Antigens/MHC

Question 1

Why is the innate immune system not enough? 3 Reasons.

Answer 1

Limited Specificity: only recognize limited number of conserved PAMPS
Less Potent: may not guarantee full resistance to infection
Lack memory: Do not learn from experience

Question 2

Why is the adaptive immune system more effective?

Answer 2

Higher specificity: Employs antigen specific lymphocyte generation (B and T lymphocyte)
Systemic: Targeted to reach the whole body
Immunological memory: once exposed to an antigen, the animal will make an immediate and stronger response against any subsequent exposure to it

Question 3

Example application of immunological memory:

Answer 3

Vaccines: induce long term memory against specific antigens

Question 4

Draw out simplified outline of adaptive immunity

Answer 4

Slide 5

Question 5

What is the trigger for adaptive immunity?

Answer 5

Antigens

Question 6

What are antigens?

Answer 6

any non-self substance that can bind to the specific lymphocyte

Question 7

What is an epitope?

Answer 7

a site on the surface of an antigen that is recognized by a specific lymphocyte receptor

Question 8

Antigen number of epitopes and differentation?

Answer 8

Multiple, same or different types

Question 9

What are immunogens?

Answer 9

antigens that can induce an immune response, after binding to its specific lymphocyte receptor/antibody

Question 10

What are the characteristics of a good antigen?

Answer 10

Large size >10Kd
Complexity: proteins vs. simple monomers
Moderate degradability: Inert and unstable molecules are poor antigens
Foreign: Non-self: molecule should have a structure that is not present in host’s own molecules (Exception: self antigens)

Question 11

Discuss different microbial vs. non-microbial antigens.

Answer 11

Slide 8

Question 12

Discuss cell surface antigens vs. auto-antigens.

Answer 12

Slide 9

Question 13

Discuss what haptens are.

Answer 13

Slide 10

Question 14

Describe the difference between exogenous and endogenous antigens.

Answer 14

Slide 11

Question 15

What are APCs?

Answer 15

specialized in the displaying antigens on their cell surface for the subsequent activation of T cells

Question 16

What are the professional APCS?

Answer 16

dendritic cells

Question 17

Where are DCs derived from and what?

Answer 17

hematopoietic cells in the bone marrow

Question 18

What are dentrites?

Answer 18

Long projections, increase SA and help with antigen trapping, increases contact between DCs and T cells

Question 18

Write out the 4 DC subpopulations are their functions.

Answer 18

Slide 16

Question 19

APC macrophage functions.

Answer 19

Slide 17

Question 20

APC B cell functions.

Answer 20

Slide 17

Question 21

What can produce endogenous antigens?

Answer 21

any nucleated cell
DCs
Macrophages
B cells

Question 22

What captures exogenous antigens?

Answer 22

APCs

Question 23

What processes endogenous antigens?

Answer 23

affected nucleated cell

Question 24

What is Ag processing?

Answer 24

the native antigen is trimmed into smaller immunogenic fragments by intracellular machinery

Question 25

Discuss DCs antigen processing and presentation.

Answer 25

Slide 21

Question 26

Discuss the activation and migration of skin DCs to secondary lymphoid organs.

Answer 26

Slide 22 and 23

Question 27

APCs degrade exogenous proteins into ____________

Answer 27

antigen peptides

Question 28

APCS present antigen peptides with ______.

Answer 28

MHCII

Question 29

Infected cells degrade the endogenous viral proteins into _____________

Answer 29

antigen peptides

Question 30

Infected cells present the antigen peptides with ______.

Answer 30

MHCI

Question 31

Compare/contrast MHC classes.

Answer 31

Slide 26

Question 32

Discuss MHC Class I

Answer 32

Slide 27

Question 33

Discuss MHC Class II

Answer 33

Slide 28

Question 34

Compare contrast MHC I and MHC II.

Answer 34

Slide 29

Question 35

Discuss exogenous antigen presentation.

Answer 35

Slide 31

Question 36

Discuss endogenous antigen presentation.

Answer 36

Slide 33

Question 37

Exogenous vs. endogenous type of T cells

Answer 37

Exogenous - CD4 T helper cells Endogenous- CD8 T cytotoxic cells

Question 38

Discuss cross-presentation.

Answer 38

Slide 36

Question 39

Memorize table on slide 37.

Question 40

Describe superantigens.

Answer 40

Slide 38

Question 41

Discuss MHC Diversity.

Answer 41

Slide 40-46

Question 42

Review disease presentation on different species.

Answer 42

Slide 47