BL Cohen lecture review Flashcards
(143 cards)
1
Q
Define pattern recognition receptor.
A
PRR. A receptor on human cells (almost all cells) that recognize foreign or damaged tissue.
2
Q
Define pathogen associated molecular pattern.
A
PAMP. Foreign molecules found on pathogens that cause an immune response.
3
Q
Define Toll-like receptor
A
TLR. A type of PRR, detects the features of pathogens.
4
Q
Define damage associated molecular pattern.
A
DAMP. Stress or damage indicators on cells that cause an immune response.
5
Q
In general, what do cytokines and chemokines do?
A
They are chemicals released by cells that cause affect the behavior of other cells.
6
Q
Which cell forms an adaptive bridge between the innate and adaptive immune response.
A
Dendritic cell
7
Q
What are the 4 basic functions of the immune system?
A
Detect, Inactivate, Destruct, and Remove invaders. RIDD!
8
Q
What is the mother of all transcription factors associated with TLR activation?
A
NF-kb (NF-kappa b)
9
Q
Is it possible to have a good adaptive immune response without a good innate immune response?
A
No.
10
Q
T or F: Lymphocytes take a long time to divide and their response is slow?
A
FALSE
11
Q
Which cell types make up our adaptive immunity?
A
T and B lymphocytes
12
Q
How does a T cell recognize an antigen?
A
A dendritic cell presents the antigen to the T cell, and the T cell recognizes part of the antigen and the MCH I receptor on the dendritic cell.
13
Q
What are the two main type of T cell?
A
Helpers and killers
14
Q
How many types of helper T cells are there?
A
5
15
Q
Name the types of helper T cells.
A
Th1, Th17, Th2, Tfh, Treg
16
Q
What cell makers (in general) are present on T helpers and T killers?
A
Helpers - CD4, Killers - CD8
17
Q
What is the name for a fully differentiated B cell?
A
a plasma cell
18
Q
Name the 5 classes of antibody.
A
IgG, M, A, D, E
19
Q
Which antibody can cross the placenta?
A
IgG
20
Q
Which type of antibody is found on B cells?
A
IgD
21
Q
Which type of antibody is found in secretions?
A
IgA
22
Q
Which type of antibody is best at activating complement?
A
IgM
23
Q
Which type of antibody stimulates mast cells?
A
IgE
24
Q
In general, what are immunopathologies?
A
Improper immune reactions to the environment or self
25
What is Type I immunopathology?
Immediate hypersensitivity mediated by IgE- these people have allergies and reactions to things in their environment.
26
What is Type II immunopathology?
Autoimmunity
27
What is Type III immunopathology?
The body makes a soluble antibody against a soluble tissue, and the inflammatory antigen-antibody combination get trapped in tissues, resulting in damage.
28
What is Type IV immunopathology?
When T cells react to an infection and damage normal tissue.
29
What are the central and peripheral lymphoid organs?
Central: Bone marrow and thymus; Peripheral: Lymph nodes, spleen, gut associated lymph tissue
30
Define antigen.
A substance with can be recognized by the immune system.
31
Define immunogen.
A substance with can be recognized by the immune system AND trigger an immune response.
32
Define antigenic determinant.
Epitope; the part of an antigen that fits into a receptor
33
Define tolerogen.
An antigen delivered in a form which does not give rise to an immune response but which prevents further immune response to that antigen.
34
Mononuclear cells is a blanket term for which cells (3 types)?
Macrophages, monocytes, lymphocytes.
35
Are the following values abnormal in a young child?
Neutrophils - 20%; Lymphocytes - 60%. Probably not. Young children have the percentage of lymphocytes to neutrophils than adults.
36
What is lymphocyte recirculation and where does it occur?
Lymphocytes jumping between lymph organs and circulation. It happens at special high cuboidal enothelial cell junctions in the postcapillary venules of the lymph nodes.
37
What are the components of a lymph node?
Cortex - contains follicles and germinal centers of dividing B lymphocytes. Deep/paracortex - mostly contains T lymphocytes.
38
Where do dendritic cells go to activate lymphocytes in the lymph node?
The interface between cortex and paracortex
39
Which type of T cell migrates from the deep cortex into the follicles?
Follicular helper T cell
40
Name the specialized cells of Peyer?s patches.
mucosal M cells - gatekeepers
41
What do lymphocytes differentiate in to?
Lymphoblasts then, for B cells, plasma cells
42
What usually happens when antibodies attach to antigen?
They precipitate, however, the amount of precipitation depends on the concentration of antibody and antigen.
43
What are Fab and Fc?
Parts of an antibody. Fab contains the light and heavy chain variable regions. Fc contains the heavy chain constant region.
44
How many domains do light and heavy chains have?
Light: 2, VL and CL. Heavy: 4-5, VH and CH1-4.
45
Which region connects Fab and Fc?
The hinge
46
Which part of the antibody defines its class?
The heavy chain Fc: gamma, alpha, mu, epsilon, delta
47
T or F: During antibody switching, the light chain changes from kappa to lambda
False. Only the heavy chain changes domain type. The light chain may be either kappa or lambda, but it cannot be switched once made.
48
How many hypervariable regions are present on each antibody?
6
49
Where are complementarity determining regions (CDRs)?
On the variable domain of heavy and light chains. They interact with epitope
50
Define allotype.
The minor differences in Ig between individuals. You have your own allotype.
51
Define idiotype.
The CDRs of the L and H chains that are unique to that particular antibody.
52
Which antibody can produce Type I immunopathology?
IgE, activates immediate hypersensitivity and allergy.
53
What is the minimum number of antibodies needed to activate complement?
2 - need 2 accessible Fc regions
54
What is agglutination?
Precipitation of large antigens
55
Which antibody class is oldest phylogenetically?
IgM
56
Which antibody is first to appear after immunization?
IgM
57
Which antibody is most abundant in the blood?
IgG
58
What is the plasma half life for IgG?
~3 weeks
59
What does opsonizing do?
Attracts macrophages to an antigen for phagocytosis
60
Which antibody triggers the release of eosinophil chemotactic factor?
IgE
61
Which classes of antibody activate the classical complement pathway?
IgG and IgM
62
What is the first step of classical complement activation?
The binding of C1q to two Fc domains simultaneously.
63
How does the body naturally prevent complement activation?
C1 esterase inhibitor
64
Which antibody activates the alternative complement pathway?
IgA
65
Which complement component initiates the alternative pathway?
C3 --> C3b binds to factor D and another C3b on the surface of a cell
66
Which antibody activates the lectin complement pathway?
None. It is activated by mannose-binding protein (MBP)
67
What is the complement binding order for each pathway?
Classic: 1, 4, 2, 3, 5, 6, ...; Alternative: 3, 5, 6...; Lectin: MBP, 4, 2, 3, 5, 6...
68
If you fail to make C6, which function of complement will you lose?
Lysis. Will not be able to make membrane attack complex (requires all complement 1-9)
69
If you fail to make C3, which functions of complement will you lose?
All of them: Lysis, chemotaxis, opsonization, anaphylatoxicity.
70
Which complement component is necessary for opsonization?
C3
71
Which complement component is necessary for chemotaxis?
C5
72
Which complement components is can cause histamine release?
C3a, C4a, C5a
73
If an antibody has a very high binding constant (K)a, what does this indicate about its specificity?
It is very specific. Ka = [AB]/[A][B]
74
What is cross-reactivity?
The ability of an antibody to bind more than one antigen.
75
Define toxoid.
A substance that is immunogenic but not toxic
76
T or F: B and T cells are specific for one antigen.
True (pretty much)
77
T or F: Individual B cells make H and L chains from both maternal and paternal genes at the same time.
F. Each B cell randomly chooses either the maternal or paternal H and L gene to make antibody.
78
T or F: The variable domain of the heavy chain is composed of VDJ segments.
TRUE
79
T or F: The variable domain of the light chain is composed of VDJ segments.
FALSE. Only V and J.
80
Which enzymes perform antibody recombination?
RAG recombinases
81
How do exonuclease contribute to antibody diversity?
Chews away a few DNA molecules randomly at the V-D and D-J joining area
82
How does deoxynucleotidyl transferase (TdT) contribute to antibody diversity?
Adds a few DNA molecules randomly at the V-D and D-J joining area
83
T or F: Many B cells and T cells fail to survive due to random nonsense mutations in their DNA antibody templates.
TRUE
84
T or F: B cells can use the other allele if their antibody gene doesn?t work out on one allele.
TRUE
85
T or F: antibody affinity generally increases over time.
True. Random mutation in the hypermutable V(D)J region can produce daughter cells that are slightly more specific to antigen over time.
86
T or F: B cells producing IgG can switch back to IgM.
FALSE
87
What is a pro-B cell?
A B cell precursor only expressing cytoplasmic mu chain.
88
What is a pre-B cell?
A B cell precursor expressing cytoplasmic mu chain and light chain elements (cytoplasmic IgM)
89
What is an immature B cell?
A B cell precursor expressing IgM.
90
What is a mature B cell?
A B cell precursor expressing IgM and IgD.
91
When does clonal abortion happen, if ever?
The immature B cell?s IgM binds antigen and triggers receptor editing. If receptor editing fails, then the B cell dies.
92
Which T cell is necessary for B cell class switching?
helper T cells
93
When does a fetus acquire the ability to make IgG?
The fetus doesn?t make IgG. Babies begin to make IgG 3-6 mo. postnatally.
94
What kind of antibody do fetuses make?
IgM
95
T or F: Full term babies have a fully functional complement system.
TRUE
96
T or F: Old people generally respond better to new pathogens than pathogens they have seen before.
FALSE
97
What surface marker to all helper T cells carry?
CD4
98
What determines the type of helper T cell produced during stimulation? (3 things)
The conditions of the periphery, the TLRs engaged, the chemokines and cytokines present
99
What do Th1s secrete?
INFgamma and IL-2
100
What do Th1s activate?
Angry M1 marcrophages
101
What do angry macrophages secrete?
TNFa and IL-1
102
What do Th17s secrete?
IL-17
103
Define cytokine.
Short-range mediators made by any cell, that affect the behavior of the same or another cell.
104
Define lymphokine.
Short-range mediators made by lymphocytes, that affect the behavior of the same or another cell.
105
Define chemokine.
Small (6-14 kD) short-range mediators made by any cell, that primarily cause inflammation.
106
What do Th2s secrete?
IL-4
107
What do Th2s activate?
M2 macrophages
108
What do Treg secrete?
TGFbeta and IL-10
109
What do Tregs do?
Thy suppress other Th cells
110
T or F: Tregs selectively turn off other classes of Th cells.
FALSE
111
What do CTLs do?
Cytotoxic T lymphocytes signal to other cells to commit apoptosis.
112
Which Th cells activate CTLs?
Th1 cells (using IL-2)
113
T or F: CD3 is on the surface of ALL T cells?
TRUE
114
What is the surface marker for a B cell?
CD20
115
What are the criteria for a T cell to recognize an antigen?
The antigen must be presented inside the MHCII of a cell from the same person as the T cell.
116
What are the TCR chains called?
alpha and beta
117
Which cytokine do APCs use to activate T cells?
IL-12
118
How many protein chains does to TCRs have?
2
119
T or F: CD3 is necessary for transducing the signal from an MHC+antigen to activate the T cell.
TRUE
120
Which cells are the only cells without an MHCI?
Red blood cells (annucleate)
121
Which cells have MHCII?
DCs, Macrophages, B cells
122
T of F: T cells have MHCII receptors?
FALSE
123
Which type of T cells recognize MHCII signals?
Thelpers
124
Which type of T cells recognize MHCI signals?
CTLs
125
T or F: Cross- presentation is when a DC presents peptides in both MHCI and MHCII to Th and CLTs.
TRUE
126
T or F: Antibody response to protein antigens is T-independent.
False. Tfh cells are required to have full response to these antigens, class switch from IgM to IgG. Some carbohydrate antigens can produce an T-independent response. (although there is T-independent activation, but we haven't learned about it yet)
127
What are mitogens and name a couple of them?
Mitogens promote T and B cell division. PLA promotes T cell mitosis and pokeweed mitogen T and B cell mitosis.
128
T or F: Double positive CD4+/CD8+ T cells in the thymus survive to become part of the body?s immune system.
False. Only single positive T cells survive. Most maturing T cells never make it from being double pos to single pos and are weeded out.
129
What does Aire do?
Generates ?out of place? peptides in order to weed out over-reactive T cells.
130
T or F: Person lacking MCHIs will develop CTLs, but not T helpers.
False. They will develop T helpers, but not CTLs. CTLs respond to MHCI and antigen, but lack of MHCI during development will not allow for CTL selection.
131
Define haplotype.
The alleles inherited from one parent.
132
T or F: One way mixed leukocyte reaction observes the reaction of a donor?s T cells to a recipient?s white cells.
False. It observes the reaction of a recipient?s T cells to a donor?s white cells. The donor?s cells are first treated to prevent their cell division.
133
T or F: MHCI genes are coded by the HLA-A, B, and C loci.
TRUE
134
T or F: MHCII genes are coded by the HLA-A, B, and C loci.
False. Coded by the HLA-D loci
135
T or F: The HLA-DR locus is most important in transplant rejection.
TRUE
136
Define syn, iso, allo, xeno, and autografts.
Syn=iso between individuals with the same genetic composition (ex identical twins). Allo between non-identical members of the same species. Xeno between members of different species. Auto from one individual to himself.
137
Which immune components mediate a hyperacute graft rejection?
Antibodies and complement. Recipients must be test for this reaction, although it is less common.
138
T or F: In graft rejection, the recipeint?s immune system recognizes antigen in the donor?s MCHs.
False. The recipients immune system recognizes the donor?s foreign MHCs.
139
T or F: ABO antigens are found only on RBCs.
False. They are actually found on every cell.
140
T or F: Matching recipient and donor HLA-A, B (MCHI) are more important than matching HLA-DR (MHCII)
False. Matching the HLA-DR is more important. CTLs are activated only if they sense a foreign MHCI and receive signals from Th1 cells recognizing foreign MCHII. However, the activated Th1s can wreak havoc through activation of inflammation. If MHCI is not compatible, but MHCII is compatible, Th1s will not be activated and neither will CTLs be fully activated.
141
T or F: Genotypic sex does not matter for transplant rejection.
False. Males make H-Y, a self antigen that is rejected by females. Males, however, can receive females grafts without problem.
142
T or F: T cells for a particular antigen are transferrable between non-identical individuals.
FALSE
143
Which HLA predisposes individuals to ankylosing spondylitis?
HLA-B27
