Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Year 2 > HIV - Infection control > Flashcards

HIV - Infection control Flashcards

1
Q

How is HIV primarily transmitted

A

Sexual intercourse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

When is HIV transmission at its highest likeliness

A

In the first month of infection or when newly infected individual is asymptomatic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Characteristics of primary HIV infection illness

A
  1. Asymptomatic

2. Unaware of infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Why does HIV develop resistance to immune system

A

Because it mutates every time it reproduces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are retroviruses

A

Enveloped viruses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the four major features of HIV

A
  1. Transmitted through sexual intercourse
  2. Remains inactive for a long time (carries on spreading it)
  3. Bad at reproducing itself accurately (mutations 50% of the time)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe the classification of HIV

A
  1. Retroviridiae -> Orthoretroviridae -> Lentivirus -> Primate Lentivirus group -> HIV -1 and HIV-2
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is reverse transcription

A

Viruses have reverse transcriptase enzymes which can turn their viral RNA into DNA when they take over host

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is a special feature of the lentivirus

A

Lenti = slow

Lentivirus has a SLOW incubation period

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Did HIV-1 and 2 come from the same source

A

No, from different sources

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the three types of HIV virus found in the world

A

M (main)
O (Outlying)
N (new)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the main sub-groups of M, O and N

A

CLADES

Clade B - predominate in Europe and USA
Clade A - west central africa
Clade C - South africa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Why is the acknowledge of clades important

A

Because different treatments may be required for treating the different clades (may only work for one clade and not another)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Define attachment

A

Viral and cell receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Define cell entry

A

Only central viral core carries nucleic acid and some associated proteins enter host cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe the interaction of viruses

A

Use cell materials for replication

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How do viruses replicate

A

Localise in nucleus, cytoplasm or both: production of progeny viral nucleic acid and proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Describe the assembly of viruses

A

Occurs in nucleus or cell membrane or cytoplasm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How are viruses released from a cell

A

Bursting open or exocytosis from the cell over time (latter is HIV)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Role of CD4

A

Recruits and facilitates maturation of B antibodies producing cells and T CD8 killer cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What Interleukins are produced by TH1

A

4,5,10,13

22
Q

What interleukins are produced by TH2

A

IFN alpha and TNF

23
Q

How does HIV effect the immune system

A

Kills CD4 by uncontrolled activation and then apoptosis (less CD8, NK cells, neutrophils etc are produced)

24
Q

Describe the vision structure

A

Nucleic acid in centre
Vision associated polymerase wrapped around acid
Protein cashed surrounds nucleic acid
Lipid envelope envelopes protein cashed
Spike projections protrude from lipid envelope

25
Q

Describe the process of CD4 cell destruction

A
  1. HIV fuses to CD4 receptor and passes contents into cell
  2. Viral cashed is uncoated and enzymes and nucleic acid are released
  3. Reverse transcriptase RNA converted to DNA
  4. Viral DNA integrated into cells by integrate enzymes
  5. When infected cell divides, viral DNA read and transcribed and long chains of viral proteins are made
  6. Viral RNA spliced and protein chains cleaved and reassembled into individual proteins that recombine to form a virus
  7. Budding here causes immature virus to be pushed out of the cell taking some membrane with it
  8. Maturation
26
Q

What receptors does CD4 bind to on the virus

A

Gp160 (made of gP120 + 41)

27
Q

What genetic trait is preserved in all primate lentiviruses

A

The interaction between CD4 and gP120

28
Q

How does binding of gP120 to CD4 affect the recpetor

A

GP120 undergoes conformational change

29
Q

What can mutations in CCR5 do

A

Influence risk of infection

30
Q

How long is the HIV viral RNA

A

9KB

31
Q

What genes does the viral RNA encode for

A

9:

Gag, Pol, Env, Tat, Rev, Nef, Vif, Vpr, Vpu

32
Q

What genes are essential for viral infectivity

A

Gag, Pol, Env, Tat, Rev

33
Q

Role of Pol

A

Encodes the enzymes, reverse transcriptase, integrate and protease

34
Q

Role of Env

A

Encodes the envelope proteins

35
Q

Role of Nef

A

Increases infectivity

36
Q

Role of Tat

A

Contributes to viral replication. Enhances production of host transcription factors

37
Q

Which cells become infected by the HIV virus

A 
CD4 T cells 
Macrophages
Astrocytes
Renal epithelial cells
Brain endothelial cells
38
Q

What CD4 is infected early on

A

CD45RO

39
Q

What CD4 cells are infected later on

A

CD45RA when infected by X4 virus

40
Q

When are dendritic cells infected by HIV

A

Early on as they trap the virus via DC-SIGN and transport virus to lymph nodes to infect T cells

41
Q

Describe the process of HIV infection from the outside world

A
  1. Virus enters mucosa
  2. Single founder virus enters
  3. Local infection in mucosal macrophages
  4. Migrate to local lymph node to present antigen to T cells
  5. Virus macrophage infects T cells and more T cells which leave lymph nodes
42
Q

Describe the effect of HIv on the humoural response

A
  1. Slow to develop effectively

2. Envelope glycoprotein (Gp120) is poorly immunogenic and has high genetic diversity

43
Q

Effect of HIV on cell-mediated immunity

A

CD8:

  1. CTLs against HIV form early decline in virus
  2. CTL responses become quantitatively and qualitatively poor
    - Virus escapes from CTL response through mutations

CD4:
Infected and don’t proliferate

44
Q

What are long-term non-progressors

A

Heterogeneous groups of individuals that don’t progress to AIDS

Don’t show signs of AIDS after 7 years infection (CD4 count greater than 600 cells)

45
Q

How does the CD4 T cell number die

A
  1. Very few are killed directly by the virus/infection
  2. Apoptosis as CD4 cells rapidly proliferate initially in response to virus (tries to maintain homeostasis in body as HIV activates too many CD4 cell than necessary)
  3. Decreased production due to CD34+ progenitors in the bone marrow being infected and disruption to environment in thymus)
  4. Redistribution of CD4 from periphery to lymphoid
  5. Bystander cell killing
46
Q

What is bystander cell killing

A

Gp120 binding to CD4 increases cell apoptosis

47
Q

How does HIV effect NK, neutrophils and macrophage function

A

Decreases it

48
Q

How does HIV effect B cells

A

Enhanced activation and decreased proliferation resulting in an increased nonspecific Ab production

49
Q

How does HIV effect T helper cells

A

Decreased TH1 response

Increased TH2 response

50
Q

What are the reservoirs of HIV in th body

A
  1. Genital tract
  2. CNS
  3. GI tract
  4. Bone Marrow

Cells:
Macrophage
Microglia
Resting T cells

Year 2 (155 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions