Association of CD4+ CD25+ FOXP3+ regulatory T-cells and human papilloma virus infection in Egyptian Women with breast cancer

Several subsets of regulatory CD4+ T cells (CD4+ Tregs) have been described in peripheral blood and tumor microenvironment and blood of breast cancer (BC) patients and may play a key role in the progression of BC. High-risk human papilloma virus (HPV) have a causal role in a significant proportion of cervical, and head, and neck tumors and may play an important role in evoking neoplasia in BC. In this study we assessed the prevalence of CD4+Tregs (CD4+CD25+ FOXP3+ cells) and CD3+ CD8+ T cells by flow cytometry in peripheral blood from a total of 55 Egyptian women, including 20 treatment-naïve BC, 15 with breast benign lesions (BBL) and 20 healthy volunteers (HV). High-risk HPV genotype type 16, 18, and 31 was investigated in breast tissue from all BC and BBL patients using Real-Time PCR. HPV was detected in 4 BC, but in none of BBL patients. The frequency of CD4+ Tregs was significantly higher in BC compared to BBL and HV, (p < 0.001). In addition, we observed a significantly higher frequency of CD3+ CD8+ T cells in peripheral blood of patients with late stage III compared to early stage I and II BC (p = 0.011). However, there was no significant association between the ratio of CD8+ T cell to CD4+ Tregs frequencies and the expression of Estrogen Receptor (ER), Progesterone Receptor (PR), and Human Epidermal Growth Factor Receptor 2 (HER2). In conclusion, CD4+ Tregs may contribute to progression BC in Egyptian women with HPV infection. The potential role CD4+ Tregs as a prognostic or predictive parameter should be analyzed in a larger longitudinal study with sufficient follow-up time.