Antigens

Definition

Antigens are molecules or molecular structures that are recognized by the immune system as foreign, triggering an immune response. These substances can be found on the surface of pathogens like bacteria and viruses, as well as on the surface of cells in the body, which can be crucial in the development of bioelectronics and biosensors that detect diseases and monitor health conditions.

5 Must Know Facts For Your Next Test

1. Antigens can be proteins, polysaccharides, or other molecules, and they are critical for the identification of pathogens by the immune system.
2. The structure of an antigen determines how well it can elicit an immune response, with larger and more complex antigens typically being more effective.
3. In bioelectronics and biosensors, antigens are often immobilized on surfaces to create devices that can specifically detect diseases by measuring antibody-antigen interactions.
4. Different types of antigens include exogenous antigens (from outside the body) and endogenous antigens (produced by the body itself), which can impact how they are detected and responded to by the immune system.
5. Antigenic variation, where pathogens change their surface proteins, poses a challenge for vaccine development and disease management, making ongoing research essential.

Review Questions

• How do antigens function in triggering an immune response within the body?
  • Antigens function by being recognized as foreign by the immune system, leading to the activation of immune cells such as B-cells and T-cells. When B-cells encounter an antigen, they differentiate into plasma cells that produce antibodies specific to that antigen. This process not only helps neutralize the pathogen but also contributes to the formation of memory cells, which provide long-term immunity against future infections by the same antigen.
• Discuss the role of antigens in the development of biosensors used for medical diagnostics.
  • Antigens play a crucial role in biosensors by serving as specific targets for detection. In these devices, immobilized antigens interact with corresponding antibodies present in patient samples. The binding event can generate measurable signals, allowing for rapid diagnosis of diseases such as infections or autoimmune disorders. By leveraging the specificity of antigen-antibody interactions, biosensors enhance diagnostic accuracy and enable real-time monitoring of health conditions.
• Evaluate how antigenic variation affects vaccine efficacy and public health strategies.
  • Antigenic variation presents significant challenges for vaccine efficacy as pathogens like influenza or HIV can alter their surface proteins to evade immune detection. This variability means that vaccines may become less effective over time or may need to be updated regularly to match circulating strains. Public health strategies must adapt by promoting research on universal vaccines and enhancing surveillance systems to quickly identify and respond to emerging strains, ensuring effective protection against infectious diseases.

Related terms

Antibodies: Proteins produced by B-cells in response to antigens, which help to neutralize or eliminate foreign substances from the body.

Immunoassay: A laboratory technique that uses antibodies to detect the presence of specific antigens in a sample, widely used in biosensors for medical diagnostics.

Vaccine: A biological preparation that provides active acquired immunity to a particular disease by introducing antigens into the body.