what are b cells in the immune system
B cells, also known as B lymphocytes, are a type of white blood cell of the lymphocyte subtype.They function in the humoral immunity component of the adaptive immune system by secreting antibodies.Additionally, B cells present antigen (they are also classified as professional antigen-presenting cells (APCs)) and secrete cytokines.hey function in the humoral immunity component of the adaptive immune system by secreting antibodies. Additionally, B cells present antigen (they are also classified as professional antigen-presenting cells (APCs)) and secrete cytokines.