Fig. 3.

HER2-CRB elicits NK cell cytotoxicity. A Percentage of killing normalized to NIST-CRB for NK92.6DF5 cells co-cultured with HER2 + HCC2218 cells for three days in the presence of titrated NIST-l or HER2-CRB. B Fold-change of BT474 cell killing normalized to time 0 h. BT474 cells were co-cultured with IL-15 prestimulated primary NK cells with an E:T ratio of 1:1 in the absence or presence of HER2-CRB. Data derived from three independent donors. C NK cell secretion of interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α) as well as chemokines CXC chemokine motif ligand 10 (CXCL10), macrophage inflammatory protein-1α (MIP-1α) and MIP-1β from experiment depicted in (B) on day 4. Three independent donors illustrated. D Fold-change of BT474 cell killing normalized by time 0 h. BT474 cells were co-cultured with primary NK cells at an E:T ratio of 1:1 in the presence of HER2-CRB, negative controls or trastuzumab with conditioned media obtained from 24 h co-culture of PBMCs and BT474 cells in the presence of HER2-4D5-TDB or NIST-TDB. Three independent donors are represented for donor conditioned media mix cultured with NK cells from 3 separate donors (9 total samples). E Area under the curve quantification from (D). Mann–Whitney test was used for statistical significance; *p, ≤ 0.05