Topology of Kell blood group protein and the expression of multiple
antigens by transfected cells
DC Russo, S Lee, M Reid and CM Redman
Lindsley F. Kimball Research Institute, The New York Blood Center, New
York.
Kell is one of the major blood group systems in human red blood cells
(RBCs). The Kell antigens are carried on a 731 amino acid glycoprotein that
is thought to span the erythrocyte membrane once. Rabbit antibodies to
three synthetic peptides, derived from different parts of the Kell protein,
were used to determine the topology of Kell protein on the RBC. Antibodies
to a C-terminal peptide and to a peptide derived from amino acid residues
410 to 439 reacted with RBCs treated with 0.2 mol/L dithiothreitol. An
antibody to the N-terminal peptide reacted with inside-out RBC vesicles but
not with right-side-out vesicles nor with intact RBCs, showing that Kell is
a type II membrane protein and that the extracellular portion of the
protein is folded by disulfide bonds. By transfection, Kell protein was
expressed on the cell surface of surrogate cells, and the transfected cells
expressed similar antigenic properties as native RBCs. Kell protein was
expressed in COS- 1 and K562 cells and in Sf9 cells infected by the
Baculovirus system. Transfected K562 cells expressed several high-incidence
antigens but not the low-incidence antigen K1.
Volume 84,
Issue 10,
pp. 3518-3523,
11/15/1994
Copyright © 1994 by The American Society of Hematology
