Human tumor antigens inducing in vivo delayed hypersensitivity and in vitro mitogenic activity.

Significant immunogenic properties were observed with an antigen extracted from tumor-liberated particles (TLP). Several different tumors were used to obtain antigens by such cell analysis and purification procedures as: gel filtration on Sephadex G-100, ion-exchange chromatography, affinity chromatography, and gel filtration on Sephadex G-200. The molecular weight determined on SDS-PAGE was about 214,000 daltons. In vivo, TLP yields delayed hypersensitivity reactions both in autologous and homologous hosts. TLP does not seem to have any nonspecific mitogenic activity, but it does have specific mitogenic activity, since lymphocyte blastogenesis (TLP-induced in presensitized patients) could mean its ability when intradermally inoculated to sensitize a lymphocytic clone.