Mucosal Immuno Flashcards
a4b7
mucosal b7 integrin,
expressed at low levels on naive T cells
MAdCAM-1
Mucosal Addressin cell-adhesion molecule 1
Key ligand for a4b7 integrin and if appropriately glycosylated it can also interact with CD62 L
Expressed on HEV for PP and MLN
CCL21
Ligand for CCR7 which is expressed by all naive and a subset of memory T cells
LFA-1
b2 integrin, importent for arrest of Naive T cells to HEV
Entry of Naive T cells into non-intestinal LN
mediated by CD62L, CCR7 and LFA-1
Entry of Naive T cells into MLN and PP
Efficient recirculation of Naive t cells through MLN and in particular PP is less dependent on CD62L, but involves a4b7
PNAd
interacts with L-selectin to initiate tethering and rolling
not expressed on PP
SILT
solitary intestinal lymphoid tissue
CCR7
expressed on cells that are migrating into regional lymph nodes. Ligand is expressed by lymphatic vessels
Intestinal DCs
Important for transport of luminal antigen to the t cell area of PP and MLN
Receive antigen from M cells in the subepithelial dome
LP DC’s can put out transepithelial dentrites
a4b7 and effector t cell homing to gut mucosa
a4b7/MAdCAM-1 interaction is important for effector t cell homing to the intestine (but not liver, llung or skin), however it is not asolutely required, because b7 deficient CD8 cells can still resolve rotavirus infection
CCL25
thymus-expressed chemokine, ligand for CCR9
CCL25 is largely expressed in the small intestine and thymus - constitutive expression on small intestinal epithelial cells (not colon)
Required for both CD4 and CD8 effector t cells to enter SI LP
CCR9
expresesd on murine small intestinal T cells, required for optimal entry of both CD4 and CD8 effector cells into the small intestine
NALT (def)
Nasopharynx associated Lymphoid tissue
