Bridging the Innate and Adaptive Immune System

Question 1

What cells do you find in the

1. Lymphoid follicle
2. Medulla
3. Paracortex

Answer 1

1. B cells
2. Macrophages and DCs
3. T cells

Question 2

What does the T cell recognize

Answer 2

The MHC and the antigen TOGETHER

Question 3

MHC 1

Answer 3

Intracellular antigens are mounted here

Recognized by CD8+ T cells

Question 4

MHC 2

Answer 4

Extracellular antigens are mounted here

Recognized by CD4+ T cells

Question 5

What type of cells can present antigens on both MHC 1 and 2?

Answer 5

Dendritic cells

This is cross presentation (can present extracellular antigens in MHC 1)

Question 6

Amino acid length for

1. MHC 1
2. MHC 2

Answer 6

1. 8-11 AA

2. 10-30 AA

Question 7

3 types of cells that can present extracellular antigens

Answer 7

DCs
B cells
Phagocytes (macrophages and neutrophils)

Question 8

What cells can present intracellular pathogens

Answer 8

Almost any nucleated cell in the body

DCs

Question 9

MHC2 protein structure

Answer 9

Alpha and beta chain
A1 and B1 at the free surface
A2 and B2 attached to membrane

Question 10

If a macrophage and a CD4 T cell recognize each other with cross linking, what do they both do?

Answer 10

Macrophage has improved oxidative killing ability

With cytokines and costimulation, the T cell proliferates

Question 11

MHC 1 protein stucture

Answer 11

A1 and 2 at the surface
A3 connects A2 to the membrane
B2 microglobulin (stabilizer) binds in the 4th corner

Question 12

What structure of protein does the
1. TCR
2. BCR
recognize?

Answer 12

1. Linear chains of amino acids

2. Protein in 3D structure

Question 13

What 3 things does a B cell do after it is activated by a CD4 T cell?

Answer 13

Isotype switching (from IgM to IgG, IgG and IgA)
Somatic mutation (small mistakes in the receptor to try to increase affinity)
Plasma cell formation

Question 14

Which cytokine is released by T helper cells to activate B cells?

Answer 14

IL-4

Question 15

4 ways the adaptive system helps the innate system after a T cell recognizes the antigen

Answer 15

Apoptosis of infected nucleated cells
Improved killing by phagocytes
B cells create memory cells and isotype switching to better antibodies
Improvement of antigen presenting skills of DCs (more easily activate other T cells)

Question 16

The majority of costimulation to T cells occurs through which receptor?

Answer 16

B7-1 or B7-2 (also called CD80/CD86)

Its receptor on the T cell is CD28