11. Immunity

An understanding of the immune system shows how cells and molecules function together to protect the body against infectious diseases and how, after an initial infection, the body is protected from subsequent infections by the same pathogen. Phagocytosis is an immediate non-specific part of the immune system, while the actions of lymphocytes provide effective defence against specific pathogens

11.1 The immune system

  1. describe the mode of action of phagocytes (macrophages and neutrophils)

  2. explain what is meant by an antigen (see 4.1.3) and state the difference between self antigens and non-self antigens

  3. describe the sequence of events that occurs during a primary immune response with reference to the roles of:

• macrophages

• B-lymphocytes, including plasma cells

• T-lymphocytes, limited to T-helper cells and T-killer cells

  1. explain the role of memory cells in the secondary immune response and in long-term immunity

Phagocytes

B-lymphocytes and T-cells

Primary and secondary immune response

Immunity 11.1

11.2 Antibodies and vaccination

  1. relate the molecular structure of antibodies to their functions

  2. outline the hybridoma method for the production of monoclonal antibodies

  3. outline the principles of using monoclonal antibodies in the diagnosis of disease and in the treatment of disease

  4. describe the differences between active immunity and passive immunity and between natural immunity and artificial immunity

  5. explain that vaccines contain antigens that stimulate immune responses to provide long-term immunity

  6. explain how vaccination programmes can help to control the spread of infectious diseases

Immunity and vaccination

Monoclonal antibodies