Increased plasma levels of stromal-derived factor-1 (SDF-1/CXCL12) enhance human thrombopoiesis and mobilize human colony-forming cells (CFC) in NOD/SCID mice

Objective Stromal-derived factor-1 (SDF-1/CXCL12) is chemotactic for lympho/hematopoietic stem cells. We have previously shown that increasing peripheral blood (PB) levels of SDF-1 with adenovectors expressing human SDF-1 complementary DNA (ad-SDF-1) leads to hematopoietic stem cell mobilization as well as migration of megakaryocytes and thrombocytosis in mice. Herein, we studied the in vivo effects of ad-SDF-1 and of an analogue peptide of SDF-1 (CTCE-0214) on human hematopoiesis in a xenotransplant model. Materials and methods Sublethally irradiated (300 cGY) NOD/SCID mice transplanted with human cord blood mononuclear cells (CB MNC) were injected with ad-SDF-1 (109 plaque forming units, IV, ×1) or CTCE-0214 (10 mg/kg/dose, IV q 24 hours ×7). Effects on megakaryocytopoiesis (CD41+ cells and platelets) as well as stem cell mobilization were monitored. Results CB MNC in NOD/SCID mice are able to differentiate into CD41+ cells and platelets, peaking at week 9 at a mean of 3.7×103/μL. IV injection of ad-SDF-1 increased human CD41+ cells by day 4 in PB and was followed by an increase in human platelet production by day 5, with return to baseline by day 30. Human colony-forming cells (CFC) were mobilized from bone marrow to spleen (by day 6–13) and to PB (by day 13). Human CD34+ and CD33+ cells were mobilized by this treatment as well. A novel SDF-1 peptide agonist (CTCE-0214) also mobilized human CFC and enhanced human thrombopoiesis. Conclusion SDF-1 and its analogue may be of clinical value in stimulating platelet recovery after chemo/radiation treatment as well as in stem cell mobilization.