Detection of immune responses against urinary bladder cancer in sentinel lymph nodes.

OBJECTIVE

The lymphatic drainage from a tumour is received in the sentinel node where the immune system encounters tumour derived antigens. We investigated anti-tumoural lymphocyte function in sentinel nodes from patients with urinary bladder cancer.

METHODS

In 14 patients undergoing cystectomy due to bladder cancer, radioactive tracer and blue dye were used to identify the sentinel node. Cell suspensions from the tumour, sentinel- and non-sentinel nodes and peripheral blood were analyzed by flow cytometry with antibodies against lymphocyte surface antigens and against the tumour cell marker cytokeratin-20. Reactivity against autologous tumour extract and the mitogen Concanavalin A was tested in proliferation assays with 3H-Thymidine incorporation. Lymphocytes were put in long-term culture with IL-2 and autologous tumour extract.

RESULTS

Sentinel nodes were detected in 12 of the 14 patients. Antigen dependent proliferation in response to autologous tumour extract was detected in 6 patients, in 5 cases in sentinel nodes, in the remaining case in a non-sentinel node. Proliferation against Concanavalin A was vigorous in lymph nodes from all patients, whereas tumour infiltrating lymphocytes were unresponsive. Lymphocytes from sentinel nodes could be expanded in vitro.

CONCLUSION

Tumour reactive lymphocytes are present in sentinel nodes draining human bladder cancers. These cells display immunologic function upon restimulation in vitro, and provide a promising source for expansion and subsequent adoptive T cell immunotherapy.