HIV Questions - Skildum Flashcards
What’s a normal CD4 count?
600-1200 cells/uL
What’s a normal CD4 count?
600-1200 cells/uL
What’s an immunocompromised cell count?
What’s an AIDS cell count?
What’s a severe AIDS cell count?
Viruses are classified by their. . .
. . .Genomic composition, capsid symmetry, presence of envelope.
What are the properties of the HIV-1 infectious particle?
-Enveloped
-Has ssRNA genome
-Has icosahedral capsid symmetry
-Carries reverse transcriptase, integrase and protease
-Infects CD4 positive cells
-
What’s an immunocompromised cell count?
What’s an AIDS cell count?
What’s a severe AIDS cell count?
Viruses are classified by their. . .
. . .Genomic composition, capsid symmetry, presence of envelope.
What are the properties of the HIV-1 infectious particle?
- Enveloped
- Has ssRNA genome
- Has icosahedral capsid symmetry
- Carries reverse transcriptase, integrase and protease
- Infects CD4 positive cells
What does the molecular structure of a nucleoside look like?
NO PHOSPHATES = Just Sugar + Base
-Nucleotides have phosphates-
Key structural features of nucleosides: 3’OH and 5’ phosphate on ribose sugar
Ex: thymidine
When a CD4 positive lymphocyte’s T cell receptor is activated by antigen, what transcription factor is activated?
NF-kB
A mature HIV-1 viral particle contains three functional enzymes within its capsid. Of these three, which two are required for the particle to infect a cell and become a provirus?
Reverse transcriptase - to transcribe genome to dsDNA
Integrase - to insert into the host genome and become a provirus
What is protease required for (third protein in the viral capsid)?
To produce infectious particles
A 53 yr old female is HIV-1 positive with a CD4 count of 130 cells/uL. She has Kaposi sarcoma lesions on her arms and torso which first appeared one month ago. What is the most likely cause of her Kaposi sarcoma?
Inefficient activation of CD8+ T cells.
A patient’s blood was collected and labeled with fluorescent antibodies against CD3, CD4 and CD8. In the dot plot, only CD3 positive cells are shown. What cells are represented by the dots in the upper right quadrant?
Immature T cells!
What does the molecular structure of a nucleoside look like?
NO PHOSPHATES
-Nucleotides have phosphates-
Key structural features of nucleosides: 3’OH and 5’ phosphate on ribose sugar
38 yr old male immigrant from Cap-Haitien, Haiti presents with dry cough that has persisted for three weeks. He is confirmed to be HIV-1 positive, with levels of CD4 cells and viral RNA consistent with AIDS. Microscopic analysis of induced sputum show P. jirovecii sporozoites. The first line treatment for his pneumonia targets. . .
Sequential steps in tetrahydrofolic acid synthesis (Trimethoprim - Sulfamethoxazole)
A 19 yr old male had unprotected sex with a person who was HIV positive. The next day, he asked his family physician whether he had contracted HIV. What test would detect HIV the soonest after exposure?
Sandwich ELISA for p24 antigen
[p24 antigen spikes soon after infection as the virus disseminates systemically]
How does an Indirect ELISA work?
The indirect ELISA measures anti-HIV antibodies in a patient’s blood.
- Antigen comes with ELISA kit
1. Starts with antigen-coated well
2. Add patients blood (has specific antibody that binds to the antigen)
3. Wash step
4. Enzyme-linked antibody binds to specific antibody
5. Wash step
6. Substrate is added and converted by enzyme into colored product; the rate of color formation is proportional to the amount of specific antibody
How does the Sandwich ELISA work?
It measures HIV antigen (e.g. p24 capsid protein) in a patient’s blood.
- Antibodies come with the ELISA kit.
1. Monoclonal antibody-coated well
2. Wash step
3. Patients blood is added and antigen binds to antibody
3. Wash step
4. A second monoclonal antibody, linked to enzyme, binds to immobilized antigen
5. Wash step
6. Substrate is added and converted by enzyme into colored product; the rate of color formation is proportional to the amount of antigen.
What antibodies appear first in HIV-1?
p24 antibodies
