γδ T cells lyse autologous and allogenic oesophageal tumours:: involvement of heat-shock proteins in the tumour cell lysis

T cells expressing gamma delta receptors were isolated from the peripheral blood of oesophageal cancer patients and analysed for their potential to lyse tumour targets. Immunophenotyping by flow cytometry showed that the dominant population of gamma delta T cells expressed the V gamma 9 and the V delta 2 T cell receptor, and a minor population expressed the V delta 1 receptor. Cytotoxicity assays revealed that activated gamma delta T cells lysed Daudi Burkitt's lymphoma and K562 cells. Lysis of autologous oesophageal tumours was higher than of allogenic tumours. Anti-hsp60 and anti-hsp70 mAb significantly inhibited the cytotoxicity of gamma delta T cells to both autologous and allogenic oesophageal tumours. Surface expression of hsp60 and hsp70 on oesophageal tumours and Daudi cells was demonstrated by flow cytometry. In conclusion, gamma delta T cells isolated from the peripheral blood of oesophageal cancer patients have the ability of kill oesophageal tumour cells. The lysis of tumour targets by the gamma delta T cells is brought about via recognition of heat-shock proteins expressed on the surface of tumour cells. gamma delta T cells isolated from the peripheral blood may have applications in adoptive immunotherapy of oesophageal cancer.