Endogenous Synthesis of Membrane b5 by Lymphocytes from Rabbits Recovering from b5 Allotype Suppression

Abstract

Abstract In the rabbit, production of b-locus allotypic determinants present on kappa-type light chains can be suppressed by perinatal exposure to anti-b5 antisera (allotype suppression) (1, 2). We have previously demonstrated that b5-bearing lymphocytes are deleted in totally suppressed rabbits with no circulating b5, and that in spontaneous escape from suppression the appearance of b5-bearing lymphocytes immediately precedes the appearance of detectable serum b5 (3). However, during recovery from allotype suppression, the proportion of peripheral blood lymphocytes with membrane b5 approaches normal levels, while circulating b5 levels remain chronically and disproportionately depressed (3). Because there is this unusual discrepancy between the number of b5-bearing lymphocytes and the amount of circulating b5 in rabbits recovering from allotype suppression, and because passive adsorption of circulating b5 molecules to lymphocytes not themselves capable of synthesizing b5 could account for the inappropriately large number of b5-bearing cells, we have investigated these lymphocytes for their ability to synthesize actively their own membrane b5 Ig after enzymatic stripping of the cell surface.