Plasma cells are the key players in fighting infections and establishing long-lasting protection to our body against pathogens.

‘Researchers have known about the functions of plasma cells, however, details of how the differentiation and function of these cells are regulated are still unknown.’

B-cells need to be activated by antigens (foreign substances) in order to develop into plasma cells. They first form plasmablasts that migrate to the bone marrow where they survive for many years or even decades. The long-lasting protection provided by active vaccines is based on this immunological memory of plasma cells. 




A Central Role for Blimp1
Scientist have known about the functions of plasma cells for quite a while. However, details of how the differentiation and function of these cells are regulated were still unknown. Now an important key to understanding the function of plasma cells has been discovered by a team headed by Meinrad Busslinger, Senior Scientist and Deputy Director at the Research Institute of Molecular Pathology (IMP) in Vienna, Austria. In a five-year project, the team succeeded in deciphering the role of the protein Blimp1 as a central regulator of plasma cell development and function. In its current issue, the science journal Nature Immunology publishes the results of the team in Vienna as well as the work of Australian colleagues that complements the Viennese results.
In detailed studies, scientists at the IMP identified all genes that are involved in the development of plasma cells in mice. First author Martina Minnich, whose PhD-thesis provided the groundwork for the publication, explains the results: "We found that more than 50 percent of these genes are regulated by Blimp1. Therefore, this factor must be of vital importance for plasma cells. Furthermore, we were able to show for the first time that Blimp1 not only switches genes off but can also switch other genes on. This is an important discovery for the understanding of plasma cell development."
"Most of the essential functions of plasma cells are controlled by the factor Blimp1", Meinrad Busslinger summarizes the results. "It regulates their mobility and migration to the bone marrow. Blimp1 is also responsible for the enormous increase in size of the endoplasmic reticulum and the strong up-regulation of antibody production in plasma cells. Humoral immunity would not be possible without Blimp1."
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Even though Blimp1 is necessary for the development of plasma cells, mature plasma cells can survive without this factor. However, when Blimp1 is switched off, they become non-functional as they no longer produce antibodies. This unexpected finding is the result of work carried out at the Walter and Eliza Hall Institute (WEHI) in Melbourne, Australia. The study, which is published back-to-back with the Austrian paper, was led by Stephen Nutt, Head of the Division of Molecular Immunology at WEHI. The picture that emerges from the Australian study perfectly complements the results obtained at the IMP.
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Another aspect of the immune system that is highly relevant for medicine is the broad spectrum of autoimmune diseases. Conditions like systemic lupus erythematosus (SLE) are an example for the serious damage to organs and tissue caused by misguided immune responses which generate plasma cells producing auto-reactive antibodies that turn against the body's own tissue.
Source-Newswise