Midterm 2 to Memorize Flashcards
MHC Class 1 Locus
only one alpha chain
Human: A B C
Mouse: K D L
short peptides, usually 9AA in length
MHC Class 2 Locus
has an alpha and beta chain
Human: DP DQ and DR
Mouse: IA and IE
longer peptides, usually 12+ AA in length
Assays you should know
In vitro T cell assay
Chromium release assay
What are the Tg you should know
OT1: CD8 T cell specific for ovalbumin peptide bound to Class 1 MHC H2-Kb, thus more likely to have much more CD8 than control
AND: CD4 T cell Specific for cytochrome C peptide bound to Class 2 MHC H2-IEk
Three kinds of proteasomes
Standard: degrade damaged or unneeded proteins by proteolysis (breaking of peptide bonds via proteases); essential for generation of peptides used in MHC:peptide presentation
Later versions of proteasomes arise due to cytokine signaling etc etc
Immuno-: degrades intracellular proteins, esp those of viral origin; arises in response to pro-inflammatory responses
Thymo-: degrades specific proteins into peptides used in positive selection; collaborates with cTECs
What are the specific functions of the subsets of Helper T cells (CD4)?
TH1: produces IFN-gamma → activate macrophages, provide help to B cells for antibody production and class switch to IgG2a, helps CTL differentiation
TH2: produces IL-4/5/13 → provide help to B cells for antibody production and class switching to IgE; helps eosinophil differentiation and activation
TH17: produces IL-17/21 → enhance neutrophil response; promote barrier integrity in the skin and GI tract (mucosal surfaces)
Regulatory: suppress T cell responses → targets other T cells rather than pathogens
BONUS – Follicular TH: produces IL-21 and ICOS → provides help to B cells via affinity maturation and germinal center formation; isotype switching; assists in antibody production
- Found in B cell zones in secondary lymphoid organs
Different members of the STAT family act downstream of inducer cytokines to direct CD4 T Cell fate.
IFN-gamma and IL-12 → STAT-1 and STAT-4 (respectively) → T-bet → TH1 development
- IL-12 is an initiating cytokine for TH1
- IFN-gamma is an initiating cytokine for TH1 that also reinforces TH1 development
- T-bet represses GATA-3 and IL-⅘, thus suppressing TH2 development
IL-4 → STAT-6 → GATA-3 → TH2 development
- IL-4 is an initiating cytokine for TH2 that also reinforces TH2 development
- GATA-3 represses T-bet and the cytokine IFN-gamma, thus suppressing TH1 development
IL-6 and IL-23 → STAT-3 → ROR-gamma-T → TH17 development
* IL-17 is an initiating cytokine for TH17 that also reinforces TH17 development
IL-6 → STAT-3 → Bcl-6 → Tfh development (follicular helper)
IL-2 → STAT-5 → FoxP3 → Treg development
Cytokines can also influence the type of antibody produced by a B cell.
IL-4 induces IgE and IgG1
IL-5 increases production of IgA
IFN-induces IgG3 and IgG2a
TGF-beta induces IgA and IgG2b
Three types of granules you should know
Perforin: aids in delivering contents of granule into the cytoplasm of target cells
- Perforin deficient mice can still kill virally-infected target cells via Fas/L pathway
Granzymes: serine proteases which activate apoptosis once in the cytoplasm of target cell
Granulysin: has antimicrobial actions and can induce apoptosis
