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GI 3 > Host defense > Flashcards

Host defense Flashcards

1
Q

Host Defense Barriers

  • Immediate:
  • Early:
  • Late:
A

Existing physical and chemical barriers

existing innate immune cells and mediators

activation of the appropriate adaptive immune cells and mediators

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2
Q

Second Line (Early)

– Phagocytes and macrophages involved in:

– Granulocytes for:

– NK cells :

A

– Phagocytes and macrophages involved in: inflammation

– Granulocytes for: anti-parasitiic

– NK cells anti-viral

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3
Q

Adaptive Immunity

  • T cells – Helper T cells (CD4)
  • Th1:___ –>inflammation
  • Th2: ___ –> anti-parasitic
  • Th17: ___–> inflammation
A

Th1 makes INF for inflammation

Th2 makes IL4 for antiparatic

Th17 makes IL17 for inflamation

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4
Q

CD8 or cytotoxic T cells are

A

antiviral and part of adaptive immunity

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5
Q

Ig with role in mucosal immunity

A

IgA

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6
Q

Ig with role in host defense

A

IgG

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7
Q

Ig with role in allergies

A

IgE

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8
Q

What are key early defense mechanisms?

A

tight junctions and epithelium that sheds

mucus from goblet cells

secreation of Cl- causing diarrhea

antimicrobial peptides like defensins

cytokines and chemokines

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9
Q

What plays a role in our second line defense mechanisms

A

Complement

Dendritic Cell

Tissue Macrophage

PMN

Eosinophils

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10
Q

three jobs that commensals do

A

Commensals:

  • 1) compete for resources with more virulent organisms
  • 2) produce their own antimicrobial peptides (AMPs) – e.g. defensins
  • 3) keep innate immune cells in an “attentive” state
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11
Q

What part of small intestine architecture provides protection?

A

Has defense molecules being secreated by Paneth cells deep in the crypts

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12
Q

What part of large intestine structure provides for immune function?

A

No villi, but have surface cell crypts secreating lots of mucs from goblet cells and there is high density of inflammatory cell groups throughout that have potential to initiate inflammation

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13
Q

Enterocytes “born” in crypt migrate from crypt toward villus apex, dislodged and shed into lumen ever ___days

  • _______ inside discarded or apoptotic epithelia
  • Apoptotic enterocytes are significant component of human feces –
A

5-6

Micro-organisms

genetic stool testing for cancer

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14
Q

– VIP (vasoactive intestinal peptide) – Acetylcholoine – Substance P – Prostaglandins & Leukotrienes – Histamine – Serotonin

A

all Secreataggues involved in epitheial barrier ion transport and can bind cAMP to increase water flow

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15
Q

Inhibitors / Absorptive molecules on epithelium

A

Norepi and somatostatin

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16
Q

Cystic fibrosis (CF) develops when dysfunctional mutations occur in the gene for the __________ channel. CF patients show a near total absence of electrolyte secretion, which may explain why some patients occasionally develop intestinal obstruction.

A

cAMPresponsive apical anion

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17
Q

: fibrogenic agent: Inhibits lymphocyte proliferation and ALSO stimulates division, differentiation, migration of surrounding epithelial cells when restituite epitheium forms aroudn an ulcer

A

TGF-β (Transforming growth factor)

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18
Q

What links first and second line Immediate-early defense mechanisms?

A

Dendritic cells link Early Innate Responses with Late Adaptive Immune Response

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19
Q

Innate receptors for bacterial_____ expressed in cytoplasm adn basolateral membfane but not on lumen surface

A

PAMPS

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20
Q

DC cells in the lamina propria express low levels of _____ for regocnitiono f pathogens

A

TLR

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21
Q

These are expressed on:) Plasma membrane of: epithelial cells, dendritic cells, Macrophages, PMNs

And recogonize Numerous bacterial, fungal, viral structures

A

TLRs

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22
Q

These are epxressed on Cytoplasm of epithelial cells, macrophages, PMNs

and REcognize: Bacterial wall components (peptidoglycans)

A

Nod-like receptors (NLRs) (e.g. Nod1)

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23
Q

Membrane receptor on phagocytes

recognize: Bacterial cell wall carbohydrate Fungal wall glycans

A

Mannose Receptor

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24
Q

Complement, MBL, and C-reactive protein are all located in the

A

plasma

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25
Where is IgM located and what PAMP does it recognize?
in plasma and gut lumen, recognizes bacterial cell walls
26
What two pattern recogonition receptors recognize microbial cell walls?
C-rective protein and Complement
27
The function of TLRs is to
activate genes necessary for defense against the recognized bacterial, viral, or fungal organism
28
Activation of INF alpha/beta that caues secreation of IFN is key in:
antiviral state
29
Expressionof cytokes: TNF, IL-1, IL-6 are activated by NFk-B and key in
acute inflammation and stimulates adaptive immunity
30
Campylobacter Clostridium Candida Cryptococcus are both
minimally invasive
31
Listeria Enteroinvasive Opportunist: Clostridium Shigella are both
Invasive
32
Enterotoxigenic E. coli Vibrio cholerae (Clostridium) (Shigella) are all
toxigenic
33
Key bacteria TLRS NLRs and miscl
TLRs: TLR2, 4, 5, NLRs: Nod1,2 C3b & MBL: complement C-reactive protein Ig
34
Key TLRs and complement for fungi
TLRs: TLR3, 4, 5, C3b: complement IgM:
35
What happens in early innate immune response?
DC samples outside--\> sends IL-12 to activate macrphates --\>sents TNF and IL1 to CD4 cells --\>Releaes IL-1 and TNF to increapse AMP secreation
36
During early innate immune response phase: DC samples outside--\> sends \_\_\_\_to activate macrphates --\>sents ____ to CD4 cells --\>Releaes _____ to increapse AMP secreation
IL-12 TNF and IL1 IL-1 and TNF
37
Fucntion of IL-6 and TNF-b in early innate immune response
soluble mediators IL-6 is pro-inflammatory TGF-b is more for innate immunity
38
When activating the adaptive response phase: DC cells to to Peyers patch and present to CD4+ T cells, what helps them differentiate into Th17 cells?
TGF-b and IL6 help take to Th17
39
When DC cells present to CD4+ cell and release _____ you get differntiation into Th1 cells
IL12 causes Th1
40
Th1 releases a shit ton of _____ to help mature naive B cells
Th1 release IFNg
41
naive B cells that swith to plasma cells in the peyers patch release what Igs toh elp in teh adaptive response phase?
release IgA and IgG
42
In the resolution phase, DCs will release ____ to act on macrophages so they rpesent to CD4 T cells
DC release IL-12
43
What cytokines to PMNs release to increase AMP production in teh reolution phase?
TFN and IL-1 to increase cAMP production
44
Th17 cells induce CD4 cells to release what cytokines to incrase pofuction of AMP on epithelium
IL-22 and IL-17
45
What do Th1 cells secreate during resolution phase and why?
secreate IFN-g to increae ion transport and increase activity of macrophages
46
If you have ulcer and epithelium is breached, we se imncrease immune trafficking to inflamed gut and will secreate _____ and ____ to attrack more immune cells like neutrophils
chemokines and C5a
47
Complement: The alternative, classical and lectin complement pathway all converge at:
C3b: opsonization and phagocytosis
48
Alterniative pathway of complment: Classic pathways; LEctin pathway:
alternative activated by microbe Classic by IgM binding to microbe lectin via MBL
49
TLRS that recognize Rotavirus
TLR3, 7, 9
50
NLRs that recognie norwalk
RIG1
51
Antibody that arecognizes enteroviruses
IgM
52
What two factors do NK cells release in anti-viral response and why
53
54
DC eats virus and present with MHC class \_\_\_\_---\> activates CD8+ that turn to \_\_\_\_
MHC class I turn to CTL that fuck virus
55
activated Th1 cells (by IL-12) produce _____ to help mature naive B cell to plasma cell
Th1 release IFN-g
56
o Name derives from their having granules that bind acidic dyes (e.g. eosin) o Circulating (average: 200/uL blood)
eosinophils: work against helmints
57
o Name derives from their having granules that bind basic dyes o Circulating (average: 40/uL blood)
Basophils work against parasites
58
o Tissue-resident, especially in mucosal epithelia and work against parasites
Mast cells
59
o Granulocytes are \_\_\_\_\_ o Granulocytes (i.e. eosinophils, basophils, mast cells) are more similar to one another than the 3 types of phagocytes (i.e. PMNs, M and DCs)
non-phagocytic
60
o Granulocytes defend the host by releasing their granule contents into the extracellular space (i.e. parasites’ environment) • This is referred to as
“degranulation”
61
Granulocytes are activated by
Ag-bound IgE binding cell surface FcεRI
62
Therefore, granulocyte activation depends on
previous exposure (i.e. sensitization) to an Ag
63
Stimulate Macrophages, activate endothelial cells --\>increased lymphocyte / leukocyte migration
cytokines
64
Disrupts parasite tegument • Tegument: the host-parasite interface; metabolically active
proteases
65
Smooth muscle contraction • Promotes parasite expulsion from the gut
vasoactive amines
66
\_\_\_ binds to bacterial surface to make the bacterium more easily ingeted by phagocytes
IgG
67
Live attenuated virus will
68
Microbiota and secreted chemical factors (lysozyme, defensins) defend the host in
the external environment of gut lumen
69
Epithelium forms a physical barrier that limits entry of pathogens
– Rapidly moving and shed into gut lumen – Restitution can repair damaged epithelium to limit microorganism entry
70
Activation by pathogens, cytokines, histamine, neural factors stimulates active \_\_\_\_\_into the lumen --\> Na+ and H2O follow--\> diarrhea
Cl transport
71
IL-4 induces which Th?
IL-4 induces Th2
72
Th2 makes what cytokines
IL-4 IL-5 IL-13
73
Whats the immune reaction from IL-4, IL-5 and IL-13 released by Th2 cells?
mast cell, eosinophil, IgE production, alternative macrophate acitvation against parasites
74
What Th cell has role in allergies
Th2 that ultimately makes IgE
75
What does IFN-gamma cause for Th
IFNg--\> Th1 activation
76
What cytokine does Th1 release adn whats its role
Th1--\>INF-g--\> macrophate activation and IgG production
77
Th1 have role in what host defense
Intracellular microbes goes bad: autoimmune dissease or chronic inflammatoin
78
What does TGF-b, IL6 and IL23 induce for Th subset
Th17
79
What does Th17 make and what role in immune reactinos
Th17 makes IL17 and IL-22 for neutrophilic acitvaiton and monocyti inflammation
80
Th that has defense against extracellular bacteria and fungi
Th17 bad: autoimmuen and inflammation

GI 3 (15 decks)

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