Immunochemical Characterization of the Antigen Specific T Cell Factor

Abstract

Some physiochemical and immunochemical properties of the suppressive T cell factor(TsF)extracted from carrier-primed thymocytes and spleen cells were investigated. Keyhole limpet hemocyanin(KLH)-specific TsF was successfully absorbed by an Immunoadsorbent com posed of KLH but not of unrelated antigen(Ascaris suum extract;Asc). The active component was recovered from the KLH-coated column by elution with 3M KCl. Despite this antigen-specificity. TsF was estimated to be between 35000 and 55000 daltons by Sephadex G-200 gel filtration. Since it has been established that TsF is a product of genes mapped in I-J subregion of major histocom-patibility complex, an attempt was made to characterize TsF by SDS-polyacrylamide gel electrophoresis after coprecipitation with anti-I-J alloantiserum and Staphylococcal protein A. The results, though not complete, suggested that TsF having both I-J determinants and the antigen binding site migrates to a position corresponding to a molecular weight around 44000 daltons under reducing condition.