Dendritic cells Flashcards
Are DCs good at sampling?
Yes
On mature DC ________ interacts with CD28 on T cells
B7.1 or B7.2
What are the four ways that DCs capture and uptake antigens?
Micropinocytosis
Receptor mediated endocytosis
Caveolae dependent endocytosis
Phaogcytosis
Steps of micropinocyotosis
Formation of large vesicles from plasma membrane
Ruffling of membrane
Uptake
What receptors do DCs express?
C-type lectins
Fc receptor
Scavenger receptors
Receptors for HSP
Is micropinocytosis uptake specfic or not?
Not
C-type lectins: m_____ receptor and D________ recognised g_________ proteins
mannose receptors and DEC205 recognised glycosylated proteins
Examples of scavenger receptor
CD38 binds apoptopic bodies
What can DCs phagocytose?
Almost any bacteria, Gram +ve cocci and bacilli, and mycobacteria
Yeast cell, fungal hyphae
Apoptopic and necrotic bodies
What triggers DC maturation
DAMPs/PAMPs
Danger signals are mostly recognised by what receptor on DCs
TLRs
TLR2 binds?
Gram positive components of cell wall
TLR3 binds?
dsRNA
TLR4 binds?
LPS
TLR5 binds?
Flagellin
What are some indirect singals?
TNF-alpha
IL-1beta
Prostaglandin- E2
TLR activation increases what process and why
Micropinocytosis to capture more antigen
Where do migrating DCs move to?
Secondary lymphoid tissue
What receptor expression increases upon maturation of DC
CCR7
Langerhams cells interact with keratinocyes via what
E-cadherin
What molecule expression is reduced upon maturation: E-_______. What are the implication
E-cadherin - losing anchoring molecule allows for movement
What are the two ligands of CCR7
CCL21 and CCL19
What is CCL21 expressed bt
endothelial cells of lymphatic vessels
What is CCL19 expressed by and where
Stromal cells in T cell zoen of lymph nodes
Describe protease activity in iDC and mature DC
iDC have low protease activity and mature DC have high protease activity, effective at chopping up invariant chain and antigens.
