GRANULOPOIESIS DURING ACUTE TOXOPLASMA-GONDII INFECTION IN MICE

There is little evidence for the role of granulocytes in the host defe nce against the protozoan parasite Toxoplasma gondii. Thus, the purpos e of this study was to assess the involvement of granulocytes during a cute murine infection with the parasite virulent RH strain. Since, all infected animals succumb to infection in a dose-dependent period of t ime, the effect of two parasite doses, 2x10(2) and 2x10(6), on granulo cytis cell compartments in the bone marrow and peripheral blood up to 2 or 6 days post infection, respectively, was investigated. The data o btained revealed that granulocytic cells at various stages of differen tiation and maturation were affected by T.gondii infection regardless of the dose applied. The observed oscillating changes in the number of cells in granulocytic proliferative and nonproliferative compartments imply that parallel with T.gondii-induced damage to granulocytic cell s, a process of stimulated production of granulocytes occurred. Althou gh some differences in the kinetics of cellular changes and in the ext ent of cell damage were found similar reactivity patterns of granulocy tic cells were seen following infection with both doses. Our results d emonstrated significant changes in granulopoiesis during T.gondii infe ction, suggesting a possible contribution of granulocytes to parasite control.