BL- Immunology of AIDS Flashcards
First described in 1981, by 2004 it was the 5th
leading cause of death in the world, the 4th in
developing countries. So far, 36 million have died.
HIV/AIDS
HIV is a nontransforming retrovirus, that is, an RNA virus that carries no oncogene, and reproduces itself by copying its RNA into DNA by means of its own enzyme:______
reverse transcriptase
Retroviridae virus family
characterized by a long incubation period.
can deliver a lots of viral RNA into the DNA of the host cell
able to infect non-dividing cells, so they are one of the most efficient methods of a gene delivery vector.
ex: HIV
lentiviruses
SIDA
another name for HIV/AIDS
Where does HIV-1 come from/orginate?
originates from a Simenon virus
SIV(cpz)—> humans (HIV)
*also crossed into gorillas (~1920)
AIDS is caused by a virus called HIV-1, for:
Human Immunodeficiency Virus.
Gorilla SIV(gor) spread to
Humans. Created another HIV subtype
There have been 4 jumps
When a virus jumps species it becomes ______
More virulent
long-term survivors
homozygous for a 32-base pair deletion in the gene for a chemokine receptor, CCR5 (they were CCR5d32).
HIV resistant
CCR5 is an HIV _____
coreceptor
elite controllers
long-term survivors group- became infected but did not progress to AIDS. Two-thirds of them have the HLA-B57 allele.
HIV is
a non transforming retrovirus
slow acting
______ is an HIV coreceptor
CCR5
HLA-B57 allele.
elite controllers
non transforming virus means
no oncogene
SET Point
Variable viral titer concentration of HIV after immune system responds to HIV.
The virus does not completely go down like normal virus
T cell number cut off for AIDs
200
below 200 you will experience opportunistic infections
HIV viral structure
RNA reverse trascriptase bilayer lipid membrane (human) gp120 gp41
The only good thing about HIV virus structure?
Bilayer lipid membrane from humans
Once this dries out, its dead
Doesn’t survive well in environment
T helper cells have ___ on the surface
CD4
_____ from HIV binds the CD4 of Th
gp120
______ from HIV invades the CD4 Th
gp41
One Fate of an HIV infected cell is?
To die.
Being ripped apart by virus leaving with it’s membrane at a high rate
Viral Resivoir
Tfh cells
Tfh cells
a distinct subset of CD4+ helper T (Th) cells that regulate the development of antigen specific B cell immunity.
If the cell does not die or become reservoir for HIV, then…..
There is latent infection
gp120 and gp41 stud the infected cell’s membrane before
the virus buds
gp120 grabs the ___ adjacent cell and fuse them
Th
This lets the HIV virus pass internally
No exposure to antibody
Reverse transcriptas has ____ rates of mutation
very high
Mutates every cycle of replication, making it hard to fight
CCR5d32
Have resistance to HIV
Th get infected less
North European Caucasians have 11% allele frequency
Antibody to HIV peaks by ________
9-12 weeks
The most common test is for _______ to HIV
antibody
Reverse transcriptase (RT) is unique to retroviruses, using their RNA template to create DNA, so it’s a _________
good drug target.
Elite Controllers have
really well controlled HIV infection
Almost all HLAB57
HLAB57 is very good to
presenting HIV antigens/peptides
Make very good CTLs
HLAB57 develop ______ to a specific drug
Delayed hypersensitivity to abacavir (an HIV treatment)
HIV diagnosis
ELISA- many false positives
Followed up with western blot for + tests
PCR- very sensitive
______ is an approved DIY HIV test, available in stores
OraQuick
Tests IgG in the mouth (crivicular fluid)
NRTI
Nucleoside reverse transcriptase inhibitors
Anti retroviral therapy
3 drug cocktail:
2 competitive inhibitors
1 non-nucleoside (NNRTI)
HIV vaccine problem
Same problem as flu
May neutralize 1 HIV, but not many of the other viruses
bnAb
bnAbs have been found, they are rare, only found in a subgroup, take years to develop, and are extensively hypermutated; no method exists now for induction of these Abs by immunization
The CD4 binding site of gp120 usually _____
does not mutate (and still be HIV)
The CD4 binding site of gp120 can be selected for by _____
bnAbs
*may be useful for vaccine development
