Question

If HIV first enters the cell in an endocytotic vesicle, instead of directly fusing with the plasma membrane, then

A) HIV infection should be hindered by microtubule polymerization inhibitors such as nocodazole.
B) HIV infection should be more efficient at lower temperatures.
C) intact cortical actin microfilaments should interfere with HIV infection.
D) cells lacking integrins should be resistant to HIV infection.
E) addition of ligands for other cell-surface receptors to stimulate their endocytosis should increase the efficiency of HIV infection.

Answer 1

If HIV first enters the cell in an endocytotic vesicle instead of fusing with the plasma membrane, cells lacking integrins should be resistant to HIV infection.

Step-by-step explanation:

If HIV first enters the cell in an endocytotic vesicle, instead of directly fusing with the plasma membrane, then:

A) HIV infection should be hindered by microtubule polymerization inhibitors such as nocodazole.

B) HIV infection should be more efficient at lower temperatures.

C) intact cortical actin microfilaments should interfere with HIV infection.

D) cells lacking integrins should be resistant to HIV infection.

E) addition of ligands for other cell-surface receptors to stimulate their endocytosis should increase the efficiency of HIV infection.

To answer the question, we need to consider the steps involved in HIV infection. In the normal process, HIV attaches to the CD4 receptor on the cell membrane, fuses with the plasma membrane, and enters the cell. However, if HIV enters the cell in an endocytotic vesicle, it bypasses the need for fusion with the plasma membrane. Therefore, options A, B, C, and E can be ruled out since they are based on the assumption that HIV fuses with the plasma membrane. Option D is the correct answer because integrins are involved in the fusion process and if cells lack integrins, HIV infection would be hindered. Thus, D) cells lacking integrins should be resistant to HIV infection.