All pathogens and infectious agents that penetrate the host organism are detected, processed, and eliminated by the immune system cells. Impaired functioning of the system results in the rapid spreading of the infectious pathogens through the organism. Human deficiency virus significantly impairs the immune system by affecting immune cells. In particular, HIV infects T-cells, dendritic cells, and macrophages that are involved in the detection and elimination of pathogens. As a result, HIV infection results in the development of acquired immunodeficiency syndrome (AIDS) and increased susceptibility to pathogens.