Can someone please help me with the following questions. I've written my specific doubts right after the question. Thank you so much!
Human immunodeficiency virus (HIV) is a retrovirus. Its genome is a single (+) stranded RNA that is packaged with the reverse transcriptase enzyme within a protein capsid. This is further packaged into an envelope that is derived from the plasma membrane of the host cell in which the virus had replicated. The surface of the envelope is covered with the envelope glycoprotein, called gp120 & gp41.
a) HIV specifically infects the T- helper (TH) cells of the human immune system. If the HIV enters the host cell by means of host receptor recognizing a viral protein, what would be the most likely ligand and its corresponding receptor during HIV infection?
b) Some individuals are resistant to HIV infection even after repeated exposure. Assuming that these individuals express a normal level of the functional receptor that you have recognized above, how can you explain their resistance to HIV?
c) In recent years, therapies have been developed to fight AIDS using nucleotide analogs. The drug used to combat AIDS is Azidothymine (AZT). The structure of AZT is very similar to thymidine except that in AZT, the 3’-OH group on the deoxyribose sugar is replaced by an azido (N3) group. Which process of the life cycle of HIV do you think is inhibited by AZT?
d) Combination therapy is the new treatment strategy for treating HIV patients.
i. Why is combination therapy more successful in preventing the emergence of the disease resistant clones?
ii. If the combination therapy involves a drug that prevents…
1) HIV binding to the target cell, what protein does this target?
2) Integration of HIV genome into host cell genome, what protein does this target?
3) The cleaving of viral polypeptide into individual proteins, what protein does this target?
e) If the AIDS patient were given combination therapy, would the patient still be able to transmit the HIV virus to his/ her partner (Yes/ No)? Explain your choice.
a) No idea.
b) Maybe their T-helper cells have some sort of mutation that makes it impossible for HIV to bind to them?
c) I'm thinking "formation of HIV RNA" because in the absence of 3' -OH bonds, phosphodiester bonds cannot form.
d) i. It kind of makes sense because a virus being resistant to multiple drugs would be very unlikely but maybe there's some definite reason why?
ii. No clue. Is this talking about proteins of the virus or of the host? Also, enzymes are also proteins, right?
Thank you a million times!