Cellular Response

• What do T-lymphocytes do when exposed to a specific antigen?

  Produce an immune response
• How do T cells bind to antigens?

  Only if presented on antigen-presenting cells
• How do T-lymphocytes mature?

  In the thymus gland
• What do T cell receptors (TCRs) do?

  Recognize specific antigens
• What are clones of T cells?

  Genetically identical cells with the same TCRs
• What happens when T cells encounter their specific antigen?

  They become activated and divide
• What do T helper cells release?

  Chemical signalling molecules called interleukins
• What is the role of T killer cells?

  To kill infected body cells
• What do perforins do?

  Punch holes in infected cell membranes
• What is the function of T memory cells?

  To speed up response to future infections
• Where do B-lymphocytes mature?

  In the bone marrow
• What do B cells gain during maturation?

  Specific cell surface receptors called BCRs
• What happens during clonal selection of B cells?

  B cells bind to antigens on APCs
• What do activated B cells differentiate into?

  Plasma cells and memory cells
• What do plasma cells secrete?

  Antibody molecules specific to the antigen
• What is the role of memory B cells?

  To remain in circulation for future responses
• What do T Killer Cells do?

  Patrol the body for APCs & attach to antigens on any infected cells & secrete toxic substances to kill any pathogens
• What do T memory cells do?

  Remain in the blood, so if reinfection occurs clonal selection can happen faster
• What happens during clonal selections for T cells?

  T cell receptors bind to complementary antigens on APCs & activate the T cell
• What happens during clonal expansion for T cells?

  The divide by mitosis, to produce killer, helper or memory T cells