Antigenische

Antigenische is the German adjective corresponding to antigenic. In immunology, antigenic describes the capacity of a substance to be recognized by the adaptive immune system, especially by antibodies or T-cell receptors. The related noun antigenicity denotes the overall potential to be recognized and bound, while immunogenicity refers to the ability to provoke a measurable immune response.

Antigenic sites, or epitopes, are the specific portions of an antigen that are recognized. B-cell epitopes are often conformational or linear sequences on surface proteins; T-cell epitopes are short peptides presented by MHC molecules. An antigen may have multiple epitopes with varying degrees of antigenicity.

Determinants of antigenicity include foreignness, size, complexity, stability, and accessibility of the epitope, as well as the host's immune repertoire. Antigenic variation, such as antigenic drift in influenza viruses, can alter antigenicity and enable immune escape. Cross-reactivity occurs when antibodies recognize similar epitopes on different antigens.

Assessment and applications: Antigenicity is commonly evaluated by binding assays such as ELISA or surface plasmon resonance. Immunogenicity requires in vivo testing. In vaccines and diagnostics, selecting antigens with high antigenicity while safe immunogenic profiles is essential. In transfusion medicine and autoimmune disease research, antigenic properties influence compatibility and pathogenesis. In German usage, the corresponding adjective is antigenisch and the noun Antigenität.