Antigen Surface

Antigens of bacterial surface structures are among the most common and important for the human immune system. They are proteins and polysaccharides that are found on the surface of the bacterial cell and participate in its interaction with the environment.

One of the most well-known antigens of surface structures is the flagellum. Bacterial flagella are used for movement in space and transmission of genetic information. The flagellum consists of a protein subunit that contains many antigenic determinants. These determinants can be recognized by the immune system and trigger the production of antibodies that will fight bacteria that have similar antigenic structures.

Another important antigen of surface structures is the capsule. The capsule is a polysaccharide shell that surrounds the bacterial cell and protects it from external factors. The capsule also contains many antigens that can be recognized by the immune system.

The cell wall is also an antigen of the surface structures of the bacterium. It is composed of peptidoglycan, which is a polymeric material made up of proteins and sugars. The cell wall is involved in protecting the bacterial cell from external influences, as well as in the transfer of genetic information between cells.

In general, surface antigens play an important role in the human immune system and can be used to diagnose and treat various bacterial infections.

Antigen surface structures

Antigens are large protein molecules, glycoproteins, that are found on the surface of bacteria and other infectious agents. They not only protect bacteria from attack by the immune system, but also participate in the process of recognizing it by cells and creating an immune response against the pathogen. Antigens are essentially markers of pathogenic microorganisms; it is on them that the immune system produces antibodies and transfers them along with the blood to bacteria, thereby depriving them of the ability to multiply and cause infection. The most well known antigens of viral infections are widely used, namely influenza virus antigens, covid antigen (SARS-CoV-2), HIV. To study the structure of these substances, methods were developed for isolating various fragments of their protein molecules; as it turned out, in terms of antigenic properties, influenza virus proteins are similar to proteins of other acute respiratory viruses. There are about 20 different influenza serotypes (hemagglutinins), each with its own unique antigenic structure. But without the help of external immune stimulation, the virus can mutate and change its antigenic structure. This is why vaccines are most often updated for the next year, otherwise the human body is simply not vaccinated against it and is not ready to react when encountering an updated version of the virus. One of the interesting aspects of the study, which allows its use in laboratory diagnostics, is the antigenic composition of the cell walls of microorganisms and their membranes. Their composition is complex, including more than 7 groups of polymers from simple carbohydrates to nitrogen-containing peptides. The cell walls of bacterial cells contain protein structures that, in general, have not been fully studied immunologically; presumably, the composition of these protein groups hides the real secret of high immune tolerance to pathogenic bacteria and viruses.