Involved Immune Response
New research reveals how the body's defenses respond to vaccinations. The findings could help to develop better vaccines.
Doctors generally recommend seasonal flu vaccinations for pregnant women, the elderly, the chronically ill and medical staff. This is adjusted every year so that the organism can fight currently rampant virus strains in the best possible way. To do this, researchers need to understand how repeated vaccinations shape the body's immune memory. A team led by Jackson Turner from the Washington University School of Medicine in St. Louis has now examined in detail how the human body's defenses react to seasonal flu vaccinations. The focus was on the contribution of the so-called B lymphocytes - these are immune cells from the group of white blood cells.
B cells form microscopically visible spherical collections called lymphoid follicles in the body. During an infection, these become so-called germinal centers in which immune cells multiply and mature. As a result, memory B cells are formed, among other things, which allow the organism to quickly form antibodies against pathogens that it has already fought successfully at any time. The processes in the germinal centers are immensely important for immune memory.
The antibodies produced by B lymphocytes make the most important contribution to immunity to influenza viruses. Each B cell first produces a specific B cell receptor (BCR) located in the cell membrane. With its help, the cell recognizes a very specific antigen, such as a component of a virus protein. The enormous variety of B lymphocytes in the body with their individually different BCR molecules ensures that the organism can react to an extremely wide range of pathogens. B lymphocytes that have not yet had contact with their antigen are called naïve B cells. If they couple to the antigen for the first time via their BCR, they migrate to a germinal center in the lymph nodes or the spleen and multiply there. The progeny produce antibodies that recognize the same target as the BCR did before…