Aim and Background: it seems that population of regulatory T cells increases in many malignancies leading to suppression of effector immune responses and thereby to progression of the disease. We aimed to assess infiltration of the regulatory T cells into tumor environment in women with breast carcinoma.
Methods: in a control-case study, 9 malignant tumor tissues from invasive intraductal breast carcinoma (case) and 8 benign breast tissues from healthy women (control) were mechanically and enzymatically processed. The prepared cell suspension was then subjected to staining of cell surface markers CD4 and CD25, and the extracellular marker FOXP3, and were finally analyzed by flow cytometry.
Results: population of regulatory T cells in malignant tumor tissues showed significant increase compared to the control (P< 0.001). A weak positive correlation was observed between size of the tumors and the infiltration of regulatory T cells. Also, there was moderate negative correlations between age of individuals and the number of regulatory T cells in both malignant and benign breast tissues.
Conclusions: increased regulatory T cells population in invasive intraductal breast tumor environment may be the major cause of immunosuppression contributing to the tumor progression. However, further studies with larger sample size are suggested to clarify this hypothesis.