Immunogens and Antigens: pgs 10-14 Flashcards
What is a substance which can react with products of the immune system?
Antigen
What is a substance which can elicit an immune response?
Immunogen
What is an antigen which cannot elicit an immune response alone?
Hapten
T/F - While all immunogens are antigens, not all antigens are immunogens.
True
What must happen in order for an immune response to be developed against a hapten?
A hapten must be covalently bound to a larger molecule which is immunogenic (aka: carrier).
What effect causes some people to become allergic to drugs like penicillin?
Hapten-Carrier effect
What four properties contribute to the immunogenicity of an antigen?
1) Foreignness
2) Size
3) Chemical complexity
4) Degradability
T/F - The more different a compound is from the equivalent host compound, the weaker the immunogen.
FALSE - The more different a compound is from the equivalent host compound, the STRONGER the immunogen.
The __________(size) the antigen, the better the immune response.
larger
What molecular weight in Da is a very good immunogen?
100,000 Da or larger
Substances with molecular weights less than _________ Da are usually NOT very strong immunogens.
10,000 Da
What are some examples of large compounds that are poor antigens?
Starch and glycogen
What are some examples of good antigens?
Proteins and carbohydrates
What is the process of how T cells present antigen?
Antigens must be taken up and degraded into smaller pieces. These pieces are then displayed on the surface of the cell in the context of class II MHC proteins. This is why it’s important that an antigen be able to be degraded in order to be a good immunogen.
Only a small portion of the antigen actually binds with the antibody. This region of antibody binding is termed the antigenic determinant or __________.
Epitope