20.3.1 HIV infects the CD4 lymphocytes
Like all viruses, HIV has to enter (i.e. infect) healthy cells in the body in order to produce more copies of itself. These newly-produced viruses are then released into the blood in order to infect other susceptible cells. You may think of an HIV-infected cell as a sort of HIV factory. However, not all cells in the human body can be infected by HIV. Its main targets are the CD4 lymphocytes. Figure 20.5 shows in more detail the mechanism of infection of a CD4 lymphocyte by HIV.