Flashcards in Chapter 9: Overview of T Lymphocyte Activation Deck (59):
Activation site of naive T cells.
Lymph nodes (peripheral lymphoid organs).
Cell type that presents antigen to naive T cells.
Action of effector T cells in lymph nodes.
Help B cells.
Action of effector T cells that migrate to the site of infection.
Activate macrophages and other functions to eradicate the microbe.
What 2 type of T cells are generated from naive T cells.
1) Effector T cells
2) Memory T cells
What cytokine do activated CD4 T cells secrete?
What is the action of CD4+ effector T cells?
Activate B cells, macrophages and other cells. Inflammation.
What is the action of CD8+ effector cells?
Activate macrophages. Kill infected cells.
Main function of effector T cells.
What happens to the T cell response as antigen is eliminated.
The T cell response decreases.
What is the first signal of T cell activation?
What is the second signal of T cell activation.
APCs activated by microbes and the innate immune response increases the expression of what?
What does B7 on APCs bind to?
CD28 on T cells.
What does CD28 on T cells bind to?
Costimulatory molecules B7-1 (CD80) and B7-2 (CD86) that are expressed on the surface of activated APCs.
What cytokine stimulates differential of naive T cells into effector T cells?
Signaling intermediates of T cell activation by costimulation of CD28.
Functional effects of T cell activation by costimulation of CD28.
Increased Bcl-X and Bcl-2 (cell survival).
Increased IL-2 and IL-2R (cell proliferation).
B7 family ligands found on APCs.
B7-1, B7-2, ICOS-L, PD-L1, PDL-2.
CD28 family member receptors found on naive T cells.
CD28, CTLA-4, ICOS, PD-1.
What receptor is best understood after CD28 on T cells?
What is the function of ICOS.
T-cell dependent antibody responses (germinal center reaction).
What 2 receptors on T cells inhibit the function of CD28?
CTLA-4 and PD-1.
How does CTLA-4 function as an inhibitor?
It binds more strongly to B-7.
How does PD-1 function as an inhibitor?
It delivers inhibitory signals that block signaling by the antigen receptor and by CD28.
Where is CD40L located?
On T cells.
Where is CD40 located?
What is the function of CD40L + CD40 binding?
Increase the expression of B7 on dendritic cells.
What is the function of the CTLA-4-Ig fusion protein?
It binds B7 and blocks the interaction of B7 with CD28.
What is the function of CD69?
Retain T cells in the lymph nodes.
What is CD25?
What is the function of IL-2R?
T cell proliferation.
What is the function of CD40L?
Amplification of effector T cell function.
What is the function of CTLA-4?
Control T cell activation response.
IL-2 interaction with how many chains of the IL-2R?
Function of IL-2.
T cell proliferation.
High-affinity IL-2Rs are transiently expressed on activation of what cells?
Naive and effector T cells.
High-affinity IL-2Rs are always expressed on what cells?
Regulatory T cells.
Role IL-2 on naive T cells.
Effector and memory T cells proliferation and differentiation.
Role of IL-2 on effector T cells.
Regulatory T cell survival.
Which cell population (CD8+ or CD4+) are greater during an infection?
CD8+ (CD8+ > CD4+).
What chemokine results in central memory T cells homing to lymph nodes?
CCR7 (and L-selectin).
Lack of what chemokine results in effector memory T cells homing to peripheral tissue?
CCR7 (and L-selectin).
What are 2 types of memory cells?
Central memory T cells and Effector memory T cells.
What is the advantage of tissue resident memory cells?
They provide a rapid response.
What cytokine maintains memory T cells?
IL-7 (promotes apoptotic protein).
What chemokine results in co-localization of naive T cells and dendritic cells to lymph nodes?
Major costimulators on APCs required for naive T cell activation.
B7-1 (CD80) and B7-2 (CD86).
Function of Ig FC portion of CTLA-4-Ig.
Prolongs half-life, not involved in the immune inhibitory function of the drug.
Number of chains of the IL-2 receptor on naive cells?
2 chains of the IL-2 receptor which bind IL-2 with low affinity.
Number of chains of the IL-2 receptor after antigen and costimulatory signals?
3 chains. Antigen and costimulatory signals induce IL-2 production and expression of a third chain (CD25) of the receptor, which increases the affinity for IL-2.
Do CD8+ or CD4+ undergo greater clonal expansion?
Production of what defines Th1 cells?
Production of what defines Th2 cells?
IL-4, IL-5, and IL-13.
Production of what defines Th17 cells?
IL-17A, IL-17F, and IL-22.
What are the 3 master regulators?
Th1 cells are associated with what master regulator?
Th2 cells are associated with what master regulator?