Blood And Immune Lecture 20 Flashcards
What does AIDS and HIV stand for
Acquired immuniodeficiency syndrome
Human immunodeficiency virus
What type of virus is HIV? How long after infection do symptoms occur?
Slow/lentivirus
Retrovirus
5-10 years
What cells does HIV infect and what is its mode of transport?
T-helper lymphocyte
Macrophages
Bodily fluids
Name the parts of the virus from outside to inside
gp120) gp41)- glycoproteins Lipid membrane Matrix proteins Capsid RNA x2 Reverse transcriptase
Enzyme that incorporates cDNA into host genome
Integrase
How many genes, mRNA and proteins does the virus code for?
9 genes
9 mRNA
19 proteins
3 main poly proteins and their proteins?
What are the poly proteins cut up by?
gag- matrix, capsid, NC
Pol- proteinase, rev. Trans., integrase
Env- SU(gp120 to CD4), TM(gp41 fusion)
Viral proteinase
3 types of of the 19 proteins that we look at?
Surface proteins
Reverse transcriptase
Proteinase
To what cells and to what does the gp120 attach in humans
Human protein CD4 on t helper cells and macrophages
Two drugs agains HIV/AIDS?
AZT- targets reverse transcriptase stopping transcription
HAART- treatment with a combination of reverse transcriptase and proteinase
Virus life cycle step 1-7
1) HIV gp120 binds to CD4( part of MHC II)
2) virus capsid transported in after fusion by receptor mediated endocytosis
3) protein coat is shed and RT makes cDNA
4) cDNA integrated - INTEGRASE
5) cell replicated
6) activation causes new virus
7) new virus’ budd off into blood
How is AIDS caused?
HIV virus eventually is created too fast for new T cells to balance and t helper cell and macrophage level drops
No T-cells= no specific immune system
How many stages? What are they?
Stage 1) immune system diminishes viral load but HIV makes it into cells in lymphatic system
2) viral load glides and HIV is released from nodes
3) extensive loss of antibodies and cell-mediated immune response. AIDS is when T cell is 20% 500-1200 normal level.
Why is HIV important?
It is a widespread epidemic
It is incurable
No vaccine, and little progress…
What does HIV proteinase consist of
Two 99 amino acid chains
