Part 3 HIV Multiple choice questions

11q: what is DC-SIGN ?


Answer: certain dendritic cells express a diversity of C-type lectin receptors on their surface, one of which is called DC-SIGN, that also binds with high affinity to the HIV gp120 envelope protein, allowing dendritic cell to facilitate the binding of HIV virus to the CD4+ T cell upon engagement of dendritic cells with CD4+ T cells .


12q: what is TRIM5-ALPHA ?


Answer: it is a cytoplasmic protein found in rhesus macaque cells which blocks SIV
( simian immunodeficiency virus ) replication at a point shortly after the virus fuses with the host cell .


13q: what is the human form of TRIM5-ALPHA ?


a. cyclophilin A
b. cyclophilin B
c. cyclophilin C
d. cyclophilin D

answer a. cyclophilin A

14q: what are the proteins in humans that bind to nascent reverse transcripts and deaminate viral cytidine , causing hypermutation of HIV genomes and inhibits progression of virus infection after virus has entered the cell ?


a. TRIM5-ALPHA protein
b. Cyclophilin
c. APOBEC proteins
d. All the above

answer c . APOBEC proteins

15q: what is the powerful strategy evolved by HIV to protect itself from the APOBEC proteins ?


a. the viral protein Vif targets APOBEC for proteasomal degradation
b. the viral protein Vpu targets APOBEC for proteasomal degradation
c. the viral protein Vpx targets APOBEC for proteasomal degradation
d. the viral protein Vpr targets APOBEC for proteasomal degradation

answer a . Vif targets APOBEC for proteasomal degradation

Part 2 HIV Multiple choice questions

6q: what is the name of the species of the chimpanzee that has been established as the natural reservoir of HIV-1 ?

answer pan troglodytes troglodytes

7q: HIV-2 is more closely related phylogenetically to which virus ?


a. HIV-1 of chimpanzees
b. Simian immunodeficiency virus ( SIV ) in sooty mangabeys
c. SIV in sykes
d. SIV in African green monkeys

answer b . SIV in sooty mangabeys

8q: what are the two major envelope proteins that surround the HIV virion ?


a. gp 120 and gp 40
b. gp 120 and gp 41
c. gp 120 and gp 42
d. gp 120 and gp 43

answer b . gp 120 and gp 41 . gp 120 externally and gp 41 below it .

9q: all of the following are true about HIV except ?


a. it is a DNA virus
b. it has the enzyme reverse transcriptase
c. the gp120 protein binds to the host cell via the receptor called CD4 molecule
d. the CD4 molecule is a protein found predominantly on a subset of T lymphocytes
e. the CD4 is also present on monocytes/macrophages and dendritic/langerhans cells

answer a . HIV is a RNA virus and not a DNA virus

10q: once gp120 binds to CD4 , the gp120 undergoes a conformational change that facilitates binding to one of a group of co-receptors . what are the two major co-receptors to which HIV attaches ?


a. CCR5 and CXCR4
b. CCR6 and CXCR5
c. CCR7 and CXCR6
d. CCR8 and CXCR7

answer a . CCR5 and CXCR4