Fig. 5.

Epitope Characterization of TZ47 and PB scFvs. (A and B) Histograms depicting results of competitive staining of PB11 scFv-CH1-Fc with TZ47 (A) and NKp30-Ig (B) on RMA-B7H6 cells. Solid colored lines indicate staining with 500 nM of a single reagent, dotted colored lines with an equimolar mixture of reagents, and gray lines with secondary reagents (2ary) only. Results are presented for PB11, TZ47, and NKp30-Ig. (C) Structural representations of B7H6 are shaded by positions at which Human B7H6 residues differed and were replaced by Macaque B7H6 residues in Chimera 1 (Domain I) and Chimera 2 (Domain II). NKp30 is also shown as a ribbon diagram, with B7H6 residues <5 Å away highlighted in orange. (D) CAR T cell activation in response to Human, Macaque, and Chimeric Hu-Mcq B7H6 expressing RMA cells is shown, in addition to controls for non-transduced RMA cells and no target cells. Colors indicate T cells that were transduced with empty vector, TZ47-CAR, PB6-CAR and NKp30-CAR. Error bars depict the standard deviation of three technical replicates and are representative of two biological replicates.