Immunology and AIDS Flashcards
When Th(CD4+) cells fall below _____ of blood, a diagnosis of AIDS is made.
200/microliter
What percentage of people living with AIDS are unaware?
16%
OraQuick is a home test for HIV antibody why is it unreliable?
Because it gives a lot of false negatives (1:12)
Which strain of HIV has not gone global yet?
HIV-2
Describe HIV.
Nontransforming retrovirus that uses reverse transcripase to copy its RNA genome to DNA
HIV is a part of what group of viruses?
Lentiviruses
What virus is HIV most closely related to?
Simian Immunodeficiency Virus, SIV
What is considered risky behavior?
Sexual contact with someone with the disease
Any contact through injured mucous membrane
Do circumcised males decrease the spread of HIV?
Yes
“Long term survivors” are genetically unique in that they….
Have a homozygous deletion of CCR5
Their T cells can’t get infected, but there DC and macrophages can
Found in 10% of Caucasians
What are Elite controllers?
HLA-B57 make effective CTL to HIV peptides presented in HLA-B57. Can become infected but did not progress to AIDS
After exposure at what time does the antigen peak in the body?
At what time does the antibody peak=?
6 weeks
9 weeks
What is a DC-SIGN?
When HIV adheres to a lectin on dendritic cells
What viral protein binds CD4+ and then CCR5?
gp120
What is gp41?
Glycoprotein associated with gp120. That, when it changes its conformation, exposes a very hydrophobic region that literally melts away the T cell’s membrane so the cell and virus fuse
What helps the double-stranded DNA copy of HIV insert into the host DNA?
Viral integrates helps it insert into a random break
How many genes does HIV encode?
9
How often is the entire population of virus replaced?
Everyday.
How can syncytium form between two T cells?
gp120/gp41 is made early and inserted into the membrane. That way a infected T cell can infect a healthy T cell without the virus being released
HIV persists in memory Tfh cells so as the disease progresses what other cell line is likely to be affected?
B cells
Name some opportunistic infections associated with AIDS.
Candida or the mouth, esophagus, and rectum
TB- Most common cause of death
Kaposi sarcoma
Burkitts
Late AIDS dementia- infection of microglia
Is a positive ELISA test enough evidence to diagnose someone with HIV?
No because ELISA has a lot of false positives. You would have to follow with a western blot for HIV antibodies
What can you do to test what therapies will have the most effectiveness?
PCR
What was the first treatment for AIDS introduced in 1987?
AZT
name two classes of Reverse transcriptase inhibitors.
- Nucleosides (NRTI)- Competitve inhibitors & chain terminators
- Non-Nucleoside (NNRTI)- Bind to hydrophobic pocket on enzymes that changes the conformation and activity of catalytic site.
You can use a protease inhibitor for products of what three genes?
gag
pol
env
Which all make proteases
What drug binds to gp41 preventing conformational change so it cannot melt the membrane?
Enfuvirtide-Fusion inhibitor
What drug acts as a CCR5 antagonist and blocks viral entry?
Maraviroc
What drug acts as a integrase inhibitor?
Raltegravir
What is the standard antiretroviral therapy (ART)?
Combines two NRTI and a third drug from a different class
What is the three pronged approach to prevention of HIV transmission?
- Safe sex
- Tenovir- anti-HIV drug used in lube
- Prophylactic ART protects noninfected partner and fetus
Is there hope for a vaccine in the future?
Yes by using a broadly neutralizing antibody that can block infection by almost all HIV strains and mutant forms
What kills more people according to the wold statistics in 2012: Seasonal influenze or AIDS?
Influenza
