T-cell subsets in tumour rejection responses.

The roles and relative importance of the various T-cell subsets in the rejection of tumours have long been the subject of controversy. In view of the fine specificity of in-vivo rejection responses with, for example, chemically induced tumours, a highly specific means of target cell killing suggests itself. These rejection responses appear to be T-cell mediated, with little evidence for the participation of antibody dependent mechanisms, so the obvious candidate for the role of tumour cell destroyer would be the cytotoxic T cell (CTL). However, with the advent of monoclonal antibodies which were thought to separate T cells alongfunctional lines into helper and suppressor/cytotoxic subsets, amore direct evaluation of the role of CTL in tumour rejection becamefeasible. In this article R. A. Robins and R. W. Baldwin discuss T-cell subsets in tumour rejection responses.