Eosinophil cationic protein stimulates and major basic protein inhibits airway mucus secretion.
Possible roles of eosinophil (EO) products in modulating the release of mucus from airway explants were investigated. Cell- and membrane-free lysates from purified human EOs (1 to 20 x 10(5)) caused a dose-dependent release of respiratory glycoconjugates (RGC) from cultured feline tracheal explants. Crude extracts from isolated EO granules also stimulated RGC release, suggesting that a granular protein might be responsible. Three proteins derived from EO granules, EO-derived neurotoxin, EO cationic protein (ECP), and major basic protein (MBP) were separated by sequential sizing and affinity chromatography. ECP (0.025 to 25 micrograms/ml) caused a dose-dependent increase in RGC release from both feline and human airway explants and also stimulated the release of the serous cell-marker, lactoferrin, from human bronchial explants. EO-derived neurotoxin (0.025 to 50 micrograms/ml) failed to affect RGC release, whereas MBP (50 micrograms/ml) significantly inhibited RGC release from feline explants. Thus, ECP stimulates RGC and lactoferrin release from airway explants, whereas MBP inhibits RGC release.
Lundgren
J D
JD
Critical Care Medicine Department, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Md.
Davey
R T
RT
Lundgren
B
B
Mullol
J
J
Marom
Z
Z
Logun
C
C
Baraniuk
J
J
Kaliner
M A
MA
Shelhamer
J H
JH
D000402:Airway Obstruction / Q000503:physiopathology; D000818:Animals; D001249:Asthma / Q000503:physiopathology; D001798:Blood Proteins / Q000494:pharmacology*; D002415:Cats; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay; D047091:Eosinophil Granule Proteins; D047208:Eosinophil-Derived Neurotoxin; D004804:Eosinophils / Q000378:metabolism; D006801:Humans; D007781:Lactoferrin / Q000502:physiology; D009093:Mucus / Q000378:metabolism*; D009498:Neurotoxins / Q000494:pharmacology; D009924:Organ Culture Techniques; D012260:Ribonucleases; D014132:Trachea / Q000187:drug effects*
D001798:Blood Proteins; D047091:Eosinophil Granule Proteins; D009498:Neurotoxins; D047208:Eosinophil-Derived Neurotoxin; D012260:Ribonucleases; D007781:Lactoferrin