Suppressed innate immune response against mammary carcinoma in balb/c mice

Abstract

Breast carcinoma is one of the leading causes of deaths among women worldwide. The immune response in breast cancer is mediated by innate and adaptive immune cells, including natural killer (NK) cells, dendritic cells (DCs) and T lymphocytes. The 4T1 mammary carcinoma line derived from BALB/c mice shares many characteristics with naturally occurring human breast cancer. We aimed to investigate the mechanisms of anti-tumour immunity using the experimental 4T1 breast cancer model in syngeneic BALB/c mice. After 12 days of tumour inoculation, mammary carcinoma-bearing mice had signifi cantly decreased numbers of NKp46 + NK cells compared with healthy mice and lower cytotoxic activity of total splenocytes and NK cells in vitro. Additionally, signifi cantly higher numbers of CD11c + DCs were detected in the spleens of tumour-bearing mice, but the number of activated CD80 +CD86 + dendritic cells was entwithsimilar to that in healthy mice, indicating an increased number of immature DCs in tumour-bearing mice. The data indicate that 4T1 mammary carcinoma progression in BALB/c mice is associated with suppressed innate anti-tumour immunity.