Resistance of porcine Sertoli cells to xenoreactive antibodies mediated complement lysis

Abstract

Objective To investigate whether porcine Sertoli cells eould resist xenoreactive antibodies mediated complement lysis. Methods Sertoli cells were isolated from testes of 10 to 15 day-old landrace pigs. Α-Gal expression on Sertoli cells was measured by FACS and cytoimmunofluorescence. The binding of human se-rum IgG and IgM with Sertoli cells was assayed by FACS. After the incubation of the cultured Sertoli cells with 20% human B serum in vitro, the cellular lysis and cytotoxicity assay were detected with CytoTox-ONETM homogeneous membrane integrity assay and MTT method, and then activation of the complement cascade was examined by immunohistochemistry and immunofluorescence. The SV40-porcine endothelium cells line (SV40-PED) was served as control cells. Results α-Gal expression was found on Sertoli cells by FACS and cytoimmunofluorescence. After incubation with 20% human serum, cellular lysis ratio of the SV40-PED was 53. 13% ± 14.53%, while lysis ratio of the Sertoli cells was significantly lower (24.38% ±0.50%, P<0.01), the viability of Sertoli cells and SV40-PED were 98.73% ± 18.84% and 52.43% ± 8.08%, respectively. With immunohistochemistry and immunofluorescence, C3c and C4d were found binding on both the Sertoli cells and SV40-PED cells, however, C5b-9 was only detected on SV40-PED cells. Conclusion In vitro, compared with the SV40-PED, Sertoli cells could resist xenoreactive antibodies of human serum mediated complement lysis by preventing the C5b-9 formation. Key words: Sertoli cells; α-Gal; Complement