Lecture 8: Special Topic AIDS Flashcards
What is a virus?
Viruses are obligate intracellular parasites. They carry all of the material, but no machinery for replication. Viruses use host machinery to produce viral nucleic acids and other viral products.
Does HIV cause an acute illness? What are some symptoms?
Yes! ; fever, chills, headache, skin rash, malaise, joint pains, muscle aches, swollen lymph nodes, stiff neck.
Is the HIV antibody test definitive?
No, early on the body does not produce antibodies to HIV immediately. A second or third test should be conducted later on. It takes days for adaptive immunity B cells, to produce antibodies. (3-4 weeks) specifically for HIV
Can you measure the amount of HIV independent of antibodies?
Yes. You can use PCR to amplify amounts of viral nucleic acids.
Timeline for HIV
Day 1:infections ; 1-2 weeks symptoms; 3-4 weeks antibody production.
Does HIV progress in the same way in all individuals?
No. But by looking at viral load a year after infection, public health officials can predict prognosis. Viral load predicts illness. The higher the viral load, the faster the development of AIDS. The lower the viral load, the slower the development of AIDS.
What type of cells does HIV infect? Why?
HIV infects Helper T cells. HIV has a protein envelope that is specific to T cells (CD4+ and chemokine receptors).
What is the role of integrase in HIV infection?
Integrase (makes nick in host cell DNA and inserts viral DNA into host cell DNA)
How does HIV establish lifelong infection?
Lifelong infection arises from viral DNA’s ability to implant itself into its hosts DNA.
What role does protease play in viral infection?
Important in maturation of a virion; cleaves complex of viral components so they can infect other cells.)
What is the role of ubiqutin in adaptive immunity?
Ubiqitin binds to viral components or pathogenic components and aids in the expression of pathogenic material on MHC I molecule for CD8+ recognition.
Are CTLs able to limit HIV replication?
Hell yeah!!!!! In Vitro… not in vivo
If CTLs are capable of limiting HIV replication, why is HIV so successful?
HIV infects CD4+ Helper cells, which orchestrate an effective immune response. The body becomes overwhelmed with opportunistic infections, and does not have the ability to deal with the virus. CD4+ declines causing AIDS.
Why would one person have a high viral load, while another does not?
Difference in genetic makeup and difference in the effectiveness of an individual’s immune system.
Are there some people immune to HIV?
To some extent. There are some individuals in the population who are not susceptible to HIV, because of mutations in CD4+ receptors, and other unknown defenses.
