Retroviruses and HIV Flashcards Preview

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Flashcards in Retroviruses and HIV Deck (61):
1

PEP Regimen

Integrase Inhibitor + 2 NRTI's given within 72 hours of infection

2

gp120

Surface envelope protein of HIV encoded on Env; Contains highly variable regions; Used for attachment  

3

Technique to monitor HIV viral loads

RT-PCR

4

LTR

long term repeat; bind cellular and viral transcription factors (promoters and enhancers)

5

HIV Regulatory proteins

TAT, REV, and NEF

6

Mutation for HIV Resistance

CCR5 mutation; 10% of Caucasians are heterozygous, 1% are homozygous

7

Structural genes of HIV

Gag, Pol, and Env

8

Predictor of disease time course and progression to AIDS

viral load after acute infection

9

Nef

non-essential HIV protein that's only required for disease progression; down-regulates CD4 and MHC Class I molecules

10

Defining feature of retroviruses

presence of Reverse Transcriptase

11

PrEP Regimen

Two NRTI's taken daily

12

Properties of Oncoviruses

Can immortalize or transform cells because they contain growth-regulating oncogenes almost identical to genes involved in cellular growth

13

How is HTLV-1 transmitted

Sexually, through breastfeeding, and by IV drug use (US)

14

HIV Integrase Inhibitors

Inhibit HIV genome integration into host cell chromosome by reversibly inhibiting HIV integrase

 

Drugs have "tegr" in middle

Raltegravir

15

Unique features of Reverse Transcriptase

Protein dimer that: 1) Can act as DNA Polymerase while using either RNA or DNA as template 2) Can remove RNA strand from RNA:DNA duplex

16

HIV protein that down-regulates CD4 and MHC Class I molecules

Nef

17

HIV Antibodies appear when?

3-8 weeks after infection

18

Preferred HIV co-receptor for sexual transmission

CCR5

19

Genes in genome of Retrovirus

Gag, Pol, Env, and LTR

20

Tax and HBZ

genes on HTLV-1 that promote viral gene expression and host cell cycle by binding to LTR or other cellular growth factors

21

HIV protein that stabilizes viral mRNA containing RRE by preventing splicing

Rev

22

Tat

HIV protein that acts as positive regulator of transcription by binding to region in LTR and recruiting RNA Polymerase II

23

Provirus

Virus that has integrated into genome

24

Treatment for HTLV-1

ATLL: anti-cancer therapy

TSP: antiretrovirals

25

gp40

transmembrane envelope protein of HIV encoded on Env

26

V3 Sequence

Can be used to predict whether HIV Strain will prefer CCR5 or CXCR4 as co-receptor

27

Diagnosis of HIV

4th Generation Diagnostic Test detects Antibodies to HIV-1 and HIV-2 as well as the p24 Antigen (which allows this test to work during window period). Confirmatory test needed to distinguish HIV-1 vs HIV-2. Previous tests performed immunoassays which only detected antibodies

28

Structure of Retroviruses

Enveloped, Icosahedral Viruses with two identical copies of Single Stranded Positive Sense RNA

29

gene that encodes reverse transcriptase, protease, and integrase

pol

30

gag

encodes the capsid and matrix proteins

31

Purpose of Combination Therapy

Virus is unlikely to mutate and develop resistance to three different mechanisms at once

32

HIV capsid protein and what gene it's on

p24 Capsid encoded on Gag

33

HIV Protease Inhibitors

Competitive inhibitors of HIV protease that prevents cleavage of Gag and Pol precursor peptides thus preventing viral maturation to infectious form

Drugs have -navir suffix

34

Diseases caused by HTLV-1

  1.  Adult T Cell Leukemia
  2.  Tropical Spastic Paraparesis (myelopathy)

35

HIV-1 vs HIV-2

HIV-2 is less virulent and less common

36

When is LTR formed?

LTR's are formed when a DNA copy is made from RNA by Reverse Transcriptase in order to allow integration into nucleus

37

Rev

HIV protein that stabilizes viral mRNA containing RRE by preventing splicing

38

env

gene that encodes surface and transmembrane proteins

39

Where is HTLV-1 prevalent

Japan and Carribean

40

Lentivirus family includes

HIV-1, HIV-2, and SIV

41

Diagnosis criteria for AIDS

1) CD4 T Cell Count < 200 per uL 2) certain opportunistic infections

42

Nucleoside/Nucleotide Reverse Transcriptase Inhibitors (NRTI's)

Competitively inhibit nucleotide binding to reverse transcriptase and cause early termination; selectively inhibit HIV RT over host cell Polymerase.

Tenofovir is a nucleotide analog and does not require phosphorylation. Nucleoside analogs require phosphorylation before they are active

43

Receptors for HIV

CD4 with co-receptor CCR5 or CXCR4

44

Most important predictor of HIV disease stage

CD4 T Cell Count

45

pol

encodes reverse transcriptase, protease, and integrase

46

Important genes encoded on HTLV-1

tax and HBZ; HTLV-1 DOES NOT contain an oncogene.

These genes encourage expression of cellular growth factors and viral mRNA

 

47

HIV viral enzymes and what gene they're on

Protease, Reverse Transcriptase, and Integrase on Pol; Reverse Transcriptase and Integrase are packaged within the viron

48

HIV Fusion Inhibitor (Enfuvirtide)

Blocks the fusion of gp41 on HIV envelope with host cell membrane

49

Gene that encodes the capsid

gag

50

Risk of HIV transmission from mother to fetus before ART vs after ART

30% vs < 2% ; women instructed not to breastfeed

51

Importance of Variable Regions

Allow Quasi Species of HIV to form within host which can allow the virus to evade immune detection or become better at binding CD4

52

HIV envelope proteins and what gene they're on

gp120 and gp40 on Env

53

Multilobulated lymphocytes known as "Flower Cells" are seen in what disease?

Q image thumb

Adult T Cell Leukemia caused by HTLV-1

54

bind cellular and viral transcription factors (promoters and enhancers)

LTR

55

HIV Entry Inhibitors (Maraviroc)

Block gp120 from binding to CCR5 (chemokine receptor antagonist); ineffective against HIV strains that bind CXCR4

56

Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTI's)

Non-competitively bind to hydrophobic region of HIV Reverse Transcriptase Efavirenz, Nevirapine, Delavirdine

57

ARV regimen for HIV+ Patient

Two different NRTI's + one of the following: 1) Integrase Inhibitor 2) NNRTI 3) Protease Inhibitor

58

Oncovirus Family includes what?

HTLV1

59

HIV Accessory Genes

Vif, Vpr, and Vpu; these genes are involved in manipulating the host cell and promoting its survival

60

gene that encodes surface and transmembrane proteins

env

61

HIV protein that acts as positive regulator of transcription by binding to region in LTR

Tat