Immune System/Dr. Li Flashcards
1
Q
which type of immunity has a greater and faster response upon subsequent challenge by the same antigen
A
adaptive
2
Q
which type of immunity has a similar magnitude of response each time
A
innate
3
Q
___ are proteins made by immune cells that affect the behavior of other cells
A
cytokines
4
Q
____ are specialized cytokines, small proteins involved in guiding white blood cells to sites where their functions are needed (through a gradient)
A
chemokines
5
Q
what type of immune cells are involved in innate immunity
A
phagocytes (neutrophils, macrophages, dendritic cells), and granulocytes (neutrophils, basophils, eosinophils, mast cells, NK cells)
6
Q
what type of immune cells are involved in adaptive immunity
A
all lymphocytes except NK cells
7
Q
_____ are the first phagocyte to sense the invading microorganism (local guards)
A
macrophages
8
Q
macrophages are located ____
A
extravascularly
9
Q
macrophages orchestrate the ___ response to infection and engulf pathogens
A
local
10
Q
where are neutrophils located
A
they circulate in the blood
11
Q
the most numerous and lethal phagocytic cells are ____
A
neutrophils
12
Q
neutrophils are _____ to the site of action
A
recruited
13
Q
_____ are professional antigen presentation cells that serve as a bridge between innate and adaptive immunity
A
dendritic cells
14
Q
where are dendritic cells located
A
tissues in contact w/ external environment (skin, nose and lungs, stomach and intestine)
15
Q
dendritic cells migrate from ____ to _____
A
site of infection to draining lymph nodes
16
Q
basophils circulate in ___
A
blood
17
Q
mast cells reside in ____
A
tissues (connective tissue, mucosa, near blood vessels)
18
Q
basophils and mast cells have a surface receptor for ___
A
IgE
19
Q
activated mast cells release substances that contribute to inflammation, such as ____
A
histamine
20
Q
mast cells are important in ___
A
allergic reactions
21
Q
role of B cells
A
produce antibodies
22
Q
role of T cells
A
CD4 (helper) and CD8 (cytotoxic)
23
Q
T and B cells are largely localized in ____ tissues
A
lymphoids
24
Q
NK cells are involved in _____ immunity and killing of _____
A
innate, virus-infected and mutated cells
25
primary lymphoid tissues
bone marrow, thymus
26
where are B & T cells developed
bone marrow
27
where are B cells matured
bone marrow
28
where are t cells matured
thymus
29
what are the secondary lymphoid tissues
spleen, adenoids, tonsils, appendix, lymph nodes, peyer's patches
30
secondary lymphoid tissues are the sites where ________ is developed
adaptive immune response
31
_____ is tissue fluid that enters the lymphatic vessels
lymph
32
which type of immunity recognizes microbes by a broad recognition mechanism
innate
33
which type of immunity recognizes microbes by highly specific lymphocyte antibodies and T cell receptors
adaptive
34
which immune response occurs at the site of infection
innate
35
the innate immune response is largely anti-____
bacteria
36
the innate immune response detects and clears pathogens by _____ and _______
complement and macrophages
37
the activation of complement system and macrophages triggers a local inflammatory response leading to _______
recruitment of more effector cells
38
the activation of _____ cells leads to initiation of the adaptive immune response
dendritic
39
acute inflammation is mediated by ____
cytokines
40
____ are proteins made by immune cells that affect the behavior of other cells
cytokines
41
_____ are specialized cytokines that guide white blood cells (via a gradient) to sites where their functions are needed
chemokines
42
an increase in neutrophils may indicate what kind of infection
bacterial
43
an increase in monocytes may indicate what kind of infection
viral
44
an increase in eosinophils may indicate ___
allergic reaction
45
dendritic cells migrate from sites of infection to ______
draining lymph nodes
46
where do basophils reside
they circulate in blood
47
where do mast cells reside
tissues
48
basophils and mast cells have a surface receptor for ___
IgE
49
activated mast cells release ____
histamine
50
mast cells are important in ____ responses
allergic
51
primary lymphoid tissues
bone marrow, thymus
52
where are t and b cells developed
bone marrow
53
where do b cells mature
bone marrow
54
where do t cells mature
thymus
55
secondary lymphoid tissues
spleen, adenoids, tonsils, appendix, lymph nodes, peyer's patches
56
secondary lymphoid tissues are sites where _____ is developed
adaptive immune response
57
how do lymph cells enter a lymph node
artery or afferent lymphatic vessel
58
how do lymph cells leave a lymph node
vein or efferent lymphatic vessel
59
what are four types of acquired immunity
natural: active, passive
artificial: active, passive
60
natural active immunity
a person develops their own immune response to a microbe (got sick)
61
natural passive immunity
one person receives preformed immunity made by another person (fetus, milk)
62
artificial active immunity
a person develops their own immune response to a microbe artificially (got a vaccine)
63
artificial passive immunity
a person receives artificial preformed immunity made by another person (monoclonal antibodies)
64
what is the complement system comprised of
more than 30 soluble proteins made by the liver (C3 is the most important)
65
where is the complement system present
local guards: blood, lymph, extracellular fluids
66
the complement system proteins are produced as _____ and can be activated by _____
proenzymes; they are activated in a cascade
67
what is the key step in activation of the complement system
cleavage of C3 and fixation of C3b to bacterium
68
what are the three pathways of complement activation
alternative pathway, lectin pathway, classical pathway
69
which pathway of complement activation is the first to act
alternative pathway
70
which pathway of complement activation is the second to act
lectin pathway
71
which pathway of complement activation is the third to act
classical pathway
72
what happens in alternative pathway
the pathogen surface creates a local environment conducive to complement activation
73
what happens in lectin pathway
mannose-binding lectin binds to pathogen surface
74
what happens in classical pathway
C-reactive protein or antibody binds to specific antigen on pathogen surface
75
what happens after C3b binds to surface components of pathogen
recruitment of inflammatory cells, opsonization of pathogens, facilitating uptake and killing by phagocytes, perforation of pathogen cell membranes
76
what is the enzyme that cleaves C3
alternative C3 convertase
77
why is the alternative pathway first
C3 has high concentrations at physiological conditions
78
__ is mannose-binding protein
C4
79
__ is C-reactive protein
C1
80
in the absence of a pathogen, C3b is ____
quickly diluted
81
what enzyme is responsible for the alternative pathway
alternative C3 convertase
82
what enzyme is responsible for the other pathways
classical C3 convertase
83
____ facilitate phagocytosis of pathogens by macrophages in complement activation
C3b (opsonins)
84
_____ induce inflammation and attract phagocytes in complement activation
C3a and C5a
85
what are the anaphylatoxins
C3a and C5a
86
what do the anaphylatoxins do
induce contraction of smooth muscle cells and the degranulation of mast cells with consequent release of histamine and other vasoactive substances, enhance vascular permeability
87
what are the roles of complement in innate immunity
lysis of bacteria via MAC, promoting phagocytosis via generation of C3b (opsonins), promoting inflammation via generation of anaphylatoxins (C3a and C5a)
88
what are the roles of macrophages in the early stage of innate immune response
phagocytosis of bacteria, orchestrating via induction of various types of cytokines, sensoring of danger signals via TLR
89
TLRs (toll-like receptors) recognize ______
PATTERNS (not a specific antigen)
90
TLRs connect with intracellular signaling pathways to ____
tell the nucleus to release cytokines
91
____ recognizes lipopolysaccharides, a major component of the outer membrane of gram-negative bacteria
TLR4
92
____ recognizes double-stranded RNA, a molecular pattern associated with viral infection
TLR3
93
with the purpose of inflammation to recruit more fighters, how do cytokines and chemokines assist
they can increase the permeability to make it easier for immune cells to come help. they also enhance the interaction of activated immune cells with inflamed endothelial cells (ligand/receptor interaction)
94
why do chemokines have a strong odor
to attract immune cells to come to the site
95
how are cytokines similar to hormones
they affect the behavior of other cells
96
autocrine action
molecules produced by cells that come back and act on themselves
97
paracrine action
produced by one cell, acts on neighboring cell, short distance
98
endocrine action
travels to distant cell
99
5 actions of cytokines
pleiotropy, redundancy, synergy, antagonism, cascading
100
describe pleiotropy of cytokines
affect multiple cell types, diverse effect
101
describe redundancy of cytokines
multiple cytokines affect cells of the same type
102
describe synergy of cytokines
cytokines acting in concert on the same cell
103
describe antagonism of cytokines
competing actions
104
describe cascading action of cytokines
cytokines acting sequentially
105
what are the cytokine generating cells for innate immunity
macrophages, endothelial cells, fibroblasts
106
what are the cytokine generating cells for adaptive immunity
T lymphocytes, macrophages, NK cells
107
both ____ and _____ are involved in cell migration
chemokines and adhesion molecules
108
carbohydrate-binding proteins are _____
selectins
109
selectin-mediated adhesion
weak which allows the neutrophil to roll along the vascular endothelial surface
110
extravasation of immune cells at the infection site is a result of _____ and _____
increased chemokine production and enhanced CAM interaction
111
type 1 interferons inhibit _______ replication and activate host defense
viral
112
what are type 1 interferons
IFN-alpha, IFN-beta
113
what are the results of interferon response
induce resistance to viral replication in all cells, increase expression of ligands for receptors on NK cells, activate NK cells to kill virus-infected cells (tells the immune system: i am infected, pls kill me)
114
how does NK cell interact with healthy/uninfected cell
inhibits killing of healthy cell
115
how does NK cell interact with virus-infected cell
kill it by inducing expression of MIC ligands
116
all immunogens are _____
antigens (but not all antigens are immunogens)
117
____ is the part of an antigen that is recognized by a single antibody
epitope
118
_____ are low molecular weight compounds that typically do not elicit a spontaneous immune response but can be recognized by antibodies. typically attached to a carrier molecule
haptens
119
what produces antibodies
B lymphocytes
120
what are the two forms of immunoglobulins
secreted, membrane-bound
121
which form of immunoglobulin are antibodies
secreted
122
what are membrane-bound immunoglobulins
they are antigen specific proteins produced by B lymphocytes, they are bound to the surface of the B lymphocytes and function as binding (receptor) sites for specific antigens
123
what is the characteristic structural feature of immunoglobulins
a sequence of domains providing stable conformation. domain: polypeptide chain folded into a sandwich held together by a sulfide bond
124
what some members of the IG superfamily
antibodies, B cell receptors, T cell receptors, MHC molecules
125
antibodies have a ____ structure
monomeric
126
describe the monomeric structure of an antibody
2 identical polypeptide heavy chains, 2 identical polypeptide light chains, polypeptide chains joined by disulfide bonds, carbohydrate
127
the variable region is responsible for ___
specificity
128
the variable region contains a ____ site
antigen binding sites
129
the constant region contains ____
binding sites for cell surface receptors and complement
130
the hypervariable region is also called _______
complementarity-determining region
131
the constant region determines ___
effector functions/how it works
132
antigen-antibody binding is based on ____
non-covalent forces (hydrogen bonds, very very strong binding)
133
_____ is the strength of binding between a single binding site and a single ligand
affinity
134
____ is the strength of binding between a molecule and a complex ligand (mult. binding sites)
avidity
135
___ is the first antibody produced
IgM
136
why is IgM the first antibody produced
the constant region that is closest to the variable region will be transcribed
137
what contributes to the diversity of antibodies
random assembling + junctional diversity
138
following antigen activation of B-cells, additional diversification occurs in V domain by _____
somatic hypermutation
139
somatic hypermutation is introduction of random single nucleotide substitutions (point mutations) throughout ______ regions
variable (more common in hypervariable)
140
what happens in isotype switching
the variable region of the antibody stays the same, but the constant region changes
141
isotype switching involves ____ between specific switch regions
recombination
142
CD4 are _____
helper t cells
143
roles of helper t cells
interact with B cells to promote antibody response, interact with macrophages to enhance phagocytosis of pathogen
144
CD8 are ____
cytotoxic T cells
145
role of cytotoxic t cells
kill cells with altered cell surface (virally infected cells, tumor cells)
146
structure of the t cell receptor
heterodimer with one alpha and one beta chain of roughly equal length, short cytoplasmic tail, transmembrane region with hydrophobic amino acids
147
both alpha and beta chains of the t cell receptor have a ____ and ____ region
variable and constant
148
variable chains of the alpha and beta chains of TCR contain hypervariable regions that determine _____
specificity for antigen
149
each T cell bears TCRs of only one specificity (______ _____)
allelic exclusion
150
an ____ is an alternative form of a gene (one member of a pair) that is located at a specific position on a specific chromosome)
allele
151
_____ organisms have one copy of each gene (and therefore one allele) on each chromosome
diploid
152
if both alleles are the same, they are _____
homozygotes
153
if the alleles are different, they are _____
heterozygotes
154
two classes of TCRs
alpha/beta and gamma/delta
155
is alpha/beta or gamma/delta the major population
alpha/beta
156
is alpha/beta or gamma/delta MHC dependent
alpha/beta
157
TCR beta chain genes have which segments
V, D, J
158
TCR alpha chain genes have which segments
V, J
159
Ig recognizes functional motifs of ___
intact antigens
160
TCR recognizes _____
processed peptides that are presented by MHC molecules
161
CD8 binds the alpha3 domain of ___
MHC class I
162
CD4 binds the beta2 domain of ____
MHC class II
