Effect of soluble heparin and heparan sulfate on the capacity of hIL-10 to up-regulate the expression of CD16 and CD64 on monocytes/macrophages.

PBMC were stimulated with either hIL-10 (10 ng/mL; A-D) or IFN-γ (10 ng/mL; E) in the presence or absence of increasing concentrations of heparin (●) or heparan sulfate (▴) for 24 hours (A,B) or 72 hours (C,D). CD64 and CD16 expression on monocytes/macrophages were determined as described in Figure 3. Results are expressed as percentage inhibition of CD16 and CD64 induced by hIL-10 ± 2 SD. For the mean fluorescence intensity induced by IL-10 compared to controls, see Figure 3. Mean fluorescence intensity induced by IFN-γ was 208.5 ± 20. Data are representative of at least 4 separate experiments.