Paired tumour infiltrating lymphocyte (TIL) and tumour cell line from bladder cancer: a new approach to study tumour immunology in vitro.

This paper reports the first example of tumour infiltrating lymphocytes (TILs) and a tumour cell line from the same individual and analyses their characteristics. The tumour cell line (CAT), derived from a patient with well-differentiated (G3pTa) TCC, has been in culture for 24 months and subcultured more than 100 times. Epithelial origin was established by electronmicroscopy and use of a range of monoclonal antibodies (Mabs) against cytokeratins. The TILs isolated from the same tumour expressed all the phenotypic characteristics of normal activated T cells and demonstrated low levels of cytotoxicity against the autologous tumour line (CAT). Comparison of cell surface molecules of these cells revealed the loss of HLA-B7, B44 and Bw6 from the CAT cells whilst maintaining HLA-A2, A3 and Bw4. Karyotypic analysis demonstrated three rearranged chromosomes (between chromosomes 4 and 11, 10 and 13, 11 and 17) on CAT cells. The potential that study of paired autologous tumour cells and TILs in culture offers for studying the role of MHC antigens in tumour rejection and the impact of different approaches to correcting the defect are reviewed.