cell biology Cell biology (also cellular biology or cytology) is a branch of biology that studies the structure, function, and behavior of cells. All living organisms are made of cells. A cell is the basic unit of life that is responsible for the living an ...

, an effector cell is any of various types of cell that actively responds to a stimulus and effects some change (brings it about). Examples of effector cells include: * The

muscle Muscle is a soft tissue, one of the four basic types of animal tissue. There are three types of muscle tissue in vertebrates: skeletal muscle, cardiac muscle, and smooth muscle. Muscle tissue gives skeletal muscles the ability to muscle contra ...

, gland or organ cell capable of responding to a stimulus at the terminal end of an

efferent nerve fiber Efferent nerve fibers are axons (nerve fibers) of efferent neurons that exit a particular region. These terms have a slightly different meaning in the context of the peripheral nervous system (PNS) and central nervous system (CNS). The efferen ...

Plasma cell Plasma cells, also called plasma B cells or effector B cells, are white blood cells that originate in the lymphoid organs as B cells and secrete large quantities of proteins called antibodies in response to being presented specific substances ca ...

, an effector B cell in the immune system * Effector T cells, T cells that actively respond to a stimulus * Cytokine-induced killer cells, strongly productive cytotoxic effector cells that are capable of lysing tumor cells *

Microglia Microglia are a type of glia, glial cell located throughout the brain and spinal cord of the central nervous system (CNS). Microglia account for about around 5–10% of cells found within the brain. As the resident macrophage cells, they act as t ...

, a glial effector cell that reconstructs the

Central nervous system The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain, spinal cord and retina. The CNS is so named because the brain integrates the received information and coordinates and influences the activity o ...

after a bone marrow transplant *

Fibroblast A fibroblast is a type of cell (biology), biological cell typically with a spindle shape that synthesizes the extracellular matrix and collagen, produces the structural framework (Stroma (tissue), stroma) for animal Tissue (biology), tissues, and ...

, a cell that is most commonly found within

connective tissue Connective tissue is one of the four primary types of animal tissue, a group of cells that are similar in structure, along with epithelial tissue, muscle tissue, and nervous tissue. It develops mostly from the mesenchyme, derived from the mesod ...

* Mast cell, the primary effector cell involved in the development of asthma

Cytokine-induced killer cells as effector cells

As an effector cell, cytokine-induced killer cells can recognize infected or

malignant Malignancy () is the tendency of a medical condition to become progressively worse; the term is most familiar as a characterization of cancer. A ''malignant'' tumor contrasts with a non-cancerous benign tumor, ''benign'' tumor in that a malig ...

cells even when

antibodies An antibody (Ab) or immunoglobulin (Ig) is a large, Y-shaped protein belonging to the immunoglobulin superfamily which is used by the immune system to identify and neutralize antigens such as bacteria and viruses, including those that caus ...

and

major histocompatibility complex The major histocompatibility complex (MHC) is a large Locus (genetics), locus on vertebrate DNA containing a set of closely linked polymorphic genes that code for Cell (biology), cell surface proteins essential for the adaptive immune system. The ...

(MHC) are not available. This allows a quick immune reaction to take place. Cytokine-Induced killer (CIK) cells are important because harmful cells that do not contain MHC cannot be traced and removed by other immune cells. CIK cells are being studied intensely as a possible therapy treatment for cancer and other types of viral infections. CIK cells respond to lymphokines by lysing tumorous cells that are resistant to NK cells or LAK cell activity. CIK cells show a large amount of cytotoxic potential against various types of tumors. Side effects of CIK cells are also considered very minor. In a few cases, CIK cell treatment lead to the complete disappearance of tumor burdens, extended periods of survival, and improved quality of life, even if the cancerous tumor cells were in advanced stages. At the moment, the exact mechanism of tumor recognition in CIK cells are not completely understood.

Fibroblast as effector cells

Fibroblast are types of cells that form the extracellular matrix and collagen. Fibroblasts are the most common connective tissues in animals. They have branched cytoplasm surrounding their nucleus, which contain two or more nucleoli. Fibroblasts play a key role when responding to tissue injury. They initiate inflammation in the presence of foreign microorganisms. Receptors found on the surface of fibroblasts regulate hematopoietic cells, start chemokine synthesis, and provide a pathway that allows immune cells to regulate the fibroblast cells. Fibroblasts are also known as tumor mediators. They suppress the tumor as an inflammatory response.

Microglia as effector cells

Microglia are located throughout the brain and spinal cord. They are the first line of immune defense in the CNS. Microglia are of utmost importance in brain maintenance. They constantly search around the CNS for any type of plaques, damaged neurons, and infections. Microglia are extremely sensitive forms of effector cells, because they must be alert enough to address possible life-threatening damage. This sensitivity is caused by unique forms of potassium channels. Microglia must always be capable of recognizing any foreign bodies, engulf them, and activate T-cells. Microglia can be found under a variety of different shapes and sizes, based on the location where they are found. The vast amount of shapes are required for the microglia to carry out their primary function. Microglia are distinguishable from macrophages because of their ability to transform, which allows them to protect the CNS under relatively short amounts of time. Microglia take on a unique phenotype when they detect local chemical signals. Microglia have a variety of different functions required to maintain homeostasis in the host body.

Mast cells as effector cells

A mast cell is a white blood cell. Mast cells are protective cells that are involved in wound healing and blood-brain barrier function. Mast cells are very similar to basophils, and mast cells once were mistaken for them. It is proven that the two cells have different lineages.{{Cite journal, last1=Franco, first1=Christopher B., last2=Chen, first2=Ching-Cheng, last3=Drukker, first3=Micha, last4=Weissman, first4=Irving L., last5=Galli, first5=Stephen J., date=2010-04-02, title=Distinguishing mast cell and granulocyte differentiation at the single cell level, journal=Cell Stem Cell, volume=6, issue=4, pages=361–368, doi=10.1016/j.stem.2010.02.013, issn=1934-5909, pmc=2852254, pmid=20362540 Mast cells respond to pathogenic parasites through Immunoglobin E signaling. These cells play a role in the inflammatory process. They can either release selective amounts or rapid amounts of compounds that induce inflammation from granules. Mast cells are inactive during allergic reactions unless an allergen binds to Immunoglobin E.

References

Cellular processes Cell signaling