Adaptive immunity Flashcards
(110 cards)
1
Q
immune response to an infection occurs in
A
three phases
2
Q
acquired ability to recognize and destroy a particular pathogen or its products
dependent on previous exposure to the pathogen or its products
directed toward an individual molecular component of the pathogen
mediated by B and T lymphocytes
A
adaptive immunity
3
Q
following the first antigen exposure
A
primary immune response occurs
4
Q
T and B cells are stimulated and activated
A
antigen-specific lymphocytes
5
Q
Each T or a B cell expresses a TCR or a BCR
A
specific for only one antigen
6
Q
expressed by all nucleated cells
A
MHC class I
7
Q
expressed by APCS: DCs, Momega. and B cells
A
MHC class II
8
Q
expressed by T cells
A
T cell recpetors
9
Q
expressed by B cells
A
B cell receptors
10
Q
T cell cannot recognize __________ antigen: antigen must be _________ to a T cell
A
free, presented
11
Q
peptides that stimulate T cells are
A
epitopes
12
Q
when are epitopes recognized
A
only when bound to an MHC complex
13
Q
ligand recognized by the TCR is
A
a complex of peptide + MHC molecule
14
Q
T cells that express monomeric CD4 molecules
A
helper T cells
15
Q
T cells that express CD8 molecules
A
cytotoxic T cells
16
Q
CD4+ Th cells recognize antigenic peptides with their TCR that are physically associated with ________________ molecules on the surface of APC
A
self-major histocompatibility complex (MHC II)
17
Q
CD8+ cytotoxic T cells recognize antigenic peptides to them by
A
target cells with TCR in association with self-MHC I molecule
18
Q
cell surface receptors important for
A
antigen recognition, signal transduction, and adhesion
19
Q
TCRs bind both
A
self MHC and foreign peptides
20
Q
TCRs and MHCs bind
A
directly to peptide antigen
21
Q
activate macrophages
secrete cytokines
activated macrophages kill intracellular bacteria
play a role in inflammation and rejection of transplanted organs
A
Th1 cells
22
Q
plays crucial role in activating granulocytes, and fighting against helminths, B cell activation and antibody production
A
Th2 cells
23
Q
activate inflammation, recruit neutrophils, fight extracellular pathogens
A
Th17 cells
24
Q
provide help for B cells
A
T (follicle helper) cells
25
limit the immune response and prevent autoimmune responses
T (regulatory) cells
26
T cells that directly kill cells infected with intracellular pathogens and tat display on their surface foreign antigens on MHCI
cytotoxic T lymphocytes
27
contact between Tc cells and target cells is required for
cell death
28
degranulation occurs and causes
pores/perforins in target/perforate cell membrane
29
granules contain _________ that cause apoptosis
granzymes
30
A CTL that is activated by antigen recognition kills the
target cell
31
during an infection or vaccination, only B cells that have a BCR specific for the particular infectious or vaccine antigen will be activated
antigen to which we are exposed, chooses the B cell clone to be activated
specificity
32
subsequent exposures to the same antigen result in rapid generation of large numbers of antibodies and generation of long lived memory B and T lymphocytes
memory
33
acquired inability to make an adaptive immune response to ones own antigens, fetal and dietary antigens
toelrance
34
critical for induction of tolerance
Treg
35
tolerance to dietary antigens
oral tolerance
36
failure to develop tolerance may result in reactions against self
autoimmunity
37
failure to develop tolerance to dietary antigens leads to
food allergies and celiac disease
38
T cell precursors travel from the bone marrow to the thymus where they mature and undergo
positive and negative selection
39
T cells that recognize self MHC and peptides retained
positive selction
40
T cells tha pass the positive section and strongly bind to self-antigens undergo apoptosis
negative selection
41
more than _____ of _______ that enter the thymus do not survive the selection process
95%, T cells
42
elimination of self reactive T cells prevents
autoimmune diseases
43
negative selection of B cells occurs in
bone marrow
44
B cell negative selection
B cells that bind to self-antigen are directed to undergo apoptosis or silenced unable to respond
45
what happens upon recognition of B cells
proliferate, making more copies of the same clone
differentiate, into memory cells and the plasma cells
produce antibodies
46
activation of B cells occurs when
the BCRs encounters foreign antigen that they recognize in secondary lymphoid tissues
47
elimination of B cells that have a BCR specific for self antigen in the bone marrow prevents
autoimmune disease
48
substances that react with antibodies or TCRs
antigens
49
substances that induce an immune response
immunogens
50
not all antigens are
immunogens
51
happens which are small molecules are not immunogenicity
large proteins are immunogenic
size
52
complex proteins and carbohydrates are good immungens while molecules with simple repeating units are poor immunogens
complexity
53
large molecules or aggregates are usually excellent immunogens
physical form
54
extrinsic factors of immunoigenicity
dose and route
55
large oral dose of an immunogenicity may induce
tolerance rather than imunity
56
antibodies do not interact with an entire antigen but only with a distance portion of the molecule called
antigenic determinant or epitope
57
B cells recognize epitopes in
folded [roteins
58
T cells with their surface bound TCRs can only recognize ________ associated with MHCI or MHCII molecules presented to them by APCs or target cells
peptide sequences
59
a complex protein antigen can harbor
multiple B cell and/or T cell epitopes
60
immune response generated from exposure to an antigen
actvie
61
immune response which is the transfer of antibodies or immune cells to a person
passive
62
______ immunity develops memory cells, therefore producing a long-lasting immunity
active
63
_______ immunity consists of pre-formed antibodies or cells and has a rapid effect. but does not confer long-lasting immunity
passive
64
transfer of snake venom to a person after a bite by a venomous snake
anitvenom contains antibodies that can save the life of the patient
65
getting a disease and recovering
natural active immunity
66
passing antibodies to nursing infants through breast milk
natural passive immunity
67
receiving a vaccination shot and developing immunity
artificial active immunity
68
receiving pre-formed antibodies
artificial passive immunity
69
Its are found on the
cell surface of B cells, as well as soluble secreted proteins in serum milk and mucosal secretion
70
five major Ig classes
IgG, IgA, IgM, IgD, and IgE
71
the heavy chains of a given antibody define its class based on
amino acid sequence
72
all five Ig classes differ in
structure, expression patterns, and consequently functional roles
73
B and T cells not yet expressed to antigen are
naive T/B cells
74
B cells have approx. __________ BCR on each cell
100,000
75
must be activated by APCs to become effector cells
do not interact directly with pathogen bu stimulate other cells
CD4 + Th2
76
With the help of CD4+Th cells activated B cells differentiate in ________ that produce soluble antibodies
plasma cells; primary antibody resposne
77
subsequent exposure to the same Ag induces
secondary antibody response and immune memory
78
inappropriate immune response that results in host damage
hypersensitivity
79
how are hypersensitivity diseases categorized
according to antigens and effector mechanisms that produce disease
80
Type I
IgE sensitization of mast cells
81
Type II and III
IgG interaction
II- with cells surface antigen
III- with soluble or circulating antigen
82
antibody mediated immediate hypersensitivity
allergy (Type I)
83
causes allergies by release of vasoactive products from IgE antibody coated
mast cells
84
what percentage of population suffers from allergies to a wide variety of agents
20%
85
trans mucosal delivery of Ag at low dose favors IgE production, driven by TH2 cells
allergens
86
injection of 20-75 micrograms into the skin
bee venom
87
ingestion of grams of allergenic food into the GI tract over long periods of time ----------> sensitization
food allergy
88
1-2mg/injection
porcine insulin
89
IM or IV injection of 1-2 gram/injection
penicillin
90
triggered when allergens cross link IgE bound to the high-affinity receptor FCERI on mast cells
allergic reactions
91
found within mucosal tissues; alert the immune system to local infection
mast cells
92
what happens upon activation of mast cells
secrete histamine
release various cytokines and chemokines
93
consequences of IgE-mediated mast cell activation depend on
dose of antigen and its route of entry
94
major allergen in feces of house dust mites
cytosine protease known as Derp1
95
Derp1 cleaves occludin:
a component of intercellular tight junctions in the airways
96
occur when T and B cell are activated to produce immune reactions against self proteins
result in host tissue damage
autoimmune diseases
97
antibodies that interact with self antigens
autoantibodies
98
responses to selfantigens or antigens associated with the microbiota that lead to tissue damage and disease are referred to as
autoimmunity
99
disease causing immune responses to the commensal microbiota are a form of _________ because the organisms from which the Age are forming and are not encoded by the human genome
xenoimmunity
100
microbiota are considered to be part of the spectrum of autoimmune disease because microbiota are considered
superorganism made up of host and microbiota together
101
response to non-self antigens on the transplanted organs
allograft rejection
102
who described it as horror autotoxicus
Paul Ehrlich
103
autoimmune responses are specifically activated by
Ags
104
responses to self-antigens or auto antigens give rise to
autoreactive effector cells
autoantibodies
105
______% of the populations of western countries are affected by autoimmune diseases and their incidence is on the rise
5%
106
we do not know what events initiate the immune response to self antigen that leads to autoimmune diseases
autoimmunity arises spontaneously
107
autoimmune disease may be triggered by
infectious agents that express epitomes resembling self Ag
108
animal models show that autoimmune disorders may also be caused by
internal dysregualtion
109
highly sepccifc destruction of insulin producing beta cells in pancreatic islets of langherens
Type I diabetes
110
islets from normal(left) and diabetic mice(right) are stained for insulin(brown) which shows beta cells and glucagon(black) which shows the alpha cells
lower panels
