2,024 research outputs found

    Functional and Homeostatic impact of Age-Related Changes in Lymph node Stroma

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    Adults over 65 years of age are more vulnerable to infectious disease and show poor responses to vaccination relative to those under 50. A complex set of age-related changes in the immune system is believed to be largely responsible for these defects. These changes, collectively termed immune senescence, encompass alterations in both the innate and adaptive immune systems, in the microenvironments where immune cells develop or reside, and in soluble factors that guide immune homeostasis and function. While age-related changes in primary lymphoid organs (bone marrow, and, in particular, the thymus, which involutes in the first third of life) have been long appreciated, changes affecting aging secondary lymphoid organs, and, in particular, aging lymph nodes (LNs) have been less well characterized. Over the last 20 years, LN stromal cells have emerged as key players in maintaining LN morphology and immune homeostasis, as well as in coordinating immune responses to pathogens. Here, we review recent progress in understanding the contributions of LN stromal cells to immune senescence. We discuss approaches to understand the mechanisms behind the decline in LN stromal cells and conclude by considering potential strategies to rejuvenate aging LN stroma to improve immune homeostasis, immune responses, and vaccine efficacy in the elderly.113Ysciescopu

    Uncovering Shakespeare\u27s Sisters in Special Collections and College Archives, Musselman Library

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    Foreword by Professor Suzanne J. Flynn I have taught the first-year seminar, Shakespeare’s Sisters, several times, and over the years I have brought the seminar’s students to the Folger Shakespeare Library in Washington, D.C. There, the wonderful librarians have treated the students to a special exhibit of early women’s manuscripts and first editions, beginning with letters written by Elizabeth I and proceeding through important works by seventeen and eighteenth-century women authors such as Aemelia Lanyer, Anne Finch, Aphra Behn, and Mary Wollstonecraft. This year I worked with Carolyn Sautter, the Director of Special Collections and College Archives, to give my 2018 seminar students the opportunity to produce a sequel to the Folger exhibit of early modern women writers. Special Collections houses an impressive array of first editions from the nineteenth and twentieth centuries, many of them acquired from Thomas Y. Cooper, the former editor of the Hanover Evening Sun newspaper, who donated over 1600 items to Musselman Library in 1965. Working with Kerri Odess-Harnish, we chose first editions of eight significant works of literature written by American and British women from the mid-nineteenth through the mid-twentieth centuries. The students worked in pairs, researching a single book and producing a report that outlines important biographical facts about the author, the book’s publication and reception history, and finally the significance of the book in the years since its publication. We hope that our project will draw attention to the wealth of literary treasures housed in Special Collections at Musselman Library, but especially to these works by eight of “Shakespeare’s Sisters.

    Gwinnett County, Georgia, A Sunbelt Community: The Invention of a Postwar Suburb

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    The Sunbelt suburbs postwar rise changed the United States political narrative through coalitions and conclaves. Suburban scholars have traced the movement’s social ramifications through various lenses, including White Flight and Urban Renewal. However, suburbanization through a suburb’s viewpoint has remained unexplored. Gwinnett County, Georgia, is a southern suburb that transformed from a rural environment to a substantial political and economic power. Its trajectory is offset by about twenty years from the familiar pattern of suburbanization. Tracing its history raises several questions about United States suburbanization both in the chronology of postwar urban history and the historic dynamics that shaped it. Gwinnett County developed into a modern suburb about twenty years after World War II, so its social and political motivations followed a very different course to modernization. In spite of its delayed development, it became one of the largest suburbs in the south by the end of the twentieth century

    Calorie Restriction Attenuates Terminal Differentiation of Immune Cells

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    Immune senescence is a natural consequence of aging and may contribute to frailty and loss of homeostasis in later life. Calorie restriction increases healthy life-span in C57BL/6J (but not DBA/2J) mice, but whether this is related to preservation of immune function, and how it interacts with aging, is unclear. We compared phenotypic and functional characteristics of natural killer (NK) cells and T cells, across the lifespan, of calorie-restricted (CR) and control C57BL/6 and DBA/2 mice. Calorie restriction preserves a naïve T cell phenotype and an immature NK cell phenotype as mice age. The splenic T cell populations of CR mice had higher proportions of CD11a-CD44lo cells, lower expression of TRAIL, KLRG1, and CXCR3, and higher expression of CD127, compared to control mice. Similarly, splenic NK cells from CR mice had higher proportions of less differentiated CD11b-CD27+ cells and correspondingly lower proportions of highly differentiated CD11b+CD27-NK cells. Within each of these subsets, cells from CR mice had higher expression of CD127, CD25, TRAIL, NKG2A/C/E, and CXCR3 and lower expression of KLRG1 and Ly49 receptors compared to controls. The effects of calorie restriction on lymphoid cell populations in lung, liver, and lymph nodes were identical to those seen in the spleen, indicating that this is a system-wide effect. The impact of calorie restriction on NK cell and T cell maturation is much more profound than the effect of aging and, indeed, calorie restriction attenuates these age-associated changes. Importantly, the effects of calorie restriction on lymphocyte maturation were more marked in C57BL/6 than in DBA/2J mice indicating that delayed lymphocyte maturation correlates with extended lifespan. These findings have implications for understanding the interaction between nutritional status, immunity, and healthy lifespan in aging populations

    The World Moves Toward 5G

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    Nutrition, diet and immunosenescence

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    Ageing is characterized by immunosenescence and the progressive decline in immunity in association with an increased frequency of infections and chronic disease. This complex process affects both the innate and adaptive immune systems with a progressive decline in most immune cell populations and defects in activation resulting in loss of function. Although host genetics and environmental factors, such as stress, exercise and diet can impact on the onset or course of immunosenescence, the mechanisms involved are largely unknown. This review focusses on identifying the most significant aspects of immunosenescence and on the evidence that nutritional intervention might delay this process, and consequently improve the quality of life of the elderly

    Global analyses revealed age-related alterations in innate immune responses after stimulation of pathogen recognition receptors

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    Aging leads to dysregulation of multiple components of the immune system that results in increased susceptibility to infections and poor response to vaccines in the aging population. The dysfunctions of adaptive B and T cells are well documented, but the effect of aging on innate immunity remains incompletely understood. Using a heterogeneous population of peripheral blood mononuclear cells (PBMCs), we first undertook transcriptional profiling and found that PBMCs isolated from old individuals (≥ 65 years) exhibited a delayed and altered response to stimulation with TLR4, TLR7/8, and RIG-I agonists compared to cells obtained from adults (≤ 40 years). This delayed response to innate immune agonists resulted in the reduced production of pro-inflammatory and antiviral cytokines and chemokines including TNFα, IL-6, IL-1β, IFNα, IFNγ, CCL2, and CCL7. While the major monocyte and dendritic cell subsets did not change numerically with aging, activation of specific cell types was altered. PBMCs from old subjects also had a lower frequency of CD40+ monocytes, impaired up-regulation of PD-L1 on monocytes and T cells, and increased expression of PD-L2 and B7-H4 on B cells. The defective immune response to innate agonists adversely affected adaptive immunity as TLR-stimulated PBMCs (minus CD3 T cells) from old subjects elicited significantly lower levels of adult T-cell proliferation than those from adult subjects in an allogeneic mixed lymphocyte reaction (MLR). Collectively, these age-associated changes in cytokine, chemokine and interferon production, as well as co-stimulatory protein expression could contribute to the blunted memory B- and T-cell immune responses to vaccines and infections
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