CBG Lecture 25&26: Immunology Flashcards
(132 cards)
1
Q
why study immunology
A
control infectious disease autoimmuno disease treatment cancer treatment transplantation veterinary immunology digestive diseases sometimes related to immune system eg. Crohns
2
Q
what type of infections are ranked number 1 on infectious disease killers
A
respiratory infections
3
Q
give an example of a digestive disease related to immune system
A
Crohns
4
Q
what are the major categories of human infection
A
virus
fungi
parasites
bacteria
5
Q
what are the major viral diseases
A
HIv-aids
Poliovirus-polio
rubeola-measles
6
Q
what are the major fungal diseases
A
tinea corporis - ringworm
candida albicans - candidiosis (thrush)
7
Q
what are the major parasitic diseases
A
plasmodium - malaria
leishmania - leishmaniasis
8
Q
what are the major bacterial diseases
A
myobacterium tuberculosis - TB
pertussis - whooping cough
vibrio cholerae-cholera
borrelia burgdoferei - lime
9
Q
what is the purpose of the IS
A
to dead with harmful pathogens and internal threats like cancer
10
Q
what is the nature of the threat of harmful pathogens
A
- bacteria and viruses grow exponentially - we dont
- microbes evolve rapidly, therefore IS must adapt - hard wiring specificity is not enough
- IS has to kill off foreign pathogens without destroying “self”
11
Q
what are general/broad difficulties IS has to face when fighting infections
A
- bacterial and viruses grow exponentially-we dont
- viruses and bacteria can evolve rapidly
- IS needs to make sure it doesnt destroy self
12
Q
outline key properties of innate IS
A
- fixed response
- rapid response -4hrs
- limited number of specificities
- constant during response
13
Q
outline key properties of adaptive IS
A
- variable response
- slower response - 4 days
- numerous highly selective specificities
- improve during response
14
Q
when does the adaptive immmune response begin
A
when a pathogen is ingested by an immature dendritic cell in the infected tissue
15
Q
name some cells involved in innate immunity
A
phagocytes
complement
NK cells
16
Q
name some cells involved in adaptive immunity
A
B lymphocytes - antibodies
T lymphocytes
effector T cells
17
Q
what constitutes the serum component of blood
A
cell free liquid minus the clotting factor
18
Q
what does serum include
A
electrolytes ABs hormones drugs microorgs
19
Q
what does plasma include
A
vell free liquid with clotting factors in solkn
includes EDTA
all of serum
20
Q
what is EDTA
A
a good anticoagulant
21
Q
if you centrifuge blood what do you get
A
55% plasma
buffy coat - leukocytes+platelets
22
Q
what makes up 55% blood
A
plasma
23
Q
what makes up buffy coat
A
leukocytes and platelets
24
Q
what makes up 4% blood
A
erythrocytes
25
what is a stem cell called
hematopoietic
26
what are hematopoeitic cells
blood cells that give rise to all the other blood cells and are derived from mesoderm. They are located in the red bone marrow, which is contained in the core of most bones.
27
what are two main types of lymphocytes
B lymphocytes - B cells
| and T lymphocytes - T cells
28
where are B and T cells produced
B - bone marrow
| T - thymus
29
what other lymphocytes are produced
memory cells
30
what do natural killer cells do
kill cells infected with certain viruses - theyre both innate and adaptive
involved in tumour surveillance
31
what is a plasma cell
a fully differentiated B cell which secretes Abs
32
what are memory cells critical for
vaccination and repeated response/exposure to infectoin
33
name a major human disease that has been eradicated
small pox
34
what cell response do most vaccines generate
B cell response - but to be super effective want a cytotoxic T cell response
35
for a vaccine to be super effective, what type cell response would you ideally want to be generated
a cytotoxic T cell response
36
what is another word for a monocyte
macrophage
37
whats the difference between monocyte and macrophages
monocytes are young macrophages in blood
| monocytes have kidney shaped nucleus, macrophages have round shaped nucleus
38
what are macrophages involved in
phagocytosis and killing of microogs- activation of T cells and initiation IS
39
what are the largest cells in the blood
monocytes/macrophages
40
why are there tssue specific macrophages
due to antigen presentation
41
describe the shape of a monocyte nucleus
kidney shape
42
why is a neutrophil a granulocyte
because it contains cytoplasmic granules
43
outline features of a neutrophil
```
granulocyte with cytoplasmic granules
polymorphonuclear
undergoes phagocytosis
short life span - hours
important at clearing bacterial infections
innate immunity
```
44
are neutophils involved in adaptive or innate immunity
innate
45
describe the nucleus of a neutrophil
polymorphonuclear and multilobular
46
what cells has a multilobular nucleus
neutrophil
47
what is complement
a group of serum proteins that activates inflammation, destroys cells and participates in opsonisation
48
is complement innate or adaptive
innate
49
what pathways can activate complement
classical or alternative pathway
50
what does complement do
produce a cascade of reactions
51
what is the membrane attack complex
forms a hole in cell membrane causing cell to lyse
52
what are mast cells associated with
allergies
53
what does antigen processing depend on
whether they originate within or outside the host cell
54
how are antigens that are produced within the cell processed
fragments of foreign proteins are antigens
antigens transported to RER
antigens combine with MHC Class 1, then transported to Golgi, then plasma membrane
cell becomes APC and stimulates destruction by CD8+ T cells - self antigens arent recognised by T cells and dont stimulate cell destruction
55
give sequence of events for processing antigens produced within cell
proteins broken into fragments -> rough ER -> MHC Class 1 -> golgi -> plasma membrane
56
give sequence of events for processing antigens originating from outside cell
proteins broken into fragments within vesicle -> fuse with golgi containing MHC2 -> complex transported to PM
57
how are antigens originating outside cell processed (eg. bacteria/viruses)
ingested by phagocytosis by macrophages, undergo endoctosis
foreign fragments broken down in a vesicle
vesicle containing the foreign fragments fuses with vesicles from Golgi containing MCHclass2
MHC Class2/antigen complex is transported to the plasma membrane
the displayed MHC2/antigen complex can stimulate other immune system cells to respond to antigen
58
outline immunologival memory case study
Faroe Islanders 0> N.Atlantic
measles epidemic 0> infected entire pop
reintroduced later, almost all inhabitants infected except those who has survived previous infection and retained immunological memory
59
what is the immune system made of
physical barriers
cells
souluble effector protesins: ABs, complement
cytokines - ocmmunication
60
name some communication signals in IS
cytokines
61
name some intrinsic epithelial barriers to infection
chemical:acids/lsozyme/antibac peptides
| normal flora - in gut
62
what is innate IS mediated/initiated by
phagocytes
NK cells
soluble proteins
63
what are phagocytes
cells specialised in phagocytosis
64
name some phagocytes
macrophages
| neutrophils
65
outline process of phagocytosis
capture
engulfment
and break down of bacterial pathogen
66
where do macrophages reside
can be tissue resident or recruited to sites of inflammation
67
what do macrophages do - what are they important for
engulf and kill viruses and bacteria
| important for antigen presentation to T cells
68
what are neutrophils attracted by
chemokines which are activated by microphages
69
what are phagocytes' recognition of pathogens based upon
pattern recognition using germline encoded receptors or proteins
70
name some receptors that macrophages express
express receptors for microbial constituents
LPS receptor - commonly found in bacterial cell wall
TLR-4 and TLR-2 : toll light receptor - recognise pathogen motifs in all cells in IT , recognises dsRNA therefore recognises virus
71
what induces the synthesis of inflammatory cytokines
bacterial components binding to signaling receptors of macrophages
72
what is TLR-4 / TLR-2
```
toll light receptor - found on macrophages
recognise dsRNA (non self - humans dont have dsRNA)
```
73
how do neutrophils respond to inflammatory stimuli
highly motile - migrate out of blood into tissues in large numbers
74
what is the most common leukocyte in blood
neutrophils (80%(
75
outline nucleus of neutrophils
distinctive lobed nucleus and intracellular granules
76
what is lifespan of neutrophils
short life span c.24hrs
77
what is a major constituent of pus
dead neutrophils
78
what is the inflammatory response
accumulation of fluid and cells at infection site - swell, red, heat pain
79
outline main roles of complement
opsonisation - complement proteins coat outser surface of pathogens so phagocytes can engulf and recognise them easier
membrane attack complex-grp of ocmplement proteins punch hole in pathogen - lysis
enhance inflammation
80
what three outcomes of complement activation
1. opsonization
2. membrane attack Complex
3. enhance inflammation
81
state how infection triggers an inflammatory response
bacteria trigger macrophages to release cytokines and chemokines
vasodilation and increased vascular permeability:heat, red,swelling
inflammatory cells migrate to tissue rekeasing inflammatory mediators that cause pain
82
what causes pain in inflammatory response
inflammatory mediators
| i
83
in inflammatory response, what causes redness and swelling
vasodilation and increased vascular permeability
84
what three pathway types of complement activation
classical - antigen:antibody complexes
MB lectin pathway:lectin bind to pathogen surface
alternative pathway - pathogen surfaces
85
what is the first line of defence against infection called
innate immunity
86
what is recognition of pathogens in innate immunity based on
pattern recognition using germ line encoded receptors or proteins
87
why is innate immunity non adaptive and not inclusive of memory cells
because pattern recognition is based on receptors that are coded for in germ line cells therefore non adaptive
also theyre evolnarily early- viruses have now evolved
88
what is adaptive immunity
specific to a particular antigen and detected by specific receptors on T and B cells
89
why is adaptive immunity called adaptive
response improves with time and results in memory = protection against reinfection with the same pathogen
90
why is adaptive immunity described as evolnarily late
only present in vertebrates
91
what are the main cells involved in adaptive immunity
T and B lymphocytes
92
what is humoral immunity
immunity due to production of antibodies due to B cells - humoral immunity
93
what can B cells differentiate into
plasma cells
memory cells
antibodies
94
what do B cells require to be fully functional
activation by T cells
95
what can b cells release
ABs but also cytokines
96
what is a BCR
b cell receptor - a membrane bound immunoglobin
97
what is a TCR
a T cell receptor
98
how does a t cell recognise a foreign antigen
as a peptide on an MHC molecule presented by an APC - antigen presenting cell
99
what are types of T cells
helper CD4+
cytotoxic CD8+
regulatory
100
where are T and B cell responses initiated
in seocnary lymphoid organs - lymph nodes and spleen
101
what are the secondary lymphoid organs
lymph nodes and spleen
102
what is antibody/humoral mediated adaptive immunity
directed agains extracellular microorgs and toxins
| B lymphocytes differentiate into plasma cells which produce ABs
103
what is cell mediated adaptive immunity
directed against intracellular microorgs
| T lymphocytes differentiate into effector cells following antigen presentation by APCs and activating B cells
104
define antigen
molecule which stimulates production of and binds specifically to an antibody
105
outline structure of antigens
primarily peptides, short strings aas but carbs, nucleic acids and lipids also potential antigens
106
what are the molecules recognised by the immune response claled
antigens
107
what are epitopes
sites within antigens to which antigen receptors bind
108
what are sites within antigens to which antigen receptors binds
epitopes
109
what area of antigens are individual antibodies made against
epitopes/antigenic determinants
110
what are antigenic determinants
epitopes
111
what is the difference between AB and T cell antigen binding
AB bind antigen directly
| T cell requires antigen/MHC complex
112
where does adaptive IR occur
lymph node and spleen
113
outline structure of ABS
2 heavy chains
2 light chains
exist as monomers, dimers or pentamers of basic structure
contains variable and constant regions
114
what is variable region of AB
antigen receptor
115
what region defines structure of AB
constant region
116
what are isotypes of ABs
```
IgA-@mucosal surfaces, large hinge region
IgM
IgG-DEFAULT ISOTYPE
IgD -defaul
IgE -parasites
```
117
what is default AB isotype
IgG
118
what is AB
secreted form of IG made m y plasma cells
119
what are different isotypes determined by
strcutural differences in constant regions fo heavy chains
120
following exposure to antigen, what happens to B lymphoctes
differentiate into plasma and memory cells
121
what do plasma cells produces
ABs of all immunoglobin classes
122
what is clonal selection
activation of antibody producing cells
123
outline clonal selection
biding of specific antigen results in proliferation of a clonal popn of cell
antigen determines clonal proliferation
124
what are T and B cell responses
clonal
125
discuss T and b cell receptor diversity
T and B cells have receptors specific for only 1 antigen and each cell is unique
126
what are effector cells aka
memory cells
127
discuss T cells and cell mediated immunity
T cells respond to antigens on surface of APCs - APCs ingest and process antigens then display fragments on their surface in association with MHC
128
which MHC/antigen complex does CD4+ bind to
MHC Class 2
129
which MHC/antigen complex does CD8+ bind to
MHC Class 1
130
what do T cells which encounter antigens do
differentiate into effector cells
131
what does antigen determine
clonal proliferaiton
132
name some APCs
macrophages
| dendritic cells
