ADCC of Y-443 and its IgG
against MDA-MB-231 cells. MDA-MB-231 cells pre-labeled with 51Cr were incubated with Y-443 (IgG1), Y-443 IgG4, or control human IgG at a ratio of 1:50 with PBMC effector cells for 4 h at 37°C, followed by measurement of 51Cr that was released into the culture supernatant. Specific cell lysis was calculated as described in Methods. The results are the mean ± S.D. of triplicate assays.