MUC1-ST induces monocytes to secrete factors associated with tumor progression and modulates the differentiation of monocytes into dendritic cells (moDCs)

(a) Representative flow cytometry histograms showing biotinylated MUC1-T or MUC1-ST binding to isolated or differentiated immune subsets from healthy donors. N=4 independent donors. (b,c) Monocytes were incubated with biotinylated MUC1-ST for (b) different time periods or (c) using different concentrations. N=2 independent donors. (d) Monocytes were treated ± neuraminidase before being incubated with 10μg/ml MUC1 glycoforms. N=3 independent donors. (e) Monocytes (N=3) and MCSF MΦ (N=2) were stained with antibodies to MUC1-ST binding Siglecs and analysed by flow cytometry. (f) Monocytes were treated with indicated concentrations of antibodies to Siglecs-3, 7 and 9 before being incubated with MUC1-ST. Graph illustrates % binding inhibition as calculated against MUC1-ST plus isotype MFI. N=3 independent donors. (g) Representative flow cytometry histograms showing the binding of MUC1-ST or PAA-ST in the presence of anti-Siglec-9 or isotype for both primary monocytes and U937 cells. Data shown are the mean and s.e.m. * p<0.05 ** p<0.01 *** p<0.001, paired or unpaired Student’s t-test where appropriate.