L12: Overview of Innate Immunity II

Question 1

What Ig molecule is bound to mast cells under mucosal surfaces?

Answer 1

predominantly IgE

Question 2

Which growth factors are necessary for maintenance of memory cells?

Answer 2

IL-7 and IL-15.

Question 3

Do differentiated effector T cells need B7 activation signaling to perform their function?

Answer 3

no. They only require and MHC:antigen complex signal

Question 4

What would happen if L-selectin was defective? Think about naive T cells.

Answer 4

Naive T cells use L-selectin to bind to CD34 on HEV (high epithelial venules) to help them pass through into secondary lymphoid tissues

Question 5

Why would you not want L-selectin on CD8+ cells?

Answer 5

you don’t want a cell that kills anything presenting its MHC class I - antigen complex to wander into a secondary lymphoid tissue full of B and helper T cells presenting those antigens

Question 6

What are the adhesion molecules Effector CD8+ T cells upregulate after activation?

Answer 6

VLA-4 which binds to VCAM-1 on endothelium. This allows effector cells to enter inflammatory sites.

Question 7

Which T helper cell would express VLA-4?

Answer 7

Think about what VLA-4 does. It lets cells move into inflammatory sites. TH1 cells have a role in inflammatory sites, so they upregulate surface VLA-4.

Question 8

What type of cell expresses Fas ligand?

Answer 8

CTLs (CD8+ killer cells). They use this to kill virus infected cells.

Question 9

What do TH1 cells do?

Answer 9

produce cytokines, express CD40 to activate macrophages, produce IFN-gamma to activate macrophages. Also can produce cytokines to activate and class switch B cells.
Promote production of IgG1, which is good for intracellular infections.
Cytokines: IFN-gamma, GM-CSF, TNF-alpha, LT, IL-3

Question 10

What do TH2 cells do?

Answer 10

Express CD40 to actiavte B cells, produce cytokines to activate and drive class switching of B cells.
Cytokines: IL-4, IL-5, IL-10, IL-13, TGF-beta

Question 11

Which T cell types produce IL-10?

Answer 11

TH2

Question 12

Which T cell types produce TNF-alpha

Answer 12

TH1

Question 13

Which T cell types produce LT?

Answer 13

TH1 and Cytotoxic T cells

Question 14

Which T cell types produce TGF-beta?

Answer 14

TH2

Question 15

Which T cell types produce GM-CSF?

Answer 15

TH1

Question 16

Which T cell types produce IL-4 and IL-5?

Answer 16

TH2

Question 17

Which T cell types produce IFN-gamma?

Answer 17

CD8 T cells and TH1

Question 18

What will IL-4 and IL-5 promote TH0 cells to differentiate to? What type of infection is this good for?

Answer 18

TH2. Extracellular infections (they activate B cells to make antibodies)

Question 19

What will IL-2 and IFN-gamma promote TH0 cells to differentiate into? What type of infection is this good for?

Answer 19

TH1. Good for intracellular infection. (promote B-cell activation and production of opsonizing antibodies such as IgG1)

Question 20

Which T helper cell type assist in extracellular bacterial infections and upregulate neutrophils?

Answer 20

TH17 cells.

Question 21

A patient is showing signs of several different autoimmune diseases, all related to T cells. What type of cell would you expect a defect in?

Answer 21

Treg cells. They downregulate T cell responses. Without them, patients suffer from an unholy autoimmune disease

Question 22

Which T cell type would activate fibroblasts?

Answer 22

TH17 cells

Question 23

What will IL-12 promote TH0 cells to differentiate into? What type of infection is this good for?

Answer 23

IL-12 promotes production of IFN-gamma. Both of these promote TH1 cell production, which are good for intracellular infections because of the IgG1 the promote

Question 24

What type of infection would you expect IL-4 to be upregulated?

Answer 24

extracellular. IL-4 will promote TH2 cell differentiation.

Question 25

How do TH2 cells downregulate TH1 production?

Answer 25

IL-10 and TGF-beta, the cytokines that Treg cells produce. They dont produce nearly as much though.

Question 26

What happens when macrophages are unable to kill the bacteria they take up?

Answer 26

they tend to form granulomas.

Question 27

What is IgM’s main function?

Answer 27

activation of the complement system

Question 28

What is IgE’s main function?

Answer 28

Sensitization of mast cells

Question 29

Which IgG molecules activate compliment system?

Answer 29

IgG3 predominantly

Question 30

Which Ig molecule is the primary opsonization immunoglobin?

Answer 30

IgG1. Very important for intracellular infections.

Question 31

Which Ig molecule type helps transport pathogens out of mucosal cells and into gut lumen for excretion?

Answer 31

IgA

Question 32

What Ig molecule helps with ADCC? What cell type carries the kill out? What receptor do they use?

Answer 32

IgG1, IgG3, IgA.

NK cells, using their Fc-gamma-3 receptors.

Question 33

What Ig do mast cells ‘hijack’ and use as antigen receptors?

Answer 33

IgE

Question 34

What complement component can degranulate mast cells?

Answer 34

C5a (attack complex)