Related Experiment Video
Updated: Jun 2, 2026

A Flow Cytometry-Based Cytotoxicity Assay for the Assessment of Human NK Cell Activity
Published on: August 9, 2017
Immunosenescence of human natural killer cells
Inmaculada Gayoso1, Beatriz Sanchez-Correa, Carmen Campos
1Department of Immunology, IMIBIC - Reina Sofia University Hospital, University of Cordoba, Cordoba, Spain.
Abstract:
Natural killer (NK) cells are a key component of innate immunity involved not only in the elimination of virus-infected or tumor cells but also in the regulation of the immune response by producing cytokines and chemokines that can activate other cellular components of innate and adaptive immunity. NK cell subsets are differentially affected by aging. Whereas CD56(bright) cells are decreased in healthy elderly individuals, the CD56(dim) subset is expanded. The expression of CD57, a marker of highly differentiated NK cells, is increased in the elderly; this supports the notion that a remodeling process of NK cell subsets occurs in aging with a gradual decrease in more immature CD56(bright) NK cells and an increase in highly differentiated CD56(dim) CD57+ NK cells. This NK cell redistribution can explain many of the phenotypic and functional changes in NK cells associated with healthy aging such as decreased proliferation and the maintenance of CD16-dependent cytotoxicity.
Related Concept Videos
Cytotoxic T Cells-mediated Immune Response
Immunological surveillance is the ability of immune cells to monitor and eliminate infected cells with intracellular pathogens, neoplastically transformed cells, and cells with non-self antigens. Cytotoxic T cells and NK...
Cells of the Innate Immune Response
Phagocytes
Phagocytes police the peripheral tissues by removing cellular debris and responding to the invasion of foreign substances or pathogens. Many phagocytes attack and remove microorganisms even before lymphocytes detect them. The human body has two general...
Immune Surveillance by NK Cells and Phagocytes
Natural Killer Cells: The Fast Responders
NK cells are large granular lymphocytes found in the blood and lymphatic system. These...
Immune Response Against Viral Pathogens
NK Cells
NK cells are a crucial part of our innate immune system, acting as the first line of defense against viral infections. These cells can recognize and kill infected cells without prior exposure to the virus, effectively slowing down the spread of infection. Additionally, NK cells produce proinflammatory...
Cell-mediated Immune Responses
Cells of the Adaptive Immune Response
