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The 7 stages of the HIV life cycle explained

The HIV virus

The HIV virus is a virus that attacks the bodies CD4 cells, these are the cells the body uses to fight diseases, infections and foreign bodies.  Once infected the virus remains in the body and if not treated will eventually overpower the bodies immune system completely leaving it vulnerable and unable to fight off infections.  The ART drugs in use today are grouped into drug classes each of these are designed to deal with different stages of the HIV virus’s life cycle.

The 7 stages of the HIV life cycle explained

#1 Binding
This is the very first stage of the HIV Lifecycle.  The HIV virus attacks the CD4 cell and attaches Itself to the cell on its surface.  It does this by first attaching to the CD4 cell’s receptor than the CCR5 or the CXCR4 coreceptor.

#2 Fusion
The second stage of the HIV life cycle is called fusion and this is done after the virus has effectively attached itself to the CD4 cell.  The entire HIV viral envelope will then fuse with the cell which allows it to gain entry into it.

#3 Reverse Transcriptase
The third stage happens once the HIV virus has entered the CD4 cell.  This allows the virus to release an HIV Enzyme or reverse transcriptase enabling it to convert the virus’s genetic makeup.  It converts its HIV RNA to HIV DNA.  This conversion is what allows the HIV Virus to enter the cell’s nucleus to integrate with it.

#4 Integration
When the HIV virus has successfully entered the CD4 cells nucleus it releases another HIV enzyme known as integrase.  This is the enzyme the virus uses to integrate its own DNA into the infected CD4 cells DNA.  This is the fourth step in the HIV virus life cycle.

#5 Replication
The fifth stage of the HIV life cycle is when the virus starts to form HIV proteins in long chains.  `These are the protein chains that the HIV virus uses to replicate itself and spread to other CD4 cells in the body.

#6 Assembly
The sixth stage of the HIV virus life cycle is when the new HIV RNA and proteins which are now produced by the infected CD4 cell make their way to the surface of the cell to assemble into noninfectious immature HIV.

#7 Budding
The final stage of the HIV life cycle is when the immature HIV is released from within the infected CD 4 that produced it.  Being an immature HIV, it is unable to infect another CD4 cell, so it releases another HIV enzyme known as a protease.  The function of This enzyme is to break up the long chains of proteins forming the immature HIV.  Once separated they then combine and mature into the infectious form of HIV,


Understanding the various stages of the HIV virus helps to better understand the disease itself and how the various drugs may help.

info3 - The 7 stages of the HIV life cycle explained
Infographic by: the-scientist.com