mucosal immunity

Question 1

physiological function of mucosal tissue

Answer 1

gas exchange
food absorbtion
sensory activity
reproduction
all functions critical to life

Question 2

mucosal tissue

Answer 2

highly vulnerable due to fragility and permeability
require effective defence mechanisms
portals of entry for non-pathogenic antigens

Question 3

mesentry lymph nodes

Answer 3

lymph nodes where all primary immune response occurs

found in the gut

Question 4

afferent lymphatic vessel

Answer 4

bring antigen into lymph node

via dendrite cells

Question 5

efferent lymphatic vessel

Answer 5

where activated cells leave and entr blood supply

Question 6

anatomy of gut mucosal immune system

Answer 6

intimate relationship between mucosal epithelia and lymphoid tissue

organised lymphoid structures unique to mucosal sites]

specialised antigen uptake mechanisms

Question 7

effector mechanisms of gut mucosal immune system

Answer 7

f

Question 8

immunoregulatory environment of gut mucosal system

Answer 8

j

Question 9

lamina propria

Answer 9

contains every cell you can imagine

where effector function happens

Question 10

peyers pathc

Answer 10

acessential to how immune response of the gut works

covered by an epithelial layer specialised cells called M cells which have characteristic membrane ruffles

Question 11

peyers patch anatomy function

Answer 11

huge absorptive cap

membrane ruffles- increase SA of the cell

Question 12

goblet cells

Answer 12

create mucous

Question 13

where M cells loacted

Answer 13

the dome

Question 14

how do M cells work

Answer 14

M cells take up antigen by endocytosis and phagoscytosis

antigen is transported across the M cells in vesicles and released at the basal surface

antigen is bound by dendritic cells which active T cells

Question 15

another role of dendritic cell in gut

Answer 15

can extend processes across the epithelial layer to capture antigen from the lumen of the gut

also occur in the lung

Question 16

intra epithelial cells

Answer 16

sit in epithelial mucosa

acting as monitors monitering infection and death of epithelial cells

Question 17

what in the mucosal immune system

Answer 17

consists of two distinct compartments

epithelium and lamina propria

Question 18

adaptive response in mucsal layer

Answer 18

T cells enter payers patches from blood vessels directed by the homing receptors CCR7 and L-selectin

T cells in the peyers patch encounter antigen transported across M cells and become activated by dendritic cells

activated T cells drain via mesenteric lymph nodes to the thoracic duct and return to the gut via the blood stream

activated T cells expressing a4B7 integrin and CCR9 home to the lamina propria and intestinal epithelium if the small intestine

Question 19

overall mucous immunity

Answer 19

medcam is found in the vascalature of other mucosal sites

lymphocytes primed in the gut can migrate to other mucosal sites

passive immunity transfer in breast milk

Question 20

what antibodies found in mucosal intestine

Answer 20

IgA
IgM
IgG

Question 21

how IgA works

Answer 21

binding of IgA to receptors on basolateral face of epithelial cell

endocytosis

transcytosis of apical face of epithelial cell

release of IgA dimer at the apical face of epithelial cell

Question 22

overall function of IgA

Answer 22

secreted Iga ON THE GUT SURFACE can binds and neutralise pathogens and toxins

IgA is able to bind and neutralise antigens internalised in endosomes

IgA can export toxins and pathogens from the lamina propria while being secreted

Question 23

intraepithelial lymphocytes

Answer 23

fully activate containing full killing machinery don’t need activation

restricted antigen receptor repertoire- don’t express normal TCR

expression of aE;B7 integrin anchors them in the epithelium

2 types with different recognition mechansisms

Question 24

where intraepithelial lymphocytes are found

Answer 24

lie withint he epithelial ,lining of the gut

they are CD8 positive T cells

Question 25

purpose of intraepithelial lymphoctes

Answer 25

virus infects mucosal epithelium cells
infected cell displays peptide to CD8 IEL via MHC class 1

activated IEL lkills infected epithelial cell by perforin/granzyme and Fas-dependant pathways

Question 26

stress in epithelium

Answer 26

occurs are a result of infection, damage, or toxic peptides and express MIC-A and MIC-B

NKG2D on IELs bind to MIC-A,B and activate the IEL

CD8 himodimers also bind to TL
activated IEL kills the stressed cell via perforin/granzyme pathway

Question 27

how is the balance between protective immunity and homeostasis maintained

Answer 27

there is a sophisticated means of discriminating between pathogen and innocuous antigens

default response to oal administration of protein state of specific peripheral unresponseiveness- oral tolerance

T cell and IgE mediated responses are inhibited more than serum IgG reponses both locally and systemically

Question 28

proposed mechanism of mucosal hyperresponsiveness

Answer 28

w

Question 29

hrherh

Answer 29

g

Question 30

eqjio

Answer 30

fiewo

Question 31

fwioe

Answer 31

ifowe

Question 32

fwnio

Answer 32

fwnieo

Question 33

fewnio

Answer 33

fwenio

Question 34

what happens when muscoal immunity becomes disregulated

Answer 34

nuon

Question 35

what happens to infected dedritic cells

Answer 35

they shuttle visures from the site of exposure to the regional lymph nodes where they concentrate virus partcicles and infect CD4+Tcells

Question 36

wgat di you give someone with crohns disease

Answer 36

immunosuppresatns

Question 37

food allergy

Answer 37

yype 1 hypersensitivity reaction initiated by crosslink of allergen specific IgE on the surface of the mast cells with the specific allergen

memory response- immune system must be primed