Use of enzyme-treated cells in immunotherapy of leukaemia.

Abstract

The in vitro treatment of tumor cells with Vibrio cholerae neuraminidase (VCN) increases their immunogenicity [5, 6, 9]. VCN-treated tumor cells frequently fail to grow in animals, and the recipients are rendered immune to a subsequent challenge with untreated viable tumor cells. Moreover, inoculation of VCN-treated cells into animals grafted with cells from the same tumor is able to impair the growth of the initial tumor-cell inoculum [10, 11]. However, using a transplantable murine leukemia, we have observed that immunotherapy with VCN or papain-treated leukemia cells abolishes the expected effects of active specific immunotherapy.