Recombinant Human Leukocyte Interferon Modulates Neutrophil Function In Vitro

Abstract

Recombinant human interferon-α2 (rIFN-αA) was evaluated as a modulator of neutrophil functions. Neutrophils treated with rIFN-αA for 1 h in vitro showed reduced chemiluminescence (CL) and aggregation in response to phagocytosis. In contrast, when certain soluble stimuli [f-met-leu-phe (fMLP) or leukotriene B4] were used, rIFN-αA treatment conferred a doubling of CL. This was paralleled by a similar increase in Superoxide anion production and a 56% increase of release of β-glucuronidase and lysozyme. The NBT test showed that IFN treatment did not increase the number of responding neutrophils. However, there was a significant increase in the displaceable binding of fML[³H]P. Enzyme release, aggregation, and CL in response to other soluble stimuli, the ionophore A23187 and phorbol myristate acetate were unaffected by IFN treatment. Likewise, chemotaxis was not affected. Thus, phagocytosis-associated events and aggregation were hampered by rIFN-γA whereas secretory responses to receptor-dependent soluble stimuli were augmented. The mechanism for the latter is most likely dependent on the observed modulation of binding of fMLP to its receptor.