Brainscape's Knowledge GenomeTM

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


See full index

Sp 15-Micro Final > Immunological Tolerance and Autoimmune Disease > Flashcards

Immunological Tolerance and Autoimmune Disease Flashcards

1
Q

What is immunological tolerance?

A

A state of unresponsiveness for a particular antigen

LEARNED prior to exposure to the antigen

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

What is self tolerance?

A

Physiological state in which the immune system does NOT react destructively against self tissue.

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

Self tolerance may be induced in immature self-reactive lymphocytes within ________ or in mature lymphocytes in ________.

A

Generative lymphoid organs (bone marrow/thymus)

Peripheral Sites

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

What is central tolerance?

A

Tolerance that involves immature self-reactive lymphocytes within generative lymphoid organs

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

______ is functional unresponsiveness or “programmed ignorance.”

A

Anergy

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

Peripheral tolerance occurs in peripheral sites and occurs when ______ lymphocytes encounter self antigen.

A

Mature Self-reactive

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

True or False: Immunological tolerance is the failure to recognize antigen.

A

FALSE, it is an active response to a particular epitope and is just as specific as an immune response.

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

Tolerance may be _______ (self or oral) or may be _____ (prevent allergies, graft rejection, etc).

A

Natural

Induced

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

Reactivity is prevented by processes that occur ______ rather than being genetically pre-programmed.

A

during development

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

Which aspect of tolerance is considered to be the most important because it prevents the body from mounting an immune attack against its own tissues?

A

Self Tolerance

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

Which aspect of tolerance is considered to be the most important because it prevents the body from mounting an immune attack against its own tissues?

A

Self Tolerance

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

Central tolerance is programmed in T cells within the ____ and in B cells within the ______.

A

Thymus

Bone Marrow

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

What happens when lymphocytes do not bind MHC through their TCR?

A

They are destined to die by apoptosis

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

_______ selection occurs in the cortical region of the thymus.

A

Positive

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

What is “positive selection” within the thymus?

A

If the TCR of a lymphocyte recognizes MHC and binds antigen with LOW AVIDITY, the lymphocyte is sent to peripheral (secondary lymphoid organs) where it is able to mature and proliferate.

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

______ selection occurs in the medullary region of the thymus.

A

Negative

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

What is “negative selection” within the thymus?

A

If the TCR of a lymphocyte binds MHC with HIGH AVIDITY, the lymphocyte is deleted.

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

During maturation in the thymus, immature T cells that recognize antigens with high avidity will die (most) or_________(few).

A

Differentiate into regulatory T cells that will act to keep other T cells in check

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

Where do regulatory T cells come from?

A

Maturing T cells in the thymus that bind with high avidity or most often deleted, but some are allowed to differentiate into regulatory cells to monitor T cell activity.

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

Lymphocyte activation and tolerance is determined by:

  1. _________ of the antigens
  2. _______ of the antigen-specific lymphocytes
  3. types of _____ received when encountering antigens
A
  1. Properties
  2. State of maturation
  3. stimuli (costimulatory molecules)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

A B cell Receptor is a _________.

A

Membrane bound antibody

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Central tolerance in B cells will occur in immature B cells within the _______, where autoreactive cells will be _______ or _______.

A

bone marrow
eliminated
inactivated until rearrangement results in a new receptor

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

B cells that are self reactive will go through ________ which is a one-chance process.

A

Receptor Editing

  • if the receptor is still self-reactive = apoptosis
  • if the receptor is no longer reactive = maturation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Nature and concentration of self Ag determine the fate of B cells. For example:

  1. Multivalent Ag induces ______
  2. High concentrations of Ag induce ________
  3. Low concentrations of Ag induce ________
A
  1. B cell death
  2. B cell death
  3. functional anergy (decrease membrane Ig)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Nature and concentration of self Ag determine the fate of B cells. For example:

  1. Multivalent Ag induces ______
  2. High concentrations of Ag induce ________
  3. Low concentrations of Ag induce ________
A
  1. B cell death
  2. B cell death
  3. functional anergy (decrease membrane Ig)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is peripheral tolerance and where does it occur?

A

It is the mechanism by which mature T cells that recognize self antigen in peripheral tissues become incapable of responding to these antigens.

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

What are the four mechanisms of peripheral tolerance?

A
  1. Clonal Deletion
  2. Clonal Anergy
  3. Suppression
  4. Ignorance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is clonal deletion?

A

A mechanism of peripheral tolerance through which the cells are eliminated by induced cell death

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

What is clonal anergy?

A

A mechanism of peripheral tolerance through which the mature cell is present but is functionally inactivated.

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

True or False: Clonal anergy is an irreversible mechanism of peripheral tolerance.

A

False.

Anergy can be REVERSED

31
Q

Suppression is a mechanism of peripheral tolerance through which cellular activity is inhibited due to interaction with ______.

A

Other Cells such as T Regulatory Cells:
CD4/CD25 T Cells
IL-10 Secreting Regulatory Cells

32
Q

The co-existence of self-reactive clones and antigen in which the cells do not respond to antigen is known as _____.

A

Ignorance (mechanism of peripheral tolerance)

33
Q

The co-existence of self-reactive clones and antigen in which the cells do not respond to antigen is known as _____.

A

Ignorance (mechanism of peripheral tolerance)

34
Q

What kind of factors will determine which mechanism(s) of peripheral tolerance are operative?

A
  • concentration of self antigen in generative organs
  • affinity of receptor for antigen
  • nature of antigen
  • concentration of costimulatory molecules
35
Q

How do T cells affect the outcome of B cell activation in the periphery?

A

There must be a coordinated response (two signal hypothesis):
Signal 1 = signal through Ag receptor
Signal 2 = signal mediated through CD40-CD40L
Cytokines released = antibody production

36
Q

The “two signal hypothesis” for B cell Activation in the periphery states that the absence of one signal would results in ______.

A

B cell anergy

37
Q

Typically, APC will attach to Naive T cells through MHC and costimulatory molecules B7 and ______.

A

CD28

38
Q

Which molecule will compete with costimulatory CD28 for B7?

A

CTLA-4

39
Q

APC that recognize foreign antigen will attach to T cells through MHC and costimulatory molecules B7- ______.

A

CD28

40
Q

Which molecule will compete with costimulatory CD28 for B7 when APC recognize self-antigen?

A

CTLA-4

41
Q

Anergic cells show a block in _____-induced signal transduction via lack of costimulation by _____ and inhibition by ______.

A

TCR
B7
CTLA-4

42
Q

What does CTLA-4 bind to?

A

B7

43
Q

If a T cell recognizes self antigen, there will be an engagement of inhibitory receptors (such as CTLA-4) that will make the T cell _______.

A

Unresponsive (anergic)

44
Q

Peripheral tolerance via apoptosis results in deletion of self-reactive cells through cytochrome c + caspase-9 (neglect) or through Fas-____+Caspase-___ (activated death).

A

FasL

8

45
Q

IL-10 inhibits functions of _____, such as IL-12 secretion or B7 expression.

A

APC’s

46
Q

TGF-beta inhibits _______ cell proliferation.

A

T

47
Q

IL-4 inhibits actions of _______.

A

IFN-gamma

48
Q

IL-10 inhibits ______ activation.

A

macrophage

49
Q

How does ignorance happen?

A
  1. Antigen is expressed in a privileged site (brain) or sequestered (formed cyst) where the T cells cannot reach the antigen due to inability to cross some endothelial barrier.
    or
  2. Antigen is not expressed in the context of MHC
50
Q

Foreign antigens may be administered in ways that preferentially _________ rather than immune responses.

A

induce tolerance

51
Q

Foreign antigens may be administered in ways that preferentially _________ rather than immune responses.

A

induce tolerance

52
Q

________ antigens administered subcutaneously or intradermally with adjuvants will favor immunity rather than tolerance.

A

Protein

*adjuvants enhance the bodies response to antigens

53
Q

High doses of antigens administered systemically without adjuvants tend to induce ______ rather than ______.

A

Tolerance rather than immunity

54
Q

Oral administration of antigen will favor ________ induction.

A

tolerance

55
Q

A state of immune _____ follows oral administration.

A

Hyporesponsiveness (maintains homeostasis so there is no immune response to food antigen)

56
Q

A low dose of orally administered Ag will _____ Th2, whereas a high dose will cause _______ or _______ of Th1 and Th2 cells.

A 
low= induction of Th2
high= deletion or anergy of Th1/Th2
57
Q

For both B lymphocytes and T lymphocytes, anergy is associated with _____tolerance and apoptosis is associated with ______tolerance.

A

Peripheral

Central

58
Q

How does central and peripheral tolerance relate to the development of autoimmunity?

A

Autoimmunity results when central and peripheral tolerance is broken
-The immune system is dysregulated and attacks the organs it was designed to protect

59
Q

True or False: Autoimmune diseases only involve the nervous, gastrointestinal, and endocrine systems.

A

False.

Autoimmune diseases can involve almost every organ system

60
Q

What are the seven common factors that can predispose an individual to autoimmune diseases?

A
  1. MHC associations
  2. Familial concordance
  3. Gender (females)
  4. Climate (equatorial range)
  5. Chemical agents
  6. Infectious agents
  7. Immune dysregulation
61
Q

Certain ______ occur at higher rates within the MHC haplotypes of autoimmune individuals but no one has the same exact halplotype.

A

Alleles

62
Q

______ hormones represent an important modulatory factor in the autoimmune response.

A

Sex

63
Q

Pregnancy causes a switch to more _____ production which makes MS better and Lupis worse.

A

Th2
MS: associated with increases in Th1
Lupis: associated with increases in Th2

64
Q

What initiates an autoimmune response?

  1. Incomplete ________
  2. Stimulation of normally ______ self reactive cells
  3. Altered ______ of anergic cells
A
  1. deletion of self reactive cells
  2. anergic
  3. regulation
65
Q

What initiates an autoimmune response?

  1. Incomplete ________
  2. Stimulation of normally ______ self reactive cells
  3. Altered ______ of anergic cells
A
  1. deletion of self reactive cells
  2. anergic
  3. regulation
66
Q

Molecular mimicry occurs when microbial antigen peptide within the MHC ______.

A

Appears like self-antigen

67
Q

What is “bystander activation” in the context of autoimmunity?

A

Antigen presenting cell with self-antigen comes into close proximity of a microbe. The microbe activates APC expression of costimulatory molecules (B7-CD28) and T cells attack self tissue.

68
Q

Autoimmune disease may be either ______ or ______ specific.

A

Systemic

Organ

69
Q

Lupus Erythematosus (SLE) and Rheumatoid Arthritis are _____ autoimmune diseases. Multiple sclerosis and Insulin Dependent Diabetes Mellitus are ______ autoimmune diseases.

A

Systemic

Organ-specific

70
Q

Lupus Erythematosus (SLE) and Rheumatoid Arthritis are _____ autoimmune diseases. Multiple sclerosis and Insulin Dependent Diabetes Mellitus are ______ autoimmune diseases.

A

Systemic

Organ-specific

71
Q

What is the most common inflammatory disorder of the central nervous system?

A

Multiple Sclerosis (MS)

72
Q

What is characterized as a “T cell mediated autoimmune disease in which T cells are specific for components of the myelin sheath” ?

A

MS (damage to CNS via myelin degradation)

73
Q

True or False: An individual may develop more than one autoimmune disease.

A

True

74
Q

True or False: An individual with Lupus may also develop MS.

A

False: These diseases are contradictory. Lupus (Th2), Multiple Sclerosis (Th1)

Sp 15-Micro Final (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions