Figure 6

Antibody-dependent cellular cytotoxicity (ADCC) of NK cells directed against ovarian cancer cell lines. Total lysates (20 μg) of each cell line were separated in a 7.5 %-SDS-polyacrylamid gel, immunoblotted with primary anti-EGFR antibody followed by peroxidase-labelled secondary antibody and visualised by chemiluminescence. (a) The expression of total EGFR (170 kDa) in three ovarian cancer cell lines are shown. The band at 53–55 kDa most likely reflects cross-reactivity of the antibody with EGFR-related protein (ERRP). (b-d) The ovarian cancer cell lines A2780, IGROV-1 and SKOV-3 were co-cultured with cetuximab (1 μg/ml) and NK cells, which were stimulated by monocytes with and without PstS-1 (NK + Mo + PstS-1) for three days. CD107a-degranulation-assay. Data are shown as means + SE of three to six independent experiments on day three. Statistical analysis was performed by unpaired t-test, statistical significance was assumed at p ≤ 0.05.