|  | Conditions Treatments | Viruses

What Are T-Cell Subsets?

T-cells, also known as T-lymphocytes, are developed in the thymus. They are a type of white blood cell that orchestrates the immune system's response to malignant or infected cells, producing the cellular immune response (cell-to-cell contact).

  1. The Basics

    • Stem cells in red bone marrow give rise to lymphocyte (type of white blood cell) precursors. Some of these precursors may be transported through the blood to the thymus to be processed into T-cells. The T-cells are transported through the blood to the lymphatic organs, such as the spleen, lymph nodes and lymphatic ducts.

    Types

    • The categorization of T-lymphocytes--particularly into cytotoxic, suppressor/effector and helper/inducer subsets--are based on the functional or structural grouping of cells.

    Identification

    • T-cell activation begins when a macrophage (a large phagocytic cell) ingests a bacterium, digesting it in its lysosomes (organelles containing digestive enzymes).

    Features

    • Activated T-cells interact directly with the antigen-presenting cell, causing cellular immune response or cell-mediated immunity. T-cells may also secrete toxins that kill their antigen-bearing target cells or prevent of target cells.

    Function

    • Helper T-cells are activated when their antigen receptor combines with a displayed foreign antigen. Once activated, the helper T-cell stimulates the B-cell to produce antibodies specific for the displayed antigen. Suppressor T-cells shut down immune reaction after invasive organisms are eliminated. Cytotoxic T-cells continually monitor the body's cells, recognizing and eliminating tumor cells and cells infected with viruses.

Viruses - Related Articles