Transitional B cells in humans: characterization and insight from B lymphocyte reconstitution after hematopoietic stem cell transplantation.

Transitional B cells have been recently identified in human peripheral blood. However, their precise role in human B cell differentiation has not been established. Therefore, besides characterizing them further in the blood of healthy adults and children and cord blood, we used the immune reconstitution after hematopoietic stem cell transplantation (HSCT) model to define their role in human B cell development.