Tumor necrosis factor-γ and tumor necrosis factor-β (lymphotoxin) stimulate the production of granulocyte-macrophage colony-stimulating factor, macrophage colony-stimulating factor, and IL-1 in vivo

A number of cell types have been shown to elaborate hematopoietic growth factors in response to inflammatory mediators in vitro. To determine if this response occurs in vivo, we have administered levels of TNF-α and TNF-β (lymphotoxin) found during an inflammatory reaction to mice. Using Northern blot analysis to detect tissue levels of hematopoietic growth factor-specific transcripts, and specific biologic and immunologic assays to detect the presence of colony-stimulating factors in the serum, we have found that TNF-α and TNF-β induce the transcription and production of granulocyte-macrophage-CSF, macrophage-CSF, and IL-1. These findings provide an in vivo mechanism for the hematopoietic response to inflammation.