HIV Flashcards
What cells do HIV infect?
CD4+ T cells
True or false: HIV causes fast progressive loss of CD4 T cells
False
-Slow progressive loss of CD4 T cells
-lentivirus –> lenti = slow
What is AIDS
Acquired immunodeficiency syndrome
HIV envelope proteins gp41 and gp120 bind to what?
CD4 T cells
What are the co-receptors of HIV and what do they do
CCR5-macrophages and memory CD4 T cells
CXCR4-naive CD4 T cells
What do all retroviruses have?
-gag
-pol
-env
What makes accessory genes?
Multiple splice variants
What are the accessory genes in HIV
-Tat & Rev: needs both to facilitate life cycle
-Vpu: arms race w/ Tetherin
-Vpr: arms race w/ SAMHD1
-Vif: arms race w/ APOBEC3
-Nef: prevents MHC I from getting to cell surface
What is an advantage of Nef
Nef: prevents MHC I from getting to cell surface
-CD8 T cells will not recognize infected
-NK cells will see MHC I is not present & kill them
Where did HIV1 come from?
Old world monkey SIV jumped to chimpanzees and gorillas
-jumped to humans (4 times, twice for each)
Where did HIV2 come from?
Directly from old world monkey to humans
Which HIV is more pathogenic 1 or 2
HIV 1
Whats the diff between SIV and HIV
-SIV in monkeys are not as pathogenic since monkeys have evolved w/ it for a long time
-HIV causes AIDS in humans and pandemic b/c we have not evolved w/ it–> accessory proteins in lentiviruses do host-virus arm races
The most diversity of HIV exists in
Africa
Host immune target factors in HIV
-Tetherin
-TRIM5a
-APOBEC3
-SAMHD1
Drug target factors in HIV
-Fusion inhibitors
-CCR5
-Protease
True or false: Once infected w/ HIV you can eventually stop taking antivirals
False
-on antivirals for life or virus will re-emerge and become AIDS
Name 2 ways to “cure” HIV
- Shock and kill –>shock cells to activate transcription of latent cells and kill infected cells
- Bone marrow transplant from donors who have mutant non functional CCR5 that is required for HIV infection
What are endogenous retroviruses (ERV)?
-type of EVE that comes from retrovirus
-can’t leave the cell (dead)
-can move
True or false: Like paiplloma viruses, endogenous viral elements do not have to be germline
False
-integrates into germline
What are endogenous viral elements (EVE)
-when viral genome becomes integrated into host genome
-must be integrated in germline
What are endogenous retroelements (retrotransposon)
-use RT and integrase to move around
True or false: Our genomes are not viral in origin
False
-Our genomes are mostly viral in genome
-LINES (mostly dead)
-SINES (jump around)
-DNA transposons
What are some consequences of transposon element movement?
-cause mutations
-genome rearrangements (caused by identical elements)
-Affects germline
What are some benefits of transposon element movement?
-Mutations can create new genes/regulation that are beneficial to us by domestication/co-option
What is an example of domesticated retroelement and how does it work?
Fv1
-domesticated viral capsid that stops viral replication
-jams into capsid & disrupts replication
How does Fv1 differ from Trim5a?
-Fv1 is domesticated
-Trim5a binds to capsid to prevent other capsid subunits from binding where Fv1 is a capsid itself and stops replication
What viruses/groups can form syncytia?
-Retroviruses (group 6)
-Paramyxoviruses (group 5)
Syncytia is usually pathogenic, but when domesticated it can be beneficial, how?
-domestication of endogenous retrovirus forms syncytiotrophoblast –>strong barrier b/c no gaps between cells since fused
-forms a layer in placenta
How many times has the domestication of syncytin happened?
10 times
