The first line of white blood cell defense against pathogens are the nk cells?

NK cells act fast. Nk cells are lymphocytes. Other lymphocytes require some level of processing of antigens before they act. Nks do not have this requirement. Therefore, they can recognize abnormal cells (infect cells or malignant cells) earlier than the other blood cells of the immune system. They are not as powerful as the other cells of the immune system, but are faster.