Knowledge Tree
NK cells
Also known as: NK cells, NK cell, natural killer cell
Facts (29)
Sources
3. The Innate Immune System - Immunopaedia immunopaedia.org.za 14 facts
claimNatural Killer T (NKT) cells are a subset of natural killer cells defined by the co-expression of T cell markers (CD3/TCR complex) and characteristic surface receptors for NK cells (CD56, CD58, and CD161).
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.
claimWhen a target cell exhibits decreased expression of MHC-I, the inhibitory signal from the Natural Killer (NK) cell's killer inhibitory receptors (KIRs) decreases, shifting the signal balance toward activation and initiating apoptosis.
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.
Pro-Inflammatory Cytokines Overview | Thermo Fisher Scientific - US thermofisher.com 6 facts
claimInterleukin-22 (IL-22) is an anti-inflammatory cytokine produced by activated T-cells and NK cells that acts on stromal and epithelial cells via the IL-22R receptor to stimulate cell survival and proliferation.
claimInterferon-gamma (IFN-γ) is a pro-inflammatory cytokine produced by T Cells and NK cells that binds to CDw119 (IFNG R1) and functions in anti-viral defense, macrophage activation, increasing neutrophil and monocyte function, and regulating MHC-I and -II expression.
referenceIL-12 is classified as an anti-inflammatory cytokine, is produced by T cells, macrophages, and monocytes, binds to the CD212 receptor, targets NK cells, macrophages, and tumor cells, and functions in activating NK cells, phagocyte cell activation, endotoxic shock, tumor cytotoxicity, and cachexia.
referenceIL-2 is classified as an adaptive immunity cytokine, is produced by Th1 cells, binds to the CD25 receptor, targets activated T cells, B cells, and NK cells, and functions in the proliferation of B cells and activated T cells, and supports NK cell function.
referenceIL-1 is classified as a pro-inflammatory cytokine, is produced by macrophages, B cells, and dendritic cells, binds to the CD121a receptor, targets B cells, NK cells, and T cells, and functions in pyrogenic activity, inflammation, cell proliferation, differentiation, and bone marrow cell proliferation.
claimInterleukin-37 (IL-37/IL-1F7) is an anti-inflammatory cytokine produced by B-cells, NK cells, and monocytes that binds to CD218a (IL-18Ra) and potentially SIGGR, and is believed to act as a negative regulator inside the cell by interacting with SMAD3 activated downstream of TGFβ activity.
The immune system and primary immunodeficiency primaryimmune.org 3 facts
claimPrimary immunodeficiencies result from a defect in one or more elements or functions of the normal immune system, such as T cells, B cells, NK cells, neutrophils, monocytes, antibodies, cytokines, or the complement system.
claimNatural killer (NK) cells are particularly important in the defense against herpes viruses, including herpes simplex, Epstein-Barr virus, and the varicella virus.
claimThe most common cells of the immune system are lymphocytes (T cells, B cells, and NK cells), neutrophils, and monocytes/macrophages, all of which are types of white blood cells.
Immunity In Depth | Linus Pauling Institute lpi.oregonstate.edu 2 facts
measurementA randomized controlled trial in 93 young men (ages 18 to 42 years) found that 12 weeks of daily supplementation with up to 4 g of EPA and 0.9 g of DHA had no effect on NK cell activity, T lymphocyte proliferation, or cytokine production.
claimDHA supplementation alone had no effect on NK cell activity, T lymphocyte proliferation, neutrophil, monocyte, or macrophage numbers, respiratory burst, or cytokine production in healthy older adults.