Term
T Cell Activation-What Gets T Cells Going?
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Definition
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1) MHC/peptide + co-stimulatory signal
TCR + CD28
TCR + IL1R
TCR + others
2)Mitogens - Important in clinical evaluation
-PHA
-ConA
3) Antibodies - Used in laboratory
Anti CD3
Anti TCR
4) Chemical Mediators - Used in laboratory
PMA + Calcium ionophores
5) Superantigens
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Term
T Cell Activation (Proliferation) |
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Definition
Usually requires 3 separate signals
2 Competence signals
-TCR engagement (signal 1)
-Co-stimulatory signal (signal 2)
1 Progression signal
-IL-2R + IL-2
-Others
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Term
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Definition
Naive CD4 T Cell
(Uncommitted)
↓
Proliferating T Cell
↓
Immature Effector T Cell (Th0)
↓
Th1 or Th2 |
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Term
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Definition
-Activates Macrophages
- induces B cells to produce opsonizing antibodies |
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Term
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Definition
-Activates B cells to produce neutralizing antibodies
- has various effects on macrophages |
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Term
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Definition
TH1 Decision making
- Viruses and some bacteria induce IL-12 secretion by dendritic cells that can activate NK cells to produce IFN-γ
- Naive CD4 T cells in the presence of IL-12 and IFN-γ are committed to becoming TH1
-Activated TH1 cells secrete IFN-γ
-IFN-γ acts on TH2 cells to inhibit proliferation |
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Term
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Definition
-Other pathogens (worms) do not induce IL-12 expression by dendritic cells but may cause NK1.1 T Cells to synthesize and secrete IL-4
-Naive CD4 T Cells activated in the presences of IL-4 are differentiated into TH2
-Activated TH2 Cells secrete IL-10 and TGF-Β
-IL-10 and TGF-B act to inhibit growth and activation of TH1 Cells |
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Term
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Definition
TdTH secretes:
Cytokines: IL-2, IL-3, IFN-γ, GM-CSF, TNF-β
Chemokines: IL-8, MCAF, MIF
Effects on Macrophage activation:
↑ Class II MHC Molecules
↑ TNF Receptors
↑ Oxygen Radicals
↑ Nitric Oxide
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Term
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Definition
-Newly recognized subset of CD4+ T cells
-Named for their production of IL-17
-Key cytokines produced include IL-17, IL-21 and IL-22
-Involved in autoimmune diseases such as Multiple Sclerosis
-Play key role in anti-microbial immunity
-IL-17 is a key recruiter of neutrophils
-IL-22 induces anti-microbial protein production by epithelial cells
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Term
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Definition
-Characterized by CD4, CD25 and FoxP3 expression
-Generally involved in down-regulating immune responses
-Produce TGF-beta and IL-10
-Critical for the prevention of autoimmune diseases
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