Brainscape's Knowledge GenomeTM

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


See full index

Pathology Kyle > Immunology 5 (Kyle) > Flashcards

Immunology 5 (Kyle) Flashcards

1
Q

What is a T cell ?

A

A T cell is a lymphocyte that is produced in the bone marrow, migrates to and matures in the Thymus, and differentiates into cells that either kill target cells that bear their cognate peptide: MHC Class 1 complex or supply help to other immune cells via production of cytokines.

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

How do T cells recognize a specific antigen?

A

T cells recognize a specific antigen through their T cell receptors.

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

Where does a T cell come from ?

A

Common Lymphoid Precursor and bears a TCR

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

Do T cell s secrete immunoglobulin molecules?

A

No

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

Describe the structure of AB T Cells

A

Most T cells bear a T cell receptor (TCR) that is composed of an A and a B chain

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

What do T cells do ?

A

Kill cells infected with viral or other intracellular pathogens

Supply helper signals which activate B cells and macrophages.

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

What are the 4 regions of a T cell receptor?

A

Variable region which binds the Ab
Constant Region
Transmembrane Region
Cytoplasmic Tail

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

What is an important surface marker on T cells that was mentioned in lecture.

What does it do?

A

CD3 is the signal transduction unit for TCR

Initiate signaling cascade upon antigen-recognition through T cell receptors

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

What are the Co receptors for the T cell receptor?

A

CD4 and CD8.

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

What does CD4 do ?

A

Has high affinity for MHC Class 2 molecules

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

What does CD8 do ?

A

Has high affinity for MHC Class 1 molecules

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

What binds to B7 molecules on antigen presenting cells ?

A

CD 28

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

What does the FAS Ligand do ?

A

Can bind to Fas expressed on the surface of target cells initiating Fas-mediated apoptosis

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

What do adhesion molecules do ?

A

Adhesion molecules initiate interactions between T cells and APC or target cells

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

What are the two regions of the Thymus ?

A

The Cortex and Medulla

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

What happens in the subcapsular region of the thymus (Think T Cell maturation)

A

T cells proliferate and differentiate to double positive CD3+ Thymocytes

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

What are the first chains to undergo rearrangement in the TCR variable region ?

A

Beta, Gamma, and Delta

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

If gamma and delta chain rearrangement are successful before beta chain rearrangement, what will the T cell be ?

A

Gamma, Delta T-Cell

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

What are the two distinct populations of T cells?

A

Gamma Delta T Cells and Alpha Beta T Cells.

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

What are the two subpopulations of Alpha Beta T cells ?

A

CD4+ and CD8+

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

What are CD4 and CD8 ?

A

Co receptors for the TCR that facilitates the interaction of TCR with the MHC complex on the antigen presenting cell

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

Can mature Alpha Beta T cells express CD4 and CD8 ?

A

They express one or the other but not both.

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

What cells express CD4+

A

Helper T cells

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

What does CD4 bind ?

A

CD4 binds to MHC Class 2 molecules.

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

What is the function of a helper T cell ?

A

Helper T cells produce cytokines and procide help to B cells as well as stumulate cells of the innate immune system to increase their activity.

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

What cells express CD8 ?

A

CD8 cells are expressed on Killa T Cells

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

What molecules does CD8 bind?

A

CD8 molecules bind to MHC class 1

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

Describe the structure of CD8 molecules

A

Heterodimer formed by an Alpha and a Beta chain that are connected by a disulfide.

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

What is CD3

A

CD3 complex is expressed on all T cells and serves as the signal transduction unit for the TCR

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

What purpose do accessory molecules serve?

A

Accessory molecules interact with proteins on antigen presenting cells and or target cells leading to either

  1. Activation of the T cell
  2. Tighter interaction between the T cell and the APC
  3. Killing of the target cell
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What are the three functions of adhesion molecules ?

A

Lymphocyte functioning antigen
CD2
Very Late Antigen

32
Q

What are Lymphokine receptors?

A

T cells express many of these receptors so that they can respond to the lymphokines produced by other cells that help to regulate T cell functions.

33
Q

How do lymphokine receptors function?

A

Lymphokine receptors function to activare protein kinase cascades that deliver signals to the nucleus of the T cell.

34
Q

Describe the structure of the thymus

A

The Thymus is an encapsulated bilobed organ . Each lobe is separated by into distince lobules by trabeculae connected to a sinus beneath the capsule

35
Q

What is each lobe of the thymus separated into?

A

A cortex and a medulla

36
Q

What does the cortex consist of ?

A

The cortex is densely packed with thymocytes and a network of epithelial cells called cortical epithelial cells.

37
Q

What do cortical epithelial cells in the thymus express?

A

MHC Class 2 and MHC Class 1 antigens.

38
Q

What is the medulla of the thymus contain?

A

The medulla is populated with medullary epithelial cells, dendritic cells, and macrophages.

39
Q

When is the thymus fully developed?

A

At birth

40
Q

What is a T Cell Receptor (TCR) ?

A

A disulfide linked heterodimer that consists of either an alpha and a beta chain or a gamma and a delta chain.

**Most are Alpha Beta

41
Q

Describe the structure of the chains that compose the T cell receptor.

A

Both chains haev a constant and a variable region representing the Ab molecule.

42
Q

Where is the hinge region and what does it do?

A

The extreme end of the carboxyterminal region.

This region anchors the molecule in the membrane of the T cell and allows some flexibility of the molecule.

43
Q

How are the variable regions of the TCR chains constructed?

A

It is constructed from a cassette of genes similar to the variable region of the antibody variable chain.

44
Q

What does the variability offer the TCR ?

A

The ability to recognize a huge number of antigens .

45
Q

What are the two lineages of T cells that are generated in the Thymus?

A

Alpha Beta T cells and Gamma Delta T cells.

46
Q

What are the T cell co-receptors that facilitate the interaction of TCR with the MHC complex on the antigen-presenting cell ?

Can T cells express both of these on their surface?

A

CD4 and CD8. T cells express one of these but not both.

47
Q

What cells express CD4? And what molecules interact with CD4 presenting cells?

A

CD4 is present on helper T cells and CD4 binds weakly to MHC 2 molecules.

48
Q

What is the function of CD4 helper T cells?

A

Helper T cells produce cytokines and provide help to B cells as well as stimulate cells of the innate immune system to increase their activity.

49
Q

What cells express CD8? What does CD8 bind? And is the function of CD8 T cells?

A

Cytotoxic Killer Cells express CD8, It binds MHC-1. CD8 cells kill cells that are presenting their cognate peptide antigen via MHC class 1.

50
Q

What is the CD3 complex?

A

CD3 is expressed on all T cells and serves as a signal transduction unit for the TCR. This protein is integral to the T cell activation.

51
Q

What do accessory molecules do?

A

Accessory molecules interact with proteins on antigen-presenting cells and or target cells leading to either 1. Activation of the T cell 2. Tighter interaction between the T cella nd the APC 3. Killing of the target cell.

52
Q

What do adhesion molecules do?

A

The primary function of adhesion moleculesis to strengthen the interaction between a T cell and antigen presenting cells or target cells.

53
Q

What do lymphokine receptors do?

A

T cells express many of these receptors so that they can respond to the lymphokines produced by other cells that help ro regulate T cell functions. Lymphokine receptors function to activate protein kinase cascades that deliver signals to the nucleus of the T cell.

54
Q

What are the two regions of the thymus?

A

Cortex and Medulla

55
Q

What type of cells are found in the cortex?

A

Thymocytes scattered macrophages and cortical epithelial cells.

56
Q

What type fo cells are found in the medulla?

A

The medulla is populated with medullary epithelial cells, dendritic cells and macrophages.

57
Q

When is T cell production in the Thymus greatest?

A

Right before puberty. After puberty the thymus begins to shrink because new T cells are not required to mantain T cell mediated immunity.

58
Q

What are T cell precursors called?

A

Thymocytes

59
Q

Describe positive selection for thymocyte maturation.

A

Positive selection for T cells with TCR that can bind to self-MHC occurs in the cortex NON-BINDERS UNDERGO APOPTOSIS

60
Q

Describe negative selection for thermocyte maturation.

A

Negative selection for T cells that bind to tightly to self MHC+ self peptid eoccurs in the Medulla.

61
Q

How are the apoptotic thymocytes killed off?

A

Via tingible body macrophages.

62
Q

How do tingible body macrophages work?

A

Tingible body macrophages: cortical thymus macrophages have distinct stainign pattern due to the chromatic material of the phagocytosed thymocytes that were not positively selected and underwent apoptosis.

63
Q

What are the most important markers for thymocyte development?

A

CD4 and CD8

64
Q

If the TCR binds to MHC-2 what will the thymocyte become?

A

CD4+

65
Q

If the TCR binds to MHC-1 what will the thymocyte become?

A

CD8+

66
Q

Where does the CD8 CD4 selection process take place?

A

At or near the cortico-medullary junction.

67
Q

It would be detrimental for an organism to have T cells that recognize self antigens, Where does this specificity get determined during T cell maturation?

A

In the Thymus.

68
Q

Which MHC molecule do the thymic epithelium cells express?

A

MHC-1 and MHC-2, Cells that Bind MHC are allowed to continue to mature.

69
Q

What is the purpose of negative selection?

A

To remove cells that bind self antigen

70
Q

What is the autoimmune regulator?

A

A transcription factor expresseed in the epithelial cells of the medullary region of the thymus.

71
Q

What does the autoimmne regulator do?

A

The autoimmune regulator causes the expression of several hundred host specific proteins by a subset of epithelial cells in the medullary region of the thymus. Their expression makes them available for uptake by medullary Antigen Presenting Cells.

72
Q

What are the two regions of the Aplha and Beta chains that make up the TCR?

A

A and B chains have a single (V) variable region and a single (C) conserved region.

73
Q

How is the variable region of the alpha segment transcribed and translated?

A

The variable region is produced by rearrangement of a V gene segment and a J gene segment.

74
Q

How is the variable region of the Beta chain transcribed and translated?

A

The Beta chain coding region is produced by rearrangement of a V region gene segment, a D gene segment, and a J gene segment.

75
Q

How is the TCR alpha chain rearranged?

Similiar to light chain Ig

A
  1. A V segment is joined to a J segment to produce a VJ junction. RNA is transcribed.
  2. The RNA is processed and splicing places the VJ junction with the Calpha region gene segment.
  3. The RNA is translated.
76
Q

How is the TCR beta chain rearranged?

Similiar to Heavy Chain Ig

A
  1. One of the two D gene segments is joined to the J gene segment to form the DJ junction.
  2. A V gene segment joins the DJ junction forming the VDJ junction. Transcription takes place.
  3. RNA splicing removes intronic sequences and joins the VDJ junction with the C region gene segment. Translation takes place.

Pathology Kyle (13 decks)

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