scholarly journals Dysregulation of Systemic Immunity in Aging and Dementia

2021 ◽  
Vol 15 ◽  
Author(s):  
Jenny Lutshumba ◽  
Barbara S. Nikolajczyk ◽  
Adam D. Bachstetter
Keyword(s):  
Immune System ◽  
Immune Cells ◽  
Cell Function ◽  
Immune Cell ◽  
Human Subjects ◽  
Brain Inflammation ◽  
Adaptive Immune Cells ◽  
Age Related ◽  
The Brain ◽  
Age Related Changes

Neuroinflammation and the tissue-resident innate immune cells, the microglia, respond and contribute to neurodegenerative pathology. Although microglia have been the focus of work linking neuroinflammation and associated dementias like Alzheimer’s Disease, the inflammatory milieu of brain is a conglomerate of cross-talk amongst microglia, systemic immune cells and soluble mediators like cytokines. Age-related changes in the inflammatory profile at the levels of both the brain and periphery are largely orchestrated by immune system cells. Strong evidence indicates that both innate and adaptive immune cells, the latter including T cells and B cells, contribute to chronic neuroinflammation and thus dementia. Neurodegenerative hallmarks coupled with more traditional immune system stimuli like infection or injury likely combine to trigger and maintain persistent microglial and thus brain inflammation. This review summarizes age-related changes in immune cell function, with special emphasis on lymphocytes as a source of inflammation, and discusses how such changes may potentiate both systemic and central nervous system inflammation to culminate in dementia. We recap the understudied area of AD-associated changes in systemic lymphocytes in greater detail to provide a unifying perspective of inflammation-fueled dementia, with an eye toward evidence of two-way communication between the brain parenchyma and blood immune cells. We focused our review on human subjects studies, adding key data from animal models as relevant.

scholarly journals 67 Immunometabolism – emerging concepts and potential applications in livestock

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 101-101
Author(s):  
Barry J Bradford
Keyword(s):  
Immune System ◽  
Communication Networks ◽  
Immune Cells ◽  
Immune Cell ◽  
Cell Types ◽  
Whole Body ◽  
Phagocytic Cells ◽  
Adaptive Immune Cells ◽  
Potential Applications ◽  
Host Microbe Interactions

Abstract Our understanding of the immune system emerged from the study of disease processes and the communication networks used by various cell types to respond to pathogens. As with many aspects of physiology, this initial view was colored by the techniques available at the time. With technical advances beginning in the 1990, research in sepsis and obesity began to identify critical interactions between the immune system and metabolism. Our current understanding of these interactions is informed by two active but largely distinct research communities. Many in the field of immunology are utilizing cellular metabolism tools to understand mitochondrial function and fuel use in response to activation of innate and adaptive immune cells, especially as these relate to cancer. From another vantage point, many metabolic physiologists are now seeking to understand the importance of tissue-resident immune cells and immune signaling molecules in metabolic homeostasis and pathologies. Beyond human health implications of recent findings, a number of immunometabolism insights have informed our understanding of livestock health. In inflammatory events, phagocytic cells are activated, and the dramatic increase in oxidative metabolism is driven primarily by glucose use. Metabolism of healthy animals is also influenced by secretions from immune cells. Studies in mice indicate that appropriate host/microbe interactions (balancing protection and tolerance) are mediated by a network of immune cell types in the gut, which is critical to both absorptive and barrier functions of the gut. Adipose tissue immune cells regulate lipolytic rate, insulin sensitivity, and perhaps whole-body inflammatory tone. Local immune cell impacts on metabolism of other organs, including the liver and pancreas, are also emerging. Immunity and metabolism are tightly interwoven, and the evolving understanding of these links may enable nutritional or pharmacological strategies to enhance resilience to disease and alter nutrient partitioning in livestock.

scholarly journals Altered Ca2+ Homeostasis in Immune Cells during Aging: Role of Ion Channels

2020 ◽  
Vol 22 (1) ◽  
pp. 110
Author(s):  
Dorina Zöphel ◽  
Chantal Hof ◽  
Annette Lis
Keyword(s):  
Immune Cells ◽  
Irreversible Process ◽  
Cell Function ◽  
Immune Cell ◽  
Compensatory Mechanisms ◽  
Cellular Environment ◽  
Age Related ◽  
Dependent Processes ◽  
Equal Density

Aging is an unstoppable process and begins shortly after birth. Each cell of the organism is affected by the irreversible process, not only with equal density but also at varying ages and with different speed. Therefore, aging can also be understood as an adaptation to a continually changing cellular environment. One of these very prominent changes in age affects Ca2+ signaling. Especially immune cells highly rely on Ca2+-dependent processes and a strictly regulated Ca2+ homeostasis. The intricate patterns of impaired immune cell function may represent a deficit or compensatory mechanisms. Besides, altered immune function through Ca2+ signaling can profoundly affect the development of age-related disease. This review attempts to summarize changes in Ca2+ signaling due to channels and receptors in T cells and beyond in the context of aging.

scholarly journals Cutaneous immune system: Age specificities

2017 ◽  
Vol 3 (1) ◽  
Author(s):  
Markelova Elena Vladimirovna ◽  
Yana Alexandrovna Yutskovskaya ◽  
Birko Oksana Nikolaevna ◽  
Bajbarina Elena Valerjevna ◽  
Natalya Sergeevna Chepurnova
Keyword(s):  
T Cells ◽  
Immune System ◽  
Immune Cells ◽  
Immune Surveillance ◽  
Acquired Immunity ◽  
Malignant Neoplasms ◽  
Elderly Persons ◽  
Skin Infections ◽  
Age Related ◽  
Age Related Changes

<p>The review is dedicated to the modern concepts in understanding the age-related changes of skin protective functions, with an emphasis on the impairments in interaction between the immune cells of innate and acquired immunity, resulting in a decrease in antigen-specific T cell immune surveillance in the skin. We discuss the various defects of T cells and their environment as well as focus on the issue of possible correction of T-reg and other cells activity in the skin which would increase the level of immune surveillance in elderly persons and reduce the risk of malignant neoplasms or skin infections developing.</p>

scholarly journals Immunosenescence and human vaccine immune responses

2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Stephen N. Crooke ◽  
Inna G. Ovsyannikova ◽  
Gregory A. Poland ◽  
Richard B. Kennedy
Keyword(s):  
Older Adults ◽  
Immune System ◽  
Clinical Outcomes ◽  
B Lymphocyte ◽  
Cell Function ◽  
Immune Cell ◽  
Vaccine Development ◽  
Older Individuals ◽  
Functional Changes ◽  
Age Related

Abstract The age-related dysregulation and decline of the immune system—collectively termed “immunosenescence”—has been generally associated with an increased susceptibility to infectious pathogens and poor vaccine responses in older adults. While numerous studies have reported on the clinical outcomes of infected or vaccinated individuals, our understanding of the mechanisms governing the onset of immunosenescence and its effects on adaptive immunity remains incomplete. Age-dependent differences in T and B lymphocyte populations and functions have been well-defined, yet studies that demonstrate direct associations between immune cell function and clinical outcomes in older individuals are lacking. Despite these knowledge gaps, research has progressed in the development of vaccine and adjuvant formulations tailored for older adults in order to boost protective immunity and overcome immunosenescence. In this review, we will discuss the development of vaccines for older adults in light of our current understanding—or lack thereof—of the aging immune system. We highlight the functional changes that are known to occur in the adaptive immune system with age, followed by a discussion of current, clinically relevant pathogens that disproportionately affect older adults and are the central focus of vaccine research efforts for the aging population. We conclude with an outlook on personalized vaccine development for older adults and areas in need of further study in order to improve our fundamental understanding of adaptive immunosenescence.

scholarly journals Immune Memory in Aging: a Wide Perspective Covering Microbiota, Brain, Metabolism, and Epigenetics

2021 ◽  
Author(s):  
Ozlem Bulut ◽  
Gizem Kilic ◽  
Jorge Domínguez-Andrés
Keyword(s):  
Immune System ◽  
Aging Process ◽  
Cell Function ◽  
Immune Cell ◽  
Immunological Memory ◽  
Metabolic Reprogramming ◽  
The Other ◽  
Immune Memory ◽  
Age Related ◽  
Wide Range

AbstractNon-specific innate and antigen-specific adaptive immunological memories are vital evolutionary adaptations that confer long-lasting protection against a wide range of pathogens. Adaptive memory is established by memory T and B lymphocytes following the recognition of an antigen. On the other hand, innate immune memory, also called trained immunity, is imprinted in innate cells such as macrophages and natural killer cells through epigenetic and metabolic reprogramming. However, these mechanisms of memory generation and maintenance are compromised as organisms age. Almost all immune cell types, both mature cells and their progenitors, go through age-related changes concerning numbers and functions. The aging immune system renders the elderly highly susceptible to infections and incapable of mounting a proper immune response upon vaccinations. Besides the increased infectious burden, older individuals also have heightened risks of metabolic and neurodegenerative diseases, which have an immunological component. This review discusses how immune function, particularly the establishment and maintenance of innate and adaptive immunological memory, regulates and is regulated by epigenetics, metabolic processes, gut microbiota, and the central nervous system throughout life, with a focus on old age. We explain in-depth how epigenetics and cellular metabolism impact immune cell function and contribute or resist the aging process. Microbiota is intimately linked with the immune system of the human host, and therefore, plays an important role in immunological memory during both homeostasis and aging. The brain, which is not an immune-isolated organ despite former opinion, interacts with the peripheral immune cells, and the aging of both systems influences the health of each other. With all these in mind, we aimed to present a comprehensive view of the aging immune system and its consequences, especially in terms of immunological memory. The review also details the mechanisms of promising anti-aging interventions and highlights a few, namely, caloric restriction, physical exercise, metformin, and resveratrol, that impact multiple facets of the aging process, including the regulation of innate and adaptive immune memory. We propose that understanding aging as a complex phenomenon, with the immune system at the center role interacting with all the other tissues and systems, would allow for more effective anti-aging strategies.

Aging Leukocytes and the Inflammatory Microenvironment of the Adipose Tissue

Diabetes ◽  
2021 ◽  
Vol 71 (1) ◽  
pp. 23-30
Author(s):  
Korbyn J.V. Dahlquist ◽  
Christina D. Camell
Keyword(s):  
Metabolic Disease ◽  
Adipose Tissue ◽  
Immune System ◽  
Immune Cells ◽  
Cell Activation ◽  
Immune Cell ◽  
Inflammatory Factors ◽  
Immune Cell Activation ◽  
Age Related ◽  
Increased Risk

Age-related immunosenescence, defined as an increase in inflammaging and the decline of the immune system, leads to tissue dysfunction and increased risk for metabolic disease. The elderly population is expanding, leading to a heightened need for therapeutics to improve health span. With age, many alterations of the immune system are observed, including shifts in the tissue-resident immune cells, increased expression of inflammatory factors, and the accumulation of senescent cells, all of which are responsible for a chronic inflammatory loop. Adipose tissue and the immune cell activation within are of particular interest for their well-known roles in metabolic disease. Recent literature reveals that adipose tissue is an organ in which signs of initial aging occur, including immune cell activation. Aged adipose tissue reveals changes in many innate and adaptive immune cell subsets, revealing a complex interaction that contributes to inflammation, increased senescence, impaired catecholamine-induced lipolysis, and impaired insulin sensitivity. Here, we will describe current knowledge surrounding age-related changes in immune cells while relating those findings to recent discoveries regarding immune cells in aged adipose tissue.

scholarly journals Adaptive immunity at the crossroads of autophagy and metabolism

2021 ◽  
Author(s):  
Shree Padma Metur ◽  
Daniel J. Klionsky
Keyword(s):  
Immune Cells ◽  
Cell Function ◽  
Immune Cell ◽  
Metabolic Stress ◽  
Energy Availability ◽  
Immune Cell Function ◽  
Adaptive Immune ◽  
Adaptive Immune Cells ◽  
Protein Synthesis Machinery

AbstractThe function of lymphocytes is dependent on their plasticity, particularly their adaptation to energy availability and environmental stress, and their protein synthesis machinery. Lymphocytes are constantly under metabolic stress, and macroautophagy/autophagy is the primary metabolic pathway that helps cells overcome stressors. The intrinsic role of autophagy in regulating the metabolism of adaptive immune cells has recently gained increasing attention. In this review, we summarize and discuss the versatile roles of autophagy in regulating cellular metabolism and the implications of autophagy for immune cell function and fate, especially for T and B lymphocytes.

Potential immunotherapy for Alzheimer disease and age-related dementia

2019 ◽  
Vol 21 (1) ◽  
pp. 21-25 ◽  
Keyword(s):  
Immune System ◽  
Alzheimer Disease ◽  
Cross Talk ◽  
Immune Checkpoint ◽  
Short Review ◽  
Immune Checkpoint Blockade ◽  
Checkpoint Blockade ◽  
New Approach ◽  
Age Related ◽  
The Brain

Emerging results support the concept that Alzheimer disease (AD) and age-related dementia are affected by the ability of the immune system to contain the brain's pathology. Accordingly, well-controlled boosting, rather than suppression of systemic immunity, has been suggested as a new approach to modify disease pathology without directly targeting any of the brain's disease hallmarks. Here, we provide a short review of the mechanisms orchestrating the cross-talk between the brain and the immune system. We then discuss how immune checkpoint blockade directed against the PD-1/PD-L1 pathways could be developed as an immunotherapeutic approach to combat this disease using a regimen that will address the needs to combat AD.

Potential immunotherapy for Alzheimer disease and age-related dementia

2019 ◽  
Vol 21 (1) ◽  
pp. 21-25 ◽  
Keyword(s):  
Immune System ◽  
Alzheimer Disease ◽  
Cross Talk ◽  
Immune Checkpoint ◽  
Short Review ◽  
Immune Checkpoint Blockade ◽  
Checkpoint Blockade ◽  
New Approach ◽  
Age Related ◽  
The Brain

Emerging results support the concept that Alzheimer disease (AD) and age-related dementia are affected by the ability of the immune system to contain the brain’s pathology. Accordingly, well-controlled boosting, rather than suppression of systemic immunity, has been suggested as a new approach to modify disease pathology without directly targeting any of the brain’s disease hallmarks. Here, we provide a short review of the mechanisms orchestrating the cross-talk between the brain and the immune system. We then discuss how immune checkpoint blockade directed against the PD-1/PD-L1 pathways could be developed as an immunotherapeutic approach to combat this disease using a regimen that will address the needs to combat AD.

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