Figure 2.

Effects of antibodies to TGF-β1 on microvesicles (MV)-mediated effects. (A) MV isolated from sera of AML patients decreased NK cell cytotoxicity as did recombinant TGF-β1. The addition of neutralizing antibodies to TGF-β1 but not of isotype IgG abrogated the effects of MV on NK cell cytotoxicity. MV isolated from normal controls (NC) did not affect NK cell cytotoxicity. The data are mean LU ± SE from experiments with eight AML samples. (B) NK cells were single-cell sorted from the blood of NC (left) and co-incubated with or without MV. NKG2D expression was decreased after co-incubation of NK-cells with MV isolated from AML patients. Antibodies to TGF-β1 abrogated the inhibitory effect of MV on NK cells. Gray-filled histograms indicate an isotype control and the solid line indicates NKG2D expression in NK cells of an AML patient. The representative data were obtained from one AML patient out of 19 examined.