Chapter 3 - Antigen
Terms
undefined, object
copy deck
- Antigen
- any substance (usually foreign) that binds specifically to an antibody or a T-cell receptor; often is used as a symonym for immunogen
- Immunogenicity
- the capacity of a substance to induce an immune response under a given set of conditions
- Immunogen
-
a substance capable of eliciting an immune response;
all immunogens are antigens, but some antigens are not immunogens (e.g., haptens) - Antigenicity
- the capacity to combine specifically with antibodies or T-cell receptor/MHC
- Genotype
-
the combined genetic material inhherited from both parents;
also the alleles present at one or more specific loci - Booster
- inoculation given to stimulate immunologic memory response
- Adjuvant
- a substance (e.g., Freund's adjuvant, alum, bacterial LPS) that nonspecifically enhances the immune response to an antigen
- Freund's incomplete adjuvant
- Freund's adjuvant lacking heat-killed mycobacteria
- Freund's complete adjuvant (CFA)
-
a water-in-oil emulsion to which heat-kiled mycobacteria have been added;
antigens are administered in CFA to enhance their immunogenicity - Granuloma
- a tumor-like mass or nodule that arises because of a chronic inflammatory response and contain many activated macrophages epithelioid cells (modified macrophages), T(H) cells and multinucleated giant cells formed by the fusion of macrophages
- Epitopes (antigenic determinant)
- the portion of an antigen that is recognized and bound by an antibody or TCR/MHC combination
- Sequential epitopes
- two or more antigenic determinants formed by a single sequence of amino acids
- Nonsequential epitopes
- epitopes that are far apart in the primary sequence of the polypeptide chain but close together in the tertiary structure of the molecule
- Conformational determinants
- epitopes of a protein that are composed of amino acids that are close together in the three dimensional structure of the protein but may not be near each other in the amino acid sequence
- Immunodominant
- referring to epitopes that produce a more pronounced immune response than others do in the same conditions
- Antigenic peptides
- in general, a peptide capable of raising an immune response and in a peptide that forms a complex with MHC that can be recognized by a T-cell recept
- Hapten
- a low molecular-weight molecule that can be made immunogenic by conjugation to suitable carriers
- Carrier
-
an immunogenic molecule containing antigenic determinants recognized by T cells;
conjugation of a carrier to a nonimmunogenic hapten renders the hapten immunogenic - Hapten-carrier conjugate
- a covalent combination of a small molecule with a large immunogenic carrier molecule or structure
- Cross reactivity
- ability of a particular antibody or T cell receptor to react with two or more antigens that possess a common epitope
- Pattern recognition receptors (PRRs)er
- receptors of the innate immune system that recognize molecular patterns or motifs present on or within pathogens but absent in the host