Immunology in the Clinic and Research Lab

Question 1

What is the antibody repertoire?

Answer 1

Total possible number of antibody binding sites

Question 2

What is antibody affinity?

Answer 2

Strength of a single interaction between an antibody and its epitope

Question 3

What is antibody avidity?

Answer 3

Sum of different affinities (Some antibodies will be multimeric and have several different binding sites)

Question 4

What is the half-life of antibodies?

Answer 4

The amount of time an antibody will remain in the body

Question 5

Describe the polyclonal antibody response

Answer 5

• When we are infected with a pathogen we mount a polyclonal antibody response
  
  • It is polyclonal because there are multiple epitopes on an antigen hence we produce a polyclonal response, antibodies with different binding specificities
• B-cells in our bodies will have a unique specificity for an antigen, the binding of the epitope to the B-cell will induce B-cell proliferation and form a clone of B-cells

Question 6

How do we produce monoclonal antibodies?

Monoclonal antibodies = Bind specifically to a single epitope

Answer 6

• Hybridoma culture
  
  • We take the antigen we want to make the Ab’s and inject it into the mouse
  • After 2 weeks we will harvest the B-cells which make the antibody
  • We take the B-cells and fuse them with myeloma cells (derived from B-cell tumour but do not produce antibodies themselves)
    
    • These cells also lack the HGPRT gene (hypoxanthine guanine phosphoribosyl transferase)
  • After we have carried out the fusion process, we have a mixture of cells
    
    • (unfused B-cells and myeloma cells and fused cells (called hybridomas)