UC Irvine

We have purified to homogeneity the αL-component (70,000-90,000) of the human LT cytolytic system. This lymphokine was purified ~ 10, 000-fold from supernatants of lectin-stimulated human tonsil and adenoid lymphocytes by molecular sieving, ion-exchange chromatography on DEAE-Sepharose, and preparative PAGE. The homogeneity of the radiolabeled molecule was confirmed both by electrophoresis and electrofocusing. The identity of the labeled peak with the lytic activity was demonstrated with a concomitant bioassay of the electrophoresed preparation; in addition, immunoprecipitation with a heterologous specific anti-αL antiserum showed simultaneous precipitation of the radiolabeled component and lytic activity. Immunological and biochemical evidence has previously shown this molecule to be a subunit of the Cx- and αH-LT forms. The latter LT classes are of intense interest because of their capacity for rapid selective cell lysis. © 1981.