T cells 2 Part 2 Flashcards
How many dendritic cells can one helper T cell scan in an hour?
1000
If a helper T cell finds its cognate antigen, what binds the two cells together?
adhesion molecules (immunological synapse)
What co-receptor on the helper T cell attaches to the MHC II molecule on the dendritic cell? (during Helper T cell Activation)
CD4
What do CD40L proteins attach to on the dendritic cell in order to lengthen the life of the dendritic cell?
CD40 proteins
How long does complete activation of the helper T cells take?
about 4-10 hours
What do Activated T cells produce that is a positive feedback for division?
IL-2
T/F: Activated helper T cells proliferate about 10,000 new cells in the first week.
True
Do Naive T cells have IL-2 receptors on their surface?
No. this allows for the specific T cells needed to be produced by helper T cells
T/F:When a helper T cell proliferates and produces more new cells, the helper T cells being made are all the same.
True, they are all specific for the cognate antigen.
Besides for remaining in the blood/lymph providing help to B cells and CTLS, what other job do Helper T cells have?
leaving the blood to enter battle sites providing help for soldiers on the front line.
How do Helper T cells help other cells?
cytokines-the communication proteins for the immune system
What do TNF, IFN-gamma, IL-4, and IL-21 all have in common?
They are all cytokines
What are the 3 major subsets of cytokines?
Th1, Th2 and Th17
Dendritic cells recoginze patterns specific to certain what?
types of pathogens
TLR4 senses LPS which characteristic of what?
Gram-negative bacteria
TLR4 senses proteins made by what?
certain viruses
TLR3 recognizes what?
double-stranded RNA
TLR2 identifies proteins specific to what?
Gram-negative bacteria
T/F:Macrophages also recognize distinct patterns
True
T/F: Different pathogens elicit different cytokines from macrophages and other cells.
true
Cells from different areas of the body make different combinations of cytokines. What cells sense the specific cytokine response?
Dendritic cells
T/F: Dendritic cells will display the same co-stimulatory molecules on their surface no matter what type of invader they encounter.
False; dendritic cell will display different co-stimulatory molecules on their surface depending on what type of invader it has encountered.
When are Th1 helper T cells used?
Viral or bacterial attack
Th1 helper cells respond with classical cytokines. What are classical cytokines?
TNF, IFN-gamma, and IL-2
T/F: one goal of Th1 Helper T cells releasing classical cytokines is deactivate infected macrophages and natural killer cells.
False; the goal is to activate these cells
What keeps the macrophages active?
IFN-gamma
T/F: one goal of Th1 Helper T cells releasing classical cytokines is to provide help to B cells for antibody production.
True
What tells B cells to make IgG3?
IFN-gamma
T/F: one goal of Th1 Helper T cells releasing classical cytokines is for IL-2 to recharge Macrophages.
False; the goal is for IL-2 to recharge natural killer cells
T/F: one goal of Th1 Helper T cells releasing classical cytokines is for IL-2 to stimulate proliferation of CTLs, NK cells and Th1 cells
True
What are Th2 Helper T cells good for defending against?
parasitic attack or food contaminated with pathogenic bacteria
What cytokines illicit a response from Th2 Helper T cells?
IL-4, IL-5, and IL-13
What is the main goal of Th2 Helper T cells?
provide help to B cells for antibody production, especially class switching to IgE
T/F: IL-13 stimulates mucus in the intestine.
True
T/F: IL-4 growth factor causes B cells to make IgA (anitbacterial in the GI).
False; this is true of IL-5
T/F: IL-5 is the growth factor to proliferate T cells (releasing Th2 cytokines).
False; this is true of IL-4
T/F: IL-4 is the growth factor for B cells that are making IgE.
True
What are Th17 Helper T cells good for defending against.
Fungal attack
T/F: IL-17 recruits massive numbers of macrophages.
False; neutrophils
