B cell positive selection: road map to the primary repertoire?
Accumulating evidence indicates that positive selection events mediate differentiation, lineage commitment, and longevity of B lymphocytes. The BCR plays a central role, dictating the likelihood that newly formed cells will complete maturation, as well as whether cells persist within mature pools. Competition among B cells for limited, life span-promoting resources, which include self-ligands, lineage-specific cytokines, and innate receptor ligands, underlie these selective processes. Together, these observations suggest that positive selection is a critical feature in the establishment and maintenance of all lymphocyte pools, prompting re-evaluation of the underlying biological rationale for this process.
Cancro
Michael P
MP
Department of Pathology, University of Pennsylvania School of Medicine, John Morgan Building Room 284, 36th and Hamilton Walk, Philadelphia, PA 19104, USA. cancro@mail.med.upenn.edu
Kearney
John F
JF
D000818:Animals; D001402:B-Lymphocytes / Q000502:physiology*; D018985:Epitopes, B-Lymphocyte; D006801:Humans; D011947:Receptors, Antigen, B-Cell / Q000502:physiology; D015398:Signal Transduction
D018985:Epitopes, B-Lymphocyte; D011947:Receptors, Antigen, B-Cell