[Differential expression of a homing-related molecule repertoire among umbilical cord blood, mobilized peripheral blood and bone marrow-derived hematopoietic stem/progenitor cells].

OBJECTIVE

To compare the expression profiles of a set of homing-related molecules (HRM) repertoire expressed on hematopoietic stem/progenitor cells (HS/PC) from different sources.

METHOD: The expression levels of HRM on HS/PC from umbilical cord blood (UCB), mobilized peripheral blood (mPB) and bone marrow (BM) were assessed using a highly sensitive 4-color flow cytometric analysis.

RESULTS

UCB-derived CD34(bright) cells, as well as mPB- and BM-derived CD34(bright) cells strongly expressed CD44, CD11a, CD18, CD62L, CD31 and CD49d. On the other hand, significantly lower expressions of CD49e, CD49f, CXCR-4 and CD54 on UCB-derived CD34(bright) and CD34(bright)CD38(-) cells, compared with those on mPB- and BM-derived CD34(bright) and CD34(bright)CD38(-) cells, were observed. None of UCB-, mPB- and BM-derived CD34(bright) cells expressed other chemokine receptors, including CCR-1, CCR-2, CCR-3, CCR-5, CXCR-1, CXCR-2, CXCR-3 and CXCR-5. Another striking finding was that only mPB-derived CD34(bright) cells expressed significant levels of both the matrix metalloproteinases MMP-2 \[(11.4 +/- 4.9)%\] and MMP-9 \[(27.6 +/- 7.8)%\].

CONCLUSION

HS/PC from UCB have some defects of expression of HRM repertoire, which might partly explain the cause(s) of delayed hematopoietic reconstitution after UCB transplant.