T-Cell function Flashcards
CD4+ T cells cells HELP other responses by ______
synthesizing cytokines
What do CD8+ T-cells do?
KILL infected host cells
Biological targets of:
Th1
Th2
Th17
Th1-Intracellular pathogens (cell mediated immunity)
Th2-worms and allergies
Th17-fungi and extracellular bacteria
CD8+ T cells function (2)
- Activation of Naïve CD8+ T cells
2. Response of CD8+ T cells – killing
Signature cytokines of Th1
IFN-g
Signature cytokines of Th2
IL-4, IL-5, IL-13
Signature cytokines of Th17
IL-17, IL-22
Signature cytokines of Treg
TGF-Beta, IL-10
What is a common approach to treating inflammatory conditions, and 2 specific examples
Blocking cytokines:
- Monoclonal AB specific for cytokine or receptor
- Kinase inhibitors
Innate cells shape T cell differentiation via ______
cytokines
Which cytokine activates TH1
IL-12
T-cell that drives cell-mediated immunity and the immune cells is and activates
Th1 (via IFN-g) activates CD8+, NK, Macrophages, IgG
Cytokine that activates Th2
IL-4
Cells activated by Th2
Eosinophils, class switching to IgE (plasma cells)
What antigens activate Th2
Innate sensing of worms and allergens
What antigens activate Th1
Innate sensing of intracellular pathogens
Which cytokine activates Th17
IL-23
Which antigens activate Th17
Innate sensing of fungi and extracellular bacteria
Th1 stimulates plasma cells to produce ____ (Ig)
IgG
B cells are also _____
antigen presenting cells
B cells present peptides from proteins internalized via _____
BCR
Full B cell activation needs a second signal from _____
a T-cell
B receives second signal from ________ interaction
CD40-CD40L
Activated CD8+ T cells induce ______
apoptosis
Activated CD8+ T cells become
___________
cytotoxic T lymphocytes (CTL)
Apoptosis vs Necrosis
In necrosis the cell rips and spills contents out (dangerous if infected with virus). In apoptosis, the cell has a controlled death and the membrane doesn’t get ruptured until phagocytosis
1st and 2nd signals for activation of naive CD8+ T cells
1st is from TCR-peptide-MHC interaction
2nd is usually cytokines (from effector CD4+ T cells) or B7-CD28 interaction with APC (usually dendritic cells)
Effector cells (do/do not) need the second signal! MHC + peptide is enough to activate killing
Do not
Activated CD8+ T cells kill target cells by two pathways:
1) Fas-FasL interaction induces apoptosis
2) Granzymes enter target via perforin channels and induce apoptosis
Chimeric antigen receptor (CAR) T cells
Patient’s T cells engineered in vitro to express a receptor specific for tumor antigen
Chimeric antigen receptor (CAR) has TWO main components
1) Recognition unit - selected to interact with tumor antigen (CD19 etc)
2) T-cell signaling unit
