Monoclonal antibodies

Question 1

What is an adjuvant?

Answer 1

Substance which non-specifically enhances immune responses- boosts antibody production.

Question 2

What are polyclonal antibodies?

Answer 2

Antibodies that are secreted by different B cell lineages. They react against different epitopes of the same antigen.

Question 3

What are the advantages of monoclonal antibodies?

Answer 3

• Very high specificity
• Low cross-reactivity
• Can be standardised worldwide
• Unlimited supply

Question 4

What are some immunological methods which use monoclonal antibodies?

Answer 4

• Affinity chromatography to purify molecules
• ELISA
• Haemagglutination
• Immunodetection on tissue sample
• Western blotting
• Flow cytometry
• Magnetic cell separation

Question 5

How do cells change once associated with memory?

Answer 5

• Expansion of clones of cells with rearranged antigen receptor genes specific for the primary antigen encountered.
• Enhanced migration and re-stimulation properties
• Survival/maintenance of those clones.

Question 6

How are memory T cells generated?

Answer 6

1. Divergent pathway of effector and memory cells.

2. Linear development: Naive cell->effector cell-> memory cell.

Question 7

What is memory T cell survival and maintenance mediated by?

Answer 7

IL15 & IL7

Question 8

How do vaccines induce protection?

Answer 8

By generating protective antibodies and inducing T cell and B cell memory.

Question 9

Why are vaccines not available for some diseases/

Answer 9

• Lack of understanding of infection life cycle.
• Complex life cycle with stage specific immune response.
• Lack of understanding of immune response to pathogen.
• Pathogen antigen variability.
• Lack of good lab models.
• Transport, storage and cost.

Question 10

Types of modern vaccines

Answer 10

1. Related- used for less harmful infection (cowpox, BCG)
2. Killed or inactivated pathogen- effectiveness depends of pathogen but low risk of infection (Salk polio virus)
3. Live attenuated pathogen- highly effective, some risk in immunocompromised patients (Sabin oral polio, MMR, chickenpox)
4. Subunit-use antigens that best stimulate the immune system (hepatitis B)
5. Conjugate- take an antigen that stimulates the immune system and link it to e.g. the coating of bacteria that normally would evoke a weak response.
6. Toxoid- some bacteria secrete toxins. Promotes body to make antibodies to deal with this toxin. (diphtheria, tetanus).
7. Virus-like- highly effective, non infectious, can contain multiple antigenic components (HPV)
8. Genetic/DNA- can encode many antigens. Protein antigens will be expressed inside host cells and cause an immune response.

Question 11

What chemical is typically used to inactivate polio virus?

Answer 11

Formalin

Question 12

Disadvantage of adjuvants?

Answer 12

Can cause adverse immune pathology, including organ damage, septic shock and autoimmunity.