AQA A Level Biology复习笔记2.5.6 The Role of Helper T cells

• Activated T-lymphocytes (those that have receptors specific to an antigen) divide by mitosis to increase in number (similar to the clonal selection and clonal expansion of B-lymphocytes)
• These T-lymphocytes differentiate into two main types of T cell:
  • helper T cells
  • cytotoxic (killer) T cells

   

• Helper T cells assist other white blood cells in the immune response
• They release cytokines (hormone-like signals) which stimulate:
  • The maturation of B-lymphocytes into antibody-secreting plasma cells
  • The production of memory B cells
  • The activation of cytotoxic T cells, which destroy virus infected cells and tumour cells
  • An increased rate of phagocytosis

   

Helper T cells and killer T cells carry out different functions during an immune response