Development of the phagocytic and cidal capacity during maturation of myeloid cells: studies on cells from patients with chronic myelogenous leukaemia.

Myeloid cells from peripheral blood of patients with chronic myelogenous leukaemia were isolated and fractionated by density gradient centrifugation using Lymphoprep gradient followed by discontinuous Percoll gradients. Six fractions were obtained, each enriched in one of the morphologically identifiable types of myeloid cells from myeloblasts to polymorphonuclear neutrophils. Each of these cell types were functionally and biochemically characterized. The development of the capacities for phagocytosis and killing of yeast cells and the ability to generate a respiratory burst of phagocytosis correlated closely with the content of cytochrome b and vitamin B12-binding protein, a marker of specific granules. These results support the notion that the specific granules provide the developing neutrophil with components which are essential for its microbicidal activity.