Expression of stromal cell-derived Factor-1/Pre-B cell growth-stimulating factor receptor, CXC chemokine receptor 4, on CD34(+) human bone marrow cells is a phenotypic alteration for committed lymphoid progenitors

We found that the stromal cell-derived factor-1/pre-B cell growth-stimulati ng factor receptor, CXC chemokine receptor 4 (CXCR4), is expressed on human CD34(+) bone marrow (BM) cells. Stringently FAGS-sorted CD34(+)CXCR4(+) BM cells completely lack myeloid, erythroid, megakaryocytic, and mixed colony -forming potential (myeloid progenitors), but give rise to B and T lymphoid progenitors, whereas CD34(+)CXCR4(-) BM cells can generate colonies formed by myeloid progenitors and can also develop into these lymphoid progenitor s. Therefore, expression of CXCR4 on CD34(+) BM cells can allow lymphoid pr ogenitors to be discriminated from myeloid progenitors. Because CD34(+)CXCR 4(+) cells are differentiated from CD34(+)CXCR4(-) cells, multipotential pr ogenitors located in the BM are likely to be negative for CXCR4 expression. CXCR4 seems to be expressed earlier than the IL-7R and terminal deoxynucle otidyl transferase during early lymphohemopoiesis. These results suggest th at the expression of CXCR4 on CD34(+) BM cells is one of the phenotypic alt erations for committed lymphoid progenitors.