Question

What is the mechanism by which the AIDS virus causes deficiency of the immune system of the infected person?

Answer 1

Hint: AIDS stands for Acquired immune deficiency syndrome. It is a syndrome in which the body loses its ability to fight infections.

Complete Answer:
- AIDS is caused by the HIV (Human immunodeficiency Virus) virus. HIV is a member of genus Lentivirus. HIV virus belongs to the family Retroviridae.
- It is a late stage of infection because a person can live many years after the entry of HIV virus without experiencing any symptoms.
- Symptoms can be seen after a long time. If the infection progresses, it increases the risk of other infections too like tuberculosis, tumors, etc.

Modes of spreading:
- Unprotected sex
- Contaminated blood transfusion
- Breastfeeding
- Mother to child during pregnancy
- Hypodermic needles

Mechanism:
- Virus after entering into the body first enters the macrophages cells (phagocytic cells of the immune system).
- Inside the macrophages virus produce viral DNA from its RNA by using the enzyme Reverse transcriptase.
- After that the viral DNA integrates itself into the host DNA and starts multiplying with the host DNA by the process of DNA replication.
- At the same time viruses enter into the T-lymphocytes (White blood cell) and also multiply there in order to form more and more viral progenies.
- The cell ruptures and releases viral progenies which then attack other T-lymphocytes.
- As a result the number of T-lymphocytes in the body of the affected person decreased and thus decreased the power of the immune system of the affected person as T-lymphocytes and B-lymphocytes with other immune cells responsible for the proper functioning of the immune system.

Note: Immune system is a complex system which provides protection to the body against infection. It is a system of many cells, and proteins that work together to defend the body. The immune system also has memory cells which keep a record of every microbe that entered the body so that it can recognise and destroy that particular microbe when it enters the body again.