Antigen Presentation

Question 1

Where does protein processing and antigen occur?

Answer 1

APCs and every eukaryotic cell in the body

Produce self antigens and nonself anitgens on MHC class I molecules

Question 2

What do dendritic cells present their peptides to?

Answer 2

Both CD4 helper cells to initiate helper cytokine release and CD8 cells for activation into killer cells

Question 3

What do macrophages present antigen to?

Answer 3

Initiate helper T cell cytokine release

Activates macrophages

Question 4

What do B cells present their antigens to?

Answer 4

Present peptide antigens to CD4 helper T cells for cytokine release

Facilitates development of T dependent antibody release and antibody class switching

Question 5

What two divisions make up adaptive immunity?

Answer 5

Cell Mediated Immunity and Humoral immunity

Question 6

What are dendritic cells?

Answer 6

Heterogeneous population of cells which have immunostimulatory capacity

Take different names depending on location

Question 7

Describe the function of dendritic cells

Answer 7

Process and present antigen on class I or class II proteins

Undergo maturation process if TLR is engaged

Migrate to draining lymph nodes

Present antigen to naive T cells (CD4 and CD8)

Question 8

What occurs in dendritic cells if the TLR is engaged?

Answer 8

Upregulate Class I and Class II proteins

Upregulate costimulatory molecules (CD80/CD86/CD40)

Question 9

Where do DCs and antigens enter the lymph node?

Answer 9

Afferent lymphatic vessels

Question 10

Where do naive T and B cells enter the lymph node?

Answer 10

Postcapillary HEV

Question 11

How do microbial products enhance the APC function of macrophages and dendritic cells?

Answer 11

PRRs stimulated

CD80/86 expression induced

Signal 2 can be delivered

T cells can be activated

Question 12

What is antigen processing?

Answer 12

Intracellular degradation of protein antigens into peptides (proteosome)

Question 13

What does the mechanism of antigen processing depend on?

Answer 13

Location of the protein and type of APC

Question 14

How are intracellular antigens processed?

Answer 14

Class I molecules bind and present peptides derived from cytoplasmic sources of antigen

Question 15

How are antigens processed in B cells?

Answer 15

Surface immunoglobulin captures extracellular antigen

The antigen is processed and presented via MHC Class II molecules

Question 16

What is the role of coreceptors CD4 and CD8 on T cells?

Answer 16

The ensure that T cell subsets bind to the proper class of MHC

Question 17

What signals are required for antigen-specific activation of naive T cells?

Answer 17

Both signal 1 - comes from TCR

And signal 2 - comes from CD28/B7

However this does not lead directly to T cell proliferation

Question 18

What are the three signals that APCs deliver to naive T cells?

Answer 18

Activation - MHC-TCR

Survival - B7/CD28

Differentiation - cytokines

Question 19

What does the activation of naive antigen-specific T cells lead to?

Answer 19

Synthesis of IL-2 and high affinity IL-2 receptors

Question 20

What three transcription factors are formed as a result of TCR signaling?

Answer 20

NFAT

NFkB

AP-1