Premium
Human carcinoembryonic antigen cDNA expressed in rat carcinoma cells can function as target antigen for tumor localization of antibodies in nude rats and as rejection antigen in syngeneic rats
Author(s) -
Pèlegrin André,
Terskikh Alexei,
Hayoz Daniel,
Chalandon Yves,
Olsson NilsOlivier,
Folli Silvio,
Buchegger Franz,
Kromer Beril,
Schwarz Klaus,
Martin Monique,
Martin Francois,
Mach JeanPierre
Publication year - 1992
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/ijc.2910520120
Subject(s) - carcinoembryonic antigen , epitope , complementary dna , microbiology and biotechnology , antigen , antibody , biology , transfection , oncofetal antigen , western blot , cancer research , cell culture , monoclonal antibody , immunology , cancer , gene , biochemistry , genetics , tumor associated antigen
We have tried to develop a new model consisting of rats transplanted with syngeneic colon carcinoma PROb cells transfected with cDNA coding for the carcinoembryonic antigen (CEA), the human tumor marker most commonly used as target for MAbs. The antigenic density of the 4 CEA‐expressing clones selected for a precise characterization ranged from 5 × 10 4 to 1 × 10 6 CEA molecules per cell. In all clones the CEA was shown to be attached to the membrane by a phosphatidylinositol (PI) anchor. Using a panel of radiolabeled MAbs directed against the 5 major epitopes described on the CEA molecule, we showed that all these CEA epitopes were expressed by the 4 transfectants. Southern‐blot analysis showed that the entire CEA cDNA was present in the transfectants. Western‐blot analysis, however, showed that the size of the CEA expressed by the 4 transfectants was slightly smaller than that of CEA produced by 2 reference human colon‐carcinoma cell lines. Two clones, expressing 1 × 10 5 and 1 × 10 6 CEA molecules per cell, respectively, were grafted s.c. in nude mice and rats. Injection of radiolabeled anti‐CEA F(ab') 2 fragments into these animals showed specific tumor localization with the highest percentages of injected doses for the transfectants expressing the highest CEA level. When grafted into immunocompetent syngeneic BDIX rats, the CEA‐expressing clones induced a strong antibody response against CEA and tumor rejections in a majority of the animals. Although the analysis of the immune response against the CEA‐cDNA‐transfected carcinoma cells is under investigation, the present results demonstrate that human CEA could function as a rejection antigen when transfected into rat carcinoma cells. © 1992 Wiley‐Liss, Inc.