B cells are infamous for running the block with T cells during the cell-mediated immune response, also known as the adaptive immune response. B cells are charged with making antibodies which recognize pathogen antigens and further the process of targeting and killing these foreigners. During a pathogenic invasion, lymphocytes like B and T cells and continuously being produced to go out and do their job. Some B cells are tasked with making antibodies, and some stay behind to become memory B cells, responsible for reminding the immune system when the same pathogen enters the body later in life.
A home base type of structure called the germinal center is produced within secondary lymph nodes when either a vaccine or a virus enters the body. This is where the memory B cells are induced to differentiate from germinal-center B cells, scientists know, but what signal exists to facilitate this transition?
Researchers previously thought that memory B cells were induced to differentiate by high-affinity germinal B cells. However, researchers from the current study, published in Nature Immunology, found that it was quite the opposite. It was the germinal center B cells with the lowest affinity maturation for antigens that were most likely to be induced to differentiate into memory B cells.
The researchers also found high expression of a transcription factor called Bach2 in the germinal cell B cells with low antigen affinity, indicating that Bach2 is important for memory B cell differentiation. This finding also appears to be key for future vaccine experiments based on targeting memory B cells to improve immune memory.
Sources: PubMed Health, Osaka University