The untwining of immunosenescence and aging

Inflammaging and Cannabinoids

Aging is a complex phenomenon associated with a wide spectrum of physical and physiological changes affecting every part of all metazoans, if they escape death prior to reaching maturity. Critical to survival, the immune system evolved as the principal component of response to injury and defense against pathogen invasions. Because how significantly immune system affects and is affected by aging, several neologisms now appear to encapsulate these reciprocal relationships, such as Immunosenescence. The central part of Immunosenescence is Inflammaging -a sustained, low-grade, sterile inflammation occurring after reaching reproductive prime. Once initiated, the impact of Inflammaging and its adverse effects determine the direction and magnitudes of further Inflammaging. In this article, we review the nature of this vicious cycle, we will propose that phytocannabinoids as immune regulators may possess the potential as effective adjunctive therapies to slow and, in certain cases, reverse the pathologic senescence to permit a more healthy aging.

Manifesto on the Value of Adult Immunization: "We Know, We Intend, We Advocate"

Immunization through vaccination is a milestone achievement that has made a tremendous contribution to public health. Historically, immunization programs aimed firstly to protect children, who were disproportionally affected by infectious diseases. However, vaccine-preventable diseases can have significant impacts on adult mortality, health, and quality of life. Despite this, adult vaccinations have historically been overlooked in favor of other health priorities, because their benefits to society were not well recognized. As the general population is aging, the issue of vaccination in older adults is gaining importance. In high-income countries, recommendations for the routine vaccination of older adults have been gradually introduced. The Italian National Immunization Plan is considered to be among the most advanced adult vaccination plans in Europe. However, available data indicate there is low adherence to vaccination recommendations in Italy. The COVID-19 pandemic has exposed the damage that can be caused by an infectious disease, especially among adults and individuals with comorbidities. The aim of this “Manifesto”, therefore, is to provide an overview of the existing evidence on the value of adult vaccination, in the Italian context, with a call to action to healthcare providers and health authorities.

Perspectives on the dynamic implications of cellular senescence and immunosenescence on macrophage aging biology

An intricate relationship between impaired immune functions and the age-related accumulation of tissue senescent cells is rapidly emerging. The immune system is unique as it undergoes mutually inclusive and deleterious processes of immunosenescence and cellular senescence with advancing age. While factors inducing immunosenescence and cellular senescence may be shared, however, both these processes are fundamentally different which holistically influence the aging immune system. Our understanding of the biological impact of immunosenescence is relatively well-understood, but such knowledge regarding cellular senescence in immune cells, especially in the innate immune cells such as macrophages, is only beginning to be elucidated. Tissue-resident macrophages are long-lived, and while functioning in tissue-specific and niche-specific microenvironments, senescence in macrophages can be directly influenced by senescent host cells which may impact organismal aging. In addition, evidence of age-associated immunometabolic changes as drivers of altered macrophage phenotype and functions such as inflamm-aging is also emerging. The present review describes the emerging impact of cellular senescence vis-à-vis immunosenescence in aging macrophages, its biological relevance with other senescent non-immune cells, and known immunometabolic regulators. Gaps in our present knowledge, as well as strategies aimed at understanding cellular senescence and its therapeutics in the context of macrophages, have been reviewed.

Insulin/IGF-1 signaling promotes immunosuppression via the STAT3 pathway: impact on the aging process and age-related diseases

BACKGROUND

The insulin/IGF-1 signaling pathway has a major role in the regulation of longevity both in Caenorhabditis elegans and mammalian species, i.e., reduced activity of this pathway extends lifespan, whereas increased activity accelerates the aging process. The insulin/IGF-1 pathway controls protein and energy metabolism as well as the proliferation and differentiation of insulin/IGF-1-responsive cells. Insulin/IGF-1 signaling also regulates the functions of the innate and adaptive immune systems. The purpose of this review was to elucidate whether insulin/IGF-1 signaling is linked to immunosuppressive STAT3 signaling which is known to promote the aging process.

METHODS

Original and review articles encompassing the connections between insulin/IGF-1 and STAT3 signaling were examined from major databases including Pubmed, Scopus, and Google Scholar.

RESULTS

The activation of insulin/IGF-1 receptors stimulates STAT3 signaling through the JAK and AKT-driven signaling pathways. STAT3 signaling is a major activator of immunosuppressive cells which are able to counteract the chronic low-grade inflammation associated with the aging process. However, the activation of STAT3 signaling stimulates a negative feedback response through the induction of SOCS factors which not only inhibit the activity of insulin/IGF-1 receptors but also that of many cytokine receptors. The inhibition of insulin/IGF-1 signaling evokes insulin resistance, a condition known to be increased with aging. STAT3 signaling also triggers the senescence of both non-immune and immune cells, especially through the activation of p53 signaling.

CONCLUSIONS

Given that cellular senescence, inflammaging, and counteracting immune suppression increase with aging, this might explain why excessive insulin/IGF-1 signaling promotes the aging process.

Is It "Aging" or Immunosenescence? The COVID-19 Biopsychosocial Risk Factors Aggravating Immunosenescence as Another Risk Factor of the Morbus. A Developmental-clinical Social Work Perspective

COVID-19 has proliferated ageism. The impetus of this article is to show that immunosenescence is a risk factor to COVID-19 and not aging per se. Based on the idea that some older people are also healthier than younger ones, the emphasis of this article is on immunosenescence and not aging as a risk factor of COVID-19 complications. The paper utilizes a biopsychosocial approach to expound on the link between immunosenescence and COVID-19 risk factors. The article explores biological factors such as malnutrition, comorbidities, substance abuse, and sex. It also expands on psychosocial factors such as mental health disorders, homelessness, unemployment, lack of physical exercises, stigma, and discrimination. The article calls for gerontological social work to assume a developmental-clinical social work perspective to prevent the early onset and progression of immunosenescence. It calls for gerontological social work to prevent factors that promote unhealthy aging. The article promotes a preventative stance to practice and not just curative approaches. Treatment involves primary prevention which emphasizes on avoiding the onset of unhealthy aging. It is this approach that gerontological social work should aim also to address in building resilience in the face of pandemics.

Immunosuppressive network promotes immunosenescence associated with aging and chronic inflammatory conditions

The functional competence of the immune system gradually declines with aging, a process called immunosenescence. The age-related remodelling of the immune system affects both adaptive and innate immunity. In particular, a chronic low-grade inflammation, termed inflammaging, is associated with the aging process. Immunosenescence not only is present in inflammaging state, but it also occurs in several pathological conditions in conjunction with chronic inflammation. It is known that persistent inflammation stimulates a counteracting compensatory immunosuppression intended to protect host tissues. Inflammatory mediators enhance myelopoiesis and induce the generation of immature myeloid-derived suppressor cells (MDSC) which in mutual cooperation stimulates the immunosuppressive network. Immunosuppressive cells, especially MDSCs, regulatory T cells (Treg), and M2 macrophages produce immunosuppressive factors, e.g., TGF-β, IL-10, ROS, arginase-1 (ARG1), and indoleamine 2,3-dioxygenase (IDO), which suppress the functions of CD4/CD8T and B cells as well as macrophages, natural killer (NK) cells, and dendritic cells. The immunosuppressive armament (i) inhibits the development and proliferation of immune cells, (ii) decreases the cytotoxic activity of CD8T and NK cells, (iii) prevents antigen presentation and antibody production, and (iv) suppresses responsiveness to inflammatory mediators. These phenotypes are the hallmarks of immunosenescence. Immunosuppressive factors are able to control the chromatin landscape, and thus, it seems that the immunosenescence state is epigenetically regulated.

The Role of T Cell Senescence in Neurological Diseases and Its Regulation by Cellular Metabolism

Immunosenescence is a state of dysregulated leukocyte function characterised by arrested cell cycle, telomere shortening, expression of markers of cellular stress, and secretion of pro-inflammatory mediators. Immunosenescence principally develops during aging, but it may also be induced in other pathological settings, such as chronic viral infections and autoimmune diseases. Appearance of senescent immune cells has been shown to potentially cause chronic inflammation and tissue damage, suggesting an important role for this process in organismal homeostasis. In particular, the presence of senescent T lymphocytes has been reported in neurological diseases, with some works pointing towards a direct connection between T cell senescence, inflammation and neuronal damage. In this minireview, we provide an overview on the role of T cell senescence in neurological disorders, in particular in multiple sclerosis and Alzheimer disease. We also discuss recent literature investigating how metabolic remodelling controls the development of a senescence phenotype in T cells. Targeting metabolic pathways involved in the induction of senescent T cells may indeed represent a novel approach to limit their inflammatory activity and prevent neuroinflammation and neurodegeneration.

Vaccination in Older Adults: An Underutilized Opportunity to Promote Healthy Aging in India

Over the last 50 years, the Indian population aged 50 years and above (older adults) has quadrupled and is expected to comprise 404 million people in 2036, representing 27% of the country's projected population. Consequently, the contribution of chronic disease to older adults' total burden of diseases in India is likely to escalate. Disease burden is notably amplified by immunosenescence, a deterioration of the immune system that develops with age, leading to increasing susceptibility to infectious diseases and other comorbidities. Older adults with infectious diseases have a higher incidence and likelihood of life-threatening comorbidities such as coronary artery disease, arrhythmia, stroke, myocardial infarction, hypertension, dyslipidemia, and diabetes mellitus. Therefore, immunization of older adults through vaccination might greatly reduce the burden imposed by vaccine preventable infectious diseases in this population. Here, we review evidence relevant to the disease burden among adults aged ≥ 50 years in India, and existing vaccination recommendations. Furthermore, we suggest a set of routine vaccinations for healthy older adults in India. There is a clear mandate to recognize the contributions of older adults to society and embrace strategies promoting healthy aging, which is described by the World Health Organization as the process of developing and maintaining functional ability and well-being in older age. Increasing vaccination awareness and coverage among older adults is an important step in that direction for India.

Prevalence of Chronic Inducible Urticaria in Elderly Patients

BACKGROUND

No data currently exist regarding the epidemiology of chronic inducible urticarias (CIndUs) in the ≥65-year-old population.

OBJECTIVE

The study aimed to determine the prevalence of CIndUs among elderly patients affected by chronic urticaria (CU).

METHODS

The medical records of all patients referred to us with a diagnosis of CU from January 2008 to September 2020 were retrospectively reviewed, and the patients with CIndUs were identified. The subjects aged 65 years or above were included in the study.

RESULTS

The number of patients aged 65 years or above was 153 out of 1970 subjects affected by CU (7.77%; 92 females (60.13%); mean age 70.96 ± 4.22). Out of 153, 26 patients (16.99%; 20 females (76.9%); mean age 71.23 ± 2.6 years) were diagnosed with CIndUs. Most subjects (25/26; 96.15%) suffered from physical urticarias. Symptomatic dermographism was the most frequent, affecting 65.38% (17/26) of our patients, followed by cold urticaria (6/26 (23.08%) cases).

CONCLUSION

Our data seem to indicate that CIndUs may also affect the elderly, although it occurs less frequently in aging patients than in lower age groups.