T Lymphocytes and Cell Mediated Immunity

• What are T lymphocytes?

  White blood cells involved in the specific immune response.
• Where are T lymphocytes made and where do they mature?

  They are made in the bone marrow and mature in the thymus gland.
• What does the cell-mediated response involve?

  T cells and body cells.
• What do T cells respond to?

  Antigens on the surface of cells.
• What is an antigen-presenting cell (APC)?

  Any cells that present a non-self antigen on their surface.
• What is the role of receptors on the surface of helper T cells?

  They allow the T cell to attach to the antigens on antigen-presenting cells (APCs).
• Once attached to antigens, helper T cells are...

  Activated and divide by mitosis, replicating and creating a large number of clones.
• The cloned helper T cells differentiate and...

  • Activate B lymphocytes
  • Stimulate further phagocytosis
  • Become memory cells
  • Become cytotoxic T cells
• What protein do cytotoxic T cells release and what is its function?

  Perforin, which creates pores in the cell-surface membrane of infected cells, leading to cell death.