Before stem cells, of whatever origin, can be used to treat patients, scientists will need to learn how to coax them to develop into the desired cell types, a major challenge. In the 12 October 2004 issue of Developmental Cell, researchers from the University of Chicago present the first rough road map, suggesting how to lead a hematopoietic stem cell down the narrowing path to becoming an antibody-producing B cell.The researchers describe four critical stages on the way from a multi-potent precursor to a committed B-cell and suggest how combinations of regulatory proteins and signaling pathways direct maturing cells through each crossroad, guiding them down one specific developmental path, preparing them to respond to signals yet to come, and blocking off other options.
