| A | B |
|---|
| Alloantibodies | immunoglobulins (antibodies) produced in response to exposure of foreign antigens of the same species |
| Autoantibodies | An immunoglobulin (antibody) produced a agains a self-antigen |
| Antigenic determinant | the combining site or sites (on the antigen) with which antibodies react |
| Epitope | a single antigenic determinant - the portion of an antigen that combines with an antibody |
| Hinge region of Abs | portion of the immunoglobulin heavy chains between the Fc and Fab region; provides flexibility to the molecule to allow two antigen-binding sites to function independently |
| Variable region of Abs | amino-terminal portions of immunoglobulins and T-cell receptor chains that are highly variable and responsible for the antigenic specificity of these molecules |
| Heavy chains | larger polypeptide of an antibody molecule composed of a variable and constant region; five major classes of heavy chains determine the isotype of an antibody |
| Light chains | smaller polypeptide of an antibody molecule, composed of a variable and constant region; two major types of light chains exist in humans (Kappa and lambda) |
| Constant regions | nonvariable portions of the heavy and light chains of an immunoglobulin and T-cell receptor |
| Antibodies (Immunoglobulins) | proteins secreted by plasma cells that bind to specific epitopes on antigenic substances |
| Antigen (Immunogen) | (a substance that is capable of inducing an immune response) a macro molecule capable of eliciting the formation of imunoglobulins |
| Hapten | Very small molecue that can bind to a larger molecule (protein) and behave as an antigen |
| Specificity | antibody can only recognize a precise segment of one antigen |
| Cross-reactivity | some Abs secreted by one plasma cell can bind to a similar, but not identical epitope (antigen binding site) |
| Avidity | The strength with which a multivalent antibody binds to a multivalanet antigen. |
| Affinity | Propensity: the bond between a single antigenic determinant and an individual combing site. |
| Amamnestic antibody response | an antibody "memory" response. This secondary type of response occurs on subsequent exposure to a previously encountered and recognized foreign antigen and is characterized by the rapid production if IgG antibodies |
| Monoclonal antibodies | purified antibodies cloned from a single cell - they are very specific antibodies |
| Opsonin | molecule that attaches to microbes or other antigens to facilitate their recognition by phagocytes |
| Fc | the portion of the Ab molecule that binds with complement |
| Fab | the portion of the Ab molecule that binds to Ag |
| Adjuvant | A substance added to a vaccine to improve the immune response. |
| Hybridoma | Cell lines created in vitro by fusion of two different cell types - usually formed from a lymphocyte or plasma cells - used to make momoclonal antibodies. |
