Question

QUESTION 1 3 po HIV predominantly infects T-helper cells, cells that are responsible for coordinating B- and T-cell activity. Based on this information, explain why HIV-infected individuals are at a very high risk for developing microbial infections. List the causative agent (virus) and discuss its properties. Name and briefly discuss 3 diseases that AIDS patients are more likely to contract. (Terminology to use: opportunistic pathogens, T and B cell purposes, CD4 cells, retrovirus, reverse transcription) TTT Arial 3 (12pt) - T-5. E. 3. des Words:0 Path: P Zil San A e re to same all ansu

Answer 1

HIV is a retrovirus of lentivirus family. It has two identical + stranded RNA molecules, the enzymes reverse transcriptase and integrase, and it surrounded with an envelope of phospholipid. HIV is often spread by dendritic cells that present in mucosal linings, which pick up the virus and carry it to the lymphoid organs. In the lymphoid organs virus  combines with the CD4 receptor of the T helper cell. Macrophages and dendritic cells also carry CD4 molecules. T helper cells (TH cells) cooperate with B cells in the production of antibodies, mainly through cytokine signaling. Once inside the host cell, viral RNA is released and transcribed into DNA by the enzyme reverse transcriptase. The viral DNA then becomes integrated with the host’s DNA with the help of viral integrase. Now the host cells act as the virus factory and produce copies of virus particles. Billions of CD4+ T cells may be infected within a few weeks, lowering their numbers. Clinically AIDS is considered when CD4+ T cell counts fall below 200 cells/μl that increases the susceptibility to opportunistic pathogens is high. (The normal population in a healthy individual is 500 to 1500 CD4+ T cells/μl.) Important AIDS indicator conditions appear, such as C. albicans infections of the respiratory tract; cytomegalovirus eye infections; tuberculosis; Pneumocystis pneumonia; toxoplasmosis of the brain; and Kaposi’s sarcoma. HIV infection devastates the immune system, which is then unable to respond effectively to pathogens.
Three diseases that AIDS patients are likely to suffer:

Tuberculosis: It is caused by bacteria Mycobacterium tuberculosis and usually affects the lungs. Typical sign and symptoms include weight loss, chills, fever, night sweating, persistent cough.

Toxoplasmosis: It is an infection caused by a parasite known as Toxoplasma gondii. Symptoms are flu like with swollen lymph nodes and muscle ache.

Pneumocystis pneumonia: It is a lung infection caused by Pneumocystis jirovecii. It is a yeast like fungus. Symptoms are fever, chills, breathlessness, fatigue etc.