Module 5-2 - HIV Flashcards
How big is the HIV issue?
1 in 7 do not know they have it and over 1 million in the US have it alone
Globally 37.9 million have it and 32 million have died
In what groups has the highest Incidence of HIV?
African American gay and bisexual men, but Latino gay and bisexual men have increased in incidence over time
What area of the US has the largest incidence of HIV?
The South (52%)
What does HIV stand for?
Human Immunodeficiency Virus
What does AIDS Stand for?
Acquired Immunodeficiency Syndrome
It is the late stage of HIV and is the disease caused by it
What is the structure of an HIV viral particle?
Oval Shaped Protein Coat
Capside with RNA, enzymes, P24 Protein, and P17
Envelope with the lipid layer, GP120 and GP41 - Glycoproteins sticking out of the lipid membrane
What is special about the HIV P24 protein?
This protein serves as an antigen that we can test for antibodies and for the the virus presence/antigen
GP120 and GP 41
Glycoproteins that are like spikes sticking out of the lipid membrane and aids HIV in getting into cells
What is one of the components of HIV that makes it unique?
It contains reverse transcriptase enzyme
Most viruses cannot…
replicate on their own, they need to be in a cell to reproduce
Retrovirus
HIV
it inserts itself as vRNA and makes DNA from the vRNA, and then splices the vDNA into the genetic material of healthy cells
So, it enters the hosts genetic material causing a permanently infected cell
What does a new virus take from an infected cell when leaving?
It takes the phospholipid bilayer for itself
Capsid
The protein shell of a virus containing its genetic material
It has 2 strands of RNA, Reverse Transcriptase, and P17 and P24 proteins in it (in HIV)
Envelope
Lipid bilayer containing the virus and capsid that has GP120 and GP41 sticking out of it (in HIV) allowing access to cells
Made from the host cells membrane as it left the cell
How exactly does a retrovirus infect cells?
The GP120 and 41 on the surface allow it to bind to CD4 receptors on T4 cells and then inject its contents into the cytoplasm
The contents (2 RNA strands and reverse transcriptase) can then be used to make DNA
What aspect of HIV causes the immune deficiency disorder?
The fact that it infects and hurts T4 cells (thus hindering the immune response)
What occurs once reverse transcriptase uses the viral RNA to make DNA?
The DNA then goes from the cytoplasm into the nucleus, and along with other viral enzymes, inserts itself into the host cell genome
Once vDNA is inserted, its there permanently and the cell is infected and no longer your own
RNA can then be made using the DNA to make virions using the cells machinery
What can occur after the vDNA has entered the genome?
It can either go latent or activate and begin making viral particles (RNA and RTranscriptase)
Latent
A virus that inserts itself and remains dormant, not producing new viral particles
It can do this if there is not the right kind of GP on the surface or if the formation of a capsid hasn’t progressed to maturity yet for example
What happens once vDNA activates to make new Virions?
Proteases will cleave proteins made by viral mRNA and package them into a protein coat
The viral particles can then be put into the protein coat to make the immature capsid
The capsid can eventually make an envelope using the phospholipid bilayer of the cell and bud off the membrane to go make more infected cells and copies
Thera re classes of HIV meds addressing…
every step of HIV reproduction
What happens since the new virion takes a chunk of the membrane with it?
It will have GP120 and GP41 on its surface of the envelope
Can then connect to CD4 on other T4 cells and invade as a result
Where do the names of GP120 and GP41 come from?
their molecular weight
Why can T8 cells have difficulty killing virus infected cells?
If the virus DNA is already in the nucleus, the T8 cell cannot identify that the cell is infected unless the virus is actively replicating already