Flashcards in Immunology 7 (Kyle) Deck (38)
What is an armed effector T cell ?
An armed effector T cell is a fully differentiated T cell that is ready to perform its effector function
Does an armed effector T cell require co-stimulation to function?
No an effector T cell does not require a co-stimulant to function properly.
Do armed effector T cells display adhesion molecules?
Yes, they express an array of adhesion molecules that direct them to appropriate tissues.
What are the three main types of effector T cells?
CD8 effector T cells ( Killer T cells or Cytotoxic T cells )
CD4 helper T cells that subdivide into T helper 1 and T helper 2 cells.
What are the cytotoxins produced by CD8 T cells
Perforin, Granzymes, and granulysin
What are the Cytokines that are produced by CD8 T cells?
IFN-y and LT
What are the cytokines produced by T-Helper 1 cells ?
What are the cytokines produced by T Helper 2 cells ?
What is the series of differentiation of Helper T cells?
Niave CD4-T cell ---> Proliferating Cell ---> Immature T cell ---> Th 1 cell or Th 2 cell.
What determines differentiation of Th-0 into Th-1 and Th-2 ?
The decision is made during T cell activation which is influenced by pathogen
What influences the first step of Th-0 differentiation?
The cytokine environment during activation influences
I the presence of IL-12 and IFN-y what will the Th-0 cell become?
CD-4 cells activated in presence of IL-12 and IFN-y will become TH-1 cells
In the presence of IL-4 and IL-6 what will the TH-0 cell become?
CD4 cells activated in presence of IL-4 and IL-6 will become Th-2 cells.
Can antigen presentation influence differentiation pathways ?
Yes and the differentiation is determined by the affinity of antigen binding and concentration of Ag will dictate differentiation.
If a low affinity antigen or low concentration of Ag is presented to Ag cells what will the Th-0 cell differentiate into?
Th-0 will differentiate into Th-2 cells.
If presented with a high affinity antigen or high concentration of Ag what will the TH-0 cell differentiate into?
When presented with a high affinity antigen or high concentration of Ag TH-0 cells will differentiate into Th-1 cells. d
What are the three effector molecules in granules of Cytotoxic T cells ?
Perforin, Granzymes, and Granulysin
What does perforin do ?
Perforin Aids in delivering contents of granules into the cytoplasm of target cell.
What do granzymes do ?
Granzymes are serine proteases which activate apoptosis once in the cytoplasm of the target cell.
What is granulysin ?
Has antimicrobial actions and can induce apoptosis.
Do granzymes enter the cell via perforin-mediated pore formation?
No, perforin pores are large enough for proteins to enter the cell but not large enough for granzymes to enter the cell.
How do granzymes enter the cell?
Perforin mediated pore formation signals the target cell to endocytose the affected membrane area for repair. The granzymes are closely associated with the membrane and are carried along for the ride.
What is the previously mentioned mechanism of granzymes entering the cell called ?
How many signals must an effector cell receive to be activated?
What is the first step of the effector function of Cytotoxic T cells (CTL) ?
The initial interaction of CD8 cell with the target is made by NONSPECIFIC ADHESION MOLECULES.
After the CTL has bound to the effector cell via nonspecific adhesion molecules but no antigen specific interactions take lace, what peahens?
Without antigen specific interaction the CTL will be released
After the nonspecific adhesion to the effector molecules and there is Antigen specific recognition, what happens next?
Antigen specific recognition induces stable pairing and focused release of effector molecules.
With nonspecific adhesion and antigen specific interaction what will happen next?
The CTL will program the infected cell to die via the release of effector molecules. The CD8 T cell is then released.
Do CTL's release granular contents?
Yes they are released in a polarized fashion.
Descrobe the steps of Polarized release of CTL granules.
1. Collision and nonspecific adhesion
2. Specific recognition redistributes cytoskeleton and cytoplasmic components of T cell
3. Release of Lytic granules at the site of cell contact.
What to Th-1 effector cells do?
Activate Infected macrophages
How do Th-1 effector cells activate infected macrophages ?
The Th-1 cell and infected macrophage come together.
2. The T cell binds to and activates the macrophage.
The activated macrophage kills the intravesicular bacteria
What coordinates the immune response to intracellular bacteria?
Activated Th1 cells
What are T cell effector molecules ?
What affect does Interleukin -2 have on T cells ?
What affect does interferon -y have on macrophages?
Activation and Increased concentration of MHC class 1 and MHC class 2.
What affect does Lymphotoxin have on macrophages?
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