HIVbio: HIV Bioinformatics

G.P.S. Raghava | Bioinformatics Centre | IMTECH | Developers | Contact
General Information
 Home HIVbio
HIV Genome
 HIV Proteome
 HIV Life Cycles
 HIV Imp Enzymes

Important Terms
 HIV Coreceptors
  HIV Tropism
  Structural Landmarks
  Important Databases

AIDS: Therapies
  Drugs : HAART
  Drug Resistance
 Protein-Proteins
 miRNA/siRNA
 Therapeutics and Vaccines

Miscellaneous
 Bioinformatics Approach
  Coreceptor Predictions
 Slides (PPT/PDF)
 HIV Videos
 Research Centres/Journals
 Discussions

HIV Life Cycle

The HIV life cycle mainly includes six steps:
1. Binding and Fusion: HIV begins its life cycle when it binds to a CD4 receptor and one of two co-receptors on the surface of a CD4+ T- lymphocyte. The virus then fuses with the host cell. After fusion, the virus releases RNA, its genetic material, into the host cell.
2. Reverse Transcription: An HIV enzyme called reverse transcriptase converts the single- stranded HIV RNA to double-stranded HIV DNA.
3. Integration: The newly formed HIV DNA enters the host cell's nucleus, where an HIV enzyme called integrase "hides" the HIV DNA within the host cell's own DNA. The integrated HIV DNA is called provirus. The provirus may remain inactive for several years, producing few or no new copies of HIV.
4. Transcription: When the host cell receives a signal to become active, the provirus uses a host enzyme called RNA polymerase to create copies of the HIV genomic material, as well as shorter strands of RNA called messenger RNA (mRNA). The mRNA is used as a blueprint to make long chains of HIV proteins.
5. Assembly: An HIV enzyme called protease cuts the long chains of HIV proteins into smaller individual proteins. As the smaller HIV proteins come together with copies of HIV's RNA genetic material, a new virus particle is assembled.
6. Budding: The newly assembled virus pushes out ("buds") from the host cell. During budding, the new virus steals part of the cell's outer envelope. This envelope, which acts as a covering, is studded with protein/sugar combinations called HIV glycoproteins. These HIV glycoproteins are necessary for the virus to bind CD4 and co- receptors. The new copies of HIV can now move on to infect other cells.

HIV Life Cycle Image