Immunology Glossary of Terms

Question 1

Immunogen

Answer 1

a substance that elicits an immune response

Question 2

Antigen

Answer 2

any substance that binds specifically to an antibody or a T-cell receptor

Question 3

Epitope

Answer 3

antigenic determinant : portion of an antigen that is recognized and bound by an Ab or T cell

Question 4

Hapten

Answer 4

a low molecular weight molecule that can be made immunogenic by conjugation to a suitable carrier

Question 5

CDRs

Answer 5

Complementarity-determining regions: portions of the variable regions of antibody molecules that protrude from the V domains and have the potential to contact antigen. The antigen-binding sites of the antibody are composed of the CDRs

Question 6

Affinity

Answer 6

The strength with which a ligand interacts with a binding site. Quantitatively represented by affinity constant KA

Question 7

Avidity

Answer 7

the strength of antigen-antibody binding when multiple epitopes on an antigen interact with multiple binding sites on an antibody.

Question 8

Cross-reactivity

Answer 8

ability of a particular antibody (or TCR) to react with two or more antigens that possess a common epitope

Question 9

Specificity, antigenic

Answer 9

capability of Ab (or TCR) to recognise and interact with a single, unique epitope.