H-2D ANTIGENS RELEASED BY THYMOCYTES AND CELL ADHESION

Publisher Website
Google Scholar
Abstract
The identity and complete purification of mouse thymocyte interaction modulation factor (T IMF) is described. Use of Ag-stained PAGE [polyacrylamide gel electrophoresis] methods shows that previous methods of purification yield preparations containing 2 protein or glycoprotein bands. T IMF activity from H-2k mice can be bound to 15.5.5 monoclonal antibody columns (anti H-2 Dk) but not to 11.4.1 columns (anti H-2 Kk). The activity can be recovered from 15.5.5 columns and runs on PAGE as a single band at approximately 34,000 daltons. This evidence and evidence relating the activity to H-2 D locus argues that T IMF is a soluble H-2 D antigen fragment equivalent to a papainized H-2 fragment. Additional evidence is presented on an improved method of assay of T IMF activity, on its activation by enzymes and serine-esterase inhibitors and of its effect on syngeneic leukocytes and macrophages. T IMF is not appreciably toxic for cells.