Cells of the mononuclear and polymorphonuclear series were analyzed throughout the course of Toxoplasma gondii infections of C57 BL/6 female mice with chronic inflammatory foci. The animals were inoculated intraperitoneally with 90-100 parasitic cysts followed by subcutaneous implantation of cover glasses (after 4 days). The shift of leukocytes from the blood to the inflammatory focus, corresponding to a prolonged infiltration of myeloid cells, was measured in a time course of 20 days. A significant decline was observed in the mature polymorphonuclear cells in the blood and a concomitant development of a marked monocytosis. Infections with T. gondii in mice with chronic inflammatory foci resulted in dedication of the entire myeloid cells system to the generation of cells that were exported to combat the inflammation, which occurred in those places, and to the chronic infection itself. The shift in the normal proportions of cells and in cells of different degrees of maturity, suggesting that a blockade in the chemokines extruded to attract polimorphonuclear cells, might account to a large extent for the failure of immune responses commonly associated with Toxoplasma subclinical infections.
Toxoplasma gondii; myeloid cells; chronic infection; leukocytes
