Replication and Mutation of HIV

HIV allows itself to be "eaten" by the defense cells and this way it gets into the defense cells of the human body. At the same time the virus brings along the enzyme "reverse transcriptase" which transforms the genetic material of the virus itself (RNA) into the human genetic material (DNA). The genetic material of the virus is then built into the one of the host cell, where it can lie dormant for many years.

When replicating, the virus tricks the defense cells in the same way. If the defense cell receives a command to replicate (for example to kill HIV or other viruses or bacteria), this triggers the replication of HIV. While replicating, the virus uses the host cell for its own purposes, exploiting its nutrients. Thousands of HIVs are immediately formed, destroying the defense cells. The new HIVs in turn attack other defense cells.



HIV is assimilated into the host cell (helper cell):

1. HIV docks with the CD4 receptor of the helper cell.
2. HIV smuggles in its genetic material (RNA).
3. Reverse transcriptase of the helper cell converts the RNA into DNA.
4. Integrase integrates the viral DNA into the DNA of the cell nucleus of the host cell.

The replication of HIV:

5. HIV-DNA is converted into RNA.
6. Protease builds up new HIV (sprouting).
7. HIV detaches itself from the host cell (budding).

When the genetic material is transformed and copies of genetic material are made for the production of new viruses, more and more new HIV variants emerge due to "translation mistakes". These variants can differ in character from the original HIV, varying for example in infectivity and in the speed with which they lead to AIDS and to death. Several million virus variants have been observed to develop in just one person infected with HIV.

This mutability enables HIV to adapt to its surroundings, and this is the reason why HIV may quickly become resistant to drugs and why attempts to develop either a vaccine, or drugs that could cure a person already infected with HIV, have been, so far, unsuccessful.