Retroviruses, AIDS, and Tumor Viruses Flashcards
what is the theory/origin of HIV
HIV has evolved from the simian virus in Africa
—-> HIV-2 ——–> HIV-1
what are the 2 subfamilies of retroviridae, and of the 2 which one can cause human disease
orthoretroviridae - cause human disease
spumaviridae - NOT cause human disease
what is the main protein specific to retroviruses and what does it do ?
reverse transcriptase
-converts ssRNA to dsDNA
what is the genome and virion for retroviridae
genome - (+)ssRNA
virion - enveloped
what is a provirus and explain the process
it is when retrovirus integrates their dsDNA into the host genome
explain the replication cycle of retrovirus
attaches and enters cell, then reverse transcriptase converts ssRNA to dsDNA
- then integrated into host genome
- transcription then translation, assembly and release
_______ levels of what must be present in order to start reverse transcription
high levels of NTP’s
why are retroviruses an exception w/regards to where it replicates w/in the host cell
most RNA viruses replicate in the cytoplasm
-Retroviruses replicate in NUCLEUS
how does integration process work for retroviruses
- must access the nucleus
- attack host DNA and create nick
- integrate via integrase
- host will repair
what is the term when the virus integrates its dsDNA into the hosts germ-line
endogenous
T/F integration of virus DNA is permanent and can not be removed
True
Can retroviruses infections be benign
Yes, happens frequently
what are the 3 types of diseases that retrovirus can cause
- slow retrovirusus - high level mutagenesis
- cytopathic retrovirus - direct tissue damage (rare)
- acute transforming virus - induce rapid tumor formation and carry host mitogenic genes
what is the family name of Human T-cell Leukemia virus (HTLV)
deltaretrovirus
what is the prevalence of Human t cell leukemia (HTLV)
very high worldwide
how is HTLV-1 transmitted ?
person to person w/in the host
-MUST have contact b/w cells
what 2 diseases can HTLV-1 cause
- Adult T cell lymphoma (ATLL)
- HTLV-1 Associated myelopathy/Tropical Spastic Paraperesis (HAM/TSP)
HAM/TSP symptoms can be associated with what virus
human t cell leukemia virus (HTLV-1)
how can HTLV -1 be prevented and treated
eliminate breastfeeding for HTLV-1 mothers
-treat specific disease
what is the specific family of the human immunodeficiency virus (HIV)
lentivirus
where is the highest prevalence of HIV
worldwide, specifically sub-saharan Africa
what are the routes of transmission for HIV
- sex (primary route)
- parenteral (needle sharing and transfusion)
- mother to infant
what is the latency period for AIDS
6 months to 25 years
what cells does HIV target
targets memory T cells (CD4+)
Gut associated lymphoid tissue (GALT) is associated w/what virus
acute infection of HIV
when the chronic infection is established in HIV, what occurs ?
replication of the virus continues
-T cell depletion over time
what iare the strategies for prevention and treatment of HIV
prevent by sexual behavior
-no vaccine but are antivirals that help
what is the most common antiviral of HIV
AZT
disease progression for retroviruses generally are very fast or slow ?
slow
T/F retroviruses can cause significant types of cancer
True
what does the antiviral AZT target to inhibit HIV
it is a reverse transcriptase inhibitor
what is the latency period for Adult t cell lymphoma (ATLL)
30-50 years
“slow retrovirus”
infected T cells enter the central nervous system in what disease
HTLV-1 Associated Myelopathy/Tropical spastic paraperesis
HAM/TSP
what are the symptoms of HAM/TSP
bladder control issues followed by lower body/back pain
-men suffer ED
