Brainscape's Knowledge GenomeTM

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


See full index

Immunology > Exam 2- Type IV Hypersensitivity > Flashcards

Exam 2- Type IV Hypersensitivity Flashcards

1
Q

true/false: type IV hypersensitivity reactions are categorized as cell-mediated immunity

A

true

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

how long do T cell-mediated hypersensitivity reactions take to become apparent?

A

24 hours
peak 48-82 hours

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

how is delayed-type hypersensitivity (DTH) transferred?

A

T-lymphocytes (not serum antibody)

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

delayed-type hypersensitivity consists of two main phases:

A

sensitization phase
effector phase

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

what cells are activated in the sensitization phase of delayed-type hypersensitivity?

A

Th1 type mostly
CD8+ cytotoxic T cells in a few cases

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

what are the primary effector cells of the delayed-type hypersensitivity?

A

macrophages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is a granuloma?

A

continued activation of the delayed-type hypersensitivity leading to macrophages adhering closely to each other, assuming and epithelioid shape and sometimes forming multinucleated giant cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what can result from a granuloma?

A

caseous (cheesy) necrosis from multinucleated giant cells releasing lytic enzymes

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

after about 24 hours, evidence of _____________ and ______________ appear, reaching maximal levels 48-72 hours after exposure to the antigen

A

erythema (redness)
induration (raised thickening)

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

what are three important cytokines of the delayed-type hypersensitivity reaction?

A

chemokine MCP-1
IFN-gamma
TNF-alpha

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

what concept explains the recognition of small molecules such as drugs by T and B cells?

A

hapten-carrier concept
haptens: small, can covalently adhere to larger molecules

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

how can a delayed-type hypersensitivity reaction be detected?

A

inject a small amount antigen intradermally and watching for skin lesion

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

what can the delayed-type hypersensitivity reaction protect from?

A

intracellular pathogens and contact antigens

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

what is a chronic granuloma?

A

infection fails to resolve
macrophages form epithelioid cells and giant cells
fibrosis and necrosis

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

what is the mechanism of contact dermatitis?

A

substances complex with skin proteins and form hapten-carrier complex
can also have metabolites do this (metabolites of drug)

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

can type IV hypersensitivity arise from allograft rejection?

A

yes

17
Q

is type I diabetes autoimmune?

A

yes, in humans. at least some in dogs

18
Q

what do patients who have equine polyneuritis have circulating in their blood?

A

antibodies to a protein found in peripheral myelin

19
Q

true/false: macrophages are the main effector cells in a DTH reaction

A

true

20
Q

true/false: in equine polyneuritis, autoimmune reaction is against central nervous system myelin protein, and involves autoimmune T cells

A

false: peripheral myeline protein

21
Q

what is special about type IV hypersensitivity compared to types I-III hypersensitivities?

A

transferred by T lymphocytes, not serum antibody

22
Q

what becomes apparent after about 24 hours of a delayed type hypersensitivity reaction?

A

erythema and induration (raised thickening- not edema)

23
Q

why is induration hard?

A

deposition of fibrin in the lesion

24
Q

what does chemokine MCP-1 do?

A

attracts monocytes and macrophages to the site of antigen deposition

25
Q

how do B and T cell recognize drugs or chemicals?

A

hapten-carrier concept
hapten may also bind to MHC molecule or alter it

26
Q

how is a delayed type hypersensitivity reaction measured experimentally?

A

by injecting antigen intradermally and watching for a characteristic skin lesion

27
Q

what is contact dermatitis caused by?

A

substances that can complex with skin proteins forming hapten-carrier complex

28
Q

how does urushiol induce a delayed type hypersensitivity reaction?

A

after it penetrates the skin, its metabolites act as haptens

Immunology (21 decks)

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