Lecture 15. Antibody Genetics

Question 1

What is an antibody ?

Answer 1

Secreted molecules of adaptive immune system

Question 2

What are the antibody effector functions ?

Answer 2

1. Binding
2. Phagocytosis and ADCC
3. Complement activation

Question 3

What does Fab stand for ?

Answer 3

Fragment antigen binding

Question 4

What does Fc stand for ?

Answer 4

Fragment crystalisable

Question 5

What is the process of antibody dependent cell cytoxicity ?

Answer 5

1. Antibodies bind antigens on the surface of target cells
2. NK cell CD16 Fc receptors recognise cell bound antibodies
3. Cross linking of CD16 triggers degranulation into a lytic synapse
4. Tumour cells die by apoptosis

Question 6

What type of affinity does an antibody that binds tightly have ?

Answer 6

High affinity

Question 7

What type of affinity does an antibody that binds loosely have ?

Answer 7

Low affinity

Question 8

What is recombination signal sequences recognised by ?

Answer 8

RAG (recombination activation gene) products

Question 9

What cells of B-cell differentiation have RAG ?

Answer 9

1. Pro-B
2. Pre-B

Question 10

What cells of B-cell differentiation do not have RAG ?

Answer 10

1. B cell
2. Plasma cell

Question 11

What heavy chains do B-cell differentiation cells have ?

Answer 11

1. Pro-B have DJ
   2.Pre-B have VDJ
2. B-cell have VDJ
3. Plasma cell have VDJ

Question 12

What cells have light chains (VJ) ?

Answer 12

1. B-cell
2. Plasma cell

Question 13

What are hypervariable regions ?

Answer 13

1. Interact with antigen
2. Sites of affinity maturation

Question 14

What is another word for affinity maturation and when does it happen ?

Answer 14

1. Somatic hypermutation
2. Class switching

Question 15

How is antibody diversity generated ?

Answer 15

1. Heavy and light chains
2. Combinatorial diversity- gene segments
3. Junctional diversity
4. Diversity gene segments
5. Somatic hypermutation