Flashcards in Differentiation And Functions Of CD4+ T Cells Deck (79)
Alpha beta TCRs recognize and bind to __.
Peptides presented within the MHC molecules and MHC itself.
These cells also express either CD4 or CD8 co-receptors.
Where does activation of T cells occur?
In the lymph nodes.
What are langerhans cells?
Immature dendritic cells which do not express high levels of B7.
They stimulate naive T cells.
What does Ag recognition involve?
Clustering of TCRs.
What is the activation of T cells initiated by?
A signaling cascade after TCRs recognize specific Ag.
What is needed to activate a T cell?
TCR, CD4 or CD8 and CD3.
CD4 for T helper cells
CD8 for CTLs
When the TCR is engaged and activates T cells, the T cell must:
Receive a co-stimulatory signal.
____ can be considered as an "amplifier" that improves signaling of T cells.
This involves B7 and CD28.
With co-stimulation, 100 fold fewer of clustered TCRs are needed for activation.
Once T cells are Ag-activated, what do they produce?
IL-2 and IL-2R, which leads to cell proliferation.
The result is the expansion of the clone of T cells that are specific for the Ag.
What do T cells differentiate into?
Effector cells or memory cells.
What drives proliferation of T cells, and is also called the "T cell growth factor"?
True or false: naive T cells do not have IL-2 receptor (IL-2R) expressed on their surface.
True or false: activted T cells produce a large amount of IL-2 and express IL-2R.
___ enhances resistance of activated T cells to apoptosis.
How do effector T cells migrate through blood vessels in peripheral tissues?
They bind to endothelial cells that have been activated by cytokines produced in response to infection in these tissues.
CD4+ cells recruit and activate phagocytes. What do the phagocytes destroy?
What do CD8+ lymphocytes kill?
True or false: each subset of T helper clls tends to oproduce a set of particular cytokines.
What do Th1 cells activate?
A cell-mediated immune response.
What do Th2 cells activate?
An Ab-mediated immune response.
What are Th17 cells involved in?
Inflammation and anti-bacterial response.
Why are PRRs important for innate and adaptive immunity?
Pathogen recognition by immature DCs through PRRs is an important bridge between innate and adaptive immunity.
What is the result of PRR signaling?
Activation and maturation of antigen-presenting cells (APCs)
APC processed antigen is presented to what cells?
Naive Th0 cells.
Secreted IL-12 assists the development and differentiation of what type of helper cell?
What are four main classes of CD4+ cells?
What causes differentiation of Treg cells?
IL-2 + TGF beta
What are the functions of Treg cells?
Suppresses tumor immunity
Promotes immune tolerance
Maintains lymphocyte homeostasis
What cytokine activates Th1?