NEUTROPHILS AS EFFECTOR-CELLS OF T-CELL-MEDIATED, ACQUIRED-IMMUNITY IN MURINE LISTERIOSIS

The control of the infections caused by Listeria monocytogenes, consid ered an example of an intracellular parasite, is thought to involve co -operation between antigen-specific T cells and activated macrophages. Here we investigated the participation of polymorphonuclear leucocyte s in the mechanisms of resistance during the immune phase of the antim icrobial response to L. monocytogenes infection. We found that BALB/c mice were unable to express T-cell-mediated (acquired) immunity to thi s pathogen in the absence of granulocytes. We propose that neutrophils should be included in the concept of cell-mediated immunity and that their antimicrobial role is not exclusively expressed during the early phases of a primary infection.