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Differential effects of interleukin‐4 on superoxide anion production by human alveolar macrophages stimulated with lipopolysaccharide and interferon‐γ
Author(s) -
Bhaskaran Geetha,
Nii Akihiko,
Sone Saburo,
Ogura Takeshi
Publication year - 1992
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.52.2.218
Subject(s) - lipopolysaccharide , superoxide , muramyl dipeptide , stimulation , interferon gamma , pulmonary alveolus , cytokine , interleukin , biology , chemistry , immunology , microbiology and biotechnology , macrophage , in vitro , biochemistry , endocrinology , immune system , enzyme
The effect of interleukin‐4 (IL‐4) on the activation state of human alveolar macrophages (AMs) and blood monocytes induced by lipopolysaccharide (LPS) or recombinant interferon‐γ (IFN‐γ) was investigated on the basis of their ability to produce superoxide anion (O 2 ‐ ). AMs were obtained from healthy donors by bronchoalveolar lavage, and O 2 ‐ productions of these cells were assayed by a cytochrome c reduction method after incubation with stimulants for 24 h. AMs produced more O 2 ‐ than autologous blood monocytes when stimulated with LPS. IL‐4 alone had little effect on O 2 ‐ production by unstimulated AMs but down‐regulated O 2 ‐ production by LPS‐stimulated AMs in a dose‐dependent manner. IL‐4 also suppressed O 2 ‐ production by AMs induced by the synergistic actions of muramyl dipeptide (norMDP) and IFN‐γ. Maximum suppression by IL‐4 of O 2 ‐ production by AMs was observed when IL‐4 was added within 1 h after initiation of LPS stimulation. AMs also showed high O 2 ‐ production when stimulated with IFN‐γ alone. In contrast to its suppression of O 2 ‐ production by LPS‐stimulated AMs, IL‐4 enhanced O 2 ‐ production by AMs stimulated with IFN‐γ. These data suggest that IL‐4 is an important regulator of O 2 ‐ production by macrophages through different pathways depending on the stimulus.