Differential expression of interleukin 1α by Thy-1+ and Thy-1− lung fibroblast subpopulations: Enhancement of interleukin 1α production by tumor necrosis factor-α

✍ Scribed by Richard P. Phipps; Clare Baecher; John G. Frelinger; David P. Penney; Peter Keng; Deborah Brown

• Publisher: John Wiley and Sons
• Year: 1990
• Tongue: English
• Weight: 535 KB
• Volume: 20
• Category: Article
• ISSN: 0014-2980
• DOI: 10.1002/eji.1830200815

✦ Synopsis

Differential expression of interleukin la by Thy-l+ and Thy-llung fibroblast subpopulations: enhancement of interleukin la production by tumor necrosis factor-a*

The purpose of this investigation was to determine whether subpopulations of murine lung fibroblasts produced interleukin 1 (IL 1). We previously identified two major populations of pulmonary fibroblasts based on the presence or absence of Thy-1. Thy-l+ and Thy-l-subsets synsthesize fibronectin and type I and I11 collagen, but only the Thy-l-population displays class I1 major histocompatibility complex antigens after stimulation with interferon -y and presents antigen to T helper clones. Interestingly, in the current study we determined that only Thy-l-fibroblast lines and clones synthesized IL 1. Although constitutive production was low, tumor necrosis factor -a (TNF-a) stimulated 5-20-fold increases in IL 1 production inThy-1-fibroblasts. The Thy-l+ fibroblasts did not produce IL 1 even after TNF-a treatment. Northern blot analysis of TNF-a treated cells revealed that in the Thy-l-subset increased mRNA levels for IL la were detected, while IL 1p mRNA was not detected. Furthermore, IL 1 activity from TNF-a-treated Thy-l-fibroblast membranes and supernatants was completely neutralized by IL la-specific antibodies. These observations support the hypothesis that the antigen-presenting Thy-l-subset is important for promoting the inflammation associated with pulmonary fibrosis. In addition, the existence of functional subsets of lung fibroblasts is further substantiated by differential expression of IL 1.