title: Paradoxical changes in innate immunity in aging: recent progress and new directions.
abstract: Immunosenescence, describing alterations, including decline of immune responses with age, is comprised of inappropriate elevations, decreases, and dysregulated immune responses, leading to more severe consequences of bacterial and viral infections and reduced responses to vaccination. In adaptive immunity, these changes include increased proportions of antigen-experienced B and T cells at the cost of naïve cell populations. Innate immune changes in aging are complex in spanning multiple cell types, activation states, and tissue context. Innate immune responses are dampened in aging, yet there is also a paradoxical increase in certain signaling pathways and cytokine levels. Here, we review recent progress and highlight novel directions for expected advances that can lead the aging field to a new era of discovery that will embrace the complexity of aging in human populations.
authors.affiliation: Sections of *Rheumatology and Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA ruth.montgomery@yale.edu.
authors.forename: Ruth R
authors.initials: RR
authors.lastname: Montgomery
authors.affiliation: Sections of *Rheumatology and Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA.
authors.forename: Albert C
authors.initials: AC
authors.lastname: Shaw
mesh_terms: D000375:Aging / Q000276:immunology*; D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D016207:Cytokines / Q000276:immunology*; D006801:Humans; D007113:Immunity, Innate; D015398:Signal Transduction / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D016207:Cytokines
keywords: Toll-like receptor; dendritic cell; immunosenescence; polymorphonuclear leukocyte; systems immunology