Antigens Flashcards
What is an antigen?
molecule that will trigger an immune response when in the body
What are the two subcategories of antigens?
immunogens: substances capable of stimulating an immune response
haptens: substances that can only trigger an immune response when combined with host proteins
What is antigenicity?
capability of binding with products of the immune response that they triggered
what is immunogenicity?
capability of inducing an immune response
What is an epitope?
portion of the antigen actually responsible for inducing the immune response and binding to products of that immune response
What are the sources of antigens?
infectious agents
altered self antigens
What are some factors that influence immunogenicity?
foreignness: self vs. non self
size: the bigger, the more immune response
chemical composition: more complex= immunogenic
What is an adjuvant?
substance that enhances immune response to an antigen
Describe T-independant antigens
don’t require helper T cells
directly stimulate B cells
lipopolysaccharides
resistant to degradation
Describe T-dependant antigens
T helper cells required for B cell stimulation
proteins
Describe Superantigens
activation of large numbers of lymphocytes at once
derived from bacteria/ viruses
Describe haptens
cannot induce an immune response on their own
conjugates with a carrier for immunogenicity
Describe autoantigens
involved in autoimmunity
