Figure 3.

High complement activation with Neu5Gc and αGal‐negative pig IgG. GGTA1/CMAH double KO pigs (n = 4) were immunized with human T cells and the hyperimmune IgG fraction purified from pooled sera by Protein A chromatography. Rabbit anti‐human T cells used here was Thymoglobulin. The two IgG preparations were differentially diluted in nonimmune IgG of the respective species to obtain similar binding titer and intensity on target human T cells by flow cytometry. A fluorescent Protein‐G reagent has been used instead of species‐specific secondary antibodies to ensure similar, reagent‐independent revelation (A). Target human T cells were used in a complement‐mediated cytotoxicity (CDC) assay where rabbit IgG and GGTA1/CMAH double KO pig IgG directed against human T cells were compared (B). Results shown here are one representative experiment of three independent assays.