Date : Friday, 22 May 2015
Time : 15:25
Title : Mechanism of HIV
Time : 15:25
Title : Mechanism of HIV
In the previous post, we got to learn the overview of how HIV virus enters and attacks us. In this post, we will discuss in further detail of the stages of HIV.
As mentioned, HIV targets mainly on CD4 lymphocyte, also called aT-cell or CD4 cell. When a CD4 cell is infected with HIV, the virus goes through multiple steps to reproduce itself and create many more virus particles.
The process is broken up into the following steps:
1. Binding and Fusion: This is the process by which HIV binds to a specific type of CD4 receptor and a co-receptor on the surface of the CD4 cell. This is similar to a key entering a lock. Once unlocked, HIV can fuse with the host cell (CD4 cell) and release its genetic material into the cell.
2. Reverse Transcription: A special enzyme called reverse transcriptase changes the genetic material of the virus, so it can be integrated into the host DNA.
3. Integration: The virus’ new genetic material enters the nucleus of the CD4 cell and uses an enzyme called integrase to integrate itself into your own genetic material, where it may “hide” and stay inactive for several years.
4. Transcription/Replication: When the host cell becomes activated, and the virus uses your own enzymes to create more of its genetic material—along with a more specialized genetic material which allows it make longer proteins.
5. Assembly: A special enzyme called protease cuts the longer HIV proteins into individual proteins. When these come together with the virus’ genetic material, a new virus has been assembled.
6. Budding: This is the final stage of the virus’ life cycle. In this stage, the virus pushes itself out of the host cell, taking with it part of the membrane of the cell. This outer part covers the virus and contains all of the structures necessary to bind to a new CD4 cell and receptors and begin the process again.
To aid your learning, here is an interactive video on the mechanisms of HIV virus in simpler terms and Disney characters! Who says we cannot incorporate Disney characters into our learning? Enjoy!
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| Life cycle of HIV |
As mentioned, HIV targets mainly on CD4 lymphocyte, also called aT-cell or CD4 cell. When a CD4 cell is infected with HIV, the virus goes through multiple steps to reproduce itself and create many more virus particles.
The process is broken up into the following steps:
1. Binding and Fusion: This is the process by which HIV binds to a specific type of CD4 receptor and a co-receptor on the surface of the CD4 cell. This is similar to a key entering a lock. Once unlocked, HIV can fuse with the host cell (CD4 cell) and release its genetic material into the cell.
2. Reverse Transcription: A special enzyme called reverse transcriptase changes the genetic material of the virus, so it can be integrated into the host DNA.
3. Integration: The virus’ new genetic material enters the nucleus of the CD4 cell and uses an enzyme called integrase to integrate itself into your own genetic material, where it may “hide” and stay inactive for several years.
4. Transcription/Replication: When the host cell becomes activated, and the virus uses your own enzymes to create more of its genetic material—along with a more specialized genetic material which allows it make longer proteins.
5. Assembly: A special enzyme called protease cuts the longer HIV proteins into individual proteins. When these come together with the virus’ genetic material, a new virus has been assembled.
6. Budding: This is the final stage of the virus’ life cycle. In this stage, the virus pushes itself out of the host cell, taking with it part of the membrane of the cell. This outer part covers the virus and contains all of the structures necessary to bind to a new CD4 cell and receptors and begin the process again.
To aid your learning, here is an interactive video on the mechanisms of HIV virus in simpler terms and Disney characters! Who says we cannot incorporate Disney characters into our learning? Enjoy!