Final; Retroviruses, AIDS, and Tumor Viruses Flashcards Preview

SP14 Microbiology > Final; Retroviruses, AIDS, and Tumor Viruses > Flashcards

Flashcards in Final; Retroviruses, AIDS, and Tumor Viruses Deck (59):
1

Who are the members of the 4H risk group for HIV/AIDS

homosexual men
heroine addicts
Haitians
hemophiliacs

2

How many types of HIV are there

HIV-1
HIV-2

3

Where does HIV seem to originate from

the simian virus from Africa

4

Which type of HIV is mostly a heterosexual disease

HIV-2

5

This a large and diverse group of viruses with a unique replication cycle

retroviruses

6

In which genre of animals are retroviruses ubiquitous, albeit benign and causing little to no impact

vertebrates

7

This retrovirus does not cause disease in humans but makes foamy structures inside the cell

spumaviruses

8

What are the two subfamilies of retroviridae

orthoretroviridae
spumaviridae

9

What is the genome of the retroviridae

+ssRNA, diploid identical copies

10

What is the virion of the retroviridae

enveloped

11

What special proteins do the retroviridae contain

reverse transcriptase
integrase
protease

12

What were retroviruses historically characterized by

nucleocapsid structure and location of the particle

13

What are retroviruses now characterized by

genome contents; either simple or complex

14

What are the genes that simple retroviruses encode

gag, pro, pol, and env genes

15

What is the replication cycle of retroviruses

attachment
entry
reverse transcription
integration
transcription
translation
assembly
release
matuation

16

This converts viral ssRNA to dsDNA

reverse transcriptase

17

This puts the viral dsDNA into the host genome making a provirus

integrase (integration)

18

This is the defining feature of a retrovirus

reverse transcription

19

Reverse transcription initiates when

once the nucleocapsid is in the cytoplasm
needs higher levels of NTPs (nucleoside triphosphate)

20

Where does reverse transcription occur

within a large complex similar to the nucleocapsid

21

Reverse transcription is this between genome copies

promiscuous
many different recombinations when different genomes are in the virion

22

What must take place in order for integration to occur

it must have access to the nucleus during mitosis
although it can also infect non-dividing cell via importation (mechanism unknown)

23

How is the viral genome integrated into the host genome

3' end processing of dsDNA
attack target DNA, nick created
host repair

24

True or False
Integration is permanent, there is no mechanism to remove it

True

25

If integrated into the germ-line, then provirus is inherited and is called what

endogenous

26

Which type of integration is identified as oncogenes

transcription factor
secreted growth factors
growth factor receptors
cell signal transduction pathway

27

True or False
There are many defective viruses made during replication

True

28

What constitutes a defective virus

missing at least one of gag, pol, or env

29

In order to make progeny of a defective virus, what must happen

a complementary infection with a virus that is not missing the defective gene

30

Many retrovirus infections are what

benign and usually not cytopathic with little impact to cell replication and physiology

31

Chronic infections of retroviruses cause what

they exert a small demand on cell and host resources but do cause viremia (virus in blood) and elicit an immune response

32

True or False
Viruses are never eliminated by the host response

True

33

In this type of retrovirus, the effect is like high-level mutagenesis and eventually results in tumoriogenesis

slow retrovirus

34

In this type of retrovirus, the majority carry cytopathic genes and directly cause tissue damage

cytopathic retrovirus

35

In this type of retrovirus, it induces rapid tumor formation, caries host genes (mitogenic or antiapoptotic) and is often replication defective because host gene replaces an essential gene

acute transforming viruses

36

What are the four distance types of Human T Cell Leukemia virus (HTLV)

1, 2, 3, and 4
HTLV-1 associated with humans

37

What type of retrovirus is HTLV-1

deltaretrovirus

38

How is HTLV-1 transmitted

person to person;
breastfeeding
sharing needles
sexual transmission (less efficient)

39

How is HTLV-1 transmitted within the host

highly cell associated
primary contact between infected and naive cells

40

What diseases can result from HTLV-1

adult T cell lymphoma/leukemia (ATLL); occurs in 2-4% of cases
HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP); occurs in 1-2% of cases

41

How long is the incubation of ATLL

30-50 years

42

What cells does ATLL infect (HTLV-1)

memory T cells
antigen activators trigger transcription of provirus, viral tax protein stimulates cell proliferation, the cell transform forming tumors with out without viral protein expression

43

How are ATLL and HAM/TSP transmitted

ATLL; mucosal infection
HAM/TSP; transfusion

44

What cells does HAM/TSP infect

infected T cells enter the CNS
activating astrocytes and microglial cells
recruiting inflammatory cells which cause further damage

45

What are the symptoms of HAM/TSP

onset 3 years after infection
starts with bladder control issues
progressing to lower back pain, leg weakness, or stiffness in hips/knees
men will suffer impotence or erectile dysfunction

46

What is used to prevent HTLV-1

eliminate breastfeeding for positive people
increased screening for blood products

47

What is used to treat ATLL

treat the lymphoma/leukemia with chemo

48

What is used to treat HAM/TSP

corticosteriods
interferon yields temporary relief of symptoms

49

What family is HIV apart of

lentivirus
two types of HIV, 1 and 2

50

How was HIV identified

due to immune deficiencies occurring in previously healthy young gay men

51

Where is the highest prevalence of HIV

in sub-sarahan Africa

52

How is HIV transmitted

sexual transmission; male to male is highest
parenteral; transfusion, needle sharing
mother to infant

53

What is the latent period of HIV

6 months to 25 years

54

In what part of the body does the HIV infection start

infection begins virus containing blood/body fluid to mucosal membrane
targets CD4+ cells
initial acute infection usually 2 weeks after exposure

55

What are the symptoms indicative of an HIV infection

mucocutaenous ulceration and weight loss
GALT seeded as a result of acute infection (reservoir)

56

What happens as HIV established a chronic infection

ongoing viral replication and T cell depletion

57

What results as a chronic HIV infection

opportunistic infections increase
wasting

58

What are the prevention strategies regarding HIV

sexual behavior and protection
blood screening

59

What are the treatments for HIV

no vaccine
antivirals; AZT is a reverse transcriptase inhibitor