wk 2 2 mucosal immunity COPY

Question 1

physiological functions of mucosal tissues

Answer 1

gas exchange 
food absorption 
sensory activities
reproduction 
#

Question 2

glands which secrete mucosas

Answer 2

lachrymal 
salivary
mammary
kidney
uro-genital tract

Question 3

where would classic lymph nodes be located in GI

Answer 3

mesentery

Question 4

distinctive anatomical featurees of gut mucosal immune system

Answer 4

intimate relaitonship betwen mucosal epithelia and lymphoid tissue
special structure
specialised mechanisms

Question 5

effector mechanisms of gut mucosal immunity

Answer 5

activated/memory t cell predominate

‘natural’ effector/ regulatory T cells

Question 6

immunoregulatory of gut mucosal cells is done by (2)

Answer 6

active down regulation of immune response

inhibitory maccrophages and tolerising dendritic cells

Question 7

disease which causes constant inflammation of gut

Answer 7

chron’s disease

Question 8

area of activationin gut immune cells

Answer 8

peyer’s patch

Question 9

which are is covered by an epithelial layer containing specialised cells called M cells, tht have characteristic membrane ruffles (M= microvilli)

Answer 9

peyer’s patch

Question 10

microvilli increases

Answer 10

surface area

Question 11

where are dendritic cells located in peye’s patch

Answer 11

intimately close to M cell, directly behind

Question 12

other than help from M cells, how can dendritic cells provide immune response

Answer 12

can do through lamina propria, extend across the layer to catch the antigen from the lumen of the gut

Question 13

`cells located in gut epithelium

Answer 13

CD4
dendritic cell 
CD8
macrophage
mast cell 
dendritic cell
IgA 
plasma celll

Question 14

MADCAM-1 is a

Answer 14

molecular adresin

on epithelium

Question 15

t/f MAdCAM is onyl found in gut

Answer 15

false

Question 16

most abundant antibody in intestinal response

Answer 16

IgA (80%) - mostly IgA2
also dimeric

(IgM = 15%)
(IgG=5%) - most abundant in systemic

Question 17

name of recdptor which allows binding of IgA to epithelial face and into luminal gut

Answer 17

poly-Ig receptor

Question 18

3 ways IgA provides protection in gut

Answer 18

secreted to gut and neutralise pathogens and toxins
bind to pathogens internalsied in endosomes and neutralise
can export toxins from within lamina propria while being secreted

Question 19

t/f IgM can replace IgA

Answer 19

true
poly-Ig can bind to dimerics, IgM also dimeric
not as good but works for those with immune defiency

Question 20

outline the characteristics of special T cells of gut

Answer 20

expresses alphaE:Beta7 = anchoring to epithelium, does not move
activated
restricted antigen receptor

Question 21

what happens when a virus infects mucosal epithelium cell

Answer 21

infected vell - displays viral peptide to CD8 IEL (MHC class I)

activated IEL kills infected epithelium by perforin/granzyme and Fas-dependent pathways

Question 22

when epithelum cells undergo stress (infection, damage, toxic peptides) and express MIC-A and MIC-B, what happens

Answer 22

IEL T cells bind to MIC-A,B via NKG2D, activates, CD8alpha:alpha bind to TL, kills strssed cell via perforin/granzyme pathway

Question 23

what happens in coeiliac disease

Answer 23

more death of epithelium cells than production

epithelium becomes flat, reduces absorption (surface area decreases)

Question 24

define oral tolerance

Answer 24

default response too oral administration of prootein state of specific peripheral unresponsiveness

Question 25

which responses require a mediated response the most in gut

Answer 25

T cell | IgE

Question 26

t/f commensal organisms help cause hyperesponsiveness of mucosa

Answer 26

false | regulates local hyporesponsiveness

Question 27

how are T cells mediated 2

Answer 27

anargy/deletion of T cells generation of regulatory T cells both immunosuppresive and induce B cells switching to IgA production

Question 28

3 things which when present in commensal bacteria inhibit dendritic cell maturation

Answer 28

PGE2 TGF-beta TSLP

Question 29

define t cell anargy

Answer 29

tolerance mechanism in which the lymphocyte is inactivated following antigen encounter, yet remains alive in a hyporesponsiveness state

Question 30

MAdCAM-1 is an adressin molecule, what is this

Answer 30

ligand receptor

Question 31

when would dendritic cells be activated in gut

Answer 31

if microorganisms penetrate epithelium dxpress strong co-stimulatory ligands and induce CD4 T cells to differentiate into effector Th1 and Th2 cells

Question 32

what activates the NFkB pathway

Answer 32

intracellular sensors in epithelial cells (PRR)

Question 33

defensins are

Answer 33

anti-microbial peptides

Question 34

how does an infection develop

Answer 34

if some of the immune response cells are over taken, oesnt work properly and so infections able to spread

Question 35

naive CD4 T cells can activate into effector Th2 or Th1 cells, what does each produce and effect

Answer 35

Th2 - IL-13 produced, epithelial repair and mucus secretion - IL-5 produced, recruits/activates eosinophils, promotes IgA production - drive B cells to produce IgE (main immuno for parasites) Th1- IL-3,IL-9 activates mast cells (histamine, TNFalpha, MMCP) - activates macrophages - activates B cells, produce IgG2a

Question 36

helminths infection is a

Answer 36

parasites infection

Question 37

which effector Th cell is appropriate fro helminths infection

Answer 37

Th2 th1 will lead to a chronic infection, IgG good at removing bacteria not parasites

Question 38

how does HIV infect

Answer 38

infects dendritic cells, expresses co-stimulation and moves to lymph nodes finds more hosts, infects CD4T cells (activated) - these migrate to carry out effector functions, widespread dissemination

Question 39

primary immunodeficiency disorders present usually with

Answer 39

mucosal dysfunction

Question 40

t/f selective IgA defiency is only viral

Answer 40

false | only bacterial

Question 41

common variable immunodefiency is due to

Answer 41

failur to differentiiate into Ig secreting cells - low immunoglobulins (IgA ect) - bacterial infection

Question 42

CVID associated infections are

Answer 42

recurrent sinopulmonary and GI infections

Question 43

XLA (x-length agammaglobulinaemia) only affects males t/f

Answer 43

true

Question 44

when does XLA present, why

Answer 44

7/8months | immunoglobulin from mother (IgG, dimeric IgA) depletes, dont make their own

Question 45

what is the defect found in XLA

Answer 45

no b cells | agammaglobulinaemia

Question 46

associated conditions of CGD (Chronic Granulomatous Disease)

Answer 46

granulomas-pneumona, liver abscess, perianal abscess, skin abscess

Question 47

associated bacteria of CGD

Answer 47

staph aureus

Question 48

CGD is failure of

Answer 48

phagocyte respiratory burst

Question 49

how is CGD treated

Answer 49

bone marrow transplant

Question 50

Severe Combined Immunodefiency (SCID) appears

Answer 50

in first few weeks

Question 51

SCID is a profound defect in

Answer 51

t and b cell imunity

Question 52

associated conditions of SCID

Answer 52

oral candidiasis chronic diarrhoea interstitial pneumonotitis

Question 53

how is type 1 hypersensitivity initiated

Answer 53

crosslinking of allergen specific IgE on surface of mast cells with specific allergen

Question 54

triggers for anaphylaxis 3

Answer 54

venom drugs food due to systemic arrival (IgE secreted by plasma)

Question 55

how does food cause anaphylaxis

Answer 55

undigested proteins absorbed across gut, enters vasculature

Question 56

why is avoidance key for allergens

Answer 56

every time allergen in presented to immune, stronger memory response

Question 57

coeliac disease is

Answer 57

hypersensitivity (non-allergic) to gluten

Question 58

treatment for coeliac

Answer 58

gluten-free diet

Question 59

gamma interferon from gluten specific t cell activat eepithelial cells which produe IL-15, what does this induce

Answer 59

proliferation and activation of IEL | intra-epithelial lymphocytes

Question 60

activation of IEL and T cells causes

Answer 60

death of epithelial cells

Question 61

characteristics of coeliac intestine

Answer 61

``` gut flattens (lymphocytes/IELs kill epithelial quicker than they can be produced) lots of IELs along mucosal surface loss of villi ```

Question 62

2 genes associated with coeliac disease

Answer 62

HLA-DQ2 | HLA-DQ8

Question 63

associated antibody production of coeliac disease 3

Answer 63

anti-gliadin anti-endomysal anti-tissuue transglutaminase

Question 64

how is coeliac disease diagnosed in adults

Answer 64

adults - serology determines if they have anti-tissue transglutaminase then biopsy

Question 65

what may cause a patient coeliac disease be misdiagnosed

Answer 65

if they are IgA deficient - wont product anti-tissue transglutaminase

Question 66

t/f b cells can present antigens in secondary response

Answer 66

true

Question 67

why is if there is no gluten, there is no antibody

Answer 67

b cell binds to gluten complex contsinign transglutminase t cell binds and produces anti-gluten b cells instead produces antibodies for transglutaminase

Question 68

characteristics of Crohn's disease

Answer 68

focal and discontinuous inflammation with deep eroding fissures also granulomas may be present

Question 69

t/f granulomas in ulcerative colits

Answer 69

false -

Question 70

where does ulceritive colitis begin

Answer 70

rectum, moves proximally and contiguously

Question 71

ulcerative colitis is due to

Answer 71

distortion of crypts with infiltration of monocytes/neutrophils and plasma cells

Question 72

t/f inflammation/ulceration of ulcertive colitis only affects surface of mucosa

Answer 72

true

Question 73

treatment for ulceritive colitis

Answer 73

non-specific anti-inflammaotry and immunosuppressive drugs steroids/azathioprine/cyclosporin/methotrexate anti-TNF alpha