Bone Marrow Neutrophils of Multiple Myeloma Patients Exhibit Myeloid-Derived Suppressor Cell Activity

Figure 1

Inhibition of T-cell proliferation and IFN-γ production by peripheral blood normal density granulocytes. (a) Inhibition of proliferation with healthy donor (HD) and MM NDG. HD NDG inhibits T-cell proliferation (), and the median proliferation is 54% (95% CI: 38–67). MM NDG also inhibits T-cell proliferation (), and the median proliferation is 48% (95% CI: 23–67). (b) The median of IFN-γ production for each group is 9400 pg/ml (95% CI: 820–13500), 460 pg/ml (95% CI: 0–1900), and 900 pg/ml (95% CI: 0–2000), respectively. Both HD NDG () and MM NDG () inhibit the production of IFN-γ. (c) The inhibitory effect of HD NDG () differs between 5 and 84% and (d) between 13 and 75% for MM NDG (). (e) The inhibition of T-cell proliferation by NDG is dose dependent (data from representative experiment). (f) NDGs become more inhibitory in the presence of the activator fMLF () (). Error bars indicate median with range. Statistical significance was tested with Wilcoxon matched pairs signed rank test.

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