Week 5 Practise Questions L14-15

Question 1

What are the main differences between monoclonal and polyclonal antibodies?

Answer 1

Monoclonal antibodies are specific to a single epitope, whereas polyclonal antibodies
may recognise several epitopes. Monoclonal antibodies will also be of a single class/subclass and the cells (hybridomas) that make them can grow indefinitely, making standardisation easier.

Question 2

What techniques have been used to make antibodies that are suitable for use in humans?

Answer 2

Use of transgenic mice expressing human antibody genes and human antibody gene libraries (usually screened using phage display). Cloning of expressed antibody genes from selected antigen-specific B cells from convalescent patients.

Question 3

How might antibodies be used to treat autoimmune disease?

Answer 3

Antibodies to leukocytes may reduce over-activity, but main use is antibodies to cytokines, complement components or their receptors to reduce inflammation.

Question 4

The antibody nivolumab is a human IgG4 antibody. Why do you think this subclass was chosen?

Answer 4

IgG4 antibodies should be of good affinity but will not activate complement, which might cause unwanted inflammation.

Question 5

Describe 2 ways in which antibodies can be improved for therapy.

Answer 5

Protein or glycoengineering to improve affinity/effector functions, tagging with a drug/prodrug or other toxic compound, use of antibody fragments (some applications), use of bi-specific antibodies.

Question 6

What is CAR-T therapy?

Answer 6

T cells from a patient are isolated and genetically manipulated in vitro to express a chimeric antigen receptor (a modified scFv antibody) that recognises a target antigen and causes T cell activation on expansion and re-injection into the patient.