Asbestos-induced release of a human alveolar macrophage-derived neutrophil chemotactic factor.
Neutrophils accumulate in the alveoli of asbestos-exposed individuals. In determining whether asbestos fibers induce the release of neutrophil chemotactic factor (NCF) from human alveolar macrophages, alveolar macrophages (10(6) cell/mL) obtained by bronchoalveolar lavage from six non-asbestos-exposed control subjects were exposed to crocidolite (0.1 and 1 mg/mL), chrysotile (1 mg/mL), or medium alone for 4 h, and NCF activity was measured in the supernatants in a 48-well microchemotaxis chamber with polycarbonate membrane filters (pore size, 3 microns) and purified human neutrophils. Alveolar macrophages in medium alone released negligible amounts of NCF (4 +/- 1 neutrophils per high-power field [N/HPF]). When macrophages were exposed to crocidolite (0.1 and 1 mg/mL), significant NCF release occurred (43 +/- 9 and 105 +/- 32 N/HPF, respectively; p less than 0.01 for each amount compare to alveolar macrophages cultured in medium alone). Chrysotile (1 mg/mL) induced similar NCF release (96 +/- 14 N/HPF; p less than 0.01 compared to unstimulated alveolar macrophages). Partial characterization of the NCF by Sephadex G-25 fine gel filtration demonstrated a molecular size of less than 1,000 daltons. These results show that human alveolar macrophages release NCF after exposure to asbestos. Release of NCF by alveolar macrophages in asbestos-exposed individuals may play a central role in the pathogenesis of asbestosis.
Hayes
A A
AA
Department of Respiratory Medicine, Sir Charles Gairdner Hospital, Western Australia.
Venaille
T J
TJ
Rose
A H
AH
Musk
A W
AW
Robinson
B W
BW
D001194:Asbestos / Q000494:pharmacology*; D002630:Chemotactic Factors / Q000378:metabolism*; D005260:Female; D006801:Humans; D016209:Interleukin-8; D007700:Kinetics; D008297:Male; D008970:Molecular Weight; D009504:Neutrophils / Q000502:physiology
D002630:Chemotactic Factors; D016209:Interleukin-8; D001194:Asbestos