Skip to main content
Biology LibreTexts

7.10.6: Key Terms

  • Page ID
  • \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)\(\newcommand{\AA}{\unicode[.8,0]{x212B}}\)

    adaptive immunity
    immunity that has memory and occurs after exposure to an antigen either from a pathogen or a vaccination
    attraction of molecular complementarity between antigen and antibody molecules
    immune reaction that results from immediate hypersensitivities in which an antibody-mediated immune response occurs within minutes of exposure to a harmless antigen
    protein that is produced by plasma cells after stimulation by an antigen; also known as an immunoglobulin
    foreign or “non-self” protein that triggers the immune response
    antigen-presenting cell (APC)
    immune cell that detects, engulfs, and informs the adaptive immune response about an infection by presenting the processed antigen on the cell surface
    antibody that incorrectly marks “self” components as foreign and stimulates the immune response
    autoimmune response
    inappropriate immune response to host cells or self-antigens
    type of hypersensitivity to self antigens
    total binding strength of a multivalent antibody with antigen
    B cell
    lymphocyte that matures in the bone marrow and differentiates into antibody-secreting plasma cells
    leukocyte that releases chemicals usually involved in the inflammatory response
    cell-mediated immune response
    adaptive immune response that is carried out by T cells
    clonal selection
    activation of B cells corresponding to one specific BCR variant and the dramatic proliferation of that variant
    complement system
    array of approximately 20 soluble proteins of the innate immune system that enhance phagocytosis, bore holes in pathogens, and recruit lymphocytes; enhances the adaptive response when antibodies are produced
    cross reactivity
    binding of an antibody to an epitope corresponding to an antigen that is different from the one the antibody was raised against
    chemical messenger that regulates cell differentiation, proliferation, gene expression, and cell trafficking to effect immune responses
    cytotoxic T lymphocyte (CTL)
    adaptive immune cell that directly kills infected cells via perforin and granzymes, and releases cytokines to enhance the immune response
    dendritic cell
    immune cell that processes antigen material and presents it on the surface of other cells to induce an immune response
    effector cell
    lymphocyte that has differentiated, such as a B cell, plasma cell, or cytotoxic T lymphocyte
    leukocyte that responds to parasites and is involved in the allergic response
    small component of an antigen that is specifically recognized by antibodies, B cells, and T cells; the antigenic determinant
    protease that enters target cells through perforin and induces apoptosis in the target cells; used by NK cells and killer T cells
    helper T lymphocyte (TH)
    cell of the adaptive immune system that binds APCs via MHC II molecules and stimulates B cells or secretes cytokines to initiate the immune response
    an organism that is invaded by a pathogen or parasite
    humoral immune response
    adaptive immune response that is controlled by activated B cells and antibodies
    spectrum of maladaptive immune responses toward harmless foreign particles or self antigens; occurs after tissue sensitization and includes immediate-type (allergy), delayed-type, and autoimmunity
    immune tolerance
    acquired ability to prevent an unnecessary or harmful immune response to a detected foreign body known not to cause disease or to self-antigens
    failure, insufficiency, or delay at any level of the immune system, which may be acquired or inherited
    localized redness, swelling, heat, and pain that results from the movement of leukocytes and fluid through opened capillaries to a site of infection
    innate immunity
    immunity that occurs naturally because of genetic factors or physiology, and is not induced by infection or vaccination
    cytokine that inhibits viral replication and modulates the immune response
    watery fluid that bathes tissues and organs with protective white blood cells and does not contain erythrocytes
    leukocyte that is histologically identifiable by its large nuclei; it is a small cell with very little cytoplasm
    large phagocytic cell that engulfs foreign particles and pathogens
    major histocompatibility complex (MHC) I/II molecule
    protein found on the surface of all nucleated cells (I) or specifically on antigen-presenting cells (II) that signals to immune cells whether the cell is healthy/normal or is infected/cancerous; it provides the appropriate template into which antigens can be loaded for recognition by lymphocytes
    mast cell
    leukocyte that produces inflammatory molecules, such as histamine, in response to large pathogens and allergens
    memory cell
    antigen-specific B or T lymphocyte that does not differentiate into effector cells during the primary immune response but that can immediately become an effector cell upon reexposure to the same pathogen
    type of white blood cell that circulates in the blood and lymph and differentiates into macrophages after it moves into infected tissue
    mucosa-associated lymphoid tissue (MALT)
    collection of lymphatic tissue that combines with epithelial tissue lining the mucosa throughout the body
    natural killer (NK) cell
    lymphocyte that can kill cells infected with viruses or tumor cells
    phagocytic leukocyte that engulfs and digests pathogens
    process that enhances phagocytosis using proteins to indicate the presence of a pathogen to phagocytic cells
    passive immunity
    transfer of antibodies from one individual to another to provide temporary protection against pathogens
    an agent, usually a microorganism, that causes disease in the organisms that it invades
    pathogen-associated molecular pattern (PAMP)
    carbohydrate, polypeptide, and nucleic acid “signature” that is expressed by viruses, bacteria, and parasites but differs from molecules on host cells
    pattern recognition receptor (PRR)
    molecule on macrophages and dendritic cells that binds molecular signatures of pathogens and promotes pathogen engulfment and destruction
    destructive protein that creates a pore in the target cell; used by NK cells and killer T cells
    plasma cell
    immune cell that secrets antibodies; these cells arise from B cells that were stimulated by antigens
    regulatory T (Treg) cell
    specialized lymphocyte that suppresses local inflammation and inhibits the secretion of cytokines, antibodies, and other stimulatory immune factors; involved in immune tolerance
    T cell
    lymphocyte that matures in the thymus gland; one of the main cells involved in the adaptive immune system

    7.10.6: Key Terms is shared under a CC BY 4.0 license and was authored, remixed, and/or curated by LibreTexts.

    • Was this article helpful?