Circulating blood cells that differentiate into macrophages in the tissue M cells Monocytes Common myeloid progenitors Eosinophils Solution Answer: b. Monocytes Monocytes are the circulating blood cells which after production from the bone marrow, circulate in the bloodstream for about 8 h, during which they enlarge; and then migrate into the tissues and differentiate into specific tissue macrophages. The differentiation of a monocyte into a tissue macrophage involves a number of changes such as :.