Layered evolution in the immune system: a view from history
1Department of Genetics, Stanford University School of Medicine, Stanford, California.
Although much had still to be learned, evidence indicating that B-1a lymphocytes very likely belonged to a distinct lineage was largely in place by the time of the first large B-1a conference in 1991. The widely respected group of immunologists attending that meeting (including Tasuko Honjo and Klaus Rajewsky) developed and ultimately published the B-1a notation still in use today. Here, I briefly review some of the early B-1a findings that underlie current studies. I close with a brief summary of recent studies, mainly from my laboratory, showing that the hematopoietic stem cell (HSC) we all know and love as the origin of the cells that populate the adult lymphoid and myeloid system today is nonetheless not the origin of the B-1a lymphocytes with which most of us work today.
Although much had still to be learned, evidence indicating that B-1a lymphocytes very likely belonged to a distinct lineage was largely in place by the time of the first large B-1a conference in 1991. The widely respected group of immunologists attending that meeting (including Tasuko Honjo and Klaus Rajewsky) developed and ultimately published the B-1a notation still in use today. Here, I briefly review some of the early B-1a findings that underlie current studies. I close with a brief summary of recent studies, mainly from my laboratory, showing that the hematopoietic stem cell (HSC) we all know and love as the origin of the cells that populate the adult lymphoid and myeloid system today is nonetheless not the origin of the B-1a lymphocytes with which most of us work today.
Related Concept Videos
Cells of the Adaptive Immune Response
B Cell Activation and Differentiation
When naive B cells encounter a specific antigen that can bind to the B cell receptor (BCR) on their surface, they undergo sensitization to respond to the antigen's presence. Sensitization begins with...
Evolution of New Traits in Microbes
Diversity of Antigen Receptors
Before encountering any antigen, lymphocytes express these receptors. On B cells, the antigen receptor is a membrane-bound antibody molecule called BCR; on T cells, it is a T cell receptor or TCR. B and T cell receptors are composed of two...
T Cell Activation and Clonal Selection
Naive T cells that have not yet encountered an antigen express two primary CD...
Introduction to Innate and Adaptive Immunity
Innate immunity is the body's natural, nonspecific defense system that acts quickly to protect against pathogens. It incorporates physical barriers like skin and mucous membranes and cellular elements such as phagocytes and natural killer cells. This part of our immune system provides an immediate,...


