Mucosal Immunity Flashcards Preview

Medical Immunology > Mucosal Immunity > Flashcards

Flashcards in Mucosal Immunity Deck (17)
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1
Q

mucosal surface

A

line the body cavaties
line internal organs
majority of infectious agents invade through this route
permeable for gas exchange/food absorption

2
Q

mucosal epithelium

A

only barrier between invasion of tissues and the commonsal bacteria
epithelial cells form monolayer barrier - tight functions

3
Q

MALT

A

Mucosal Associated Lymphoid Tissue

lymphoid tissue in the musosa
has peyers patches where local B and T cells reside
peyers patches have specialised M cells for endocytosis and phagocytosis

4
Q

Stem cells differentiate into different cell types

A

enterocytes - absorption of food
paneth cells - antimicrobial peptide production
goblet cells - mucous secretion

5
Q

Antimicrobial peptides

A
a defensins - membrane dysfunction
lactoferrin
RNAses
lysozyme 
cathelecidin 
lectins
6
Q

immunoglobin A

A

major antibody of mucous
no inflammation - no initiation of complement
protease resistant
epithelial cells Fc receptors bind and take them up into the lumen of the gut

7
Q

intraepithelial lymphocytes (IELs)

A

type a = CD8 cell
kill infected cells, recognise MHC1+peptide
release granzyme
type b = NK cell
triggered by stress signals MICa and Micb recognised by NKG20

8
Q

innate lymphoid cells

A

detect environmental changes by sensing and secreting cytokines
ILC1 = Th1
ILC2 = Th2
ILC3 = Th17

9
Q

ILC1

A

TBET transcription factor activated by IL-12

secrete IFN-y

10
Q

ILC2

A

GATA transcription factor activated by IL10
secrete IL-5 and Il-9
lead to antibody production, eisonophil activation = helminth

11
Q

ILC3

A

respond to IL23 ROryt transcription factor

neutrophil activation - Il-17

12
Q

M cells

A

special dendrite like cells sample environment

13
Q

tregs

A

anti inflammatory

14
Q

homing of B and T cells

A

sample luminal contents

homed back to musocal surfaces via madCAM receptors on mucosal bind retinoic acid

15
Q

aberrant mucosal immunity

A

chrons - NOD2 mutation, activation or PRR, NFkB signalling - inflammation
coeliac - HLA-DQ2 binds gliadin on gluten - inflammation

16
Q

Shigella

A

penetrates gut epithelium by invading M cells
cell wall peptides bind NOD1 receptors and activate NFKb pathway, Epithelium secrete CXCLB to recruit neutrophils, inflammation
shiga toxin inhibits translation - stops protein synthesis and causes cell death
uses type 3 secretion system

17
Q

clostridium difficile

A

shows importance of human commensal in protecting against disease
broad strain antibiotics wipe out resident and allow clostridium to colonise,
Secretes toxin A which inactivates GTPases, changes in cell morphology and damage to tight junctions