PT - JOURNAL ARTICLE AU - Linder, Ewert AU - Edgington, Thomas S. TI - Immunobiology of the Autoantibody Response DP - 1973 Jan 01 TA - The Journal of Immunology PG - 53--62 VI - 110 IP - 1 4099 - http://www.jimmunol.org/content/110/1/53.short 4100 - http://www.jimmunol.org/content/110/1/53.full SO - J. Immunol.1973 Jan 01; 110 AB - Antierythrocyte autoantibodies directed against HB autoantigen, a cryptic site on the murine erythrocyte membrane, have been implicated previously in both direct cellular injury and autologous immune complex injury in NZB mice. Identification, isolation and characterization of this autoantigen in soluble form are sought in order to facilitate studies of the immunobiology and cellular immunology of the autoimmune response. Anti-HB autoantibodies are qualitatively neutralized not only by soluble autoantigen present in mouse plasma but also by the purified low density lipoprotein (LDL) fraction of plasma or serum. The LDL-associated HB autoantigen fraction, which is immunochemically analogous to the membrane bound autoantigen HB, appears to represent the soluble erythrocyte autoantigen SEA-HB. This soluble erythrocyte autoantigen is apparently not identical to the LDL lipid or apoprotein per se, since anti-LDL antibody does not react with erythrocyte surface HB determinants and a generic parallel but quantitative discrepancy is observed between the concentration of LDL and SEA-HB in immunoabsorption experiments. These data suggest that SEA-HB may be carried by plasma lipoproteins due to lipophilic or other properties of this autoantigen or that it may represent a minor subpopulation of murine LDL molecules.