6 - The Processing and Presentation of Antigen

Question 1

Function of invariant chain, in which molecule can your find it?

Answer 1

Prevents any normal cellular peptides from being bound
MHC class II

Question 2

Risk of absence of spleen or functional asplenia (sickle cell anemia)

Answer 2

Susceptibility to infection by encapsulated bacteria and blood-borne pathogens

Question 3

Which are the three signals of the antigen recognition by TCR when presentation is through MHC type II?

Answer 3

1- T-cell activation
2- coestimulatory molecules
3- cytokines

Question 4

Most important growth factor for T-cells and stimulation of proliferation of T-cells clones. Who produces it?

Answer 4

IL-2

T-lymphocyte itself ▶️ paracrine

Question 5

What coestimulatory signal triggers transcription of several cytokines?

Answer 5

CD28 (T-cell) ➕ B27 (APC)

Question 6

Function of CTLA-4 (CD152), in what cell is it?

Answer 6

Competes with CD28 for binding to B7 ▶️ downregulator

T-cells

Question 7

What would happen if stimulation of a T-cell is done without costimulatory signals?

Answer 7

Anergy

Question 8

What types of CK’s and pathogens favor TH1 differentiation?

Answer 8

• IL-12, IFN-gamma
• some intracellular bacteria (listeria, mycobacterium), some parasites (leishmania)

*all infect macrophages

Question 9

What types of CK’s and pathogens favor TH2 differentiation?

Answer 9

• IL-4

- extracellular pathogens, helminths, response to allergens

Question 10

How do you identify T reg cells? Function, cytokine produce.

Answer 10

• CD25, ⬆️ FOXP3 expression
• inhibit TH1
• IL-10

*prevention of autoimmunity

Question 11

How do you identify TH17? Function.

Answer 11

• ⬆️ RORgammat expression

- tissue damage associated in some autoimmune disease

Question 12

Cytokines produced by TH2. What CK inhibits it?

Answer 12

• IL-4, IL-5, IL-6, IL-10, IL-13, TGFB

- IFN-gamma

Question 13

Cytokines produced by TH1

Answer 13

• INF-gamma, IL-2, TNF-B

- IL-4, IL-10