B cells are designed to only react to foreign antigens, and if the dendritic cell presents something foreign, the B cell turns into a plasma cells and starting cranking out antibodies which then flow into the lymph and exit the lymph node.

B细胞仅仅用于对异体抗原起反应，并且如果树突状细胞呈递异体物质，B细胞就会转变为浆细胞，开始制造抗体而抗体随淋巴流出淋巴结。