t-cell-response

T Cell Response

• T cells, sometimes known as T lymphocytes, are a type of white blood cell involved with the specific immune response

  • They are produced in the bone marrow and finish maturing in the thymus, which is where the T in their name comes from

• Mature T cells have specific cell surface receptors called T cell receptors

• These receptors have a similar structure to antibodies and are each specific to a particular type of antigen

 Mature T cells have many different types of receptor on the cell surface membrane; these receptors will bind to different antigens on antigen presenting cells

• T cells are activated when they encounter and bind to their specific antigen on the surface of an antigen presenting cell 

  • This antigen-presenting cell might be a macrophage, an infected body cell, or the pathogen itself

• These activated T cells divide by mitosis to increase in number

  • Dividing by mitosis produces genetically identical cells, or clones, so all of the daughter cells will have the same type of T cell receptor on their surface 

• As they divide by mitosis the T cells differentiate into three main types of T cell

  • T helper cells

    • Release chemical signalling molecules that help to activate B cells

  • T killer cells

    • Bind to and destroy infected cells displaying the relevant specific antigen

  • T memory cells

    • Remain in the blood and enable a faster specific immune response if the same pathogen is encountered again in the future