Tumour specific immunogenicity of methylcholanthrene-induced sarcoma cells after incubation in neuraminidase.

IT was previously suggested (Currie and Bagshawe, 1967) that effective antigenic expression by some types of tumour cell may be inhibited by the presence of sialic (N-acetylneuraminic) acid in the cell periphery. Treatment of the cells from several " non-specific " transplantable mouse tumours with neuraminidase results in a marked increase in their immunogenicity when subsequently injected into intact host mice and leads to a powerful anti-tumour immunity in these animals. So far this phenomenon has been reported using the Ehrlich (Lindenmann and- Klein, 1967), Landschuitz (Currie, 1967), and TA3 (Sanford, 1967) ascitic tumours. The antigenic discrepancies between these tumours and their respective host mice are probably related to strain-specific histocompatibility differences, i.e. these tumours are malignant allografts. Little of the information obtained from the study of such tumours is of immediate relevance to the growth and development of autochthonous tumours where the only tumour-host antigen discrepancy (if any) is specific to the tumour. The purpose of this paper is to report studies of the effects of incubation i