Title of article :
Interleukin-6 secretion by bacterial lipopolysaccharide-stimulated bovine alveolar macrophages in vitro
Author/Authors :
Jian، نويسنده , , Zijian and Yang، نويسنده , , Zhengang and Miller، نويسنده , , Mark Steven and Carter، نويسنده , , Candace D. and Slauson، نويسنده , , David O. and Bochsler، نويسنده , , Philip N.، نويسنده ,
Abstract :
Interleukin-6 (IL-6) is a pluripotent cytokine that may play a role in pulmonary defense against bacterial pathogens. We have quantitated the response of bovine alveolar macrophages (bAM) to bacterial lipopolysaccharide (LPS; E. coli 055:B5) in vitro using the IL-6 sensitive 7TD1 cell line. Bacterial LPS in the absence of serum induced IL-6 secretion from bAM (1 × 106 ml−1) over a range of LPS concentrations from 10 ng ml−1 to 10 μg ml−1. This resulted in IL-6 levels ranging from approximately 5 to over 200 U ml−1. IL-6 secretion by LPS-stimulated bAM was increased by 24 h poststimulation, and continued to increase up to 72 h after stimulation. Fetal bovine serum (FBS, 1% vol/vol; 320 μg ml−1) enhanced IL-6 secretion from macrophages in the presence of LPS by approximately 10-fold compared with LPS alone. A bovine serum fraction (1 μg ml−1 protein) prepared using ion-exchange chromatography also markedly enhanced IL-6 secretion versus LPS alone. The stimulatory effect of IL-6-like activity in the bAM supernatants was neutralized by an anti-human IL-6 polyclonal antibody. Northern blot analysis revealed increased IL-6 mRNA at 2 h poststimulation with LPS + FBS, peak levels at 4 h, and levels were decreased by 6 h poststimulation. Results suggest that IL-6 is secreted by bovine alveolar macrophages, and that bacterial LPS and serum components synergize to produce this response.
Keywords :
Bovine , macrophage , Lung , Bacterial lipopolysaccharide , IL-6
Journal title :
Astroparticle Physics