Wbcs helps fight infection due to the maturation of what?

Leukocytosis: Polymorphonuclear leukocytes are manufactured in the bone marrow, released into the blood stream and often adhere to the walls of blood vessels. When infection occurs they exit thru spaces between cells and enter tissues where they eat bacteria or foreign items, like a pacman. They mature from blasts, to promyelocytes, metamyelocytes, myelocytes, and bands to pmnls.