Diseases of the immune system have gained considerable importance in recent years in particular in developed countries. The growing problems of allergic reactions, asthmatic diseases of the respiratory tract, the re-emergence of infectious diseases, the link between viral infection and cancer and the growing importance of automimmune diseases make a research effort in this area necessary. The aspects of the immune system are currently under investigation by the specialists in immunity and the sientists intend to continue their focus on on very important paghogen, namely on the human immunodeficiency viruses (HIV), which cause AIDS.