Lecture 16 - Human retroviruses Flashcards
Which countries/areas of the world have the highest prevalence of HIV-1 infections
Africa and Asia; 28% Africa
What 5 things make up the retrovirus structure
capsid, RNA, envelope glycoproteins, matrix proteins, reverse transcriptase
What are the 2 envelope glycoproteins of the retrovirus structure?
gp41 and gp120
What is a provirus?
genetic material of a virus
What are the 4 essential proteins?
gag, pro, pol, env
What are the 6 steps in the retrovirus replication cycle?
penetration, reverse transcriptase, integration to host DNA, transcription/translation, assembly, budding, release
What is the host receptor that HIV attaches to?
CD4
Which type of cells does HIV 99% replicate in?
uninfected CD4 lymphocytes
Which type of cells does HIV <1% replicate in?
macrophages and infected resting CD4 lymphocytes
Are HIV viruses lysogenic or lytic viruses? Why?
lysogenic, they can be latent
What is HTLV viruses?
human t-cell leukemia-lymphoma virus
Which HIV causes AIDS in Africa and has less infections?
HIV-2
Which HIV is the main causative agent of AIDS?
HIV-1
How many clinical categories of HIV infections are there?
3
Which clinical category of HIV infection includes asymptomatic patients as well as mildly symptomatic?
category A
Which clinical category of HIV infections includes severely infected persons and can lead to cancer?
category C
What happens to a person infected with HIV for 2 years?
acute infection
What happens to a person infected with HIV for 4 years?
asymptomatic infection
Around what year of HIV infection will the infected individual experience Candidiasis (yeast infection)?
7 years
What happens to a person infected with HIV for 12-16 years?
PCP, dementia, wasting and death
What happens to the brain of a patient infected with AIDS?
destruction of brain tissue
What are the 4 possible sites if inhibition of HIV replication?
fusion, reverse transcriptase, integrase, protease
How was HIV infection identified as a viral infection?
blood bank filtered blood into the filter to give to hemophiliac patients who got infected with HIV = virus passed through the filter
By 2010, how many people in the US were infected with AIDS and how many people died?
1 MIL infected; 500K died
How many people worldwide are affected with AIDS and how many people died?
33 MIL infected ; 1.6-2.6 died
What percentage of the US population is infected with AIDS?
0.5-1.2%
What shape is the HIV virus?
icosahedral
What gene is the proteins gp120 and gp 41 expressed on?
same gene but cleaved by protease
What protein does gag gene encode for?
p17 protein in the matrix and capsid proteins too
What proteins does pol gene encode for?
polymerase and reverse transcriptase
How long does the provirus within the human chromosome?
years = latency
How long does it take for HIV to replicate?
2.6 days
Which HIV type causes 95% of AIDS infections?
95%
How long does it take for a person to develop AIDS from an HIV infection?
10-16 years
How many drugs must one use for later stages of HIV?
cocktail of 3
Why are first antivirals only effective for a short time during initial stages of infection?
due to mutations
Why are glycoproteins not used as a target?
hard to target
What makes reverse transcriptase difficult to target?
has many errors or mutations
What are the main sites of inhibition of HIV replication?
protease and reverse transcriptase
