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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
Q

Where is IgM located and what PAMP does it recognize?

A

in plasma and gut lumen, recognizes bacterial cell walls

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26
Q

What two pattern recogonition receptors recognize microbial cell walls?

A

C-rective protein and Complement

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27
Q

The function of TLRs is to

A

activate genes necessary for defense against the recognized bacterial, viral, or fungal organism

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28
Q

Activation of INF alpha/beta that caues secreation of IFN is key in:

A

antiviral state

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29
Q

Expressionof cytokes: TNF, IL-1, IL-6 are activated by NFk-B and key in

A

acute inflammation and stimulates adaptive immunity

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30
Q

Campylobacter Clostridium

Candida Cryptococcus

are both

A

minimally invasive

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31
Q

Listeria Enteroinvasive

Opportunist: Clostridium Shigella

are both

A

Invasive

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32
Q

Enterotoxigenic E. coli Vibrio cholerae

(Clostridium) (Shigella) are all

A

toxigenic

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33
Q

Key bacteria

TLRS

NLRs

and miscl

A

TLRs: TLR2, 4, 5,

NLRs: Nod1,2

C3b & MBL: complement C-reactive protein Ig

34
Q

Key TLRs

and complement for fungi

A

TLRs: TLR3, 4, 5,

C3b: complement IgM:

35
Q

What happens in early innate immune response?

A

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
Q

During early innate immune response phase:

DC samples outside–> sends ____to activate macrphates

–>sents ____ to CD4 cells

–>Releaes _____ to increapse AMP secreation

A

IL-12

TNF and IL1

IL-1 and TNF

37
Q

Fucntion of IL-6 and TNF-b in early innate immune response

A

soluble mediators

IL-6 is pro-inflammatory

TGF-b is more for innate immunity

38
Q

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?

A

TGF-b and IL6 help take to Th17

39
Q

When DC cells present to CD4+ cell and release _____ you get differntiation into Th1 cells

A

IL12 causes Th1

40
Q

Th1 releases a shit ton of _____ to help mature naive B cells

A

Th1 release IFNg

41
Q

naive B cells that swith to plasma cells in the peyers patch release what Igs toh elp in teh adaptive response phase?

A

release IgA and IgG

42
Q

In the resolution phase, DCs will release ____ to act on macrophages so they rpesent to CD4 T cells

A

DC release IL-12

43
Q

What cytokines to PMNs release to increase AMP production in teh reolution phase?

A

TFN and IL-1 to increase cAMP production

44
Q

Th17 cells induce CD4 cells to release what cytokines to incrase pofuction of AMP on epithelium

A

IL-22 and IL-17

45
Q

What do Th1 cells secreate during resolution phase and why?

A

secreate IFN-g to increae ion transport and increase activity of macrophages

46
Q

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

A

chemokines and C5a

47
Q

Complement:

The alternative, classical and lectin complement pathway all converge at:

A

C3b: opsonization and phagocytosis

48
Q

Alterniative pathway of complment:

Classic pathways;

LEctin pathway:

A

alternative activated by microbe

Classic by IgM binding to microbe

lectin via MBL

49
Q

TLRS that recognize Rotavirus

A

TLR3, 7, 9

50
Q

NLRs that recognie norwalk

A

RIG1

51
Q

Antibody that arecognizes enteroviruses

A

IgM

52
Q

What two factors do NK cells release in anti-viral response and why

A
53
Q
A
54
Q

DC eats virus and present with MHC class ____—> activates CD8+ that turn to ____

A

MHC class I

turn to CTL that fuck virus

55
Q

activated Th1 cells (by IL-12) produce _____ to help mature naive B cell to plasma cell

A

Th1 release IFN-g

56
Q

o Name derives from their having granules that bind acidic dyes (e.g. eosin) o Circulating (average: 200/uL blood)

A

eosinophils: work against helmints

57
Q

o Name derives from their having granules that bind basic dyes

o Circulating (average: 40/uL blood)

A

Basophils work against parasites

58
Q

o Tissue-resident, especially in mucosal epithelia and work against parasites

A

Mast cells

59
Q

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)

A

non-phagocytic

60
Q

o Granulocytes defend the host by releasing their granule contents into the extracellular space (i.e. parasites’ environment) • This is referred to as

A

“degranulation”

61
Q

Granulocytes are activated by

A

Ag-bound IgE binding cell surface FcεRI

62
Q

Therefore, granulocyte activation depends on

A

previous exposure (i.e. sensitization) to an Ag

63
Q

Stimulate Macrophages, activate endothelial cells –>increased lymphocyte / leukocyte migration

A

cytokines

64
Q

Disrupts parasite tegument

• Tegument: the host-parasite interface; metabolically active

A

proteases

65
Q

Smooth muscle contraction • Promotes parasite expulsion from the gut

A

vasoactive amines

66
Q

___ binds to bacterial surface to make the bacterium more easily ingeted by phagocytes

A

IgG

67
Q

Live attenuated virus will

A
68
Q

Microbiota and secreted chemical factors (lysozyme, defensins) defend the host in

A

the external environment of gut lumen

69
Q

Epithelium forms a physical barrier that limits entry of pathogens

A

– Rapidly moving and shed into gut lumen

– Restitution can repair damaged epithelium to limit microorganism entry

70
Q

Activation by pathogens, cytokines, histamine, neural factors stimulates active _____into the lumen –> Na+ and H2O follow–> diarrhea

A

Cl transport

71
Q

IL-4 induces which Th?

A

IL-4 induces Th2

72
Q

Th2 makes what cytokines

A

IL-4

IL-5

IL-13

73
Q

Whats the immune reaction from IL-4, IL-5 and IL-13 released by Th2 cells?

A

mast cell, eosinophil, IgE production, alternative macrophate acitvation against parasites

74
Q

What Th cell has role in allergies

A

Th2 that ultimately makes IgE

75
Q

What does IFN-gamma cause for Th

A

IFNg–> Th1 activation

76
Q

What cytokine does Th1 release adn whats its role

A

Th1–>INF-g–> macrophate activation and IgG production

77
Q

Th1 have role in what host defense

A

Intracellular microbes

goes bad: autoimmune dissease or chronic inflammatoin

78
Q

What does TGF-b, IL6 and IL23 induce for Th subset

A

Th17

79
Q

What does Th17 make and what role in immune reactinos

A

Th17 makes IL17 and IL-22 for neutrophilic acitvaiton and monocyti inflammation

80
Q

Th that has defense against extracellular bacteria and fungi

A

Th17

bad: autoimmuen and inflammation

GI 3 (15 decks)

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