Migration of stromal cells supporting mast-cell differentiation into open wound produced in the skin of mice.

Mutant mice of Sl/Sld genotype are depleted of tissue mast cells due to a defect of stromal cells which may support the differentiation of mast cells. Number of mast cells did not increase in the skin of Sl/Sld mice grafted on the back of the congenic +/+ mice even 50 weeks after the transplantation. When the wound was produced in the central part of the Sl/Sld skin graft, a considerable number of mast cells appeared within the scar resulting from the wound. The appearance of mast cells in the scar was shown to be due to the differentiation of circulating precursors into mast cells rather than the simple migration of mature mast cells by using giant granules of bgJ/bgJ mice as a marker for newly-formed mast cells. Therefore, the present results seem to suggest that normal stromal cells of the +/+ host origin migrate into the wound produced in the grafted skin of Sl/Sld mice and support the differentiation of circulating precursors into mast cells.