Lecture 2: Cells & Organs of the Immune System Part 1 Flashcards
1
Q
What are the 8 keys to an effective immune system mentioned in the lecture?
A
- redundancy, resiliency (multiple levels or protection)
- Complete coverage of the entire body
- Discriminates healthy from sick (tolerance, specificity, inhibitability)
- ready responsiveness (fast)
- Diversity, resiliency, adaptability, specificity
- communication (between immune and non-immune cells)
- memory
- self-limiting to restore homeostasis after pathogen has been removed
2
Q
what are the 4 defense systems that are always ON and ready?
A
- physical and chemical barriers
- Local non-immune cells (epithelial cells, M cells)
- Sentinel cells and molecules
- circulating\ready-made effector cells and molecules
3
Q
list 5 areas where physical\chemical barriers exist
A
- skin
- oral
- airway
- intestines
- cervical (reproductive)
4
Q
what are the 3 common layers for physical\chemical barriers to pathogens?
A
- Commensal microflors
- epithelial and associated cells
- sentinel cells
5
Q
what are the 3 main functions of commensal microflora?
A
- maintain balance
- help with digestion
- crowd out pathogens
6
Q
what is the main function of epithelial and associated cells?
A
often produce mucus or antimicrobial peptides\chemicals
7
Q
what are the 3 main functions of sentinel cells?
A
- tolerance to commensals
- first line of detection for infection
- Differ based on location
8
Q
sentinel cells typically ____ (stay in one spot, or move around)?
A
stay in one tissues (resident cells)
9
Q
list 5 functions of sentinel cells that vary based on the types of cells present
A
- direct detection and elimination of pathogens
- recruitment of other immune cells and molecules by releasesing cytokines (including chemokines)
- early polarization of immune response
- phagocytosis of pathogens
- antigen presenting
10
Q
circulating\ready-made effector cells and molecules are present in the ____ tissues or ____ in the absence of infection
A
lymphoid; circulation
11
Q
list 7 functions of effector cells that vary based on location
A
- direct detection and elimination of pathogens
- recruitment of other immune cells and molecules by releasesing cytokines (including chemokines)
- polarization of immune responses
- antigen uptake by phagocytosis & micropinocytosis
- antigen presentation
- memory
- antibody production
12
Q
what is Hematopoiesis?
A
formation and development of red and white blood cells
13
Q
EVERY leukocyte derives from ______ cells
A
self-renewing pluripotent hematopoietic stem cells
14
Q
what are the 3 lines of cellls that are made from hematopoeitic stem cells?
A
- WBC
- RBC
- platelets
15
Q
Granulocytes are derived from ___ and make what cell types?
A
granulopoiesis; neutrophils, eosinophils, basophils, mast cells
16
Q
Monocytes are derived from ____ and make what cell types?
A
monocytopoeisis; monocytes, macrophages, dendritic cells
17
Q
Lymphocytes are derived from ___ and make what cell types?
A
lymphopoiesis; T cells, B cells, NK cells, NKT cells
18
Q
RBC are derived by what process?
A
erythropoiesis
19
Q
platelets are derived from what process?
A
thrombopoiesis
20
Q
site of hematopoeisis in fetuses 0-2 months old
A
yolk sac
21
Q
site of hematopoesis in fetuses 2-7 months old
A
liver and spleen
22
Q
site of hematopoeisis in fetuses 5-9 months old
A
bone marrow
23
Q
site of hematopoeisis in infants
A
bone marrow in practically all bones
24
Q
site of hematopoeisis in adults
A
vertebrae, ribs, sternum, skull, sacrum, pelvis and the end of teh femurs
25
____ tissue in the bone marrow is primarily involved in the production of leukocytes
lymphoid
26
what are the 3 major components of teh bone marrow microenvironment (niche)?
1. extracellular matrix
2. stromal cells
3. hematopoeitic growth factors
27
in the extracellular matrix of the bone marrow, there is attachment ____ cells and ___ cells via adhesion molecules
stem cells and hematopoietic progenitor cells
28
what are the stromal cells located in the bone marrow?
endothelial cells, perivascular cells, nerve cells, macrophages and osteoblasts
29
the stromal cells of the bone marrow provide ____ (4) to promote the growth of hematopoietic stem cells
support (scaffold)
nutrients
hematopoeitic growth factors
express adhesions molecules that influence differentiation
30
hematopoietic growth factors made by stromal cells are presented to ____ cels
immobilized stem cells
31
leukocytes differentiate from hematopoietic stem cells into 2 main lineages: ___ & ___
myeloid and lymphoid
32
when a hematopoietic stem cell goes down the myeloid pathway, what cell types are made?
granulocytes (neutrophils, eosinophils, basophils, mast cells), monocytes (monocytes, macrophages, dendritic cells), and RBC
33
T lymphocytes migrate to the ___ for maturation
thymus
34
additional differentiation, maturation and activation-induced maturation of immune cells occurs in the periphery in response to ____
stimulation, growth, or tissue resident factors
35
when a hematopoietic stem cell goes down the lymphoid pathway, what cell types are made?
dendritic cells, T helper cells, cytotoxic T cells, B cells, and innate lymphoid cells
36
how does a developing immune cell know what to become?
tightly regulated transcription factors that specialize cells by chromatin modification
37
environmental factors trigger transcription factors to turn on\off in cells developing from HSC, ___ allows fine tuning of the system
redundancy
38
Ikaros drive the differentiona of ____ and shuts down the ___ pathway
lymphocyes; myeloid
39
if PU.1 is low, HSC will follow the ___ pathway, if PU.1 is high, HSC will follow the ___ pathway
lymphoid; myeloid
40
t/f maintenance of pluripotency in HSC is controlled by an array of factors
t
41
2 key regulatory molecules for general granulopoiesis are
IL-3; granulocyte-macrophage-colony stimulating factor (GM-CSF)
42
what is a key regulatory molecule for HSC differentiation into neutrophils?
G-CSF
43
what is a key regulatory molecule for HSC differentiation into basophils?
IL-4
44
what is a key regulatory molecule for HSC differentiation into eosinophils?
IL-4
45
list 2 maturation characteristics of granulocytes
1. nuclear segmentation
| 2. acquisition of primary, then secondary granules
46
there is _____ by mature forms of granulocytes
negative feedback inhibition
47
what is the rate of formation of granulocytes?
1-2 x10^9 granulocytes/kg/day
48
what are the 4 classic signs of inflammation?
redness (rubor)
swelling (tumor)
pain (dolor)
heat (calor)
49
tissue damage causes teh release of ____ and ___ factors that trigger a local increase in blood flow and capillary permeability
vasoactive and chemotactic
50
are granulocytes early or late responders to infection?
very early
51
t/f granulocytes respond to an array of extracellular pathogens including bacteria and paracytes
t
52
how long does it take for granulocytes to respond to teh new pathogen?
minutes to 48 hours
53
are the responses of granulocytes antigen specific?
no; they have a quick, broad response to stamp out infection
54
granulocytes are derived from which HSC lineage pathway?
myeloid
55
granulocytes are classes based on what 2 features?
1. morphology
| 2. granule staining pattern
56
t/f granulocytes release products to recruit other immune cells that may be capable of specific responses
t
57
give an example of a molecule that can be found in a neutrophil's granules
antimicrobial proteins like defensins and lysozyme
58
what is the function of antimicrobial proteins in neutrophils?
direct harm to pathogens
59
give an example of a molecule that can be found in the granules of eosinophils
cytokines like IL-4, IL-10, IL-13 and TNF-alpha
60
what is the function of the cytokines found in the granules of eosinophils?
modulation of the adaptive immune response
61
give an example of cytokines found in the granules of basophils
IL-4, IL-13
62
give an example of a lipid mediator found in the granule of basophils. What is the function?
leukotrienes; inflammation
63
what is the most abundant leukocyte in the blood? what % does it occupy?
neutrophils (50-70%)
64
neutrophils circulate in the blood for ___hours before returning to tissues where they will only live for ___ hours
7-10; 48
65
describe the morphology of neutrophils
1. have a segmented nucleus (3-4 lobes connected by chromatin strands)
2. primary granules (large and dense with lysosomal function)
3. seconadry granules (smaller, contain complement activators and enzymes)
4. tertiary granules (phosphatases and metalloproteinases
66
what is another name for a neutrophil?
polymorphonuclear leukocyte (PMN)
67
t/f neutrophils are highly responsive and are typically the 1st responders to an infection
t
68
neutrophils respond to inflammatory molecules called __ to sward sites of infection
chemokines
69
what are 4 functions of neutrophils?
1. phagocytize bacteria and debris
2. secrete proteins to kill bacteria and signal for tissue remodeling
3. assist in shaping the adaptive immune response when needed
4. dead neutrophils accumulate as the major cell component in pus
70
what are the 2 major approaches to killing bacteria that have been engulfed by a neutrophil?
1. oxygen dependent
| 2. oxygen independent
71
the oxygen dependent approach to killing bacteria involves reactive ___ and ___ intermediates. What are some exaples of these intermediates?
1. reactive oxyegn intermediates (hydroxyl radical, hydrogen peroxide, hypochlorite anion
2. reactive nitrogen intermediates (nitric oxide)
72
what molecules are used to kill engulfed bacteria in the oxygen independent way?
defensins, lysozymes, hydrolytic enzymes (collagenase), and tumor necrosis factor
73
eosinophils account of about __% of leukocytes
1-3
74
t/f eosinophils circulate throgh the blood and into tissues
t
75
eosinophils are especially present in what organ?
small intestine
76
what is the morphology of eosinophils?
2 nuclear lobes, spericla granules, about 12-17 micrometers in diameter
77
eosinophils are involved in anti___ function and are also involved in ___ and ___
parasitic; allergy and asthma
78
what cell type releases cytokines to instruct adaptive immune responses and coordinate immune responses especially against multicellular parasites like worms?
eosinophils
79
how do eosinophils ilicite theri response?
use of lysosomal and oxygen radicals and contain an anti-parasite protein
80
the anti-parasite protein contained in eosinophils is called ____
eosinophil cationic protein (ECP)
81
basophils make up about __% of leukocytes
<1
82
basophils are important for killing ___
extracellular parasites, including multicellular worms
83
what is the morphology of basophils?
2 nuclear lobes, spherical purple granules, 12-17 micrometers in diameter
84
how do basophils ilicite their response?
bind to circulating antibody\antigen complexes (i.e. trapped pathogens) and release granule contents (histamines, leukotrienes, prostaglandins, and cytokines)
85
mast cells are made in the ___ and released into the blood as _____ that differentiate once they enter tissues, usually at the barrier between body and the environment (like at the skin)
bone marrow; immature precursors
86
t/f mast are distinct from basophils, but they have very similar functions
t
87
mast cells are characteristically found surrounding ___ and ___
blood vessels and nerves
88
there are at least 2 types of mast cells: ____ & ____
connective tissue mast cells and mucosal mast cells
89
mast cells are important to anti____ function and are involved in ____ reactions
parasite; allergic
90
mast cells are important to immune ___ cells
polarizing
91
mast cells release their granule contents, which includes :
histamines, leukotrienes, prostaglandins, and cytokines
92
t/f mast cells are sentinel cells
t
93
what is the key factor\protein in monocytopoiesis?
monocyte-colony stimulating factor (M-CSF)
94
what are the maturation characteristics of monocytes?
gradual nuclear folding and acquisition of cytoplasmic granules
95
what are the 3 stages of development of a monocyte?
1. monoblast
2. promocyte
3. mature monocytes which further differentiate in the tissues to dendritic cells and macrophages
96
what monocytes differentiate into dendritic cells in the presence of what factors?
granulocyte-monocyte colony stimulating stimulating factor: GM-CSF, IL-4
97
monocytes differentiate into macrophages in the presence of what factor?
monocyte colony stimulating factor
98
macrophages are dispersed throughout the body and travel by ____ movement through the tissues
amoeboid
99
what are the name of macrophages found in the lungs?
alveolar macrophages
100
what is the name for macrophages found in the connective tissues?
histiocytes
101
what is the name for macrophages found in the liver?
kupffer cells
102
what is the name for macrophages found in the kidney?
mesangial cells
103
what is the name for macrophages found in the brain?
microgial cells
104
what is the name for macrophages found in the bone?
osteoclasts
105
what are 4 things that activate macrophages?
1. phagocytosis
2. inflammatory Th1 cytokines (like IFN gamma)
3. inflammatory mediators
4. bacterial components
106
After activation, what 5 things about macrophages are increased?
1. phagocytic activity
2. killing ability
3. secretion of inflammatory mediators
4. migration
5. ability to activate T cells
107
what is the sentinel function of monocytes?
detect infections and signal immune responses
108
t/f monocytes can differentiate into macrophages in the tissues
true
109
monocytes & macrophages do what 2 things to dead (apoptotic) cells?
phagocytize and recycle
110
monocytes & macrophages kill the pathogens they ingest by what 2 methods?
1. oxygen dependent
| 2. oxygen independent
111
how do monocytes & macrophages recruit immune cells into the inflammatory site?
release cytokines and chemokines
112
monocytes and macrophages present antigens to ___ cells
T
113
what 4 changes are involved in monocytes becoming macrophages?
1. increased size (5-10 fold)
2. Increased number & complexity of organelles
3. increased phagocytic activity
4. increased levels of hydrolytic enzymes
114
t/f there are many subtypes of dendritic cells with specialized functions
t
115
what is the morphology of dendritic cells?
spread out with many dendrites upon differentiation in the tissues
116
Langerhans dendritic cells are found in the ____
lymph node
117
intersitial dendritic cells are found in the ___ and ___
lymph node and spleen
118
what are the 4 common types of dendritic cells?
langerhans, interstitial, monocyte-derived, & plasmacytoid derived
119
what cells are the most potent APC with ready function?
dendritic cells
120
dendritic cells take up potential antigens by what 3 methods?
1. phagocytosis
2. pinocytosis
3. receptor mediated endocytosis
121
once dentritic cells take in the antigens of pathogens, they load the antigens into ___ and ____ molecules
MHCII and MHCI
122
after dendritic cells load pathogen antigens into MHCI and MHCII, they then travel to the ____, where they present the antigens to the ___ cells
lymph node; T cells (T cell activation)
123
dendritic cells produce ___ to polarize the immune response
cytokines
124
t/f T cells, B cells, NKT cells, NK cells, and innate-like lymphocytes arise from the same stem cell
t
125
list 5 key hematopoietic growth factors involved in lymphopoiesis
IL-2, IL-3, IL-4, IL-5, IL-7
126
the stages of lymphopoiesis are characterized by ____ rather than ___
surface antigen expression (CD antigens) rather than morphologic factors
127
B cells mature in the ___
bone marrow
128
NK cells mature in the ___ and the ___
periphery and thymus
129
T cells and NKT cells develop in the ___, but mature in the ____
bone marrow; thymus
130
Innate lymphoid cells (ILCs) develop in the ___. The ___ may be involved in some subtypes of ILCs
bone marrow; thymus
131
lymphocytes account for what % of WBC?
20-40%
132
what are 6 types of lymphocytes?
1. T cells
2. B cells
3. innate lymphoid cell
4. NK cells
5. cytotoxic T lymphocyte(CTL)
6. plasma cells
133
what is the morphology of naive (quiescent) T and B lymphocytes?
1. round nucleus (size of RBC)
2. small rim of blue cytoplasm
3. 9 um in diameter
134
what is the morphology of large granular lymphocytes like ILCs, NKC, CTLs and plasma cells?
1. larger cell
2. more cytoplasm
3. large granules containing perforin and granzyme
135
CD4+ T cells are what types of T cells?
helper T cells and regulatory T cells
136
CD8+ T cells are what types of T cells?
cytotoxic T lymphocytes
137
what is the ratio of CD4 to CD8 positive T cells in healthy blood?
2:1
138
T cells can be activated by ___cells based on experience and timing with antigens
memory
139
what cells are known as the "Generals of the immune response"?
CD4+ T cells
140
what are the functions of CD4+ T cells?
help to activate CD8+ T cells, B cells, macrophages and other immune cells and regulate the immune response
141
how do CD4+ T cells illicit their effects?
by producing a range of different cytokines
142
t/f subsets of helper T cells polarize the immune response
t
143
what are the functions of CD8+ t cells?
killing virus-infected and cancer cells and produce cytokines like IFN gamma
144
Regulatory T cells are mostly what type of T cell?
CD4+
145
what is the function of naive B cells?
express membrane-bound immunoglobulin (antibodies)
146
what is the function of Plasma B cells?
work as activated "antigen factories"
147
what is the function of memory B cells?
maintained after infection to form memory responses
148
B cells function as antigen presenting cells in what scenarios?
in secondary immune response
149
which subsets of ILCs mirror the functions of CD4+ T cells with polarized function?
ILC1,2,3
150
t/f ILCs are primarily tissue resident
t
151
what is teh major function of ILCs?
cytokine production to polarize immune function
152
what are the functions of NK cells (4)?
1. discriminate self from non-self
2. secrete granzyme\perforin to kill target cells
3. kill via death receptors
4. secrete cytokines to olarize immune responses
153
NKT cells express functional ___ receptors that interact with ___ and ___
T cell; CD1 & conserved glycolipid moieties
154
NKT cells develop in the ___ and mature in the ___
bone marrow; thymus
155
what are the functions of NKT cells?
kill virus-infected and cancer cells & make pro-inflammatory cytokines to direct other immune cels
156
___- tissues are the sites of lymphoid development / maturation
primary lymphoid tissues
157
____ and ____ are primary or central lymphoid organs and are the site of lymphocyte maturation
thymus; bone marrow
158
___ tissues are the sites of lymphoid activation
secondary lymphoid tissues
159
what are the secondary lymphoid tissues?
lymph nodes
speen
mucosal-associated lymphoid tissues (MALT) such as
gut-associated lymphoid tissues (GALT)
160
antigens are trapped in ___ tissues, providing an opportunity for interaction with mature lymphocytes and antigen-dependent maturation of T and B cells
secondary lymphoid tissues
161
secondary lymphoid tissues contain ___ that permit transit of immune cells
high endothelial venules (HEV)
162
_____ tissues are the site of lymphocyte activity
teriary lymphoid
163
teriary lymphoid tissues typically contain ___ (more/fewer) lymphoid cells than secondary lymphoid organs
fewer
164
t/f tertiary lymphoid tissues can import lymphoid cells during an inflammatory response
t
165
give an example of a tertiary lymphoid tissue
cutaneous-associated lymphoid tissue (CALT_
166
what is the morphology of the thymus?
bi-lobed, encapsulated organ with lobules, separated by connective tissue strands (trabeculae)
167
the outermost part of the thymus is called the ___ and is densely packed with ___
cortex; immature proliferating thymocytes
168
the inner part of the thymus is called the ___ and is sparsely populated with ___
medulla; more mature thymocytes
169
during maturation, thymocytes interact with what 4 types of cells?
1. cortical epithelial cells
2. medullary epithelial cells
3. dendreitic cells
4. macrophages
170
the ___ are the site of generation for T and B cell antibody responses to sepcific antigens
lymph nodes
171
the ___ provides a location where lymphocytes can interact with antigens & antigen-presenting cells, especially interdigitating dendritic cells
lymph nodes
172
what happens to particulate matter and microorganisms in the lymph nodes that prevents them from entering the blood stream?
phagocytosis
173
what is the morphology of the lymph nodes?
bean-shaped capsules
174
how do lymph nodes get blood supply?
1. sinuses (subcupsular, cortical medullary)
| 2. blood vessels (arterioles, venules, post capillary venules)
175
t/f there are both efferent and afferent lymph vessels
t
176
the parenchyma of the lymph nodes can be divided into what 3 groups?
1. cortex (lymphoid follicles)
2. paracortex
3. medulla (medullary cords)
177
the primary follicles of the lymph node cortex contain what 3 cell types?
naive B, follicular dendritic, macrophages
178
the secondary follicles of the lymph cortex contain ___ cells in __ centers
activated B cells in germinal centers
179
the paracortex of the lymph node contains what 2 cell types?
1. T cells
| 2. interdigitating dendritic cells
180
the medulla of the lymph nodes contains what 3 cell types?
phagocytic macrophages, antibody-secreting plasma cells, some activated memory T and B cells moving into the efferent lymph
181
the reticular network (stroma) of the lymph nodes is made up of what 3 things?
1. extracellular matrix
2. reticular fibers
3. fibrolastic reticular cells
182
what is the function of the reticular network (stroma)?
provides structure and support to lymphocyte compartments
183
define "lymphatic system"
a network of vessels that collect fluid and lymphocytes that have flitered from the capillaries, through tissues and then returning them to the blood stream
184
in the process of lymphatic circulation, ___ and ___ are transported and concentrated in the lymph nodes to enable their interactiosn
leukocytes and antigens
185
the fluid component of blood (plasma) that leaks out of capillaries is called ___
interstitial fluid
186
most of the interstitial fluid that leaks out of capillaries returns back through capillaries and into the blood, but the small amount that does not is called ___ and it is collected by tiny open ___ capillaries
lymph; lymphatic capillaries
187
lymphatic capillaries join and become progressively larger lymphatic vessels, ultimately draining via the ___ duct into the ____ vein and back into the blood to return ___ and ___
thoracic; left subclavian; fluid and activated lymphocytes
188
afferent lymphatic vessels bring lymph ___ (in/out)
in
189
the lymph that enters the afferent vessels contains ____, ____ and a few ___ from tissues and brings these thinsg inot regional lymph nodes
antigen-carrying dendritic cells, particulate antigens and a few lymphocytes
190
efferent lymphatic vessels carry lymph ___ (in/out)
out
191
efferent lymphatic vessels carry lymph away from lymph nodes via the ___ and into venous circulation
thoracic
192
what is carried in efferent lymph from nodes and to the rest of the body to help fight infection?
antibodies made by plasma B cells, distributing effector cells and antibodies
193
what organ is the location where immune responses are mounted against antigens in the blood?
spleen
194
old/defective red blood cells are phagocytosed and recycled in what organ?
spleen
195
the ____ is a large ovoid organ situated in the upper left quadrant of the abdominal cavity and is surrounded by a capsule
spleen
196
the spleen consists of ___ pulp and ___ pulp, which are separated by a ____ zone
red and white; marginal zone
197
what is the function of the white pulp of the spleen?
generation of T & B cell responses (antibodies) against blood-borne antigens
198
what is the function of the marginal zone of the spleen?
interdigitating dendritic cells trap blood-borne antigens and transport them to the white pulp
199
what is the function of teh red pulp of the spleen?
macrophages phagocytose blood borne pathogens and defective/old RBCs
200
the skin has a ___(high/low) pH that helps resist pathogens
low
201
what is contained in tears that helps fight pathogens?
lysozymes
202
t/f sloughing off of the skin's surface helps remove surface bacteria
t
203
what does commensal bacteria mean?
beneficial bacteria
204
Tolerogenic dendritic cells phagocytose things and present them to ___ T cells
supressive T cells like T regulatory cells
205
what IL turns off the immune response?
IL-10
206
what feature is only expressed by T-Regulatory cells and can help us identify them?
Fox3T transcription factor
207
t/f in many cases )including COVID), it is not the actual pathogen that kills you, but an immune response that is too hihg
t
208
what does polarization of the immune response mean?
different aspects of the immune system are activated for different types of reactions
209
circulating ready-made effector cells have ___ and ___, (B and T cells) while sentinel cells do not
memory; antibody production
210
hematopoietic stem cells are ____(rapid\slow) dividing
slow
211
what is the first site of specification for hematopoiesis?
the mesoderm (germ layer that arises during gastrolation)
212
the mesoderm can be found between the ___ (which forms the ___) and the ___ (which forms the ___)
ectoderm (skin and neurons); endoderm (guts and lungs)
213
maturation of HSC occurs in the ____, which is derived from the mesoderm
AGM (aorta gonad mesonephrous)
214
why is the placenta sometimes stored for transplants of immune cells?
there is immune cell production in the placenta
215
the extracellular matric inside the medullary cavity of bone consists of what 3 main components?
1. viscous proteoglycan
2. insoluble collagen fibers
3. stromal cells
216
what are stromal cells?
basically everything BUT HSC (so things like endothelial cells, nerves, osteoblasts etc.)
217
what are the functions of the stromal cells?
provide scaffold and nutrients (like cytokines release small soluble proteins)
218
adhesion molecules will bind to ___ on immune cells and give specific signals from ___
receptors; differentiation
219
t/f dendritic cells can arise from both myeloid and lymphoid pathways
t
220
t/f CD8+ T cells take longer to form, but they give long lasting memory
t
221
t/f B cells dont secrete antibodies until they become plasma cells
t
222
do innate lymphoid cells move around?
no, they are stationary and help ensure barriers stay intact (also send signal to help repair barrier if broken)
223
___factors tell immune cells what to differentiate into
transcription
224
there can be some progression of teh lymphoid pathway if PU1 is only presnet after ____ is produced. In this case, teh cell will become a ___ cell
lymphoid progenerator; B
225
what dictates which transcription factors will be expressed?
outside signals (cytokines and cytokine receptors that are being triggered by cytokines from the environment or adhesion molecules they are touching
226
granulopoeisis causes cells to become ____ (smaller or larger)
smaller
227
when phagocytes come through the endothelium, this is called ___
extravastation
228
neutrophils are gobbled up by ___ cells after ___ days of life
macrophages; 2 days
229
the lobular nucleus neutrophils helps in the function of ____
netosis (dumping their chromatin onto sites of infection to trap bacteria so it can be gobbled up by neutrophils)
230
neutrophils have granules that contain ___ to help kill the things they gobble up
enzymes
231
what is chemotoxis?
movement of immune cells to the site where chemokines are
232
neutrophils produce cytokines for the education of ___ and ___ cells
T and B
233
what is the role of defensins?
poke holes in bacteria
234
what type of enzyme is eosinophil cationic protein (ECP)?
ribonuclease
235
basophils can bind to ___ on pathogens and then can ____ things to kill the bacteria
antigens; exocytose
236
describe the granules of mast cells
densly staining, very many in the cytoplasm
237
what is shape of the nucleus of mast cells?
spherical
238
where are mast cells mainly found in the body?
under the skin and in the gut
239
mast cells have toll-like receptors for ____ (which is responsible for the allergic response
IgE
240
activated monocytes turn into ___ or ___ cells
macrophages or dendritic cells
241
t/f monocytes can phagocytize, but not as much as macrophages or dendritic cells
t
242
t/f mast cells protect against bacteria and parasites
t
243
alveolar cells move around in the alveolar space gobbling up pathogens that are trapped in the ___
surfactant
244
when macrophages are activated, they can make a T cell response to ___ via the production of ___
TH1; IFN gamma
245
macrophages can kill things better after being activated, because they will have higher production of ____
superoxide anions etc.
246
activated macrophages produce more cytokines to create more ___
inflammation
247
macrophages decide to use their ____ to phagocytize a pathogen because of one of what 2 reasons?
pseudopodia; 1. there are toll-like receptors for things that are on the surface of the pathogen, or 2. because the pathogen is covered in anti-bodies and the macrophage has the Fc receptor for the tail portion of the antibody
248
describe the process of macrophage phagocytosis and antigen presentation:
1. macrophage determines that it needs to phagocytize the pathogen
2. engulfed into a phagosome
3. lysosome fuses with the phagosome and its enzymes and low pH degrade the bacteria
4. bacterial peptides are loaded by chaperone proteins into class 2 MHC
5. macrophage presents antigen to help activate CD4+ T cells
249
when a monocyte becomes a macrophage, is there an increase or decrease in pseudopodia?
increase
250
plasmacytoid dendritic cells are found in the ___ and ___ and are really good at recognizing ___
blood and spleen; viruses
251
plasmacytoid dendritic cells have which toll-like receptors? What do they recognize?
TLR 7,8,&9; recognize viral nucleic acid
252
once plasmacytoid dendritic cells recognize a virus through TLR, they can make lots of ___, which is very important for eliminating viruses
type 1 IFN
253
what is the most important type of antigen presenting cell?
dendritic cells
254
dendritic cells produce things to activate T cells, such as IL__
12
255
what cells are the most common lymphocytes?
T cells
256
all T cells express CD_
3
257
t/f CD4+ T cells make a lot of cytokines and each T cell doesnt make all cytokines, it makes a specific group of cytokines depending on the differentiation of the cd4+ cell
t
258
each B cell is coated in ___ and has different ___ specificity
antibodies; antigen
259
what usually happens to B cells with auto-reactivity?
usually deleted in the bone marrow
260
how to B cells present antigens to CD4+ T cells?
antigen is internalized, chopped up in the B cell then presented on class 2 MHC to the CD4+ T cells
261
t/f B cells need to come in contact with the right T cells receptor or the T cell will not release the cytokines needed for a B cell to become a plasma cell
t
262
which acts first in the immune response, NK cells or T cells?
NK cells
263
NKT cells have characteristics of both ___ and ___ cells
NK and T cells
264
CD1 doesnt present peptides, but rather presents ____ because ___
conserved glycolipid moieties; because it recognizes special glycolipids as being pathogenic
265
ILC 1,2,3 mirror which T helper subsets?
1,2,17
266
secondary lymphoid tissues contain a special type of venule called ____, which is how immune cells from the blood reach teh lymph nodes and the spleen
high endothelial venule
267
what is CALT?
places in the skin with increased number of immune cells
268
t/f the cortex of the thymus is filled with rapidly dividing thymocytes, but 99% will never leave the thymus bc there will be something wrong with them
t
269
give 2 reasons why Thymocytes may be dfective and neve leave the thymus
1. T cell receptor may not be active
| 2. they are selfreactive
270
why do lymph nodes get swollen during infection?
they are being filled with replicating T and B cells
271
what are the 3 main regions of the lymph node?
1. cortex
2. paracortex
3. medulla
272
in the lymph nodes, where are B cells found?
follicles in the cortex
273
in the lymph nodes., where are t cells found?
paracortex
274
where is the lymph nodes are t and b cells activated and where plasma b cells are making lots of antibodies?
medulla
275
how does lymph move through the lymphatic system?
contracting smooth muscles that line the vessels, and there are one-way valves
276
the periarterial lymphoid sheath is a ___ cell zone
T
