Effect of neoadjuvant chemotherapy on regulatory T cells in the peripheral blood of patients with breast cancer

Objective To investigate the effect of neoadjuvant chemotherapy on CD4+CD25+Foxp3+ T regulatory(Treg)cells in the peripheral blood of patients with breast cancer.Methods A total of 68samples of peripheral blood of patients with breast cancer were collected on the 1st day before neoadjuvant chemotherapy and the 10th day after neoadjuvant chemotherapy.The proportion of Treg,CD3+,CD4+and CD8+ T cells in peripheral blood in the total amount of T cells was detected by flow cytometry.Independent-sample t test or paired t test was used for the quantitative data analysis.Results The percentage of CD4+CD25+Foxp3+regulatory T cells in the peripheral blood of the breast cancer patients before chemotherapy(4.77±0.76)% was significantly higher than that(0.68%±0.36)%in the healthy doners(t=21.176,P=0.000).The proportion of Treg cells in T lymphocytes was significantly decreased from(4.77±0.76)% before neoadjuvant chemotherapy to(1.59±0.58)% after neoadjuvant chemotherapy(t=19.041,P=0.000);but CD4+/CD8+ was significantly increased from(1.19±0.43)%before neoadjuvant chemotherapy to(1.95±0.72)% after neoadjuvant chemotherapy(t=8.280,P=0.000).The treg cells in the chemotherapy-effective group were significantly decreased compared with the chemotherapy-ineffective group,with a statistical difference between the two groups(t=8.227,P=0.000).Conclusions Neoadjuvant chemotherapy can regulate the immune-tolerance of breast cancer patients,and improve their immune function.Neoadjuvant chemotherapy may inhibit tumor through reducing Treg cells in the peripheral blood of patients with breast cancer.