Microbio Week 10 - Retroviruses and HIV (Exam 3) Flashcards
What is the causative agent in 2 diseases?
HTLV
What 2 diseases does HTLV-1 cause?
Adult T-cell Leukemia/Lymphoma (ATLL)
HTLV-1 Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP)
What disease occurs in people infected with HTLV-1 before the age of 20?
Adult T-cell Leukemia/Lymphoma (ATLL)
What disease can HTLV-2 potentially cause?
HTLV-1 Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP)
T/F: The majority of people infected with HTLV are symptomatically infected
FALSE, majority of people are ASYMPTOMATICALLY infected
What 3 ways is HTLV transmitted?
Breastfeeding
Sex
IV drug use
Is HTLV contagious or non-contagious?
Non-contagious
Is HIV contagious or non-contagious?
Non-contagious
How many strands of the same RNA are carried by retroviruses?
2 (diploid)
What does HIV use to make its +ssRNA into a viral DNA copy (called the provirus)?
Reverse transcriptase
What will integrate the proviral DNA into the cellular chromosome in HIV infections?
Integrase
Where does the viral DNA stay integrated in for the life of the cell in HIV infections?
In cellular DNA
Capsid protein in HIV; used in some diagnostic tests
p24
Cleaves the viral polyprotein and matures the virion in HIV
Protease
DNA-dependent DNA polymerase that makes proviral DNA from the viral +ssRNA in HIV
Reverse transcriptase
Puts the proviral DNA into the cell chromosome in HIV
Integrase
Is HIV naked or enveloped?
Enveloped
Viral envelope glycoproteins in HIV
gp120 and gp41
Envelope glycoprotein that binds the receptors, CD4, and secondary receptor, CCR5 or CXCR4 in HIV
gp120
Envelope glycoprotein that has a fusion domain. Fuses the lipid bilayer of virus with the plasma membrane, allowing capsid to enter the cytoplasm of the cell
gp41
T/F: Detergents and drying will kill HIV since it is an enveloped virus
True
What is the accepted way to clean off contaminated surfaces in regards to HIV?
10% bleach solution
Virucidal
Is there a lot of viral diversity in a person infected with HIV?
YES
Why is there a lot of viral diversity in a person infected with HIV?
Reverse transcriptase error rate and no proofreading activity
Why do we need drugs from 2 classes of antivirals in order to treat HIV?
Due to HIV’s diversity
How many drugs are used for HIV treatment
2-3
What type of HIV infection - acute or chronic?
A lot of virus is being produced in the body, and some people feel like they have the ‘flu’ or
mononucleosis
Acute HIV infection
What type of HIV infection - acute or chronic?
The immune system reduces the amount of virus to a lower level
Chronic HIV infection
Are people more likely to spread HIV during the acute phase of infection or the chronic phase of infection?
Acute phase
During infection, people infected with HIV may also have swollen ___________ ___________
lymph nodes
What is the receptor for HIV?
CD4
What type of cells does HIV infect?
CD4+ T cells (mostly)
Macrophages
Microglial cells
Dendritic cells
What is the secondary receptor for HIV?
CCR5 or CXCR4
Upon initial infection, HIV almost always uses which receptor only?
CCR5
Initial HIV infections caused by ONE virus are almost always _________ restricted
CCR5
What are people with a deletion in CCR5 mostly protected from?
HIV infection
Where does HIV establish infection?
Gut-associated lymph tissue (GALT)
Where does HIV remain during chronic infection?
GALT
What does HIV infection of the GALT early on result in?
Dysbiosis of the gut
Leakage of bacterial products into blood
What is a significant contributor to chronic immune activation seen in people living with HIV?
Leakage of bacterial products into blood
During acute infection, where can HIV establish an infection?
Brain
What type of HIV infection - acute or chronic?
Latently infected HIV cells are established. These cells are very long-lived; if antiviral drugs are removed, the virus from these cells will reseed the infection.
(ON EXAM)
Acute HIV infection
Why can we not cure people of HIV? (ON EXAM)
Latent reservoir
How soon after exposure to HIV must you start antiviral treatment?
Within 72 hours
What type of HIV infection - acute or chronic?
Gradual loss of CD4+ T cells, leading to the loss of a functional immune system and the development of acquired immune deficiency syndrome (AIDS)
Chronic HIV infection
What happens over many years without treatment for HIV?
Destruction of lymph nodes
What type of HIV infection - acute or chronic?
B cells do not function as well
Chronic HIV infection
T/F: If infected with HIV, everyone goes on to chronic infection
True
HIV infection in the brain can continue, resulting in cognitive decline; the worst manifestation is ___________________ _______________
HIV-associated dementia (HAD)
When is a person with HIV considered to have AIDS?
If CD4 count is below 200 cells/μl or an AIDS-defining opportunistic infection is diagnosed
What happens when the CD4 count gets too low in those infected with HIV?
Opportunistic infections start
Most opportunistic infections in HIV occur when the CD4 count is below 200 cells/μl, but some can happen at a higher CD4 T cell count, like…
Thrush
Oral hairy leukoplakia
Kaposi’s sarcoma
People living with HIV can have more recurrent…
Oral herpes
Oral warts
Shingles
Molluscum contagiosum
Without treatment, over _____% of people with HIV will develop AIDS and die from opportunistic infections, cancer, or complications of HIV infection
95
What is the average time from HIV infection until development of AIDS (without treatment)?
8 years
What is treatment for HIV called? (3 different names, all mean the same thing)
Highly Active Antiretroviral Therapy (HAART) Combination Antiretroviral Therapy (cART) Antiretroviral Therapy (ART)
There need to be drugs from _____ different classes of antiretrovirals when treating HIV
2
What is the HIV treatment goal?
Reduce virus to undetectable levels
People who don’t reach undetectable levels with HIV treatment have a higher risk of what?
Drug-resistant HIV
T/F: It is less likely, even with years of treatment for HIV, that the CD4 counts will rebound to pre-infection levels
True
The lower the CD4 cells are before HIV treatment starts, the less likely the _________ _________ architecture will return to normal
lymph node
There could be more damage to the ________ due to ________ replication of the HIV virus
brain; active
T/F: New studies show that most people living with HIV who have undetectable viral loads under treatment show no increase in cognitive decline over time
True
When should you start HIV treatment?
ASAP
What are the 5 benefits of starting HIV treatment early?
- Less lymph node destruction
- Less dysfunction in GALT
- Less thymus loss
- CD4 counts can reach uninfected levels
- Lower co-morbities