Damage to respiratory epithelium by guinea-pig eosinophils stimulated with IgG-coated Sepharose beads.
BACKGROUND
There are no reports of respiratory epithelial damage induced by immunoglobulin-stimulated eosinophils.


OBJECTIVE
We tried to induce damage to respiratory epithelium by guinea-pig (GP) eosinophils stimulated with guinea-pig IgG (GP-IgG)-coated Sepharose 4B beads.


METHODS
GP tracheal epithelium was cultured together with GP eosinophils that had been collected from the peritoneal cavity, purified on a Percoll gradient, and stimulated with GP-IgG-coated beads (GP eosinophils:beads = 20:1). Damage to the epithelium was observed with an inverted microscope.


RESULTS
After 24 h of culture with three 10(6) eosinophils, irregularity of the surface of the epithelium, desquamation, shedding of cilia, and abnormal beating of cilia were observed. This damage was first observed after 12 h of incubation, and was more severe at 24 h. No damage was found when beads coated with human serum albumin (HSA) were used. GP eosinophils stimulated with GP-IgG released significantly more EPO than those stimulated with HSA, at 6 and 24 h. Heparin and catalase partially inhibited the epithelial damage. O2-production by eosinophils was also enhanced with GP-IgG-coated beads.


CONCLUSIONS
Both granule basic proteins and reactive oxygen radical may be responsible for epithelial damage, probably via an EPO + H2O2 + halide system. These results confirmed that stimulated eosinophils can damage respiratory epithelium.
Hirata
A
A
Department of Medicine and Clinical Immunology, Dokkyo University School of Medicine, Tochigi, Japan.
Motojima
S
S
Fukuda
T
T
Makino
S
S
D000818:Animals; D047209:Eosinophil Peroxidase; D004804:Eosinophils / Q000201:enzymology / Q000502:physiology*; D004848:Epithelium / Q000503:physiopathology; D006168:Guinea Pigs; D006801:Humans; D007074:Immunoglobulin G / Q000008:administration & dosage / Q000494:pharmacology*; D008163:Luminescent Measurements; D008863:Microspheres; D010544:Peroxidases / Q000378:metabolism; D011719:Pyrazines; D012709:Serum Albumin / Q000494:pharmacology; D013499:Surface Properties; D013997:Time Factors; D014132:Trachea / Q000503:physiopathology*
D007074:Immunoglobulin G; D011719:Pyrazines; D012709:Serum Albumin; C048193:2-methyl-6-phenyl-3,7-dihydroimidazo(1,2-a)pyrazin-3-one; D047209:Eosinophil Peroxidase; D010544:Peroxidases