Recombinant glycophorins C and D as tools for studying Gerbich blood group antigens.
BACKGROUND
The Gerbich blood group system antigens are carried on glycophorin C (GPC) and glycophorin D (GPD) and variants thereof. These glycoproteins have been expressed in a heterologous system to study the individual antigens and to determine whether Ana is antithetical to Ge2.


METHODS
cDNAs encoding GPC, GPD, GPC.Yus, GPC.Ge, GPC.Lsa, and GPD.Lsa were transfected and stably expressed in a human embryonic kidney cell line (293T). Individual Gerbich antigens were analyzed with MoAbs and human polyclonal antibodies by flow cytometry and immunoblotting. Recombinant GPD and GPD.Ana were expressed transiently and analyzed for expression of Ge2 and Ana antigens.


RESULTS
All recombinant variants were detected with sialidase-resistant and -sensitive anti-Ge2, anti-Ge3, and anti-Ge4. Ge4 antigen expression was depressed in GPC.Ls(a) transfectants as well as on Ls(a+) RBCs. GPD.An(a) recombinant protein expressed Ana and Ge2 antigens.


CONCLUSIONS
Cell lines stably expressing glycosylated Gerbich proteins were developed in a heterologous system by transfecting individual variant forms of GPC and GPD. Unexpectedly, it was found that Ge4 antigen is reduced in both the GPC.Ls(a) recombinant and the Ls(a+) RBCs. It was also shown that Ana and Ge2 antigens were expressed on a single GPD.An(a) protein and, therefore, they cannot be antithetical.
Schawalder
Alissa
A
Immunochemistry Laboratory, New York Blood Center, New York, NY 10021, USA.
Reid
Marion E
ME
Yazdanbakhsh
Karina
K
D000911:Antibodies, Monoclonal; D001789:Blood Group Antigens / Q000032:analysis / Q000235:genetics*; D002460:Cell Line; D018076:DNA, Complementary; D005434:Flow Cytometry; D014644:Genetic Variation; D006021:Glycophorins / Q000032:analysis / Q000235:genetics*; D006801:Humans; D015151:Immunoblotting; D011994:Recombinant Proteins; D014162:Transfection
D000911:Antibodies, Monoclonal; D001789:Blood Group Antigens; D018076:DNA, Complementary; D006021:Glycophorins; D011994:Recombinant Proteins