Neutrophil haptotaxis induced by mouse MNCF: interactions with extracellular matrix glycoproteins probably contribute to overcoming the anti-inflammatory action of dexamethasone.
OBJECTIVE
The Macrophage-derived Neutrophil Chemotactic Factor (MNCF) has been characterized as a dexamethasone-resistant neutrophil chemotactic lectin produced by rat macrophages. This study was undertaken to evaluate different MNCF cellular sources and investigate the mechanisms by which MNCF overcomes the anti-inflammatory actions of dexamethasone.


METHODS
The mouse macrophage-like cell line P388D1 and thioglycollate-elicited mouse macrophages were studied regarding their capacity to release MNCF. Neutrophil migration assays were performed in vivo and in vitro, in either the presence or absence of extracellular matrix glycoproteins (ECM).


RESULTS
Mouse and P388D1 macrophages release a lectin that reproduces the activities of rat MNCF. The ability of MNCF to induce neutrophil adhesion and haptotaxis is enhanced through its interaction with laminin and fibronectin. These properties are not inhibited by dexamethasone.


CONCLUSIONS
Together, our results suggest that dexamethasone-resistant neutrophil migration induced by MNCF occurs probably because of its interactions with ECM.
de Toledo
K Alves
KA
Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av Bandeirantes 3900, Campus USP, 14049-900, Ribeirão Preto, São Paulo, Brasil.
Bernardes
E Soares
ES
Baruffi
M Dias
MD
Roque-Barreira
M-C
MC
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D002460:Cell Line; D002465:Cell Movement; D003907:Dexamethasone / Q000494:pharmacology*; D005353:Fibronectins / Q000502:physiology*; D016209:Interleukin-8 / Q000502:physiology*; D007797:Laminin / Q000502:physiology*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009504:Neutrophils / Q000502:physiology*; D014409:Tumor Necrosis Factor-alpha / Q000502:physiology
D000893:Anti-Inflammatory Agents; D005353:Fibronectins; D016209:Interleukin-8; D007797:Laminin; D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha; D003907:Dexamethasone