Nature of Antigens and the Major Histocompatibility Complex Flashcards
(110 cards)
1
Q
An ____ is a substance that is specifically recognized by the adaptive immune system.
A
Antigen
2
Q
____ is capable of binding to antibodies.
A
Antigen
3
Q
____ can’t stimulate antibody production.
A
Antigen
4
Q
Antigens can be ____.
A
Immunogenic or Non-immunogenic
5
Q
An ____ is a substance capable of causing adaptive response.
A
Immunogen
6
Q
____ can bind to antibodies and stimulate its production.
A
Immunogen
7
Q
What is the chief distinction between antigens and immunogens?
A
- Antigen = cannot stimulate immune response.
- Immunogen = can stimulate immune response.
8
Q
TRUE OR FALSE.
All immunogens are antigens, and all antigens are immunogens.
A
False
Reason: Antigens cannot stimulate antibody production.
9
Q
TRUE OR FALSE.
Hapten alone can stimulate antibody production.
A
False
Reason: Haptens need to bind to carrier-protein first.
10
Q
Factors Influencing the Immune Response
A
- Age
- Dose
- Route of Inoculation
- Health status
- Genetics
11
Q
↑ immune dose = ____.
A
↑ immune response
12
Q
____ is the ability of an immunogen to stimulate a host response.
A
Immunogenicity
13
Q
Traits of Immunogen
A
- Macromolecular size
- Chemical composition and molecular complexity
- Foreigness
- Ability to be processed and presented with MHC molecules
14
Q
The best immunogens have a molecular weight of ____.
A
100,000 Da
15
Q
Immunogens should have a molecular weight of at least ____ in order to be recognized.
A
10,000 Da
16
Q
The best immunogens have a chemical composition of ____.
A
proteins and polysaccharides
17
Q
Immunogens composed of ____ are less immunogenic.
A
carbohydrates
18
Q
Immunogens composed of ____ are non-immunogenic.
A
lipids and nucleic acid
19
Q
What kind of antigens are not foreign in the body?
A
Self-antigens
20
Q
Why can’t Haptens cause immune response on their own?
A
Because they’re small in size
21
Q
Main Parts of Antigen
A
- Antigenic determinant/ Epitope
- Carrier
22
Q
____ are molecular shapes or configurations that are recognized by B or T cells.
A
Antigenic determinants (Epitope)
23
Q
____ is where the antibody binds.
A
Antigenic determinant (Epitope)
24
Q
An epitope can be ____.
A
- Sequential
- Linear
- Conformational
25
____ are non-immunogenic materials that, when combined with a carrier, create new antigenic determinants.
Haptens
26
____ is responsible to give the antigen its required size.
Carrier
27
____ are usually made up of protein.
Carriers
28
Carriers are usually made up of ____.
protein
29
The ____ is the number of combining sites.
Valence
30
____ are precise molecular shapes or configurations recognized by B cells, or the peptide sequences detected by T cells.
Epitopes
31
Kinds of Epitope
* Linear
* Conformational
32
# **Kinds of Epitope**
____ consist of sequential amino acids on a single polypeptide chain.
Linear epitopes
33
# **Kinds of Epitope**
____ result from the folding of one or more polypeptide chains.
Conformational epitopes
34
____ are capable to recognize both linear and conformational epitopes.
B cells
35
B cells are capable to recognize ____ epitope.
linear and conformational epitopes
36
____ respond to linear epitopes.
T cells
37
T cells are capable to recognize ____ epitope.
linear
38
____ are substances administered with an immunogen that increases the immune response.
Adjuvants
39
____ are substances added to the vaccine in order to enhance the immune response.
Adjuvants
40
How do adjuvants enhance the immune response?
* By prolonging the existence of immunogen.
* By increasing the effective size of immunogen.
* By increasing the number of macrophages involved in antigen processing.
41
Types of Antigens
* Autoantigens
* Alloantigens
* Heteroantigens
* Heterophile antigens
42
# **Types of Antigens**
____ are those antigens that belong to the host.
Autoantigens (self-antigens)
43
# **Types of Antigens**
____ are from other members of the host's species, and these are capable of eliciting an immune response.
Alloantigens
44
# **Types of Antigens**
____ are from other species, such as plants, animals, or microorganisms.
Heteroantigens
45
# **Types of Antigens**
____ are heteroantigens that exist in unrelated plants or animals but are either identical or closely related in structure so that antibody to one will cross-react with antigen of the other.
Heterophile antigens
46
____ is a large multi-gene locus consisting of several thousand kilobase pair of DNA on a single chromosome.
Major Histocompatibility Complex (MHC)
47
MHC is also known as ____.
Human Leukocyte Antigens (HLA)
48
HLA is a complex located at ____.
chromosome 6
49
____ brings antigen to the cell surface for recognition by T cells.
Human Leukocyte Antigens (HLA)
50
MHC is found on ____.
human chromosome 6
51
Roles of MHC
* Intercellular recognition and discrimination of self/non-self.
* Development of humoral and cell-mediated immune responses.
* Susceptibility to disease and autoimmunity
52
____ have a role in intercellular recognition and discrimination of self/non-self.
Major Histocompatibility Complex (MHC)
53
____ have a role in development of humoral and cell-mediated immune responses.
Major Histocompatibility Complex (MHC)
54
____ plays a role in susceptibility to disease and autoimmunity.
Major Histocompatibility Complex (MHC)
55
Nature of HLA Antigens
* Glycoprotein component of cell membrane
* Present in all nucleated cells
* Products of the genes of MHC
56
MHC molecules are found on the ____ of chromosome 6.
short arm
57
Three Categories of MHC
* Class I
* Class II
* Class III
58
# **Categories of MHC**
____ are coded for at three different locations or loci, termed A, B, and C.
Class I molecules
59
# **Categories of MHC**
____ are situated in D region, and have several different loci, known as DR, DQ, and DP.
Class II
60
# **Categories of MHC**
____ code for complement proteins and cytokines such as tumor necrosis factor.
Class III
61
# **Class I MHC Molecules**
Cellular Distribution
* **All nucleated cells**
* **Low/undetectable in:** liver hepatocyte, neural cells, muscle cells, and sperm cells.
62
# **Which MHC Category?**
Present in all nucleated cells
Class I MHC
63
The highest concentration of MHC Class I molecules is found in ____.
* Lymphocytes
* Myeloid cells
64
# **Class I MHC Molecules**
Structure
One α-chain + β2 microglobulin
65
# **Which MHC Category?**
One α-chain + β2 microglobulin
Class I MHC
66
# **Class I MHC Molecules**
The α-chain is located at ____.
chromosome 6
67
# **Class I MHC Molecules**
The β2 microglobulin is located at ____.
chromosome 15
68
# **Class I MHC Molecules**
Classes
**HLA:** A, B, C
69
# **Which MHC Category?**
**HLA:** A, B, C
Class I MHC
70
# **Class I MHC Molecules**
Non-classical classes
**HLA:** E, F, G
71
# **Which MHC Category?**
**HLA:** E, F, G
| Non-classical classes
Class I MHC
72
# **Class I MHC Molecules**
Size of peptide bonds
8 - 11 amino acids
73
# **Which MHC Category?**
8 - 11 amino acids
Class I MHC
74
# **Class I MHC Molecules**
Nature of peptide binding cleft
Closed at both ends
75
# **Which MHC Category?**
**Nature of peptide binding cleft:** Closed at both ends
Class I MHC
76
# **Class I MHC Molecules**
Interaction with T-cells
Present endogenous (intracellular) antigen to CD8+ T-cells
77
# **Which MHC Category?**
Present endogenous (intracellular) antigen to CD8+ T-cells
Class I MHC
78
# **Class II MHC Molecules**
Cellular Distribution
* B cells
* Thymocytes
* Macrophages
* Dendritic cells
* Thymic epithelial cells
79
# **Which MHC Category?**
____ are usually found in antigen-presenting cells (APCs).
Class II MHC
80
The most effective APC is the ____.
dendritic cells
81
____ have high levels of MHC Class II.
Dendritic cells
82
# **Class II MHC Molecules**
Structure
α-chain + β chain
83
# **Which MHC Category?**
α-chain + β chain
Class II MHC
84
# **Class II MHC Molecules**
Classes
**HLA:** DP, DQ, DR
85
# **Which MHC Category?**
**HLA:** DP, DQ, DR
Class II MHC
86
# **Class II MHC Molecules**
Non-classical classes
**HLA:** DM, DN, DO
87
# **Which MHC Category?**
**HLA:** DM, DN, DO
Class II MHC
88
# **Class II MHC Molecules**
Size of peptide bonds
13 - 18 amino acids
89
# **Which MHC Category?**
13 - 18 amino acids
Class II MHC
90
# **Class II MHC Molecules**
Nature of peptide binding cleft
Open at both ends
91
# **Which MHC Category?**
**Nature of peptide binding cleft:** Open at both ends
Class II MHC
92
# **Class II MHC Molecules**
Interaction with T-cells
Present exogenous antigen to CD4+ T-cells
93
# **Which MHC Category?**
Present exogenous (intracellular) antigen to CD4+ T-cells
Class II MHC
94
The main role of the ____ is to bind peptides within cells and transport them to the plasma membrane, where T cells can recognize them in a phenomenon.
Class I and Class II MHC molecules
95
Application of HLA Typing/Matching
* Organ transplantation
* Paternity Testing
* Forensic medicine, anthropology
* Studies of racial ancestry and migration
* Diagnostic and genetic counselling
* Basic research
96
HLA B27
Ankylosing Spondylitis,
Reiter's Syndrome
97
Ankylosing Spondylitis,
Reiter's Syndrome
HLA B27
98
HLA B47
Congenital Adrenal Hyperplasia
99
Congenital Adrenal Hyperplasia
HLA B47
100
HLA B5
Behcet's Disease
101
Behcet's Disease
HLA B5
102
HLA CW6
Psoriasis Bulgaris
103
Psoriasis Bulgaris
HLA CW6
104
HLA DR3
Type 1 Diabetes Mellitus
105
Type 1 Diabetes Mellitus
HLA DR3
106
HLA DR4
Rheumatoid Arthritis
107
HLA DR5
Gold Induce Nepropathy,
Kaposi's Sarcoma, Chronic Lymphatic Leukemia
108
Gold Induce Nepropathy,
Kaposi's Sarcoma, Chronic Lymphatic Leukemia
HLA DR5
109
HLA B8
HIV Infection
110
HIV Infection
HLA B8
