CD4+CD25+ regulatory T cells in the peripheral blood of patients with breast cancer and non-small cell lung cancer.

It is well known that immunosuppression may contribute to the progression and chemotherapy-resistance of cancer. Recent studies have demonstrated that lymphocytes with the phenotype of CD4+CD25+ regulatory T cells (T-regs) contribute to immune dysfunction in cancer patients, and a relative increase in CD4+CD25+ regulatory T cells is related to immunosuppression and tumor progression in patients with some malignancies. In the present study, we evaluated the prevalence of T-regs in the peripheral blood of patients with breast cancer and non-small cell lung cancer. The phenotype of lymphocyte CD4+CD25+ cells was analyzed in peripheral blood of patients with breast cancer (n=22) and non-small cell lung cancer (NSCLC) (n=17). The population of CD4+CD25+ cells in CD3+ and CD4+ cells was evaluated by flow cytometric analysis with triple-color staining. Patients with breast cancer did not have a higher percentage of CD4+CD25+ cells in the total CD3+ and CD4+ cells in their peripheral blood than healthy volunteers. In contrast, patients with recurrent NSCLC had significantly higher percentages of CD4+CD25+ cells in CD3+ (47.6%) and CD4+ (71.0%) than healthy volunteers (n=10) who had CD4+CD25+ cells in CD3+ (33.7%, p=0.02) and CD4+ (52.2%, p<0.03). The population of CD4+CD25+ T-regs in the peripheral blood of patients with non-small cell lung cancer was significantly higher than that in healthy volunteers but not in breast cancer patients. These findings suggest that the use of T-reg-targeted immunomodulatory therapy may be a more effective strategy for patients with non-small cell lung cancer than for those with breast cancer.