Brainscape's Knowledge GenomeTM

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


See full index

Immunology > Tolerance And Mechanisms Of Autoimmunity > Flashcards

Tolerance And Mechanisms Of Autoimmunity Flashcards

1
Q

What is tolerance

A

Controlled unresponsiveness

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

Where is central tolerance achieved

A

Thymus

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

How is central tolerance acheived

A

Deletion of t cellls with the potential to react against self at too high an affinity

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

What percent of T cells entering thymus fail to come out the other side

A

95-99

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

What happens when T cell is deleted

A

Killed, or rendered anergi(unresponsive)

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

Problem with anergic cells

A

Remain available. If activated could participate in autoimmune responses at a later stage

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

Indifference or ignorance

A

T cell fails to encounter a peptide presented bc not there or insufficient levels

In periphery available to activation possibly to self

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

Peripheral tolerance

A

When peripheral T cells encounter. Exceptionally high peripheral antigen levels, this may lead to activation induced cell death (ACID) and deletion

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

Example of peripheral tolerance

A

Common self antigen is taken up by a resting nonactivated dc. In absence of danger signal costimulatory molecules are not up regulated by DC.

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

Final mechanism of peripheral tolerance

A

Self antigens ma simply not be presented int h periphery as a mechanism of attaining and maintains tolerance through ignorance
-limit mhc
-restrict expression to intracellular compartment or to a tissue that is unavailable for presentation
-

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

Immunologic police

A

Treg

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

The activation of Tregs s antigen __

A

Specific

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

Treg have tcr and require activation through the tcr to regulate

A

Once activated treg can regulate the cells around them .

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

What are the three Treg

A

CD4, CD25 cells
Tr1
TH3

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

CD4 CD25 T reg

A

CD4+, TCR +
Inhibits T cell responses
Arises naturally, mainly thymus derived;high expression of Foxp3

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

Foxp3

A

Transcription factor important in Treg function and low expression of CD127 (IL7 receptor)

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

TR1

A

CD4, TCR+
Inhibits T cell responses
Produced IL10
Arises naturally or may be induced by repeated antigen injection

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

TH3

A

CD4, TCR+
Produces TGFb
Induced by oral administration of antigen

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

Treg is able to suppress the activation of an effector cell recognizing the same ___ WHEN BOUNT TO SAME APC

A

Peptide

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

Autoimmunity

A

Loss of immunological tolerance to self

Common

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

What are the two main reasons for autoimmunity

A
  1. Not all T cells are deleted in the thymus and so some T cells remain available
  2. As discussed in, T cell receptors show enormous plasticity for the peptide -MHC complexes with which they can interact
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

One TCR can interact with many more that one ___

A

Peptide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

So, under normal circumstances, there are T cells that can recognize _ antigens

A

Self

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What happens when self t cels are activated

A

Tissue damage , then autoimmune disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

How may people have autoimmune disease at some point int heir life

A

5%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Autoimmune potential

A

Ubiquitous
Reflects t and B cell receptor diversity
Healthy response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Physiological autoimmunity

A

Non pathogenis may include t regs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Pathological autoimmunity

A

Results in autoimmune disease, common 5% result of complex interactions of genetic and environmental factors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Autoantigens to acetylcholine receptor

A

Myasthenia Travis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Autoantigens of thyroid stimulating hormone receptor

A

Graves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Autoantigens is thyroid peroxidases; thyroglobulin

A

Hashimoto thyroiditis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Autoantigens islet cell cytoplasmic targets, insulin, glutamic acid decarboxylase, IA-2, zinc transporter 8

A

Type 1 diabetes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

H+, K+, ATPase (gastric pump); intrinsic factor

A

Pernicious anemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

21a hydroxylase

A

Addison’s disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Desmoglein 3

A

Pemphigus vulgaris

36
Q

Tyrosinase

A

Vitilgo

37
Q

Cytochrome p4502D6

A

Autoimmune hepatitis

38
Q

Various rbc surface targets

A

Autoimmune haemolytic anemia

39
Q

Pyruvate dehydrogenase complex in mitochondria

A

Primary biliary cirrhosis

40
Q

Collagen type IV

A

Good pasture syndrome

41
Q

IgG

A

RA

42
Q

Double stranded DNA; Sm; SS-A;SS-B;histones

A

Systemic lupus erythematosus

43
Q

SS-A, SS-B

A

Sjorgrens syndrome

44
Q

DNA topoisomerase

A

Systemic sclerosis

45
Q

Ribonucleotides

A

Mixed CT disease

46
Q

Important principles of autoimmune disease

A

Multifactorial
Often progresses much more slowly than immune reactions to pathogenic control, suggesting that control mechanisms may continue
Has tendency to remit and relapse, indicating that control mechanisms may recover and temporarily restore tolerance

47
Q

What is the key event of developing an autoimmune disease

A

Activation cd4 that recognize rely peptide

48
Q

What are the four checkpoints that must be overcome for autoimmunity

A

Failure of central tolerance
Failure of peripheral regulation
Presentation of autoantigens(or mimic)
Costimulatory

49
Q

Autoimmune polyglandular syndrome type I APS the I

A

Multiple autoimmune disorders
AD
Mutation in nuclear protein that regulates the transcription of other genes in the thymus
CHECK POINT 1

50
Q

Defective AIRE

A

Incomplete tolerance toa. Range of autoantigens and multiple organ specific autoimmune diseases
Rare

51
Q

CD4, 25 TRegs needs what transcription factor

A

FoxP3

52
Q

Foxp3 defective

A

IPEX

2nd checkpoint

53
Q

IPEX

A

Immune dysregulation, polyendocrinopathy, enteropathy, x linked syndrome
Rare
Defective tregs and develop a range of organ specific autoimmune disease

54
Q

CTLA4

A

Switches off activated T cells

55
Q

Ctla4 knockout

A

Severe uncontrolled T cell activation and proliferation with manifestations of autoimmunity

56
Q

In humans with CTLA4 polymorphism

A

Increased risk of developing autoimmune thyroid disease and type 1 diabetes although precisely how this leads to reduced T cell regulation and autoimmunity is not known

57
Q

Checkpoint three

A

Ok

58
Q

Some form of tissue damage or injury leads to release of hidden self antigens

A

Or mimicry
Antigen or epitope in the pathogen looks like a self antigen or epitope
T or B cells made that can recognize self

59
Q

Strep M protein antigen’s autoantigens (mimicry_

A

Cardiac myosin

60
Q

Result of cardiac myosin/strep M protein issue

A

Autoimmune cardiomyopathy in post strep rheumatic fever

61
Q

Trypanosomiasis cruzi b13 antigen’s mimic

A

Cardiac myosin

62
Q

Result of cardiac myosin attack frommimicry on trypanosoma cruzi b13

A

Chagas’ disease with associated cardiomyopathy

63
Q

Hepatitis C virus E1 protein mimic

A

Cytochrome p4502d6

64
Q

Effect of hepatitis c virus e1 protein and attack on cytochrome p4502d6 mimicry

A

Autoimmune hepatitis type 2

65
Q

H pylori acetate kinase mimic

A

H+K+ atpase (gastric proton pump)

66
Q

Result of mimic attack of gastric proton pump with h pylori

A

Autoimmune gastritis

67
Q

Pyruvate dehydrogenase complex E2 of bacteria mimic

A

Pyruvate dehydrogenase e2 complex in human

68
Q

Attack of pyruvate dehydrogenase e2 complex

A

Primary biliary cirrhosis

69
Q

Type 1 diabetes hla susceptibility

A

DQA10301/DQB10302 (DQ8) high risk

DQA10501/DQB10201 (DQ2)high risk

70
Q

Type 1 diabetes protection hla

A

DQA10102/DQB10602 (DQ6)

71
Q

MS HLA susceptibility

A

DRB1*1501 (DR2)

72
Q

RA hla susceptibility

A

DRBq*0404

73
Q

Coeliac disease hla susceptible

A

DQA10501/DQB10201 (DQ2)

74
Q

HLADQB57

A

Strong influence over shape of protein

75
Q

HLADQB57Asp

A

Closed groove

76
Q

HLADQb57ala or ser

A

More relaxed
Favor presentation of an important epitope(islet or mimicry) (ASP fail to present)
Poor at presentation of critical islet autoantigens epitope in thymus , thus failing to delete potential islet autoreactive T cells(Asp good at this)
Poor at presentation of critical islet autoantigen epitope in thymus, thus failing to generate regulatory T cell populations that can prevent autoimmunity developingin the periphery (asp good at thymus expression

77
Q

Major criteria for being an autoimmune disease

A

Evidence of loss of tolerance:presence of T or B cell autoimmunity
Clinical response to appropriate immune suppression
Passive transfer of the putative immune effector causes the disease

78
Q

Minor criteria of autoimmune disease

A

Animal model that resembles
Evidence that in animal model, passive transfer of the putative immune effectors reproduces the disease in a naive animal
HLA association

79
Q

Diabetes arises spontaneously

A

NOD-animal

Type 1 diabetes human

80
Q

Immunization with myelin basic protein or key peptides

A

Animal-experimental allergic encephalomyelitis

MS

81
Q

Immunization with adjuvant(M Tb)

A

Adjuvant arthritis -animal

RA-human

82
Q

Immunization with collagen

A

Collagen induced arthritis -animal

RA-human

83
Q

Treatment for autoimmune diseases

A

Blanket immune suppression-replacement therapy or suppression with corticosteroids
Immune suppression targeted at t or B cell

84
Q

Corticosteroids

A

Have effects on almost every compartment of the immune system interfering with cell activation and migration

85
Q

Downside of corticosteroid thepay

A

Side effects

86
Q

Effectors (bad guys)

A

Immune system

87
Q

Cops

A

Treg

Immunology (14 decks)

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