concept

Natural killer (NK) cells

Also known as: NK cells, natural killer (NK) cell

Facts (41)

Sources

3. The Innate Immune System - Immunopaedia immunopaedia.org.za Immunopaedia 12 facts

claimKiller inhibitory receptors (KIRs) on Natural Killer (NK) cells recognize MHC-I molecules on normal cells and inhibit activation and killing through immunoreceptor tyrosine-based inhibitory motifs (ITIMs) located in their intracytoplasmic tail.

claimNatural killer (NK) cells are large granular lymphocytes derived from bone marrow precursors that are found mainly in peripheral circulation (5 to 20 percent of total lymphocytes), spleen, liver, and bone marrow.

procedureDuring antibody-dependent cellular cytotoxicity, Natural Killer (NK) cells recognize target cells via IgG antibodies attached to the target cells through Fab regions, while the Fc portion of the IgG antibody engages the CD16 (Fc-gRIII) receptor on the NK cell, linking the two cells and inducing the apoptotic pathway.

claimNatural Killer (NK) cells belong to the lymphoid lineage but do not express T cell (TCR/CD3 complex) or B cell (CD19) surface markers, and they are considered the third most important lymphocyte subset.

claimKiller activating receptors (KARs) on Natural Killer (NK) cells detect molecules on altered target cells, such as malignant or virus-infected cells, and provide an activation signal via immunoreceptor tyrosine-based activation motifs (ITAMs).

claimNatural Killer (NK) cells possess a morphology similar to activated cytotoxic lymphocytes, characterized by a large size, an abundant endoplasmic reticulum, and preformed granules containing perforins and granzymes.

claimNatural Killer (NK) cells are typically identified by the expression of CD16 (Fc-yRIII) and CD56, resulting in a CD3-/CD56+/CD16+ phenotype.

claimNatural Killer (NK) cells stimulate inflammatory responses by secreting IFN-gamma, TNF-alpha, GM-CSF, and chemokines including CCL4, CCL5, and CCL22.

claimNatural Killer (NK) cells utilize a balance of activating and inhibitory signals generated by cell surface receptors to regulate their killing activity.

claimNatural Killer (NK) cells can kill target cells through antibody-dependent cellular cytotoxicity (ADCC), a hybrid mechanism where IgG molecules link the innate and adaptive immune systems.

claimNatural Killer (NK) cells contribute to the innate immune response by nonspecifically eliminating target cells, such as virus-infected or malignant cells, through apoptosis independently of T or B cells.

procedureOnce the signal balance shifts toward activation, Natural Killer (NK) cells initiate a killing mechanism by releasing intracellular granules containing perforin and granzymes to induce apoptosis in target cells.

The components of the immune system - Immunobiology - NCBI - NIH ncbi.nlm.nih.gov Janeway CA Jr, Travers P, Walport M · Garland Science 6 facts

claimNatural killer cells circulate in the blood as large lymphocytes containing distinctive cytotoxic granules.

claimNatural killer cells recognize and kill abnormal cells, such as tumor cells and virus-infected cells, and are considered important in the innate immune defense against intracellular pathogens.

claimNatural killer cells are a lineage of lymphoid cells that lack antigen-specific receptors and are part of the innate immune system.

claimNatural killer cells recognize and kill abnormal cells, such as tumor cells and virus-infected cells, and are considered important in the innate immune defense against intracellular pathogens.

The immune system and primary immunodeficiency primaryimmune.org Immune Deficiency Foundation 6 facts

claimNatural killer (NK) cells are particularly important in the defense against herpes viruses, including herpes simplex, Epstein-Barr virus, and the varicella virus.

claimNatural killer (NK) cells kill cells infected with viruses and do not require the same thymic education that T cells require.

claimNatural killer (NK) cells defend against viruses and potentially prevent cancer by injecting virus-infected cells with cytotoxic granules.

claimNatural killer (NK) cells kill virus-infected cells by injecting them with cytotoxic granules.

claimNatural killer (NK) cells defend against viruses and may help prevent cancer.

claimNatural killer (NK) cells are named for their ability to easily kill cells infected with viruses.

Immunity In Depth | Linus Pauling Institute lpi.oregonstate.edu Linus Pauling Institute 5 facts

claimLeptin promotes the phagocytic function of immune cells, stimulates pro-inflammatory cytokine production, and regulates the functions of neutrophils, natural killer (NK) cells, and dendritic cells.

referenceSelenium supplementation affects cytotoxic lymphocytes and natural killer cells in humans, as reported by Kiremidjian-Schumacher et al. in Biological Trace Element Research (1994).

claimVitamin A is necessary for the normal function of innate immune cells, specifically natural killer (NK) cells, macrophages, and neutrophils.

claimZinc deficiency impairs innate immunity by negatively affecting the complement system, the cytotoxicity of natural killer cells, the phagocytic activity of neutrophils and macrophages, and the ability of immune cells to generate oxidants that kill invading pathogens.

claimVitamin A deficiency reduces the number and killing activity of natural killer (NK) cells.

How the Immune System Works with Primary Immunodeficiency igcares.com IGCares 4 facts

claimThe innate immune system relies on cells that require no additional training to function, including neutrophils, monocytes, natural killer (NK) cells, and complement proteins.

claimNatural killer (NK) cells are derived from the bone marrow and are present in relatively low numbers in the bloodstream and tissues.

claimNatural killer (NK) cells defend against viruses and possibly prevent cancer by injecting virus-infected cells with a chemical "killer potion."

claimNatural killer (NK) cells do not require the same thymic education that T-cells require.

Parts of the Immune System | Children's Hospital of Philadelphia chop.edu Children's Hospital of Philadelphia 3 facts

claimNatural killer cells possess the ability to fight tumor cells.

claimUnlike neutrophils, macrophages, and dendritic cells, which use phagocytosis, natural killer (NK) cells attach to infected cells and release chemicals into them to kill them.

claimNatural killer (NK) cells prevent viral infections from becoming too severe while the adaptive immune system generates a targeted response.

Cellular rejuvenation: molecular mechanisms and potential ... - Nature nature.com Nature Mar 14, 2023 2 facts

claimMelendez et al. found that natural killer cells act as an extrinsic barrier for in vivo reprogramming, as reported in Development in 2022.

claimThe interaction between the activating NKG2D receptor and its ligands expressed on senescent cells determines the involvement of natural killer (NK) cells in the elimination of those senescent cells.

Approaching Inflammation Paradoxes—Proinflammatory Cytokine ... frontiersin.org Frontiers 1 fact

claimThe abbreviation NK stands for natural killer.

A Comprehensive Review on the Therapeutic Properties of ... traditionalmedicine.actabotanica.org Acta Botanica 1 fact

referenceA study published in the 'Journal of Ethnopharmacology' found that Echinacea extracts enhance immune response by stimulating the production of immune cells and activating natural killer cells.

Cellular senescence: from homeostasis to pathological implications ... frontiersin.org Frontiers 1 fact

referenceRetinoic acid receptor activation reprograms the senescence response and enhances the anti-tumor activity of natural killer cells, as reported in a 2024 study in Cancer Cell.