DCs and Monos Flashcards
What is the purpose of CD80/CD86 expression on DCs?
Coreceptors for CD28 on T cells. These regulate the threshold for T cell activation.
What cytokines can DCs produce that shape T cell differentiation?
IL-12 (Th1)
IL-23, IL-6, IL1-a (Th17)
TGFB (Treg)
What are the markers and transcription factors for migratory DCs?
These are CCR7+ DCs, expressing the TF Id2, and arise from cDC1s and cDC2s present in tissues that upregulate CCR7 and migrate to the LN.
How to derive monocyte-derived DCs from PBMCs in vitro?
Treat with GM-CSF and IL-4. They are APCs, but we are not sure if they are true DCs.
What is the general progression of DC progenitors?
In the BM: Monocyte DC progenitor (MDP) > Common DC Progenitor (CDP) > Pre-DC. Through signaling of CD135/Flt3
Then, Pre-DC exits BM and enters circulation and seeds tissues and LNs, where the cells undergo further differentiation.
What markers were used to classify different subsets of pre-DCs?
SiglecH and Ly6D.
This led to the realization that pDCs are ontologically distinct from other DC lineages. They express high SiglecH and Ly6D and are unable to process or present antigen to naive T cells. They produce high levels of IFNg.
How can you target a cell population that has a transcription factor shared by other cell types?
If you know where the specific enhancers are that are specific for encoding the transcription factor for that cell, you can delete the cell-specific enhancer for the transcription factor.
Where does cDC2 imprinting occur and with what transcription factor?
cDC2 imprinting happens in the peripheral tissues and involves T-bet.
What are Esam+ cDCs?
cDC2As
What do DCs do in response to TLR3 ligation?
Upregulate costimulatory molecules (CD86), produce IFNa/B, IL-6, TNFa, etc.
What does CLEC9A recognize and which DC subtype expresses it?
Recognizes exposed actin filaments; expressed on cDC1.
What type of T cells do CCR7+ DCs induce primarily?
Tregs (and suppress Th17 in gut)
How do lymphocytes enter and exit secondary lymphoid organs?
Lymphocytes enter through High endothelial venules and exit through efferent lymphatics
DCs and antigen will enter through afferent lymphatics
What are the anatomical sections of the LN, beginning at the outermost part and going inward?
Hilus, subcapsular sinus, cortex, paracortex, medulla
What cells are in the cortex of the LN?
B cell follicles and interfollicular T cells (also fDCs)
What cells are in the paracortex of the LN?
T cells and DCs
What cells are in the medulla of the LN?
Some B cells and plasmacells.
What anatomical region of the LN are the HEVs located?
paracortex, which is mostly T cells and DCs. B cells continue on to the cortex/B cell follicles.
Blood flow through LN
Afferent artery, branched loops into cortex & capillary beds for oxygen exchange, regroup into postcapillary venule, HEV in paracortex, efferent vein.