Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

VBSC 211: The Immune System > Exam 3: Chapter 5 > Flashcards

Exam 3: Chapter 5 Flashcards

1
Q

What are naïve CD8+ T cells?

A

Cells activated by MHC Class 1 peptides presented by APCs

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

What are the different forms of any given gene called?

A

Alleles

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

What is antigen processing?

A

Process in which pathogens and other proteins are chopped up into smaller pieces called peptides

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

How are the MHC genes arranged on the chromosome?

A

The class 1 and class 2 gene families are in separate regions and are separated by the class 3 region

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

How do the CDR regions of the TCR contact the peptide MHC?

A

CDRs 1 and 2 bind to the alpha helices of the MHC, and CDR 3 binds the peptide

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

How many T cell receptors (TCRs) are expressed by each T cell?

A

1

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

What do chaperone proteins do, in terms of MHC Class 1?

A

Aid in the assembly of the MHC Class 1 heterodimer and facilitate the binding of peptides

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

What is directional selection?

A

The type of selection that favors one allele over others due to its ability to protect against a pathogen

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

What are the unique features of helper T cells?

A

They are CD4+ and help activate effector cells to fight extracellular pathogens

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

What are the specifics of the MHC Class 1 binding pocket?

A

Binds to the ends of peptides, prefers peptides of ~ 9 AAs

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

In which MHC type does allotype equal isoform?

A

MHC Class 1

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

What do HLA-E and HLA-G do?

A

Present peptides to NK cells only

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

Which class region also includes genes involved in the immune response?

A

Class 2

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

What components form the CD3 complex?

A

2 epsilon domains, 2 zeta domains, 1 delta domain, and 1 gamma domain

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

What kind of combinatorial diversity is observed in the TCR alpha chain?

A

VJ combination (like the light chain of antibodies)

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

What is MHC called in humans?

A

Human Leukocyte Antigen Complex (HLA)

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

How are the binding sites of TCRs determined?

A

By the hypervariable regions, or CDRs

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

Which MHC class has multiple possible genes for each isotype?

A

Class 2

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

Compare and contrast the structure of an antibody versus a T cell receptor.

A

Both TCRs and antibodies are made up of variable and constant regions. Antibodies are formed from 4 proteins, while TCRs are formed from 2 proteins. Antibodies can be on the cell surface or secreted, while TCRs are only ever present on cell surfaces

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

What are the unique features of cytotoxic T cells?

A

They are CD8+, are activated by intracellular pathogens, and kill infected cells

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

What is degenerate specificity?

A

The ends of the peptide and specific anchor residues are recognized rather than individual peptides, allowing MHCs to bind to a wider variety of peptides

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

What is the function of the proteosome?

A

To chop proteins into peptides

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

How are the peptides generated by the proteosome transported into the ER?

A

By the Transporter associated with Antigen Processing (TAP)

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

What syndrome is associated with TAP mutations?

A

Bare-Lymphocyte Syndrome - less than 1% of the normal amount of Class 1 MHC is present on the cell surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What do HLA-DP, HLA-DQ, and HLA-DR do?
Present peptides to CD4+ T cells
26
What are alloantibodies?
Antibodies produced by a pregnant woman in response to the paternal MHC present within the fetus's cells
27
What is gene conversion?
When one gene unequally shares genetic information with another gene
28
What do HLA-DM and HLA-DO do?
Regulate peptide loading in the phagolysosome
29
What are the two mechanisms that generate diversity in MHC molecules?
1. MHC gene families contain multiple chain genes | 2. Genetic polymorphisms
30
What happens once the MHC Class 2 molecule reaches the vesicle?
The invariant chain is cleaved, leaving behind the CLIP fragment that still prevents peptide binding
31
What do T cell receptors recognize?
Peptide antigens that are presented by MHC
32
When TCR binds, what does it make contact with?
Both the peptide and the MHC molecule
33
What is cross presentation?
When MHC Class 1 molecules present extracellular antigens
34
Where do the hypervariable regions of TCRs occur?
In the loops between the Ig domains
35
What are the two types of diversity that contribute to differences in the TCR alpha and beta chains?
Combinatorial diversity and junctional diversity
36
Which MHC class do CD4+ T cells interact with?
MHC Class 2
37
What is the role of the invariant chain?
To block the binding of peptides to the MHC Class 2 molecule while it is still in the ER and to deliver the Class 2 molecule to the appropriate vesicles for peptide binding
38
How is CLIP removed so that MHC Class 2 molecules can bind peptides?
Via the action of HLA-DM
39
What are gamma-delta T cells?
T cells that express a gamma:delta heterodimer
40
What is the immunoproteosome?
A special form of the proteosome for MHC Class 1, which is induced by Ifn-gamma
41
What are the two types of MHC?
MHC Class 1 and MHC Class 2
42
What is interallelic conversion?
When two alleles of the same gene exchange genetic information equally
43
What are the different HLA Class 1 isotypes?
HLA-A, HLA-B, HLA-C, HLA-E, HLA-F, HLA-G
44
What is the combination of allotypes that forms an MHC molecule called?
Isoform
45
Why is it important that MHC molecules are polymorphic?
Being polymorphic provides MHC molecules with degenerate binding specificity, which allows them to bind a wide variety of peptides
46
What are alloreactive T cells?
T cells that will recognize self-peptides presented by allogenic MHC
47
What is antigen presentation?
When MHC displays a peptide on the cell surface
48
What are the specifics of the MHC Class 2 binding pocket?
Binds with the side chains of peptides, and thus can bind to larger peptides than MHC Class 1
49
What are the different HLA Class 2 isotypes?
HLA-DM, HLA-DO, HLA-DP, HLA-DQ, HLA-DR
50
What is MHC restriction?
The requirement that T cells must recognize both the peptide and the specific MHC structure in order to be activated
51
What is balancing selection?
The type of selection that acts to maintain MHC diversity by selecting for heterozygotes with haplotypes that minimally overlap
52
What is an alloreaction?
When a transplanted organ presents self-peptides complexed with allogenic MHC, leading to rejection
53
What do alloantibodies do?
Attack transplanted tissues in a woman if they have the same MHC as a man who fathered a previous pregnancy
54
What is ERAP?
A peptidase that shortens peptides so that they fit into the MHC Class 1 molecule
55
What part of MHC Class 2 does CD4 bind to?
The beta-2 domain
56
What is directional selection caused by?
An epidemic disease
57
What are alpha-beta T cells?
T cells that express an alpha:beta heterodimer
58
What is the function of cytotoxic T cells?
To kill infected cells
59
How does TCR interact with antigen?
Via cell-to-cell interactions
60
What is the role of calnexin?
To stabilize the Class 1 heavy chain until Beta-2 microglobulin binds
61
What forms the antigen binding domain of the TCR?
The variable regions of the TCR alpha and TCR beta chains
62
What is the MHC Class 1 molecule composed of?
An MHC heavy chain (with domains alpha-1, alpha-2, alpha-3, and a transmembrane domain) and Beta-2 microglobulin
63
What molecules form the peptide-loading complex?
Class 1 heterodimer, calreticulin, tapasin, TAP, ERp57, and PDI
64
Where do Class 2 peptides bind?
In vesicles known as the MHC Class 2 compartment
65
What part of MHC Class 1 does CD8 bind to?
The alpha-3 domain
66
What do HLA-A, HLA-B, and HLA-C do?
Present peptides to CD8+ T cells and NK cells
67
How can APCs be activated, if not infected by the virus itself?
By phagocytosing infected dead cells
68
Why is it important that the cell is compartmentalized?
Peptides derived from intracellular pathogens (MHC Class 1) and are generated in a separate compartment than peptides derived from extracellular pathogens (MHC Class 2)
69
Which Class 1 HLA remains intracellular with an unknown function?
HLA-F
70
What kind of combinatorial diversity is observed in the TCR beta chain?
VDJ combination (like the heavy chain of antibodies)
71
What is a unique feature of gamma-delta T cells?
They can bind antigens that are not presented by MHC
72
What are the proteins encoded for by different alleles called?
Allotypes
73
What is SCID?
Severe Combine Immunodeficiency - null mutations in RAG 1 and RAG 2 block TCR and immunoglobulin rearrangements, leading to a lack of B and T cells
74
What is the MHC Class 2 molecule composed of?
An alpha chain and a beta chain, each containing a transmembrane domain, an Ig-like domain, and a peptide bonding domain
75
What is the combination of MHC alleles on the chromosome called?
Haplotype
76
How are new MHC genes generated?
Point mutations and recombination
77
What is the CD3 complex?
Complex required for the proper transport of TCR that also relays signals into the cell once TCR binds its antigen
78
Which MHC class do CD8+ T cells interact with?
MHC Class 1
79
Why can allogenic MHC alloreactions be treated, but alloantibody alloreactions cannot?
There are drugs available that can inhibit T cell activation, but none that can inhibit the antibody response
80
What is the function of helper T cells?
To help activate other effector cells
81
What regions of a peptide do MHC molecules recognize?
The ends and the backbone
82
Why are alpha-beta T cells and gamma-delta T cells mutually exclusive?
The delta chain locus is contained within the alpha chain locus, and gets deleted when the alpha chain is rearranged
83
How are autologous MHC isoforms and allogenic MHC isoforms different?
The self MHC isoforms are referred to as autologous, while all others are considered allogenic

VBSC 211: The Immune System (10 decks)

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