The impact of serum incubation time on IgM/IgG binding to porcine aortic endothelial cells.
The results of the assay for measuring anti-non-Gal antibodies (which affect pig xenograft survival) in recipients are important. Serum incubation time and concentration may be important factors in the extent of antibody binding to the graft. The aim of this in vitro study was to determine the optimal incubation time and serum concentration for measuring anti-non-Gal antibody binding to porcine aortic endothelial cells (pAECs). Pooled human, naive, and sensitized baboon sera were incubated with wild-type, α1,3-galactosyltransferase gene-knockout (GTKO), and GTKO/human CD55 pAECs. IgM/IgG binding to pAECs after varying serum incubation times (0.5, 1, 2, and 3 hour) and concentrations (5, 10, 20, and 40 μL) was determined by flow cytometry. An increase in incubation time from 30 minutes to 2 hour was associated with increases in anti-non-Gal IgM/IgG binding to GTKO and GTKO/hCD55 pAECs of pooled human, naive and sensitized baboon sera (P<.05). Pooled human serum showed a significant increase in anti-non-Gal IgM (1.5 times) and a minimal increase in anti-non-Gal IgG antibody binding. IgM/IgG binding of sensitized baboon serum to GTKO pAECs after 2-hour incubation was 1.5 times and 2 times greater than after 30-minutes incubation, respectively, whereas naïve baboon sera showed minimal (non-significant) increase in anti-non-Gal IgM/IgG antibody binding. With 2-hour incubation, increasing the serum concentration from 5 μL to 20 μL significantly increased antibody binding to non-Gal antigens in pooled human and sensitized baboon serum. With naïve baboon serum, only IgG was significantly increased. Increasing the serum incubation time contributed to improve the sensitivity of detecting anti-non-Gal antibodies, without affecting cell viability in vitro.
['Zhang|Zhongqiang|Z|0000-0002-4410-4675', 'Gao|Bingsi|B|', 'Zhao|Chengjiang|C|', 'Long|Cassandra|C|', 'Qi|Haizhi|H|', 'Ezzelarab|Mohamed|M|', 'Cooper|David Kc|DK|0000-0002-8899-9431', 'Hara|Hidetaka|H|']
D000818:Animals D030801:Animals, Genetically Modified D000910:Antibodies, Heterophile D042783:Endothelial Cells D055786:Gene Knockout Techniques D006084:Graft Rejection D006085:Graft Survival D064593:Heterografts D006801:Humans D007074:Immunoglobulin G D007075:Immunoglobulin M D013552:Swine D013997:Time Factors D014183:Transplantation, Heterologous
porcine aortic endothelial cells anti-non-Gal antibodies human baboon α1,3-galactosyltransferase gene-knockout Xenotransplantation