Adenovirus-mediated expression of human secretor type alpha(1,2) fucosyltransferase reduces level of Gal alpha(1,3)Gal epitope.

AIM

To test the potential of human secretor type alpha(1, 2) fucosyltransferase [Se alpha(1,2)FT] to downregulate the expression of Gal alpha(1,3)Gal epitope (gal epitope) in cultured cell lines.

METHODS

Expression of Se alpha(1,2) FT was mediated by human adenoviral vector. Flow cytometric analysis was used to compare the expression level of H blood group antigen or gal epitope. MTT was employed to assess the susceptibility of mouse NIH3T3 cells to human natural antibody and complement mediated lysis.

RESULTS

A recombinant replication-deficient adenovirus (rAdv) containing human Se alpha(1,2)FT cDNA (Ad5hSeFT) was designed and successfully constructed. Flow cytometric analysis showed that after mock infection, Ad5null infection, and Ad5hSeFT infection, the mean fluorescence intensity (MFI) values for the binding of Ulex europaeus I (UEA-I) lectin to NIH3T3 cells were 2.3 +/- 0.6, 2.1 +/- 1.0, and 36.5 +/- 5.9, respectively; MFI values for the binding of Griffonia simplicifolia isolectin B4 (GS-IB4) lectin to NIH3T3 cells were 167 +/- 23, 170 +/- 19, and 100 +/- 14, respectively; MFI values for the binding of human natural IgG and IgM antibodies to NIH3T3 cells were 31 +/- 3, 32 +/- 4, and 22 +/- 4, respectively.

CONCLUSION

H blood group antigen was detected on NIH3T3 cells after Ad5hSeFT infection and resulted in more than 40% reduction in the level of gal epitope on the cell surface. This reduction increased the resistance of NIH3T3 cells to lysis by normal human serum.