Fig 1.

Specific antigen-recognition by a genetically engineered T cell leads to cytolytic killing of a tumour cell. The T cell is transduced with a viral vector encoding either a new antigen-specific TCR or chimeric antigen receptor CAR. (a) The tumour cell presents peptide fragments from tumour-associated antigen (TAA) on its surface in association with HLA class I. Specific recognition of the peptide/HLA complex leads to TCR signalling which triggers cytolytic killing of the tumour cell through secretion of perforins and granzymes and FasL-Fas interaction. (b) The tumour cell expresses a TAA on its surface. Specific recognition of the TAA leads to CAR signalling which triggers cytolytic killing of the tumour cell as described in (a).