Characteristics of Heterologous Membrane Antigen on Cultured Human Cells

Summary

HM Ag (heterologous membrane antigen) is incorporated into membranes of cultured human cells grown in media containing bovine serum. Natural antibody against HM Ag isfound in human sera. Immune adherence tests assayed the HM Ag on a human sarcoma cell line (SA-2). HM Ag was removed from the cell membranes of SA-2 grown in media with fetal calf serum (FCS) after the cells were transferred into agamma human serum (2-3 wk) or into whole human serum (1-2 wk). Cells grown in human serum reincorporated HM Ag into their membranes within 24 hours after transfer to medium with 20% FCS. The incorporation did not occur at 0° C and was suppressed with metabolic inhibitors. Treatment with neuraminidase removed the antigen, though treatment with proteinase did not. Anti-HL-A antibody reactivity was higher to cells grown with agamma human serum than to cells grown with FCS.