Immunology Flashcards
1
Q
Antigens
A
Foreign substances that provoke immune response
2
Q
Antibodies
A
Bind antigens, inactivating or eliminating them
3
Q
Immunity
A
Ability to resist disease or infection
4
Q
Immunology
A
Study of how body defends against foreign invaders and harmful substances
5
Q
Immune system protects against what 4 classes of pathogen?
A
Bacteria
Viruses
Fungi
Protists
6
Q
4 diseases of immune system
A
Allergy
Autoimmunity
Transplantation rejection
Graft vs. host disease (foreign immune cells from graft attack host cells)
7
Q
2 components of immune system
A
Innate
Adaptive
8
Q
Innate vs adaptive immunity: specificity
A
Innate: non-specific
Adaptive: specific
9
Q
Innate vs adaptive immunity: speed
A
Innate: fast
Adaptive: slow
10
Q
Innate vs adaptive immunity: memory
A
Innate: no memory
Adaptive: memory
11
Q
Innate immunity: cells
A
Macrophages
Dendritic cells
Neutrophils
12
Q
Innate immunity: components
A
Anatomical features, complement, toll-like receptors, cytokines
13
Q
Name of cells responsible for innate and adaptive immune responses
A
Leukocytes (white blood cells)
14
Q
Leukocytes originate from _____ stem cells in the _____ ____.
A
Pluripotent
Bone marrow
15
Q
What does pluripotent mean?
A
Capable of differentiating into a wide variety of cells
16
Q
5 major types of leukocytes
A
Basophils Eosinophils Neutrophils Monocytes Lymphocytes
17
Q
Monocytes mature into what 2 types of cells?
A
Macrophages or dendritic cells
18
Q
Lymphocytes mature into what 3 types of cells?
A
T cells
B cells
NK cells
19
Q
Basophils, eosinophils, neutrophils, and monocytes come from common _______ progenitor cell in ____ _____.
A
Myeloid
Bone marrow
20
Q
Lymphocytes come from ______ progenitor cell in ____ ____.
A
Lymphoid
Bone marrow
21
Q
Macrophages come from monocytes in the ______.
A
Blood
22
Q
3 macrophage functions
A
Phagocytosis
Cytokine/chemokine production
Antigen presentation
23
Q
Phagocytosis: _____ and _____ pathogens
A
Engulf
Destroy
24
Q
Phagocytosis uses what two types of chemicals for degradation of pathogens?
A
Reactive oxygen species (hydrogen peroxide)
Reactive nitrogen species (nitric oxide)
25
5 steps of phagocytosis
1. Pseudopodia surrounds pathogen
2. Phagosome forms around pathogen
3. Phagosome fuses with lysosome forming phagolysosome
4. Reactive oxygen and nitrogen species are released
5. Pathogen is degraded
26
3 types of antigen presenting cells
Macrophages
Dendritic cells
B cells
27
What antigen presenting cells do (3 steps)
1. Take in protein antigen
2. Process antigen
3. Present peptide fragments bound to MHC molecules to T helper cells
28
5 non-cellular components of innate immune response
```
Physical barriers
Chemical barriers
Complement
Toll-like receptors
Cytokines
```
29
Physical barriers of innate immune system (2)
Skin
| Mucous membranes
30
Chemical barriers of innate immune system (3)
Acidic pH of stomach
Lysozyme in tears and breast milk
Defensins (antimicrobial peptides)
31
Complement system: how many serum proteins?
Over 30
32
Complement system is activated by ______ ______.
Enzymatic cleavage
33
Complement system "complements" activity of what?
Antibodies
34
3 functions of complement system
Opsonization
Chemotaxis
Membrane attack complex
35
Opsonization of bacteria by complement system: what happens, example complement factor that participates
Microbes are coated for phagocytosis
| C3b
36
Chemotactic factors of complement system: what happens, example complement factor that participates
Phagocyte migration from blood to site of infection
| C5a
37
Opsonization by complement steps (3)
C3b is bound to microbe
Macrophage recognizes C3b
Phagocytosis of pathogen
38
In membrane attack complex, what is formed in pathogen membrane that results in degradation of the pathogen? The membrane attack complex can form where in Gram positive bacteria? Gram negative bacteria?
Pore
Gram positive bacteria- plasma membrane
Gram negative bacteria- outer membrane
39
Toll-like receptors are also called _____ _____ receptors.
Pattern recognition
40
At least how many distinct receptors in toll-like receptor family?
10
41
Toll-like receptors bind ___-____ _____ ______.
Pathogen-associated molecular patterns
42
Toll-like receptor ____ recognizes LPS.
4
43
Toll-like receptor ____ recognizes peptidoglycan.
2
44
Toll-like receptor ____ recognizes dsRNA. What type of pathogen has dsRNA?
3
| Viruses
45
Toll-like receptor ____ recognizes flagellin. What is flagellin?
5
| Protein that makes up filament of flagella
46
Toll-like receptor cascade steps (4)
1. TLR binds PAMP, initiating signal transduction cascade
2. Cascade activates human transcription factor NFkappaB, which moves into nucleus
3. Genes for cytokines are activated
4. Cytokines are released from cell
47
Cytokines bridge ____ and ____ immune responses
Innate
| Adaptive
48
Cytokines are ____ _____ molecules.
Protein signaling
49
5 examples of cytokines
```
Interleukins
Tumor necrosis factor
Chemokines
Interferons
Endogenous pyrogens
```
50
3 functions of interleukins
Stimulate cell growth
Differentiation
Proliferation
51
3 functions of tumor necrosis factor
Increases vascular permeability
Induces fever
Activates B and T cells
52
What an increase in vascular permeability enables
Immune cells in blood vessels to enter regions of infection
53
Chemokines stimulate ___ ___ to ___ ___
Cell migration
| Infection sites
54
Interferons are produced in response to what? What do they do to these pathogens?
Viruses
| Block viral replication and assembly
55
Endogenous pyrogens induce what? How do they work (2 steps)?
Fever
Circulate to brain
Induce neurons to make prostaglandins
56
3 steps of inflammation
1. Bacteria trigger macrophages to release cytokines and chemokines
2. Vasodilation and increased vascular permeability cause redness, heat, and swelling
3. Inflammatory cells migrate into tissue, releasing inflammatory mediators that cause pain
57
Non-cellular components of adaptive immune response
Antibody
Antigen receptors
Major histocompatability complex (MHC)
58
2 cells of adaptive immunity
B cells and T cells
59
B cells come from ___ ___ in ____ ____ and mature in ___ ___.
Stem cells in bone marrow
| Mature in bone marrow
60
T cells come from ___ ___ in ___ ___ and mature in ___.
Stem cells in bone marrow
| Mature in thymus
61
2 branches of adaptive immunity
Humoral
| Cell-mediated
62
Humoral adaptive immunity involves ____ made by ___ ___.
Antibodies
| B cells
63
Humoral adaptive immunity defends against ____ pathogens.
Extracellular
64
Cell mediated adaptive immunity involves what kind of cells defending against what type of pathogens?
T cells
| Intracellular pathogens
65
Innate vs adaptive immunity: site of initiation
Innate: site of infection
Adaptive: lymphoid organs and tissues
66
Primary lymphoid organs: what happens there, 2 examples
Where lymphocytes mature
| Bone marrow and thymus
67
Secondary lymphoid organs: what happens there, 2 examples
Where lymphocytes engage antigen
| Spleen, lymph nodes
68
B cells are activated by what 2 potential sources?
T cells and/or antigen
69
2 types of cells that B cells develop into
Plasma cells
| Memory cells
70
Plasma B cells do what 2 things?
Produce and secrete antibodies
71
Memory B cells are ____ and last for _____.
Quiescent
| Last for decades
72
Under what conditions can memory B cells become activated again? When activated, what do they become?
Second exposure to antigen
| Plasma cells
73
Antibodies are ____ made by B cells.
Proteins
74
Antibodies can be attached to ____ _____ ____ or free in ___ and ____.
B cell surface
| Blood and tissues
75
Antibodies do what to antigens for what 2 potential purposes?
Bind antigens
| Neutralization or opsonization
76
Affinity definition in context of antibodies
Strength with which antibody binds to antigen
77
Epitope
Part of antigen that antibodies bind
78
Can one antigen have more than one epitope? If so, do they bind to the same or different antibodies?
Can have several epitopes
| Different antibodies
79
5 classes of antibodies
```
IgM
IgG
IgA
IgE
IgD
```
80
IgM: features (2)
First antibody produced after antigen exposure
| IgM secreting plasma cells can switch and produce other Ig class
81
IgG: features (3)
Major Ig in serum
Can cross placenta
Can activate complement
82
IgA feature
Major Ig in secretions (saliva, breast milk, tears)
83
IgE: feature
Allergic reactions called type 1 hypersensitivities
84
IgD: features (2)
Found on B cell surfaces
| Role in signaling
85
Half life of Ig is measured in what?
Days
86
Which class of Ig is the most stable? About how long is its half life?
IgG
| About 20 days
87
Antibodies are made up of 2 identical ___ ____ and 2 identical ___ ___.
Heavy chains
| Light chains
88
Where on the antibody is the antigen binding site? What is this region called?
Outer portion of light chain and outer portion of heavy chain
Variable region
89
Fc fragment is located where on the antibody?
Lower sections of heavy chain
90
Fab fragment is located where on antibody?
Upper section of heavy chain and light chain
91
Light and heavy chains and 2 heavy chains are connected by what type of bonds?
Disulfide
92
Process of antibody gene segment rearrangement is called what?
VDJ recombination
93
4 gene segments for heavy chain
Variable
Diversity
Joining
Constant
94
3 gene segments for light chain
Variable
Joining
Constant
95
What are the enzymes that carry out VDJ recombination?
Recombination activating gene (RAG) enzymes
96
In which cells are RAG enzymes active? How do they carry out VDJ recombination?
B cells
| Randomly cut and paste gene segments together
97
Order of antibody gene assembly in heavy chain
D, then J, then V
98
Antigen binding sites are made from what gene segments in heavy chains? Light chains?
Heavy chains: V, D, J
| Light chains: V, J
99
When does VDJ rearrangement occur in the life cycle?
Early in embryonic life, before infection
100
Tolerance in antibodies is formed how?
Removal of self-reactive B cells
101
Clonal selection: 3 steps
1. Antibodies are generated randomly before infection
2. Upon infection, antigen "selects" B cell with antibody that matches it
3. B cell proliferates, forming clone of identical cells, each with antibody for the antigen
102
Where does tolerance in antibodies occur?
Bone marrow
103
Major mechanism of tolerance in antibodies is called what?
Clonal deletion
104
Secondary exposure for adaptive immune system: speed and magnitude compared to primary exposure, what cells are activated, basis of what practice?
Faster and greater than primary exposure
Memory B cells are activated
Basis of immunization
105
Lag period in adaptive immune response
Time it takes for antibodies to be generated after exposure to antigen
106
When are T cells activated?
When their receptors bind antigens presented by other cells
107
Helper T cells: functions (2)
Make cytokines
| Activate B cells, macrophages, or other T cells
108
Cytotoxic T cells: function
Kill cells expressing foreign antigen
109
2 chemicals used by Tc cells
Perforins (form pores)
| Granzymes (induce apoptosis)
110
Cluster of differentiation molecules: 2 purposes
Co-receptors for T cells
| Determine T cell's identity
111
What is the CD for T helper cells? T cytotoxic cells?
T helper cells: CD4
| T cytotoxic cells: CD8
112
T cell receptors are made up of how many polypeptide chains? What 2 types of regions? Bound to T cell or can exist apart from T cell?
2 polypeptide chains
Variable and constant regions
Bound to T cell
113
When can T cell receptors bind antigens?
When presented to them by other cells in the context of a Major Histocompatibility Complex (MHC) molecule
114
T cell receptors are expressed from gene segments rearranged in which organ?
Thymus
115
MHC is a collection of genes encoding what?
Cell surface proteins for self/nonself recognition
116
In humans, MHC is also called what?
Human Leukocyte Antigen (HLA) complex
117
Humans have how many sets of MHC genes? How many are expressed?
```
2 sets (one from each parent)
Both are expressed
```
118
How does relation influence HLA similarity?
The closer 2 people are related, the more similar their HLAs
119
Class I MHCs are found on what types of cells?
All nucleated cells of body
120
Class II MHCs are found on what types of cells?
Only on antigen presenting cells (B cells, macrophages, dendritic cells)
121
Class I MHCs present peptides that originate where from what type of pathogens? What type of T cells do they present to?
Cytoplasm
Intracellular pathogens
CD8 cytotoxic T cells
122
Class II MHCs present peptides that come from what type of pathogens taken up how? What type of T cells do they present to?
Extracellular pathogens
Taken up by phagocytosis
CD4 helper T cells
123
4 steps of antigen processing and 1 step of antigen presentation
1. Dendritic cell takes up pathogen for degradation
2. Pathogen is taken apart inside dendritic cell
3. Pathogen proteins are unfolded and cut into small pieces
4. Peptides bind to MHC molecules and the complexes go to the cell surface
5. T cell receptors bind to peptide: MHC complexes on dendritic cell surface
124
How long are peptides presented by MHC molecules?
About 10 amino acids in length
125
Another name for white blood cells, particularly neutrophils
Polymorphonuclear leukocytes
126
Membrane attack complex is made up of what complement proteins?
C5-9
