Topic 13 of 50 in the MU Plovdiv syllabus for Microbiology (Medicine, Years 2 and 3). The free AceMed note covers it in 3 sections, about 491 words (4 min of reading), with 14 flashcards.
In this note
Antigens structure and properties. Antigenic structure of microorganisms.
Antigens: Structure and Properties
Antigenic Structure of Microorganisms
Antigens: Structure and Properties
Antigens (Ag) are substances capable of stimulating an immune response, often leading to antibody production.
The specific part of the antigen recognised by an antibody or T-cell receptor is called the epitope or antigenic determinant.
Antibodies typically recognise conformational epitopes (complex, three-dimensional structures), while T cells recognise linear peptides when presented by MHC molecules.
A Hapten is a small molecule that is not immunogenic on its own but can trigger an immune response when attached to a larger carrier protein.
Properties (Antigenicity): Antigenicity refers to the ability of a substance to bind with an antibody or immune cell receptor. A stronger antigenicity means it can better elicit an immune response.
Foreignness: Antigens must generally be foreign to the body to trigger an immune response. This means they must come from outside the host (e.g., bacteria, viruses, or foreign proteins).
Size: Larger molecules, such as proteins, are typically stronger antigens compared to smaller molecules like haptens.
Complexity: Antigens with complex structures, like proteins with multiple amino acids or sugars, tend to elicit stronger immune responses.
Solubility: Soluble antigens often trigger a better immune response than insoluble ones.
Stability: Stable antigens are more likely to elicit a consistent immune response.
Continue reading free
The whole note, all 3 sections, is free with an AceMed account, with its 14 flashcards. Premium adds flashcard recall, highlights and Ask AI.
