cell mediated response

• T lymphocytes/T cells


  Involved in the specific immune response, the second line of defense after a pathogen has entered the bloodstream
• T cells


  • Made in the bone marrow, mature in the thymus
• Cell-mediated response


  The response involving T cells
• Specific immune response


  Response to an exact antigen or cell surface molecule
• Antigen presenting cells (APCs)


  Cells that present a non-self antigen on their cell surface membrane, e.g. infected body cells, phagocytes, transplant cells, cancer cells
• Cell-mediated immune response


  Pathogen engulfed by phagocyte

  2. Antigen presented on APC

  3. Helper T cells bind to antigen on APC and activate

  4. Activated helper T cells divide and differentiate into:

  • More helper T cells
  • Memory T cells
  • Cytotoxic T cells
• Cytotoxic T cells


  Destroy abnormal or infected cells by releasing perforin, which creates pores in the cell membrane causing cell death
• Example: Cytotoxic T cells destroy infected cells in the throat during a cold, preventing further virus replication