Flashcards in Sexually transmitted viruses Deck (34):
What marks a patient positive with HIV?
A tcell count less than 200 uL or the presence of pneumocystis carinii, kaposis sarcoma.
Which serotype is more likely to develop into AIDS?
HIV-2 is less likely to lead to AIDS than HIV-1
What does gp-120 bind?
gp-120 in HIV binds CD4 (T cells, monocytes, and macrophages)
It then can bind with a co receptor either CCR5 and CXR4.
What characteristics do CCR5 tropic HIV particulates have?
These guys have the gp120 bind to CCR5 and are typically passed from person to person early in the disease infecting macrophages and microglia.
What characteristics do the X-4 tropic HIV particulates have?
Uses CXCR4 as a co-receptor.
*Approximately 40% of patients transition from R5 to X4 during the course of the disease.
*Associated with the rapid progression of HIV.
Which molecule found in HIV mediates fusion?
gp41 mediates fusion between the viral envelope and the plasma membrane.
The prophase HIV virus is referring to which part of the HIV life cycle?
The prophase virus is the virus following insertion into the host genome via Integrase.
By what method do progeny HIV virions leave the cell?
They leave the cell by budding!
A heterozygous deletion of the CCR5 gene causes what in HIV?
A heterozygous deletion causes a longer asymptomatic period before the onset of AIDS.
What occurs following a homozygous deletion of CCR5 gene?
No infection with R5-tropic HIV viruses will occur!
HIV maturation describes the process where what occurs?
The process of the viral protease cleaving the gag and gag-pol viral polypeptides. This is essential for the infectivity of the virion.
What is the overall transmission risk of HIV from mother to child?
When is the child most at risk for contracting HIV from mother in the process of birth?
Most at risk during birth, least likely before and after birth.
Describe HIV - Acute HIV syndrome
Seen 3-6 weeks following infection with symptoms very similar to infectious mononucleosis.
Burst of viremia seen but may not have detectable levels of anti-HIV antibodies at this time.
When does the bodies immune response usually begin curtailing HIV infections?
Shortly after the initial burst of viremia seen in Acute HIV syndrome the immune system creates antibodies and cause the viral levels to decrease.
What occurs during the HIV chronic phase?
A very low level viremia as the virus is currently replicating and undergoing antigenic drift of gp120 and cell to cell fusion.
Can last up to 10 years!!
How does HIV progress to AIDS?
HIV progresses to aids as CD4 cell levels drop through copious budding, interference with cellular processes, and other mechanisms.
What virus causes oral Hair leukoplakia?
Epstein- Barr Virus
What organism causes thrush?
What organism causes Neoplasms?
Kaposis sarcoma (HHV8) and B-cell lymphomas.
What are targets for diagnosis of HIV?
p24 antigen immunoassay
Anti- gp120 immunoassay
Viral genome Nucliec acid test (NAT)
HIV-1/2 antigen antibody combination immunoassay detects what specifically?
HIV p 24 antigen (viral protein)
What is the purpose of the HIV 1/2 antigen antibody combination immunoassay?
Screens for HIV diagnosis.
What does the HIV 1/2 antibody differentiation immunoassay test for?
HIV 1 antibodies
HIV 2 antibodies
What is the purpose of the HIV 1/2 antibody differentiation immunoassay test?
Differentiates between HIV-1 and HIV-2 infections.
The HIV nucleic acid test searches for what specifically and what is it's purpose?
Searches for HIV RNA genomes
Its purpose is to detect RNA genomes detectable at earlier times of the infection.
What sort of dianostic test can detect provirus in infected cells?
How does Maraviroc work?
It is a chemokine coreceptor agonist that prevents gp 120 interaction with CCR5 in R5 tropic HIV patients.
How does Enfuvartide work?
Enfuvartide is a fusion inhibitor that binds to gp41 and prevents conformational change needed for viral fusion.
How does Azidothymidine work?
This is a nucleoside inhibitor (NRTI) that causes chain termination in the provirus.
How does Nevirapine work?
This is a nonnucleoside inhibitor that binds to the reverse transcriptase and inhibits its activity.
How does Raltegravir work?
This is an integrase blocker that blocks the integration of DNA copy of the viral genome into the cellular genome.
How does Saquinavir work?
This drug is a protease inhibitor that inhibits the viral protease causing production of immature defective HIV particles.