Aim: to study the effect of human bone marrow derived mesenchymal stem cells (hMSCs) on cytokines secretion (IFN-γ, TNF-α, IL-10, IL-6, IL-4 and IL-2) of allogeneic DC-CIK cells (in co-culture of CIK cells with DC), which investigate the mechanism of immunoregulation induced by hMSCs.
Methods: the hMSCs from bone marrow were isolated, expanded and identified by cell morphology, differentiation into neuron-like cells with NSE, fat-like cells with red-oil stain, and expression of CD29, CD44. The DC and CIK cells from peripheral blood were isolated, expanded and identified by CD1α, HLA-DR or CD3(+);CD56(+);. The hMSCs were co-cultured with DC-CIK cells according to ratio 1:10. The expression of the six cytokines in supernatant was evaluated by flow cytometry after 4 days of DC-activated CIK cells in co-culture with hMSCs.
Results: the hMSCs displayed a fibroblast-like morphology and the positive cells of CD29 and CD44 were 96.6%, 94.6%, which have the capacity of differentiation into neuron-like cells with expressed NSE as well as fat-like cells with red-oil stain positive. The expression of CD1α, HLA-DR in DC was (91.9 ± 10.04)% and (88.8 ± 8.92)%. The CD3(+);CD56(+); double positive cells in DC-CIK cells was (29.23 ± 12.23)% compared to CIK cells with (15.98 ± 2.49)%. The cytokines secretion of DC-CIK cells in co-culture with hMSCs was IFN-γ (135.05 ± 48.19) ng/L; TNF-α (11.33 ± 1.42) ng/L; IL-10 (10.15 ± 2.25) ng/L; IL-6 (494.63 ± 235.222) ng/L; IL-4 (7.07 ± 2.30) ng/L and IL-2 (1074.6 3 ± 303.74) ng/L. In control group (DC-CIK cells) the secretion of IFN-γ, TNF-α, IL-10, IL-6, IL-4 and IL-2 was (717.6 ± 248.15) ng/L; (17.78 ± 7.52) ng/L; (29.95 ± 12.76) ng/L; (8.03 ± 0.21) ng/L, (9.08 ± 3.07) ng/L as well as IL-2 1 250 ng/L.
Conclusion: the secretion of IFN-γ and IL-10 were down-regulated. It probably implied that hMSCs had the effect of immunoregulation on DC-CIK cells.