Mucosal immunity Flashcards
immunoregulatory environment of the gut mucosa =__
is maintained by +
active downregulation of immune response - tolerance
inhibitory macrophages and tolerisng dendritic cells
Epithelial layer over Peyer’s patch =
function=
M cells (microruffle cells) large SA for taking in antigens by endo and phagocytosis to be picked up by dendritic cells below and then > T cells below that
T cells enter peyer’s patches via ___ directed by __+__
are activated and then go to ___>> (they express __+___ and so bind to __ on the mucosal endothelium)
bloodstream CCR7 and L-selectin receptors lymphatics>thoracic duct>blood α4:β7 integrin and CCR9 MadCAM1
intraepithelial immune cells =
dendrites and CB8+ T cells
lamina propria immune cells in the gut =
CD4+ Ts macros mast cells IgA dendritic cells plasma cells
humoral response in the intestines composition of Igs =
80% dimeric IgA, 15% IgM, 5% IgG
systemic humoral response composition of Igs =
reverse of intestinal
80% IgG, 15% IgM, 5% monomeric IgA
If virus infects gut epithelial cell __ presents it to T cells and causes apop by __
MHC-I
perforin/granzyme and Fas dependant pathway
If gut epithelial cell is stressed eg. Coeliacs they express ___ and bind to __ on T cells = apop by __
MIC-A+B
NKG2D
perforin/granzyme
Hyporesponsiveness in the gut mucosa is maintained by __+__
regulatory T cells
commensal bacteria
__ deficiency may give false negative Coeliac’s test
Selective IgA immunodeficiency
Chronic granulomatous diseas (CGD) causes __/__ granulomas present as +++
= no __ cells
S. aureus/ inflammatory
pneumonia, liver/ perianal/skin abscesses
no B cells
SCID is a T+/B cell deficiency
manifests as:
GI infectious agents =
T+B
oral candidiasis/chronic dirrhoea / interstitial pneumonitis
CMV/EBV/HIV/rotavirus
Coeliac’s is a type __ hypersensitivity reaction
__ cell mediated
genetic susceptibility in ___+__
4
T
HLA-DQ2 + 8
Golden standard for diagnosis of Coeliac’s =
biopsy
