Identification of H- and L-ferritin subunit binding sites on human T and B lymphoid cells.

Monoclonal antibodies to the H and L subunits of ferritin were used in indirect immunofluorescent studies to investigate the subunit specificity of ferritin binding to transformed T and B lymphoid cell lines. Pre-incubation of cells with recombinant H ferritin followed by antibodies to the H subunit produced a labelling pattern in which all cells showed strong fluorescent stippling. Corresponding experiments with liver ferritin and an antibody to the L subunit revealed that most cells were lightly stippled, but 3-5% of the cells were intensely labelled. These two labelling patterns were distinct as assessed by cross-blocking experiments with recombinant H and liver ferritins. These results imply that different binding sites exist for each subunit.