N-acetyl- β-D-Glucosaminidase (NAG) isoenzymes release from human monocyte-derived macrophages in response to zymosan and human recombinant interferon-γ

Abstract

Secretion of N-acetyl- β-D-glucosaminidase (NAG) isoenzymes by human blood monocyte-derived macrophages in response to zymosan and human recombinant interferon-γ was studied. Macrophages were found to release NAG in response to zymosan, but interferon-γ has no effect on secretion. Isoenzyme separation by isoelectric focusing demonstrates that non stimulated and zymosan or interferon-γ treated macrophages release predominantly NAG B and, to a lesser extent, NAG A isoenzymes. In all these conditions, the intracellular intermediate form NAG I could not be detected in the media. Thus, activated macrophages may not be the source of NAG intermediate forms I and P in pathological or maternal serum. In contrast, macrophages could contribute to a significant elevation of urinary activity and NAG B excretion in response to inflammatory conditions.