Increased number of cytotoxic CD3+ CD28- gammadelta T cells in peripheral blood of patients with cutaneous malignant melanoma.

BACKGROUND

A rise of CD3+ TCRgammadelta+ CD28- T cells has previously been observed after an in vitro long-lasting activation or even during viral infection.

OBJECTIVE

The aim of this study was to investigate the expression of CD28 on lymphocytes bearing CD3/TCRgammadelta receptors in cancer, i.e. cutaneous melanoma.

METHODS

TCRgammadelta lymphocytes were analysed in 41 Caucasian melanoma patients and 39 healthy individuals by flow cytometry. Patients were stratified according to the American Joint Committee on Cancer (AJCC) clinical stage.

RESULTS

The number of circulating CD3+ TCRgammadelta+ T cells was significantly increased in both AJCC stages I-II and AJCC stage III patients compared with healthy individuals. This increase was mediated by an accumulation of the CD3+ TCRgammadelta+ CD28- T-cell subset, which expressed a high amount of perforin both in normal individuals and melanoma patients.

CONCLUSION

This work shows, for the first time, a rise of the cytotoxic CD3+ TCRgammadelta+ CD28- T-cell population in melanoma patients, which may be important in anticancer surveillance.