Cell, helper
A type of T cell that participates in the immune response by recognizing foreign antigens and secreting substances called cytokines that activate T and B cells. Helper cells fall into two main classes: those that activate other T cells to achieve cellular inflammatory responses; and those that drive B cells to produce antibodies in the humoral immune response. These two classes of response are generally incompatible with one another and require coordination by substances called cytokines to promote one response while dampening the other. The HIV virus attacks T-helper cells, knocking out the body’s ability to defend itself against infections. Helper cells have CD4 markers on their surface and are also known as CD4 cells, T-4 cells, T-helper cells, and helper T cells.

Medical dictionary. 2011.

Look at other dictionaries:

  • antigen-specific T-cell helper factor — a soluble factor produced by helper T cells that activates other lymphocytes that are specific for the stimulating antigen; it may itself bind antigen …   Medical dictionary

  • helper T cell — noun T cell with CD4 receptor that recognizes antigens on the surface of a virus infected cell and secretes lymphokines that stimulate B cells and killer T cells; helper T cells are infected and killed by the AIDS virus • Syn: ↑helper cell, ↑CD4… …   Useful english dictionary

  • helper T cell — help·er T cell .hel pər tē n a T cell that participates in an immune response by recognizing a foreign antigen and secreting lymphokines to activate T cell and B cell proliferation, that usu. carries CD4 molecular markers on its cell surface, and …   Medical dictionary

  • helper factor — A group of factors apparently produced by helper T lymphocytes that act specifically or nonspecifically to transfer T cell help to other classes of lymphocytes. The existence of specific T cell helper factor is uncertain …   Dictionary of molecular biology

  • helper cells — helper T cells differentiated T lymphocytes whose cooperation (help) is required for the production of antibody against most (T dependent) antigens. Activation of B lymphocytes (B cells) requires recognition of the antigenic determinant against… …   Medical dictionary

  • helper-inducer T cell — n T4 CELL …   Medical dictionary

  • helper T cell — n. a type of T cell that helps coordinate the immune response, especially by activating B cells: the AIDS virus targets and destroys these T cells …   English World dictionary

  • helper T lymphocyte — or helper T cell noun (immunology) A thymus derived lymphocyte which co operates with B lymphocytes to enable them to produce an antibody when stimulated by an antigen • • • Main Entry: ↑help …   Useful english dictionary

  • Cell — The basic structural and functional unit in people and all living things. Each cell is a small container of chemicals and water wrapped in a membrane. Each cell in the human body there are 100 trillion cells in each of us contains the entire… …   Medical dictionary

  • helper T cell — noun Date: 1974 a T cell that participates in an immune response by recognizing a foreign antigen and secreting lymphokines to activate T cell and B cell proliferation and that usually carries CD4 molecular markers on its cell surface called also …   New Collegiate Dictionary

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