The studies on the T cell response against EBV carrying B cells demonstrated its high power in vivo. Malignancies with phenotypes similar to the in vitro transformed B cells occur only in severely immunosuppressed patients. Presently the goal of the studies is the identification of the antigens recognised by T lymphocytes and their association with the various HLA alleles. The studies on human sarcomas and carcinomas still struggle with the demonstration of specific T cell responses and the characterisation of the target molecules on the tumor cells. The main goals are the possibilities to readminister tumor reactive T cells for therapeutic purposes and the use of in vitro assays for guidance of the design and schedule for immunotherapy protocols.

By one-dimension isoelectric focusing we analysed the major histocompatibility complex class I antigen expression on human tumours. Blood lymphocytes of the patients, processed in parallel, served as a basis for comparison. The prerequisite for the analysis is the preparation of metabolically active tumour cell suspensions devoid of significant leucocyte contamination. The method was found to be suitable for study of the expression of HLA alleles on ex vivo tumour cells and allowed the detection of changes imposed by in vitro treatment with interferon γ and tumour necrosis factor α.