Objective: To analyze the expression of the CD(40) and its ligand (CD(40)L) on bone marrow stromal cells (BMSC), and investigate interleukin-3 (IL-3), IL-6, Flt3 ligand (FL) and stem cell factor (SCF) production of BMSC after stimulated with CD(40) agonistic monoclonal antibody (5C11) and its role in the regulation of hematopoiesis.
Methods: BMSC were freshly isolated from adult bone marrow. The expression of CD(40) on these cells was determined with flow cytometry, the concentrations of IL-3, IL-6, FL and SCF in the supernatant at 24, 48 and 72 hours after BMSC cultured with 5C11 at a dose of 20 micro g/ml were determined by the ELISA assay. After BMSC incubated with 5C11 for 24 hours, the supernatant was collected and cultured with purified cord blood CD(34)(+) cells for 7 days under 37 degrees C in a fully humidified atmosphere supplement with 5% CO(2). Colony formation assay and Annexin V assay were employed to determine the proliferation and apoptosis of the CD(34)(+) cells.
Results: BMSC expressed CD(40) and the production of IL-6 and FL increased after stimulated with 5C11 while IL-3 and SCF had no change. The supernatant collected from the stimulated BMSC promoted proliferation of CD(34)(+) cells, increased the CFU-GM yields and had anti-apoptosis effects.
Conclusion: CD(40) ligandization on BMSC increased the production of IL-6 and FL and promoted the proliferation of CD(34)(+) cells. The couple CD(40)/CD(40)L may be involved in the control of hematopoiesis via modulation of the cytokine network in the bone marrow.