Immunotoxins composed of monoclonal antihuman T Iymphocyte antibody and single chain ribosome—inactivating proteins:antitumor effects in vitro and in Vivo / 中国免疫学杂志

ABSTRACT

Two new single chain ribosome—inactivating proteins,polygonin2 from the roots ofPolygonatum odoratum and momordin2,from the seeds of Momordica charantia,inhinited pro-teib synthesis potentially in rabbit reticulocyte lysate,but were relatively low toxic to Molt—4 cells.polygonin2 and momordin2 were conjugated to H65 monoclonal antibody that recognizedhuman T lymphocyte CD5 surface antigen using a heterobifunctional crosslinking reagent 2—iminothiolane.The resulting immunotoxins,referred to as H65—PGN2 and H65—MOR2,showed potent specific cytotoxicity to target cell Molt—4 and human peripheral blood T lympho-cyte,but had no effect on human hematopoietic cells.Injection of Molt—4 cells s.c.into Balb/cnu/nu mice developed into a solid tumor.Administration of the H65—PGN2 or H65—MOR2immunotoxins i.p.10 ug per mice at 48—h intervals suppressed tumor growth specifically.Theresulting showed that clinical studied were warranted to use these conjugates for the therapy ofautoimmune diseases as well as the ex vivo purging of T lymphocyte in ABMT.