11. What is the mechanism by which the AIDS virus causes deficiency of immune system of the infected person?
AIDS is a viral disease caused by the HIV virus. It is considered to be one of the most dangerous diseases with no cure until now. HIV affects the immune system of the body and makes it unable to perform its usual functions. The mechanism by which HIV virus causes deficiency of the immune system is as follows:
1. After entering into the system, HIV binds itself to the surface receptors present on helper T-cell and introduces its RNA and reverse transcriptase enzyme into these cells.
2. After this, by utilizing the host cell's machinery, HIV produces a copy of DNA itself through reverse transcription.
3. This copy of DNA gets incorporated into the genome of the host cell. This is called the provirus form, which directs the viral genome to produce new virus particles.
4. The subsequent formation and release of viral particles destroy the host cell. As a result, the number of T helper cells decreases.
5. AIDS occurs when the count of helper T-cells falls very much and the body is unable to fight against diseases.