Intro to Immunology Flashcards
Antigen Presentation & recognition Cytokines
1
Q
What does MHC stand for?
A
Major Histocompatibility Complex
2
Q
True or False: Class 1 MHC molecules present antigens to CD4+ T cells.
A
False
3
Q
What type of T cells do Class 1 MHC molecules primarily interact with?
A
CD8+ T cells
4
Q
Fill in the blank: Class 1 MHC molecules are composed of a heavy chain and a _____ chain.
A
β2-microglobulin
5
Q
Class 2 MHC molecules are primarily expressed on which type of cells?
A
Professional antigen-presenting cells (APCs)
6
Q
What is the primary function of Class 2 MHC molecules?
A
To present extracellular antigens to CD4+ T cells
7
Q
True or False: Both Class 1 and Class 2 MHC molecules have a similar overall structure.
A
True
8
Q
What is the main structural component that Class 2 MHC molecules have that Class 1 does not?
A
An additional α chain
9
Q
Class 1 MHC molecules are found on which type of cells?
A
All nucleated cells
10
Q
What is the role of the peptide binding groove in MHC molecules?
A
To bind and present peptide fragments of antigens
11
Q
How many transmembrane domains do Class 1 MHC molecules have?
A
One
12
Q
How many transmembrane domains do Class 2 MHC molecules have?
A
Two
13
Q
What is the size range of peptides that bind to Class 1 MHC molecules?
A
8 to 11 amino acids
14
Q
What is the size range of peptides that bind to Class 2 MHC molecules?
A
13 to 25 amino acids
15
Q
True or False: Class 1 MHC molecules can present endogenous antigens.
A
True
16
Q
True or False: Class 2 MHC molecules can present exogenous antigens.
A
True
17
Q
What is the genetic basis for the diversity of MHC molecules?
A
Polymorphism in MHC genes
18
Q
What is the significance of MHC restriction in T cell activation?
A
T cells can only recognize antigens presented by MHC molecules of the same type.
19
Q
What are the two main classes of MHC molecules?
A
Class 1 MHC and Class 2 MHC
20
Q
What is the main structural feature that distinguishes Class 1 MHC from Class 2 MHC?
A
Class 1 MHC has a single heavy chain, while Class 2 MHC has two chains (α and β).
21
Q
Fill in the blank: The genes for MHC molecules are located on chromosome _____ in humans.
A
6
22
Q
What is the role of the α1 and α2 domains in Class 1 MHC molecules?
A
They form the peptide-binding groove.
23
Q
What is the role of the β1 and β2 domains in Class 2 MHC molecules?
A
They form the peptide-binding groove.
24
Q
True or False: MHC molecules play a role in autoimmune diseases.
A
True
25
What is the purpose of the polymorphism in MHC genes?
To enhance the ability of the immune system to recognize a diverse array of antigens.
26
What does MHC stand for?
Major Histocompatibility Complex
27
True or False: MHC polymorphism refers to the variation in MHC gene sequences among individuals.
True
28
Fill in the blank: MHC genes are crucial for the _____ of the adaptive immune response.
presentation of antigens
29
What is the significance of MHC polygeny?
It allows for a diverse range of MHC molecules to present different antigens.
30
Multiple Choice: Which of the following is a main function of MHC molecules? A) Energy production B) Antigen presentation C) Cell division
B) Antigen presentation
31
How many classes of MHC molecules are there?
Two classes: MHC class I and MHC class II
32
True or False: MHC class I molecules present antigens to CD4+ T cells.
False
33
What is the role of MHC class II molecules?
To present antigens to CD4+ T helper cells.
34
Fill in the blank: MHC polymorphism is thought to be driven by _____ selection.
pathogen
35
What is the primary benefit of having a diverse MHC repertoire?
Increased ability to respond to a wide variety of pathogens.
36
Multiple Choice: Which type of T cell interacts with MHC class I molecules? A) CD4+ T cells B) CD8+ T cells C) B cells
B) CD8+ T cells
37
True or False: Genetic diversity in MHC can influence susceptibility to diseases.
True
38
What is the relationship between MHC polymorphism and autoimmune diseases?
Certain MHC alleles are associated with a higher risk of developing autoimmune diseases.
39
Fill in the blank: The ability of an individual to present a wide variety of antigens is referred to as _____ diversity.
functional
40
What is the consequence of low MHC diversity in a population?
Increased vulnerability to infectious diseases.
41
Multiple Choice: Which of the following is NOT a characteristic of MHC molecules? A) They are highly polymorphic B) They are encoded by a single gene C) They are essential for T cell activation
B) They are encoded by a single gene
42
What does the term 'allelic diversity' refer to in the context of MHC?
The existence of multiple different alleles at a given MHC gene locus.
43
True or False: MHC molecules are found on all nucleated cells.
True
44
What is the primary function of MHC class I molecules?
To present intracellular antigens to CD8+ T cells.
45
Fill in the blank: The genes encoding MHC molecules are located on chromosome _____ in humans.
6
46
What is one mechanism through which MHC diversity is maintained in populations?
Balancing selection due to pathogen pressure.
47
Multiple Choice: MHC molecules are crucial for which immune process? A) Phagocytosis B) Antigen presentation C) Clonal expansion
B) Antigen presentation
48
True or False: All individuals have the same set of MHC alleles.
False
49
What is the impact of MHC mismatching in organ transplantation?
It increases the risk of transplant rejection.
50
Fill in the blank: The diversity of MHC alleles can lead to differences in _____ responses among individuals.
immune
51
What does MHC stand for?
Major Histocompatibility Complex
52
True or False: MHC molecules are essential for T cell recognition of antigens.
True
53
Fill in the blank: MHC restriction refers to the requirement that T cells recognize both the _______ and the _______ presented by MHC molecules.
antigen, MHC molecule
54
What are the two main classes of MHC molecules?
MHC Class I and MHC Class II
55
Which type of T cell primarily interacts with MHC Class I molecules?
CD8+ T cells
56
Which type of T cell primarily interacts with MHC Class II molecules?
CD4+ T cells
57
True or False: MHC molecules are genetically identical in all individuals.
False
58
What is the role of MHC Class I molecules?
To present endogenous antigens to CD8+ T cells.
59
What is the role of MHC Class II molecules?
To present exogenous antigens to CD4+ T cells.
60
Which cells express MHC Class II molecules?
Professional antigen-presenting cells (APCs) such as dendritic cells, macrophages, and B cells.
61
What is the consequence of a mismatch in MHC molecules during organ transplantation?
Rejection of the transplanted organ.
62
True or False: MHC restriction is important for the immune system's ability to distinguish self from non-self.
True
63
What is the significance of polymorphism in MHC genes?
It allows for a diverse range of antigens to be presented to T cells.
64
Short answer: What is the process by which MHC molecules present antigens?
Antigen processing and presentation.
65
Multiple choice: Which of the following is NOT a function of MHC molecules? A) Antigen presentation B) Immune response activation C) Enzyme secretion
C) Enzyme secretion
66
What is the term for the unique set of MHC molecules present in an individual?
MHC haplotype
67
Fill in the blank: T cells undergo positive and negative _______ during development in the thymus.
selection
68
True or False: MHC molecules can present both peptide fragments and lipids.
True
69
What is the primary function of CD8+ T cells in relation to MHC Class I?
To kill infected or cancerous cells.
70
What type of immune response involves MHC Class II molecules?
Helper T cell response
71
Short answer: How do MHC molecules contribute to autoimmune diseases?
By presenting self-antigens that trigger an immune response against the body's own tissues.
72
Which cytokine is primarily produced by CD4+ T cells to activate other immune cells?
Interleukin-2 (IL-2)
73
True or False: MHC molecules can only present antigens from pathogens.
False
74
What is cross-presentation in the context of MHC molecules?
The ability of certain APCs to present exogenous antigens on MHC Class I molecules.
75
Multiple choice: Which of the following best describes MHC restriction? A) T cells can recognize any antigen B) T cells can only recognize antigens presented by their specific MHC C) T cells do not require MHC to recognize antigens
B) T cells can only recognize antigens presented by their specific MHC
76
What are the two main classes of MHC molecules involved in peptide antigen binding?
Class I and Class II MHC molecules.
77
True or False: Class I MHC molecules present antigens to CD4+ T cells.
False.
78
Fill in the blank: Class I MHC molecules typically present ___________ derived from intracellular proteins.
peptides.
79
What type of T cells do Class II MHC molecules interact with?
CD4+ T helper cells.
80
True or False: Class II MHC molecules are expressed on all nucleated cells.
False.
81
What is the primary source of peptides presented by Class I MHC?
Intracellular proteins.
82
Multiple Choice: Which of the following is NOT a characteristic of Class II MHC molecules? A) Present extracellular antigens B) Found on all cells C) Interact with CD4+ T cells D) Involved in immune response
B) Found on all cells.
83
What is the role of Class I MHC molecules in the immune response?
To present endogenous antigens to CD8+ cytotoxic T cells.
84
Fill in the blank: Class II MHC molecules primarily present ___________ derived from extracellular proteins.
peptides.
85
True or False: Peptides presented by Class I MHC are typically 8-10 amino acids long.
True.
86
True or False: Peptides presented by Class II MHC are typically longer, around 13-25 amino acids.
True.
87
What is the primary cellular location for Class I MHC molecule expression?
On the surface of all nucleated cells.
88
What is the primary cellular location for Class II MHC molecule expression?
On professional antigen-presenting cells (APCs) like dendritic cells, macrophages, and B cells.
89
Multiple Choice: Which type of T cell responds to antigens presented by Class I MHC? A) CD4+ T cells B) CD8+ T cells C) B cells D) NK cells
B) CD8+ T cells.
90
What is the mechanism by which Class II MHC molecules acquire peptides?
By endocytosis of extracellular proteins.
91
Fill in the blank: Class I MHC molecules present antigens to ___________ T cells.
CD8+.
92
Fill in the blank: Class II MHC molecules present antigens to ___________ T cells.
CD4+.
93
What is the consequence of a T cell recognizing a peptide-MHC complex?
Activation of the T cell.
94
True or False: Both Class I and Class II MHC molecules are essential for adaptive immunity.
True.
95
What is the significance of polymorphism in MHC molecules?
It allows for a diverse range of peptides to be presented to T cells.
96
Multiple Choice: Which of the following best describes the peptide binding groove of Class I MHC? A) Open at both ends B) Closed at both ends C) Variable size D) Fixed size
B) Closed at both ends.
97
Multiple Choice: Which MHC class is involved in presenting antigens for CD8+ T cell activation? A) Class I B) Class II C) Both A and B D) Neither A nor B
A) Class I.
98
What is the role of the T cell receptor (TCR) in the recognition of peptide-MHC complexes?
The TCR binds to the peptide-MHC complex, initiating T cell activation.
99
Fill in the blank: The process by which MHC molecules present peptides is known as ___________.
antigen presentation.
100
True or False: Class II MHC molecules can present peptides derived from intracellular proteins.
False.
101
What are the main categories of antigen recognition molecules?
The main categories are antibodies, T cell receptors (TCRs), and major histocompatibility complex (MHC) molecules.
102
True or False: Antibodies are a type of antigen recognition molecule.
True
103
Fill in the blank: T cell receptors are primarily involved in recognizing _____ antigens.
peptide
104
What is the role of major histocompatibility complex (MHC) molecules?
MHC molecules present peptide fragments to T cell receptors.
105
What are the two classes of MHC molecules?
MHC Class I and MHC Class II.
106
Which cells express MHC Class I molecules?
All nucleated cells.
107
Which cells express MHC Class II molecules?
Professional antigen-presenting cells (APCs) such as dendritic cells, macrophages, and B cells.
108
What is the function of co-receptors in T cell activation?
Co-receptors enhance the sensitivity of T cells to their specific antigens.
109
Name the two main co-receptors associated with T cell receptors.
CD4 and CD8.
110
True or False: CD4 co-receptors are found on cytotoxic T cells.
False
111
What type of T cells express CD8?
Cytotoxic T cells.
112
What is the primary function of antibodies?
Antibodies bind to specific antigens to neutralize them or mark them for destruction.
113
Fill in the blank: Antibodies are also known as _____.
immunoglobulins
114
What are the five classes of antibodies?
IgG, IgA, IgM, IgE, and IgD.
115
Which antibody class is the most abundant in serum?
IgG.
116
True or False: IgM is the first antibody produced in response to an infection.
True
117
What is the role of B cell receptors (BCRs)?
BCRs recognize and bind to specific antigens directly.
118
What is the difference between BCRs and antibodies?
BCRs are membrane-bound forms of antibodies found on B cells, while antibodies are secreted forms.
119
What does the term 'clonal selection' refer to?
The process by which specific B or T cells are activated and proliferate in response to an antigen.
120
Fill in the blank: The region of an antibody that binds to an antigen is called the _____ region.
variable
121
What is the constant region of an antibody responsible for?
Determining the class and effector functions of the antibody.
122
True or False: T cell receptors undergo somatic hypermutation.
False
123
What is somatic hypermutation?
A process that occurs in B cells to increase the affinity of antibodies for their antigens.
124
What is the significance of antigen diversity in the immune system?
It allows the immune system to recognize and respond to a vast array of pathogens.
125
Name one mechanism by which antigen recognition molecules can achieve diversity.
V(D)J recombination.
126
What is the role of CD28 in T cell activation?
CD28 provides a necessary co-stimulatory signal for T cell activation.
127
What are the two main classifications of cytokines?
Cytokines can be classified into pro-inflammatory and anti-inflammatory cytokines.
128
True or False: Cytokines are only produced by immune cells.
False
129
Fill in the blank: Cytokines play a crucial role in _____ and _____ responses.
immune, inflammatory
130
What is the function of pro-inflammatory cytokines?
They promote inflammation and the immune response.
131
Name one example of a pro-inflammatory cytokine.
Interleukin-1 (IL-1)
132
What is the role of anti-inflammatory cytokines?
They help to reduce inflammation and promote healing.
133
Multiple Choice: Which of the following is an anti-inflammatory cytokine? A) TNF-alpha B) IL-10 C) IL-6
B) IL-10
134
True or False: Cytokines can only act on nearby cells.
False
135
What is the term for cytokines that act on the same cell that produces them?
Autocrine signaling
136
Fill in the blank: Cytokines can be classified based on their _____ and _____ activity.
function, signaling
137
What type of cytokines are responsible for the activation of T cells?
Cytokines like IL-2 and IL-12.
138
Multiple Choice: Which cytokine is known for its role in fever induction? A) IL-10 B) IL-1 C) IFN-gamma
B) IL-1
139
What is the primary source of cytokines in the body?
Immune cells such as macrophages and lymphocytes.
140
True or False: All cytokines are proteins.
True
141
What is the role of chemokines?
They are a subset of cytokines that specifically direct the migration of immune cells.
142
Fill in the blank: Cytokines can influence the _____ of immune cells.
proliferation
143
What is the difference between interleukins and interferons?
Interleukins are primarily involved in communication between leukocytes, while interferons are involved in antiviral responses.
144
Multiple Choice: Which of the following cytokines is primarily involved in the antiviral response? A) IL-1 B) IFN-alpha C) IL-6
B) IFN-alpha
145
What is the function of tumor necrosis factor (TNF)?
TNF is involved in systemic inflammation and is capable of inducing apoptosis.
146
True or False: Cytokines can have overlapping functions.
True
147
What is the role of transforming growth factor-beta (TGF-beta)?
It is primarily an anti-inflammatory cytokine that also plays a role in tissue repair.
148
Fill in the blank: Cytokines can activate _____ and _____ cells.
B cells, T cells
149
What are the main signaling pathways through which cytokines exert their effects?
JAK-STAT pathway and MAPK pathway.
150
Multiple Choice: Which cytokine is known for its role in chronic inflammation? A) IL-10 B) IL-6 C) IL-4
B) IL-6
151
What is the role of IL-4 in the immune system?
IL-4 promotes B cell differentiation and the production of antibodies.
152
True or False: Cytokines can have both local and systemic effects.
True
153
What are cytokines?
Cytokines are small proteins that are important in cell signaling.
154
True or False: Cytokines can only be produced by immune cells.
False
155
Fill in the blank: Cytokines play a crucial role in the _____ response.
immune
156
What is one of the main functions of cytokines?
To mediate and regulate immunity, inflammation, and hematopoiesis.
157
Which cytokine is primarily involved in the inflammatory response?
Tumor necrosis factor (TNF)
158
Multiple Choice: Which of the following is a type of cytokine? A) Interleukin B) Hemoglobin C) Insulin
A) Interleukin
159
What is the role of interleukins?
Interleukins are cytokines that mediate communication between white blood cells.
160
True or False: Cytokines can have autocrine, paracrine, and endocrine effects.
True
161
What is the primary function of chemokines?
To induce chemotaxis in immune cells.
162
Fill in the blank: _____ are cytokines that promote the growth and differentiation of blood cells.
Colony-stimulating factors
163
What do interferons primarily do?
Interferons help to inhibit viral replication and activate immune responses.
164
Multiple Choice: Which cytokine is known for its role in allergic responses? A) Interleukin-4 B) Interferon-gamma C) Tumor necrosis factor
A) Interleukin-4
165
What is the significance of the cytokine storm?
A cytokine storm is an overproduction of cytokines that can lead to severe inflammation and tissue damage.
166
True or False: All cytokines have the same mechanism of action.
False
167
What are the two main categories of cytokines?
Pro-inflammatory and anti-inflammatory cytokines.
168
Fill in the blank: _____ cytokines are involved in the enhancement of the immune response.
Pro-inflammatory
169
What role do cytokines play in cancer?
Cytokines can promote tumor growth and metastasis or inhibit cancer cell growth, depending on the context.
170
Multiple Choice: Which of the following is NOT a function of cytokines? A) Cell growth B) Cell communication C) Oxygen transport
C) Oxygen transport
171
What is the effect of anti-inflammatory cytokines?
They help to reduce inflammation and promote healing.
172
True or False: Cytokines can only act on cells of the immune system.
False
173
What is the role of transforming growth factor-beta (TGF-β)?
TGF-β is involved in immune regulation and tissue repair.
174
Fill in the blank: The binding of cytokines to their receptors triggers _____ signaling pathways.
intracellular
175
Multiple Choice: Which cytokine is primarily produced by T helper 1 cells? A) Interleukin-6 B) Interferon-gamma C) Interleukin-10
B) Interferon-gamma
176
What is the importance of cytokine receptors?
Cytokine receptors determine the specificity and response of target cells to cytokines.
177
True or False: Cytokines are only involved in the immune response and have no other functions.
False
