Immunization against a rat colon carcinoma by sodium butyrate-treated cells but not by interleukin 2-secreting cells.
OBJECTIVE
Vaccination of patients with colon cancer with irradiated autologous tumor cells and bacille Calmette-Guérin (BCG) was reported to augment mean survival. It was recently observed that a local treatment combining recombinant interleukin 2 and the differentiation agent sodium butyrate cured rats with colon cancer peritoneal carcinomatosis. To optimize vaccination protocols, the comparison of the efficacy of irradiated tumor cells mixed with BCG with that of interleukin 2-gene-transfected cells and of tumor cells pretreated with sodium butyrate was performed.


METHODS
The poorly immunogenic rat colon carcinoma cells PROb were used in a vaccination assay. Interleukin 2-transfected PROb cells, either proliferating or irradiated, were used. The efficiency of irradiated PROb cells mixed with BCG, of interleukin 2-transfected cells, or of cells pretreated with sodium butyrate was tested.


RESULTS
Vaccination with irradiated parental cells and BCG did not provide protection. Irradiated interleukin 2-transfected cells were poorly efficient in the vaccination assay. Conversely, vaccination with irradiated parental cells pretreated with sodium butyrate before injection provided good protection.


CONCLUSIONS
Interleukin 2-secreting cells efficiently vaccinated animals when injected while replicating but not after irradiation. Conversely, sodium butyrate pretreatment provided a simple and efficient vaccination scheme that generated a long-term immune memory and allowed the use of irradiated cells.
Patry
Y
Y
INSERM Unité 419, Institut de Biologie, Nantes, France.
Douillard
J Y
JY
Meflah
K
K
Le Pendu
J
J
D000818:Animals; D001500:BCG Vaccine / Q000276:immunology; D002087:Butyrates / Q000494:pharmacology*; D020148:Butyric Acid; D003110:Colonic Neoplasms / Q000276:immunology*; D007376:Interleukin-2 / Q000378:metabolism*; D008212:Lymphocyte Depletion / Q000379:methods; D051381:Rats; D011919:Rats, Inbred Strains; D014162:Transfection; D014407:Tumor Cells, Cultured; D014611:Vaccination; D014612:Vaccines
D001500:BCG Vaccine; D002087:Butyrates; D007376:Interleukin-2; D014612:Vaccines; D020148:Butyric Acid