Cancer tumour immunology

The transformation of a cell to the cancerous state is normally associated with increased surface expression of antigens recognized as foreign by the host immune system. These surface antigens, often termed tumour antigens or tumour surface antigens, are either not expressed at all by the untransformed cell or are expressed at such low levels that they fail to induce immunological tolerance. 

In contrast to the above situation, cancers induced by viruses generally exhibit immunological cross-reactivity. Any specific virus will often induce expression of the same tumour antigen no matter what cell type it transforms. Moreover, in some cases, different transforming viruses can induce production of the same tumour antigen(s). Immunodetection/immunotherapy of such cancers is thus rendered attractive. Once a tumour antigen is identified, antibodies raised against it will likely cross-react with several other tumour types. 

Using an indirect immunoperoxidase technique an antigen, immunologically related to a glycoprotein of mouse mammary tumour virus, has been identified in sections of human breast cancer. Cross-reactivity between the human and murine antigens is due to the polypeptide rather than the oligosaccharide component. ... 

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