HIV & the Immune System (Cambridge (CIE) O Level Biology): Revision Note

HIV & the Immune System

• The HIV virus infects a certain type of lymphocyte in the immune system

• Normally lymphocytes seek out and destroy pathogens that enter the body, producing antibodies that attach to pathogens, enhancing phagocytic activity

• However, HIV infects a certain type of lymphocyte and uses the cells’ machinery to multiply

• This reduces the number of lymphocytes in the immune system, and also the number of antibodies that can be made

• This decreases the body’s ability to fight off infections, eventually leading to AIDS (Acquired immunodeficiency Syndrome)

• The weakened immune system is susceptible to infections that would normally have been dealt with by a fully-functioning immune system

  • e.g influenza, pneumonia, skin cancer