The macrophage-derived lectin, MNCF, activates neutrophil migration through a pertussis toxin-sensitive pathway.
The macrophage-derived neutrophil chemotactic factor (MNCF) is a D-galactose-binding lectin that induces neutrophil migration in vitro and in vivo. Neutrophil recruitment induced by MNCF is resistant to glucocorticoid treatment and is inhibited by the lectin-specific sugar, D-galactose. In the present study, we characterized the binding of MNCF to neutrophils and the responses triggered by this binding. Exposure to MNCF resulted in cell polarization, formation of a lamellipodium, and deep ruffles on the cell surface. By confocal microscopy, we observed that MNCF was evenly distributed on the cell surface after 30 min of incubation. The labeling intensity progressively diminished with longer incubations. Internalization kinetics showed that MNCF/ligand complexes were rapidly internalized, reaching maximum intracellular concentrations at 120 min and then decreased thereafter. The binding and internalization of MNCF were selectively inhibited by D-galactose. MNCF-induced neutrophil chemotaxis was inhibited by pertussis toxin. This fact strongly suggests that the MNCF-ligand on the neutrophil surface is a G-protein-coupled receptor (GPCR), similar to receptors for well-established neutrophil attractants. Our observations on the ability of MNCF to activate neutrophils are consistent with the increasing evidence for the participation of animal lectins in the innate immune response.
Moreno
Andréa N
AN
Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, 3900 Ribeirão Preto, SP 14049-900 Brazil.
Pereira-da-Silva
Gabriela
G
Oliver
Constance
C
Jamur
Maria Célia
MC
Panunto-Castelo
Ademilson
A
Roque-Barreira
Maria Cristina
MC
D016764:Cell Polarity; D002634:Chemotaxis, Leukocyte / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D016209:Interleukin-8 / Q000502:physiology*; D037102:Lectins / Q000502:physiology*; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D009504:Neutrophils / Q000502:physiology*; D037342:Pertussis Toxin / Q000494:pharmacology*; D011134:Polysaccharides / Q000378:metabolism; D043562:Receptors, G-Protein-Coupled / Q000502:physiology
D016209:Interleukin-8; D037102:Lectins; D011134:Polysaccharides; D043562:Receptors, G-Protein-Coupled; D037342:Pertussis Toxin