Macrophage colony-stimulating factor (CSF-1) gene expression in human T-lymphocyte clones.

Macrophage colony stimulating factor (CSF-1) is one of several cytokines that control the differentiation, survival, and proliferation of monocytes and macrophages. A set of 11 human T-cell clones, chosen for their phenotypic diversity, were tested for their ability to express CSF-1 mRNA. After 5 hours of stimulation with phorbol myristate acetate (PMA) + calcium ionophore (Cal), all T-cell clones expressed a major 4-kb transcript, a less abundant 2-kb transcript, and several other minor species.

Molecular cloning of a cDNA encoding a human macrophage migration inhibitory factor.

A cDNA encoding a human macrophage migration inhibitory factor (MIF) was isolated, through functional expression cloning in COS-1 cells, from a cDNA library prepared from a lectin-stimulated T-cell hybridoma, T-CEMB. The 115-amino acid polypeptide encoded by the MIF cDNA (p7-1) was effectively released from the transfected COS-1 cells and yielded readily detectable MIF activity in the culture supernatant despite the apparent lack of a classical protein secretory sequence. Insertional mutational analysis and elution of MIF activity from polyacrylamide gel slices demonstrated that the Mr 12,000 protein with MIF activity released by the COS-1 cells is encoded by p7-1.

Leukaemia inhibitory factor is identical to the myeloid growth factor human interleukin for DA cells.

Leukaemia inhibitory factor (LIF) is a cytokine that induces macrophage differentiation of the murine M1 myeloid leukaemia cell line. We have isolated a cDNA clone encoding a novel human haemopoietic growth factor, human interleukin for DA cells (HILDA) that supports the proliferation of the murine interleukin-3-dependent leukaemic cell line, DA-la (refs 3-5). HILDA proved to be identical to LIF.

Interleukin 6: identification as a hematopoietic colony-stimulating factor.

Interleukin 6 is a multifunctional cytokine that exerts a variety of effects on different cell types. These effects include differentiation of B cells and cytotoxic T cells, growth promotion of hybridomas and activation of hepatocytes and mitogen-stimulated helper T cells. We identified and molecularly cloned a cDNA encoding a novel myeloid colony-stimulating activity from a human T cell line.

Stimulation of murine hemopoietic colony formation by human IL-6.

A novel hemopoietic CSF has been identified in the medium conditioned by lectin-stimulated human T cells. The cDNA clone encoding this factor, isolated by functional expression cloning in monkey cos-1 cells, proved to be identical with the cDNA encoding the cytokine B cell stimulatory factor-2/IFN-beta 2, a factor now known as IL-6. In the murine system, IL-6 indirectly supports the formation of several different types of hemopoietic colonies, including those derived from early blast cells, and directly supports the proliferation of granulocyte/macrophage progenitors.