Virology of the human immunodeficiency virus type 1.

Understanding the mode of replication of the human immunodeficiency virus (HIV) is necessary for explaining the natural history of HIV infection and for the development of therapeutic and prophylactic agents. The life cycle of HIV involves infective particles, the attachment of the virus to specific cell receptors, reverse transcription of the viral RNA into DNA by using viral encoded enzymes, integration of the viral DNA into the host genome, use of the host machinery to transcribe and translate viral genes, and the formation of budding particles. Viral encoded genes, regulated by a complex interaction of viral and host proteins with viral sequences, ultimately encode for the viral structural proteins, regulatory proteins, and enzymes necessary for the formation of mature infectious particles. Blocking one or more steps in the viral life cycle and preventing enhancement of virus production are important approaches in the control of HIV.