Characterization of monkey peripheral neutrophil granules during infection

Rhesus monkey (Macaca mulatta) neutrophils were shown to contain the azurophilic granule marker enzymes myeloperoxidase and β glucuronidase but were deficient in the specific granule markers alkaline phosphatase (AKP) and lysozyme. Isopycnic centrifugation of leukocyte homogenates on linear sucrose gradients resulted in cosedimentation of myeloperoxidase and β glucuronidase with an equilibrium density of 1.18. After an intravenous inoculation of monkeys with Salmonella typhimurium AKP activity became marked, whereas that of β glucuronidase decreased and myeloperoxidase remained unchanged. Lysozyme was undetected throughout the course of the experiment, but was present in oil induced peritoneal macrophages and peripheral mononuclear cells. The induced AKP exhibited partial latency and had an equilibrium density of 1.15. It is unclear, however, whether the induced AKP is associated with specific granules or cytoplasmic membranes. Hence, while these data are consistent with the presence of azurophilic granules in polymorphonuclear neutrophils from infected monkeys, the presence of specific granules in polymorphonuclear neutrophils of both uninfected and infected monkeys remains moot.