L-33

Question 1

What are the three major immune cell communication methods?

Answer 1

• soluble molecules (cytokines and chemokines) binding to receptors on a cell membrane
• cell surface bound receptors binding to cell surface bound ligand
• antigen being presented to cell surface bound receptors

Question 2

What is an antigen?

Answer 2

An antigen is anything that has the potential to be recognised by the immune system

Question 3

What is a foreign antigen? Give three examples:

Answer 3

A foreign antigen is any antigen from outside the body

• transplants
• pathogens
• some chemicals

Question 4

What is a self antigen?

Answer 4

Any antigen inside the body

Question 5

In what circumstance is the immune system not tolerant of self antigens?

Answer 5

When the person has an autoimmune disease

Question 6

How do activated dendritic cells communicate with T cells?

Answer 6

• make cytokines that bind to receptors on T cell membranes

- have cell surface bound receptors that bind to T cell surface bound ligand (or vice versa0

Question 7

What does MHC stand for?

Answer 7

Major histocompatibility complex

Question 8

What does MHC do?

Answer 8

MHC is used by the dendritic cell to present the antigen to the T cell receptor in order to activate the T cell

Question 9

What types of antigens dies MHC-I present?

Answer 9

Endogenous (intracellular)

Question 10

Which cells is MHC-I expressed on?

Answer 10

all nucleated cells

Question 11

Which types of antigens does MHC-II present?

Answer 11

Exogenous (extracellular)

Question 12

Which cells is MHC-II expressed on?

Answer 12

Only on antigen presenting cells such as dendritic cells and most phagocytic cells

Question 13

What are cytokines?

Answer 13

molecules that control growth and activity of immune cells

Question 14

Give two examples of cytokines:

Answer 14

• interleukins

- interferons

Question 15

What are chemokines?

Answer 15

Molecules that stimulate cell migration

Question 16

What types of cells produce chemokines and cytokines?

Answer 16

• innate immune cells
• adaptive immune cells
• epithelial cells

Question 17

How do helper T cells activate B cells?

Answer 17

• making cytokines that bind to receptors on B cell membranes
• have cell surface bound receptors that bind to a B cell surface bound ligand (or vice versa)

Question 18

How can B cells be activated by the complement pathway?

Answer 18

Antibody binding to a pathogen can trigger the classical pathway of complement activation. However, complement fragments that are bound to antigen can also help active B cells to make antibodies

Question 19

What do B cells do?

Answer 19

Make antibodies

Question 20

What are the 10 steps of the complete immune response?

Answer 20

1. Nail breaks the physical barrier
2. Pathogens enter the body
3. Chemical mediators lead to vasodilation and entry of phagocytic cells to tissue to eat and destroy pathogens
4. The complement pathway is triggered
5. Dendritic cells in the skin become activated through recognition of PAMPs
6. Dendritic cells move to local draining lymph node
7. Activated dendritic cells activate T cells via MHC
8. T cells and complement activate B cells
9. B cells produce antibody
10. Complement, phagocytosis, and antibodies help clear the pathogen