Exposure to organic dust causes activation of human plasma complement factors C3 and B and the synthesis of factor C3 by lung epithelial cells in vitro.
Exposure in swine confinement buildings induces an intense airway inflammation. Twenty-two volunteers, of whom eleven wore a half-mask, were exposed for 3 hr in a swine barn. Blood samples were drawn before and after exposure. The ratio C3b/totalC3 in plasma decreased from 6.8 to 5.0% (p = 0.02) without mask and from 6.6 to 5.9% (p = 0.01) with mask (p = 0.67 between groups). The ratio Bb/totalB decreased from 14.5 to 13.5% (p < 0.01) without and 14.6-13.3% (p = 0.09) with mask (p = 0.25 between groups). Epithelial cells (A549) incubated up to 24 hr with 0.1 mg/mL dust suspensions were analysed for C3, IL-6 and IL-8 secretion. Cumulative C3 synthesis of dust stimulated cell cultures was 43,000 pg/mL compared to 25,000 pg/mL in unstimulated cells. Cumulative dust-induced IL-6 and IL-8 secretion was 200 and 3000 pg/mL, respectively and below detection in unstimulated cells. The activation of complement in vivo and induced C3 synthesis by epithelial cells suggests a role of complement in the airway reaction to organic dust exposure.
Acevedo
Fernando
F
Lung and Allergy Research, Institute of Environmental Medicine, Karolinska Institute, Stockholm, Sweden.
Palmberg
Lena
L
Larsson
Kjell
K
D000328:Adult; D000395:Air Pollutants, Occupational; D000818:Animals; D002277:Carcinoma / Q000473:pathology; D045744:Cell Line, Tumor; D003176:Complement C3 / Q000032:analysis* / Q000378:metabolism; D003179:Complement C3b / Q000032:analysis; D011415:Complement Factor B / Q000378:metabolism*; D004391:Dust; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000032:analysis; D016209:Interleukin-8 / Q000032:analysis; D008175:Lung Neoplasms / Q000473:pathology; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure; D013552:Swine / Q000276:immunology*
D000395:Air Pollutants, Occupational; D003176:Complement C3; D004391:Dust; D015850:Interleukin-6; D016209:Interleukin-8; D003179:Complement C3b; D011415:Complement Factor B