Retroviruses, AIDS, and Tumor Viruses

Question 1

what is the theory/origin of HIV

Answer 1

HIV has evolved from the simian virus in Africa

—-> HIV-2 ——–> HIV-1

Question 2

what are the 2 subfamilies of retroviridae, and of the 2 which one can cause human disease

Answer 2

orthoretroviridae - cause human disease

spumaviridae - NOT cause human disease

Question 3

what is the main protein specific to retroviruses and what does it do ?

Answer 3

reverse transcriptase

-converts ssRNA to dsDNA

Question 4

what is the genome and virion for retroviridae

Answer 4

genome - (+)ssRNA

virion - enveloped

Question 5

what is a provirus and explain the process

Answer 5

it is when retrovirus integrates their dsDNA into the host genome

Question 6

explain the replication cycle of retrovirus

Answer 6

attaches and enters cell, then reverse transcriptase converts ssRNA to dsDNA

• then integrated into host genome
• transcription then translation, assembly and release

Question 7

_______ levels of what must be present in order to start reverse transcription

Answer 7

high levels of NTP’s

Question 8

why are retroviruses an exception w/regards to where it replicates w/in the host cell

Answer 8

most RNA viruses replicate in the cytoplasm

-Retroviruses replicate in NUCLEUS

Question 9

how does integration process work for retroviruses

Answer 9

• must access the nucleus
• attack host DNA and create nick
• integrate via integrase
• host will repair

Question 10

what is the term when the virus integrates its dsDNA into the hosts germ-line

Answer 10

endogenous

Question 11

T/F integration of virus DNA is permanent and can not be removed

Answer 11

True

Question 12

Can retroviruses infections be benign

Answer 12

Yes, happens frequently

Question 13

what are the 3 types of diseases that retrovirus can cause

Answer 13

• slow retrovirusus - high level mutagenesis
• cytopathic retrovirus - direct tissue damage (rare)
• acute transforming virus - induce rapid tumor formation and carry host mitogenic genes

Question 14

what is the family name of Human T-cell Leukemia virus (HTLV)

Answer 14

deltaretrovirus

Question 15

what is the prevalence of Human t cell leukemia (HTLV)

Answer 15

very high worldwide

Question 16

how is HTLV-1 transmitted ?

Answer 16

person to person w/in the host

-MUST have contact b/w cells

Question 17

what 2 diseases can HTLV-1 cause

Answer 17

• Adult T cell lymphoma (ATLL)

- HTLV-1 Associated myelopathy/Tropical Spastic Paraperesis (HAM/TSP)

Question 18

HAM/TSP symptoms can be associated with what virus

Answer 18

human t cell leukemia virus (HTLV-1)

Question 19

how can HTLV -1 be prevented and treated

Answer 19

eliminate breastfeeding for HTLV-1 mothers

-treat specific disease

Question 20

what is the specific family of the human immunodeficiency virus (HIV)

Answer 20

lentivirus

Question 21

where is the highest prevalence of HIV

Answer 21

worldwide, specifically sub-saharan Africa

Question 22

what are the routes of transmission for HIV

Answer 22

• sex (primary route)
• parenteral (needle sharing and transfusion)
• mother to infant

Question 23

what is the latency period for AIDS

Answer 23

6 months to 25 years

Question 24

what cells does HIV target

Answer 24

targets memory T cells (CD4+)

Question 25

Gut associated lymphoid tissue (GALT) is associated w/what virus

Answer 25

acute infection of HIV

Question 26

when the chronic infection is established in HIV, what occurs ?

Answer 26

replication of the virus continues

-T cell depletion over time

Question 27

what iare the strategies for prevention and treatment of HIV

Answer 27

prevent by sexual behavior

-no vaccine but are antivirals that help

Question 28

what is the most common antiviral of HIV

Answer 28

AZT

Question 29

disease progression for retroviruses generally are very fast or slow ?

Answer 29

slow

Question 30

T/F retroviruses can cause significant types of cancer

Answer 30

True

Question 31

what does the antiviral AZT target to inhibit HIV

Answer 31

it is a reverse transcriptase inhibitor

Question 32

what is the latency period for Adult t cell lymphoma (ATLL)

Answer 32

30-50 years

“slow retrovirus”

Question 33

infected T cells enter the central nervous system in what disease

Answer 33

HTLV-1 Associated Myelopathy/Tropical spastic paraperesis

HAM/TSP

Question 34

what are the symptoms of HAM/TSP

Answer 34

bladder control issues followed by lower body/back pain

-men suffer ED