Antigens

Question 1

What are immunogens?

Answer 1

substances capable of stimulating an immune response

Question 2

What are haptens?

Answer 2

substances that will not, by themselves, stimulate an immune response, but will do so when complexed with a larger molecule

Question 3

What is immunogenicity?

Answer 3

how well the antigen induces an immune response

Question 4

What is antigenicity?

Answer 4

how well the antigen is able to react with products of the immune system that it induced

Question 5

What is an epitope or antigenic determinant?

Answer 5

a part of an antigen that is responsible for inducing the immune response and binding to the products of the immune response

Question 6

What are the factors effecting immunogenicity?

Answer 6

• foreignness
• size
• chemical composition
• physical properties
• degradability
• genetic factors
• age
• route of transmission

Question 7

What are adjuvants?

Answer 7

substances that enhance the body’s immune response to an antigen

Question 8

List the chemical nature of antigens from most to least immunogenic

Answer 8

proteins > polysaccharides > nucleic acids > lipids

Question 9

Describe T-independent antigens

Answer 9

• directly stimulate B lymphocytes to produce antibodies without the need of helper T cells
• activate lymphocytes polyclonally
• resistant to degradation

Question 10

Describe T-dependent antigens

Answer 10

• indirectly stimulate B lymphocytes to produce antibodies

- require the presence of helper T cells

Question 11

What are superantigens?

Answer 11

• can activate a large number of lymphocytes at one time non-specifically
• derived from bacteria or viruses

Question 12

What are autoantigens?

Answer 12

• natural constituents of the body

- play a role in autoimmunity