effector cell

(noun)

a plasma B cell or cytotoxic T cell, which are the main types of cells responsible for the humoral and cellular immune responses, respectively

Related Terms

Examples of effector cell in the following topics:

  • Immunological Memory

    • As B cells and T cells mature into effector cells, a subset of the naïve populations differentiates into B and T memory cells with the same antigen specificities .
    • A memory cell is an antigen-specific B or T lymphocyte that does not differentiate into an effector cell during the primary immune response, but that can immediately become an effector cell on re-exposure to the same pathogen.
    • As the infection is cleared and pathogenic stimuli subside, the effector cells are no longer needed; they undergo apoptosis.
    • If the pathogen is not encountered again during the individual's lifetime, B and T memory cells will circulate for a few years or even several decades, gradually dying off, having never functioned as effector cells.
    • As a result, memory B cells and plasma cells are made.

  • Cell-Mediated Immunity

    • Cell-mediated immunity involves cytotoxic T cells recognizing infected cells and bringing about their destruction.
    • Unlike B cells, T lymphocytes (T cells) are unable to recognize pathogens without assistance.
    • As with B cells, the clone includes active TC cells and inactive memory TC cells.
    • The resulting active TC cells then identify infected host cells.
    • B plasma cells and TC cells are collectively called effector cells because they are involved in "effecting" (bringing about) the immune response of killing pathogens and infected host cells.

  • Components of Plasma Membranes

    • The plasma membrane (also known as the cell membrane or cytoplasmic membrane) is a biological membrane that separates the interior of a cell from its outside environment.
    • Plasma membranes must be very flexible in order to allow certain cells, such as red blood cells and white blood cells, to change shape as they pass through narrow capillaries.
    • The plasma membrane also plays a role in anchoring the cytoskeleton to provide shape to the cell, and in attaching to the extracellular matrix and other cells to help group cells together to form tissues.
    • The membrane also maintains the cell potential.
    • Membrane receptors provide extracellular attachment sites for effectors like hormones and growth factors, which then trigger intracellular responses.

  • Regulating Immune Tolerance

    • The pocket contains antigen-presenting cells, such as dendritic cells, which engulf the antigens, then present them with MHC II molecules on the cell surface.
    • Antigen-presenting cells, T cells, and B cells aggregate within the Peyer's patch, forming organized lymphoid follicles.
    • There, some T cells and B cells are activated.
    • Other antigen-loaded dendritic cells migrate through the lymphatic system where they activate B cells, T cells, and plasma cells in the lymph nodes.
    • The activated cells then return to MALT tissue effector sites.

  • Homeostatic Process

    • The human organism consists of trillions of cells working together for the maintenance of the entire organism.
    • While cells may perform very different functions, the cells are quite similar in their metabolic requirements.
    • Maintaining a constant internal environment with everything that the cells need to survive (oxygen, glucose, mineral ions, waste removal, etc.) is necessary for the well-being of individual cells and the well-being of the entire body.
    • Adjustment of physiological systems within the body is called homeostatic regulation, which involves three parts or mechanisms: (1) the receptor, (2) the control center, and (3) the effector.
    • The effector responds to the commands of the control center by either opposing or enhancing the stimulus.

  • Regulatory Mechanisms for Cellular Respiration

    • Access of glucose to the cell can be regulated using the GLUT proteins that transport glucose .
    • In addition, different forms of the GLUT protein control passage of glucose into the cells of specific tissues.
    • These regulators, known as allosteric effectors, may increase or decrease enzyme activity, depending on the prevailing conditions, altering the steric structure of the enzyme, usually affecting the configuration of the active site.
    • A cascade of events that occurs upon insulin binding to a receptor in the plasma membrane causes GLUT4-containing vesicles to fuse with the plasma membrane so that glucose may be transported into the cell.

  • Control of Homeostasis

    • The receptors sense changes in the environment, sending a signal to the control center (in most cases, the brain), which, in turn, generates a response that is signaled to an effector.
    • The effector is a muscle or a gland that will carry out the required response.
    • Specialized cells in the pancreas (part of the endocrine system) sense the increase, releasing the hormone insulin.
    • If calcium levels decrease, specialized cells in the parathyroid gland sense this and release parathyroid hormone (PTH), causing an increased absorption of calcium through the intestines and kidneys.
    • In order to adjust to the lower oxygen levels at the new altitude, the body increases the number of red blood cells circulating in the blood to ensure adequate oxygen delivery to the tissues.

  • Catabolite Activator Protein (CAP): An Activator Regulator

    • When glucose levels drop, cyclic AMP (cAMP) begins to accumulate in the cell.
    • When glucose levels decline in the cell, accumulating cAMP binds to the positive regulator catabolite activator protein (CAP), a protein that binds to the promoters of operons that control the processing of alternative sugars, such as the lac operon.
    • Two cAMP molecules bind dimeric CAP with negative cooperativity and function as allosteric effectors by increasing the protein's affinity for DNA.

  • Cellular Differentiation

    • Three basic categories of cells make up the mammalian body: germ cells, somatic cells, and stem cells.
    • Pluripotent stem cells undergo further specialization into multipotent progenitor cells that then give rise to functional cells.
    • Hematopoietic stem cells (adult stem cells) from the bone marrow that give rise to red blood cells, white blood cells, and platelets
    • Mesenchymal stem cells (adult stem cells) from the bone marrow that give rise to stromal cells, fat cells, and types of bone cells;
    • Epithelial stem cells (progenitor cells) that give rise to the various types of skin cells

  • Gene Expression in Stem Cells

    • In mammals, there are two broad types of stem cells: embryonic stem cells, which are isolated from the inner cell mass of blastocysts, and adult stem cells, which are found in various tissues.
    • Stem cells can now be artificially grown and differentiated into specialized cell types with characteristics consistent with muscle or nerve cells through cell culture.
    • In one, the daughter cells are initially equivalent but a difference is induced by signaling between the cells, from surrounding cells, or from the precursor cell.
    • Stem cells are indicated by (A), progenitor cells by (B), and differentiated cells by (C).
    • Pluripotent, embryonic stem cells originate as inner cell mass (ICM) cells within a blastocyst.