Immunoreactivity of Common Red Blood Cell Antigens in Cytoskeleton-Free Red Blood Cell Microvesicles

Background eleton-free microvesicles can be generated from normal red blood cells (RBCs). These RBC vesicles maintain a representative sampling of the lipid bilayer and several membrane proteins. We investigated RBC antigen segregation and persistence of immunoreactivity in RBC microvesicles. s eleton-free RBC microvesicles were generated from erythrocytes expressing known RBC antigens. Antigen segregation into vesicles was documented by immunospecific antigen-antibody binding using IgG eluates and 125I Protein A. 125I Protein A counts per minute (cpm) ratios between antigen-positive vesicles sensitized with 11 eluates compared with those of vesicles incubated with normal human serum are reported. s eleton-free RBC microvesicles preserved the antigenic expression of the original RBCs. Differences in cpm between eluate-sensitized vesicles and those incubated with normal human serum ranged from 3:1 for the Fyb antigen to 65:1 for the D antigen. sions tudy demonstrates that molecules bearing common RBC antigens segregate into microvesicles, fully preserving their epitope-bearing activity. The major proteins of the RBC cytoskeleton are not required for such antigen expression.