Question

Recent advances in HIV research have led to development of drugs that can prevent the spread of HIV virus in the host. Thinking about the replication cycle of the HIV virus, list a likely drug target encoded by the HIV viral genome and explain in your own words how this new drug might work to stop the spread of HIV virus in the host.

Answer 1

The HIV can infect a healthy person through blood contact, sexual reletionship with an infected person or from an infected mother to her unborn child.

After entering the host body, the virus enters the macrophages.

Here , the viral RNA is replicated to form viral DNA by the enzyme reverse transcriptase. The viral DNA now gets incorporated into the host's DNA and directs the infected cells to produce viruses. The macrophages continue to produce virus particles.

Now , the virus particles enter helper T- lymphocytes in the blood and continue to replicate and produce viral progenies. This results in the reduction in the number of T- lymphocytes in the body of the infected person.

With the decrease in the number of T-cells, the immunity of the person also decreases . The person is unable to produce any immune response even against common bacteria, other viruses and parasites.

The HIV is a retrovirus i.e it has a RNA genome. It needs the help of certain transcription enzymes to replicate its RNA into DNA . If the drugs are targetted to make the transcripyion enzymes inactive then the virus will not be able to convert its RNA into DNA and thus will not be able to replicate itself inside the host cell.

These drugs could be an effective way to stop viral replication inside the host cell.

Another drug could be designed to target the viral RNA. Some nucleosides or nucleotided could be introduced in the body of the infected person [in the form of medicines ] which would target the viral RNA and disturb its sequence so that it is incapable of using the host DNA for replicating .