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Human Monocyte to Macrophage Differentiation In Vitro: Characterization and Mechanisms of the Increased Antibody‐Dependent Cytotoxicity Associated With Differentiation
Author(s) -
Sagone Arthur L.,
Rinehart John J.
Publication year - 1984
Publication title -
journal of leukocyte biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.819
H-Index - 191
eISSN - 1938-3673
pISSN - 0741-5400
DOI - 10.1002/jlb.35.2.217
Subject(s) - biology , in vitro , monocyte , cytotoxicity , macrophage , cellular differentiation , immunology , microbiology and biotechnology , antibody , biochemistry , gene
Human monocyte‐to‐macrophage differentiation in vitro is associated with marked enhancement in the capacity to bind and lyse antibody‐opsonized red blood cells (rbc). We previously demonstrated that this was due in part to an increased number of Fc receptors. The current study further characterized the mechanism of this enhanced macrophage as antibody‐dependent cellular cytotoxicity (ADCC). We observed that 1) macrophages but not monocytes lysed “innocent bystander” rbc as well as opsonized rbc; 2) macrophages exhibited an increased hexose monophosphate shunt activity compared to monocytes; 3) macrophage produced H 2 O 2 but not OH·; and 4) macrophage lyses of opsonized rbc were 80% O 2 dependent. We conclude that human monocyte‐to‐macrophage maturation in vitro is associated with an enhanced O 2 ‐dependent cytotoxic mechanism normally present in monocytes. The enhanced H 2 O 2 production noted in macrophages may reflect an increased generation of several other reactive oxygen species in these cells. One of these oxygen radicals may be the mediator of the enhanced macrophage cytotoxicity and of the “innocent bystander” phenomenon observed.