormones during aging hematopoiesis.

What's Sex Got to Do With COVID-19? Gender-Based Differences in the Host Immune Response to Coronaviruses

The novel severe acute respiratory syndrome coronavirus 2, the cause of the coronavirus disease 2019 (COVID-19) pandemic, has ravaged the world, with over 22 million total cases and over 770,000 deaths worldwide as of August 18, 2020. While the elderly are most severely affected, implicating an age bias, a striking factor in the demographics of this deadly disease is the gender bias, with higher numbers of cases, greater disease severity, and higher death rates among men than women across the lifespan. While pre-existing comorbidities and social, behavioral, and lifestyle factors contribute to this bias, biological factors underlying the host immune response may be crucial contributors. Women mount stronger immune responses to infections and vaccinations and outlive men. Sex-based biological factors underlying the immune response are therefore important determinants of susceptibility to infections, disease outcomes, and mortality. Despite this, gender is a profoundly understudied and often overlooked variable in research related to the immune response and infectious diseases, and it is largely ignored in drug and vaccine clinical trials. Understanding these factors will not only help better understand the pathogenesis of COVID-19, but it will also guide the design of effective therapies and vaccine strategies for gender-based personalized medicine. This review focuses on sex-based differences in genes, sex hormones, and the microbiome underlying the host immune response and their relevance to infections with a focus on coronaviruses.

Possible protective role of 17β-estradiol against COVID-19

Severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) is the virus that causes coronavirus disease 2019 (COVID-19); a worldwide pandemic as declared by the World Health Organization (WHO). SARS-CoV-2 appears to infect cells by first binding and priming its viral-spike proteins with membrane-associated angiotensin-converting enzyme 2 (ACE2) and transmembrane protease serine 2 (TMPRSS2). Through the coordinated actions of ACE2 and TMPRSS2, SARS-CoV-2 spike proteins fuse with plasma membranes and ultimately the virus enters cells. ACE2 is integral to the renin-angiotensin-aldosterone system (RAAS), and SARS-CoV-2 down-regulates protein expression levels of ACE2. Once infected, patients typically develop acute respiratory distress syndrome (ARDS) and a number of other severe complications that result in a high rate of fatality, especially in older (>60 years) adults and in people with pre-existing medical conditions. Data now indicate clearly that among people of all age groups, COVID-19 fatalities are higher in men than women. Here, attention is focused on these sex differences and posit a role of estrogen in these differences as well as possible therapeutic and protective actions of 17β-estradiol against COVID-19.

Natural killer cell mobilization and egress following acute exercise in men with prostate cancer

NEW FINDINGS

What is the central question of this study? What are the characteristics of the NK cell response following acute moderate-intensity aerobic exercise in prostate cancer survivors and is there a relationship between stress hormones and NK cell mobilization? What is the main finding and its importance? NK cell numbers and proportions changed similarly between prostate cancer survivors and controls following acute exercise. Consecutive training sessions can likely be used without adverse effects on the immune system during prostate cancer treatment.

ABSTRACT

Prostate cancer treatment affects multiple physiological systems, although the immune response during exercise has been minimally investigated. The objective was to characterize the natural killer (NK) cell response following acute exercise in prostate cancer survivors. Prostate cancer survivors on androgen deprivation therapy (ADT) and those without (PCa) along with non-cancer controls (CON) completed a moderate intensity cycling bout. NK cells were phenotyped before and 0, 2 and 24 h after acute exercise using flow cytometry. CD56 total NK cell frequency increased by 6.2% at 0 h (P < 0.001) and decreased by 2.5% at 2 h (P < 0.01) with similar findings in CD56^dim cells. NK cell counts also exhibited a biphasic response. Independent of exercise, ADT had intracellular interferon γ (IFNγ) expression that was nearly twofold higher than CON (P < 0.01). PCa perforin expression was reduced by 11.4% (P < 0.05), suggesting these cells may be more prone to degranulation. CD57^- NK cells demonstrated increased perforin and IFNγ frequencies after exercise with no change within the CD57⁺ populations. All NK and leukocyte populations returned to baseline by 24 h. NK cell mobilization and egress with acute exercise appear normal, as cell counts and frequencies in prostate cancer survivors change similarly to CON. However, lower perforin proportions (PCa) and higher IFNγ expression (ADT) may alter NK cytotoxicity and require further investigation. The return of NK cell proportions to resting levels overnight suggests that consecutive training sessions can be used without adverse effects on the immune system during prostate cancer treatment.

Sex differences in SARS-CoV-2 infection rates and the potential link to prostate cancer

The recent outbreak of infections and the pandemic caused by SARS-CoV-2 represent one of the most severe threats to human health in more than a century. Emerging data from the United States and elsewhere suggest that the disease is more severe in men. Knowledge gained, and lessons learned, from studies of the biological interactions and molecular links that may explain the reasons for the greater severity of disease in men, and specifically in the age group at risk for prostate cancer, will lead to better management of COVID-19 in prostate cancer patients. Such information will be indispensable in the current and post-pandemic scenarios.

Accelerated epigenetic age and cognitive decline among urban-dwelling adults

OBJECTIVES

Epigenetic modifications are closely linked with aging, but their relationship with cognition remains equivocal. Given known sex differences in epigenetic aging, we explored sex-specific associations of 3 DNA methylation (DNAm)-based measures of epigenetic age acceleration (EAA) with baseline and longitudinal change in cognitive performance among middle-aged urban adults.

METHODS

We used exploratory data from a subgroup of participants in the Healthy Aging in Neighborhoods of Diversity across the Life Span study with complete DNA samples and whose baseline ages were >50.0 years (2004-2009) to estimate 3 DNAm EAA measures: (1) universal EAA (AgeAccel); (2) intrinsic EAA (IEAA); and (3) extrinsic EAA (EEAA). Cognitive performance was measured at baseline visit (2004-2009) and first follow-up (2009-2013) with 11 test scores covering global mental status and specific domains such as learning/memory, attention, visuospatial, psychomotor speed, language/verbal, and executive function. A series of mixed-effects regression models were conducted adjusting for covariates and multiple testing (n = 147-156, ∼51% men, k = 1.7-1.9 observations/participant, mean follow-up time ∼4.7 years).

RESULTS

EEAA, a measure of both biological age and immunosenescence, was consistently associated with greater cognitive decline among men on tests of visual memory/visuoconstructive ability (Benton Visual Retention Test: γ₁₁ = 0.0512 ± 0.0176, p = 0.004) and attention/processing speed (Trail-Making Test, part A: γ₁₁ = 0.219 ± 0.080, p = 0.007). AgeAccel and IEAA were not associated with cognitive change in this sample.

CONCLUSIONS

EEAA capturing immune system cell aging was associated with faster decline among men in domains of attention and visual memory. Larger longitudinal studies are needed to replicate our findings.

Perceived stress, cytomegalovirus titers, and late-differentiated T and NK cells: Between-, within-person associations in a longitudinal study of older adults

Cytomegalovirus (CMV) and psychological stress are implicated as drivers of immunological aging. It is unknown, however, whether associations among CMV titers, stress, and immune aging are more stable or dynamic over time. The present investigation tested the between-person (stable differences) and within-person (dynamic fluctuations) associations of CMV titers and perceived stress on late-differentiated T and natural killer (NK) peripheral blood cells in a longitudinal study of older adults aged 64-92 years (N = 149). Participants reported stress levels and provided blood biannually for 2.5 years (up to 5 waves per person) to assess CMV IgG titers and composites of late-differentiated CD8 T cells (CD28- and CD57 + subsets) and CD56dim NK cells (CD57+, NKG2C+, and FcεRIγ- subsets). In multilevel models that controlled for demographic variables, higher CMV titers were associated with higher proportions and counts of aged T and NK cells between people and lower counts of aged T cells within people. Perceived stress was associated with higher counts of aged T cells between people, but was not associated with aged NK cells. A significant interaction between stress and CMV titers on T cells between people indicated that older adults with lower stress levels and lower CMV titers had the lowest proportions of late-differentiated T cells, whereas those with higher stress levels had high proportions, regardless of CMV control. Our results provide evidence for longer-term, between-person associations among CMV titers, stress, and immunological aging, rather than dynamic within-person associations. We propose that targeting factors that promote low, stable perceived stress in older adults may retard T cell differentiation and ultimately support healthy aging.

A longitudinal study of the stability, variability, and interdependencies among late-differentiated T and NK cell subsets in older adults

The stability and variability of older adults' late-differentiated peripheral blood T and natural killer (NK) cells over time remains incompletely quantified or understood. We examined the variability and change over time in T and NK cell subsets in a longitudinal sample of older adults; the effects of sex, cytomegalovirus (CMV) serostatus, and chronic disease severity on immune levels and trajectories; and interdependencies among T and NK cell subsets. Older adults (N = 149, age 64-94 years, 42% male) provided blood every 6 months for 2.5 years (up to 5 waves) to evaluate late-differentiated CD8 T cells (CD28-, CD57+) and CD56dimNK cells (CD57+, NKG2C+, FcɛRIγ-). In multilevel models, most of the variance in immune subsets reflected stable differences between people. However, CD56dimNK cell subsets (CD57+ and FcɛRIγ-) also increased with age, whereas T cell subsets did not. Independent of age, all subsets examined were higher in CMV-positive older adults. Men had higher levels of CD56dim CD57+ than women. Chronic disease was not associated with any immune subset investigated. T and NK cell subsets correlated within each cell type, but interdependencies differed by CMV serostatus. Our results suggest the accumulation of these stable cell populations may be driven less by chronological aging, even less by chronic disease severity, and more by CMV, which may differentially skew T and NK cell differentiation.

The Modulatory Effect of Gender and Cytomegalovirus-Seropositivity on Circulating Inflammatory Factors and Cognitive Performance in Elderly Individuals

Aging is characterized by a chronic increase in the systemic levels of inflammatory cytokines even in ostensibly healthy individuals. The drivers of age-related increase in systemic inflammation are unclear but one potential contributor may be a persistent infection with Cytomegalovirus (CMV). In this study, we characterized the inflammatory status of 161 older participants recruited to undergo a six-month training intervention. We investigated the influence of gender and CMV-seropositivity on the main inflammatory and anti-inflammatory circulating biomarkers, such as cytokines, receptor antagonist, soluble receptor, immune cells, and relevant metabolic markers. We found that both gender and CMV-seropositivity modulate circulating peripheral biomarkers, and that CMV-infection modifies associations among the latter. Moreover, we observed an interaction between CMV-serostatus and gender associations with cognitive abilities: gender differences in fluid intelligence (Gf) and working memory (WM) were noted only in CMV-negative individuals. Finally, we found that in the CMV-seronegative participants Gf, episodic memory (EM), and WM correlated negatively with pro-inflammatory tumor necrosis factor (TNF); and EM correlated positively with anti-inflammatory interleukin (IL)-10. In CMV-seropositive individuals EM and Gf correlated negatively with pro-inflammatory IL-6, while EM, Gf, and WM correlated negatively with anti-inflammatory IL-1RA. We conclude that both CMV-serostatus and gender may modulate neuroimmune factors, cognitive performance and the relationship between the two domains and should therefore be considered in comparative and interventional studies with elderly people.

Glycation interferes with natural killer cell function

One hallmark of molecular aging is glycation, better known as formation of so-called advanced glycation end products (AGEs), where reactive carbonyls react with amino-groups of proteins. AGEs accumulate over time and are responsible for various age-dependent diseases and impairments. Two very potent dicarbonyls to generate AGEs are glyoxal (GO) and methylglyoxal (MGO). The plasma level of such dicarbonyls is higher in aging and age-related diseases. Natural killer (NK) cells are cells of the innate immune system and provide a major defense against tumor cells and virus infected cells. They are able to kill modified or infected cells and produce different cytokines to modulate the function of other immune cells. Here we investigated the effect of GO- and MGO-induced glycation on the function of NK cells. Using the human NK cell line NK-92, we could demonstrate that both GO and MGO lead to glycation of cellular proteins, but that MGO interferes much stronger with NK cell function (cytotoxicity) than GO. In addition, glycation of NK cell targets, such as K562 tumor cells, also interferes with their lysis by NK cells. From this data we conclude that glycation acts negatively on NK cells function and reduces their cytotoxic potential towards tumor cells.

Sex Hormones Regulate Innate Immune Cells and Promote Sex Differences in Respiratory Virus Infection

Sex differences in the incidence and severity of respiratory virus infection are widely documented in humans and murine models and correlate with sex biases in numbers and/or functional responses of innate immune cells in homeostasis and lung infection. Similarly, changes in sex hormone levels upon puberty, pregnancy, and menopause/aging are associated with qualitative and quantitative differences in innate immunity. Immune cells express receptors for estrogens (ERα and ERβ), androgens (AR), and progesterone (PR), and experimental manipulation of sex hormone levels or receptors has revealed that sex hormone receptor activity often underlies sex differences in immune cell numbers and/or functional responses in the respiratory tract. While elegant studies have defined mechanistic roles for sex hormones and receptors in innate immune cells, much remains to be learned about the cellular and molecular mechanisms of action of ER, PR, and AR in myeloid cells and innate lymphocytes to promote the initiation and resolution of antiviral immunity in the lung. Here, we review the literature on sex differences and sex hormone regulation in innate immune cells in the lung in homeostasis and upon respiratory virus infection.

Sex Differences in HIV Infection: Mystique Versus Machismo

Biological sex is a determinant of both susceptibility to and pathogenesis of multiple infections, including HIV. These differences have effects on the spectrum of HIV disease from acquisition to eradication, with diverse mechanisms including distinct chromosomal complements, variation in microbiota composition, hormonal effects on transcriptional profiles, and expression of different immunoregulatory elements. With a comparative biology approach, these sex differences can be used to highlight protective and detrimental immune activation pathways, to identify strategies for effective prevention, treatment, and curative interventions.

The Confluence of Sex Hormones and Aging on Immunity

The immune systems of post-pubescent males and females differ significantly with profound consequences to health and disease. In many cases, sex-specific differences in the immune responses of young adults are also apparent in aged men and women. Moreover, as in young adults, aged women develop several late-adult onset autoimmune conditions more frequently than do men, while aged men continue to develop many cancers to a greater extent than aged women. However, sex differences in the immune systems of aged individuals have not been extensively investigated and data addressing the effectiveness of vaccinations and immunotherapies in aged men and women are scarce. In this review, we evaluate age- and sex hormone-related changes to innate and adaptive immunity, with consideration about how this impacts age- and sex-associated changes in the incidence and pathogenesis of autoimmunity and cancer as well as the efficacy of vaccination and cancer immunotherapy. We conclude that future preclinical and clinical studies should consider age and sex to better understand the ways in which these characteristics intersect with immune function and the resulting consequences for autoimmunity, cancer, and therapeutic interventions.

Cryopreserved whole blood for the quantification of monocyte, T-cell and NK-cell subsets, and monocyte receptor expression by multi-color flow cytometry: A methodological study based on participants from the canadian longitudinal study on aging

Immunophenotyping by multi-color flow cytometry is arguably the best tool to identify and quantify distinct cell lineages from the peripheral blood and other biological fluids/tissues. Effective in both clinical and research settings, it can be used to estimate the frequency of a given cell type or measure its phenotypic or functional properties. Normally, immunophenotyping is performed in fresh or fractionated blood (i.e., PBMCs) the same day, or within 24 hours of collection; however, this may not be feasible for all study designs. We have previously shown that cryopreserved blood, a biospecimen that is simple and inexpensive to prepare, is comparable to fresh blood for the enumeration of major leukocyte cell types. For the following study, we sought to extend these observations to distinct subsets of: monocytes (classical, intermediate, and non-classical), T-cells (CD4/CD8 naïve, central and effector memory, senescent, and terminally differentiated, and regulatory T-cells), and NK-cells (CD56 bright and dim); we also examined the expression of monocyte cell-surface receptors CX3CR1, CCR2, TLR2, and TLR4. Our results indicate that cryopreserved blood is comparable to fresh blood; with exception to relatively rare subsets and lowly expressed receptors, the absolute or relative frequency of cell subsets generally correlated >0.80 between blood types, while monocyte receptor expressed was mostly >0.70. Furthermore, the day-to-day coefficient of variation for most cell subsets and parameters was below 20%. Given these findings, we suggest that cryopreserved peripheral blood be given greater consideration for studies in which the quantification of distinct leukocyte subsets is required. © 2018 International Society for Advancement of Cytometry.

Human Body Composition and Immunity: Visceral Adipose Tissue Produces IL-15 and Muscle Strength Inversely Correlates with NK Cell Function in Elderly Humans

Natural killer (NK) lymphocyte-mediated cytotoxicity and cytokine secretion control infections and cancers, but these crucial activities decline with age. NK cell development, homeostasis, and function require IL-15 and its chaperone, IL-15 receptor alpha (IL-15Rα). Macrophages and dendritic cells (DC) are major sources of these proteins. We had previously postulated that additional IL-15 and IL-15Rα is made by skeletal muscle and adipose tissue. These sources may be important in aging, when IL-15-producing immune cells decline. NK cells circulate through adipose tissue, where they may be exposed to local IL-15. The objectives of this work were to determine (1) if human muscle, subcutaneous adipose tissue (SAT), and visceral adipose tissue (VAT) are sources of IL-15 and IL-15 Rα, and (2) whether any of these tissues correlate with NK cell activity in elderly humans. We first investigated IL-15 and IL-15Rα RNA expression in paired muscle and SAT biopsies from healthy human subjects. Both tissues expressed these transcripts, but IL-15Rα RNA levels were higher in SAT than in skeletal muscle. We also investigated tissue obtained from surgeries and found that SAT and VAT expressed equivalent amounts of IL-15 and IL-15Rα RNA, respectively. Furthermore, stromal vascular fraction cells expressed more IL-15 RNA than did adipocytes. To test if these findings related to circulating IL-15 protein and NK cell function, we tested 50 healthy adults aged > 70 years old. Plasma IL-15 levels significantly correlated with abdominal VAT mass in the entire cohort and in non-obese subjects. However, plasma IL-15 levels did not correlate with skeletal muscle cross-sectional area and correlated inversely with muscle strength. Plasma IL-15 did correlate with NK cell cytotoxic granule exocytosis and with CCL4 (MIP-1β) production in response to NKp46-crosslinking. Additionally, NK cell responses to K562 leukemia cells correlated inversely with muscle strength. With aging, immune function declines while infections, cancers, and deaths increase. We propose that VAT-derived IL-15 and IL-15Rα is a compensatory NK cell support mechanism in elderly humans.

High-resolution phenotyping identifies NK cell subsets that distinguish healthy children from adults

Natural killer (NK) cells are critical in immune defense against infected, stressed or transformed cells. Their function is regulated by the heterogeneous expression of a wide array of surface receptors that shape its phenotypic diversity. Although NK cells develop in the bone marrow and secondary lymphoid tissues, substantive differentiation is apparent in the peripheral blood including known age-related variation. In order to gain greater insight into phenotypic and functional variation within peripheral blood NK cells across age groups, we used multi-parametric, polyfunctional flow cytometry to interrogate the NK cell variability in 20 healthy adults and 15 5-10, 11-15 and 16-20 year-old children. We found that the normative ranges in both adults and children displayed great inter-individual variation for most markers. While the expression of several receptors did not differ, among those that did, the majority of the differences existed between adults and the three pediatric groups, rather than among children of different ages. Interestingly, we also identified variation in the individual expression of some markers by sex and ethnicity. Combinatorial analysis of NK cell receptors revealed intermediate subsets between the CD56bright and CD56dim NK cells. Furthermore, on examining the NK cell diversity by age, adults were discovered to have the lowest developmental diversity. Thus, our findings identify previously unappreciated NK cell subsets potentially distinguishing children from adults and suggest functional correlates that may have relevance in age-specific host defense.

Natural killer cell subsets and receptor expression in peripheral blood mononuclear cells of a healthy Korean population: Reference range, influence of age and sex, and correlation between NK cell receptors and cytotoxicity

BACKGROUND

The purpose of this study was to identify CD56^bright and CD56^dim natural killer (NK) cell subsets and analyze their receptors expression in a healthy Korean population, and to determine whether receptor expression correlates with age, sex, and cytotoxicity.

MATERIALS AND METHODS

We performed multicolor flow cytometry assays to analyze the expression of various NK cell receptors (CD16, NKG2A, NKG2C, NKG2D, CD57, DNAM-1, CD8a, CD62L, NKp30, and NKp46) on both CD3^-/CD56^dim and CD3^-/CD56^bright NK cells in whole-blood samples from 122 healthy donors. The expression of these receptors was compared according to age (<30years, n=22, 30-60years, n=73 and >60years, n=27) and gender (male, n=61, female, n=61). NK cell cytotoxicity assays were performed with peripheral blood mononuclear cells (PBMCs) from 18 individuals. The results were compared to the expression levels of NKp30 and NKp46 receptors.

RESULTS

A normal reference range for NK cell receptor expression in two NK cell subsets was established. NKp46 and NKG2D expression gradually decreased with age (p<0.01 and p<0.05, respectively) whereas NK cell proportion and numbers, frequencies of CD56^dim cells, and CD57 expression increased with age (p<0.01 in all cases). Men showed greater NK cell proportion and numbers, frequencies of CD56^dim cells, and CD57 expression compared to those of women (p<0.05 and p<0.001; p<0.01 and p<0.01, respectively). Notably, the expression of NKp46 was negatively correlated with NK cell frequency (r=-0.42, p<0.001). Furthermore, NK cell cytotoxicity was found to positively correlate with NCR expression (p=0.02), but not NK cell proportion (p=0.80).

CONCLUSION

We have established a profile of NK cell surface receptors for a Korean population, and revealed that age and gender have an effect on the expression of NK cell receptors in the population. Our data might explain why neither NK cell numbers nor proportions correlate with NK cell cytotoxicity.

Human cells involved in atherosclerosis have a sex

The influence of sex has been largely described in cardiovascular diseases. Atherosclerosis is a complex process that involves many cell types such as vessel cells, immune cells and endothelial progenitor cells; however, many, if not all, studies do not report the sex of the cells. This review focuses on sex differences in human cells involved in the atherosclerotic process, emphasizing the role of sex hormones. Furthermore, we report sex differences and issues related to the processes that determine the fate of the cells such as apoptotic and autophagic mechanisms. The analysis of the data reveals that there are still many gaps in our knowledge regarding sex influences in atherosclerosis, largely for the cell types that have not been well studied, stressing the urgent need for a clear definition of experimental conditions and the inclusion of both sexes in preclinical studies.

Trajectories of Stress, Depressive Symptoms, and Immunity in Cancer Survivors: Diagnosis to 5 Years

PURPOSE

Five-year disease endpoint trajectories are available for every cancer site. In contrast, there are few longitudinal, biobehavioral studies of survivors extending beyond the first or second year following diagnosis. This gap is addressed with stress, depressive symptom, and immunity data from breast cancer patients followed continuously for 5 years.

EXPERIMENTAL DESIGN

Women (N = 113) diagnosed and surgically treated for breast cancer and awaiting adjuvant therapy completed self-report measures of stress and depressive symptoms and provided blood for immune assays [natural killer cell cytotoxicity (NKCC) and T-cell blastogenesis]. Assessments (N = 12) were repeated every 4 to 6 months for 5 years.

RESULTS

Multiphase linear mixed models show phases of change and identified specific time points of change. Cancer stress shows two distinct phases of decline, with the change point being 12 months. In contrast, a steep decline in depressive symptoms occurs by 7 months, with stable, low levels thereafter. NKCC shows a steady upward trajectory through 18 months and upper limit stability thereafter, whereas there was no reliable trajectory for T-cell blastogenesis.

CONCLUSIONS

For the first time, trajectories and specific time points of change in biobehavioral data for breast cancer survivors are provided, traced through 5 years. Following diagnosis, the breast survivor experience is one of a co-occurrence of change (recovery) in psychologic and innate immunity markers from diagnosis to18 months, and a pattern of stability (depression, NKCC) or continued improvement (stress) through year 5. These data provide new directions for survivorship care and detail of the biobehavioral trajectory. Clin Cancer Res; 23(1); 52-61. ©2016 AACR.

Data correlations between gender, cytomegalovirus infection and T cells, NK cells, and soluble immune mediators in elderly humans

We describe a cohort of 50 elderly subjects, age at least 70 years. We present gender-specific findings in T lymphocyte markers and soluble immune mediators. We show the correlation between cytomegalovirus infection status with CD56(dim) NK cell responses to a variety of stimuli and with CD56(bright)/CD56(dim) NK cell ratio. We also present the correlation of retinol binding protein (RBP)-4 plasma levels with NK cell responses and we explore the relationship between gender and adiponectin, 25(OH)D (vitamin D), and RBP4 in affecting CD56(dim) NK cell responses. These data are discussed in Al-Attar et al. (2016) [1].