Enzymes and Chemical Mediators test 3 Flashcards
Enzyme responsible for cleaving the loop during VDJ recombination?
Rag 1 and 2
Enzymes responsible for hairpin opening and end-processing during VDJ recombination?
Artemis, TdT
What is Bruton’s tyrosine kinase?
Upon binding of PIP3: phosphorylates phospholipase C, this allows survival of the pre-B-cell.
What chemokine guides T-cells to lymph nodes and cause T-cells to leave high endothelial venules?
CCL19 and 21 guides T-cells and binds to CCR7 on T-cells which causes extravasation at HEV via L-selectin and LFA-1.
Which molecules are expressed on DC’s to costimulate T-cells (second signal)?
B7 on DC’s binds CD28 on T-cells.
Which signal causes T-cells to proliferate?
IL-2
What are the two methods CD8 cells kill and what enzymes are involved?
CD8 cells primarily use granzymes and perforin to kill cells. Perforin makes a hole into which granzymes enter and activate caspases.
CD8 cells also use FasL to activate Fas receptors on the target cell.
What cytokines cause Th1 cell differentiation and what are the associated transcription factors and what infections do these cells fight?
IL-12 and IFN-gamma
T-bet, STAT-4, STAT-1
Intracellular microbes (mycobacteria)
What cytokines cause Th2 cell differentiation and what are the associated transcription factors and what infections do these cells fight?
IL-4
GATA-3, STAT-6
Helminths and mast cells
What cytokines cause Th17 cell differentiation and what are the associated transcription factors and what infections do these cells fight?
IL-1, IL-6, IL-23, and TGF-Beta
RORgammat and STAT-3
Extra cellular fungi and bacteria
Which cytokines guide B and T- cell migration to the follicular boundary where they meet each other?
CCL-21 guides B-cells via CCR-7 and CXCL-13 guide T-cells via CXCR-5
Which enzyme is responsible for Somatic Hypermutation?
AID (activation induced cytidine deaminase)
Also is used in isotype switching
What cytokine is responsible for each Ig isotype?
IFN-gamma: IgG
IL-4: IgE
Mucosal tissue cytokines: IgA
