List the steps of retrovirus like HIV that causes AIDS.
The HIV virus has reached pandemic disease proportions, since it's discovery in the 80's. The major ways this disease is transmitted is by sexual contact with an infected person, from a blood transfusion from an infected individual, and from mother to child while being born. The HIV virus is classified as a retrovirus, meaning it affects aspects of a person's immune system, which normally eliminates invading pathogens such as the cold and influenza viruses. The steps of progression, in general, are:
1. Entry- HIV typically enters the body using one of the entry methods described above. Spermatozoa tend to harbor the HIV virus in an infected individual, so sexual contact is one of the leading contributors to the spread of the virus. Once inside the human body, it attaches to site-specific macrophages, where it binds to the surface of the cell.
2. Incorporation of genetic material- Once bound to the surface of the macrophage it is invading, the virus inserts it's RNA and enzymes, including transciptase, integrase, ribonuclease, and protease, into the cell's nucleus, where it integrates with the cell's DNA.
3. Dormancy- Once the invasion and integration of the macrophage's DNA is complete, the HIV virus may go through a dormant time range. This is called the latent stage of HIV infection.
4. Assembly- The final stage is to assemble the newly manufactured HIV-integrated DNA and release it into the body's environment, where it will repeat the process by invading and infecting other cells.
It should be noted the HIV virus tends to attack T-cells and other lymphocytic cells that are most numerous when there is an attack of another virus or pathogenic bacteria. People who die because of AIDS (acquired immunodeficiency syndrome) don't die as a direct result of the HIV virus, they die because of their body's inability to combat other pathogens that are normally defeated by their body's immune system.