Simultaneous production of interleukin 6, interferon-beta and colony-stimulating activity by fibroblasts after viral and bacterial infection.

Different viruses were compared with the double-stranded RNA poly(rI).poly(rC) and interleukin (IL) 1 for their IL 6-inducing potential in several human and animal cell types. The laboratory viruses Sendai, Mengo and Newcastle disease virus were found to dose dependently stimulate IL 6 production in diploid fibroblasts. A similar effect was obtained with the human pathogens, measles and rubella virus. Concomitantly with IL 6, two other cytokine activities, i.e., interferon-beta and colony-stimulating activity for granulocytes and monocytes, were induced. In addition, these three activities were also produced by fibroblasts in response to Escherichia coli, whereas lipopolysaccharide was only marginally active. The specificity of the induction phenomenon was confirmed by the lack of IL 6 induction with inactivated infectious agents and by the complete neutralization of produced IL 6 by specific antibodies. This study indicates that the coordinate production of hemopoietic growth factors and interferon, originating from cells that do not classically belong to the immune system, can influence the local and systemic reactions observed during host defence against various infectious agents.