IAHI [Week 2] Flashcards
What are 3 characteristics of germ line encoded receptors and give 2 examples?
- Heritable, set order, and the same in each cell.
2. PRRs (TLR) and MHC
What TFs are activated from a PAMP binding a PRR, what cytokines get released, and what is the body’s response?
- NFκB or IRF3
- TNFα, IL-1, and IL-6
- Activate neutrophils and initiate fever
What secretes G-CSF and GM-CSF?
Macrophages and T Helper
What is the effect of G-CSF and GM-CSF?
Induce proliferation in bone marrow and the egress of PMNs
What cells secrete IL-8 and what is its function?
- Macrophages, endothelial cells, airway smooth muscle cells
- Help pull PMNs out of circulation to site of infection (chemotaxis)
What are the main 4 signaling molecules that control neutrophil influx?
G-CSF, GM-CSF, IL-8 and chemokines
What cells secrete chemokines and what are their effects?
- Macrophages, DC, endothelial cells, T lymphocytes, fibroblasts, and platelets
- Promote migration of neutrophils to infected site via a gradient, activate integrin so PMNs form stable adhesions
Do chemokines function in a cell contact dependent or independent manner?
Cell contact independent
What are 3 characteristics of receptors produced by genetic recombination and what are two examples?
- Inherit segments, Pre “clonal expansion” each cells have different arrangements, not necessarily the same as parents.
- TCR and Ig
How are chemokines classified?
By their biochemical structure - location of Cys residues
In concert with TNFα and IL-1, what else promotes the 4 stages of PMN extravasation?
Chemokines
Is T cell activation cell contact dependent or independent?
Cell contact dependent
After T cell activation what 3 things result from the signaling pathway?
- CD40L expression -> B cell Ig class switching
- IL-2 and IL-2R expression - proliferation
- DNA synthesis - division
IL-2 is a cytokine that provides ____________, cell contact independent, ____________________ feedback to the T helper cell producing it.
- Autocrine
2. Pro-proliferative
What is the 2nd signal required for T cell activation?
Interaction of CD28 and B7
What are two “CD” names for B7?
CD80 and CD86
What is the function of CTLA-4?
It inhibits T cell proliferation by competing with B7 to provide a “stop” signal thru CD28
What are 3 examples of APC derived signals and what type of T cell do they promote?
- IL-12 - Th1 (Via Th expression of IFNγ)
- TGFβ - Treg (suppresses Th1 & Th2)
- IL-10 - Promotes Treg
What happens if the APC doesn’t provide a cytokine?
Default to Th2 cell
What three autocrine signals are released by Th cells?
- IFNγ
- TGFβ
- IL-10
What is the effect of Th released IFNγ?
- Promotes Th1- more IFNγ
- Activates macrophages
- Class switch IgG
- Suppresses Th2 devleopment
What is the effect of Th released TGFβ and IL-10?
Furthers Treg development
What 2 cytokines do Th2 cells release and what is their effect?
- IL-4: Class switch IgG1, IgE; suppress Th1
2. IL-5: Class switch IfA; promote eosinophilia
What 3 cytokines direct Th17 development?
TGFβ, IL-6, and IL-23