We plan to obtain biological tools (monoclonal, polyclonal antibodies and riboprobes) to examine in situ gene transcription and protein expression of a newly characterized cytokine: HILDA (Human Interleukin Da). This cytokine is produced by lymphocytes, monocytes/Macrophages and several tumor cell lines. Target cells are macrophages, embryonic stem cells, bone marrow progenitors and possibly endothelial cells. Antibodies will be prepared against HILDA and hydrophylic non-glycosylated HILDA peptides. Transcription and expression of HILDA - in comparison with other cytokines - will be studied in allotransplantation (rejection and tolerance) and in autoimmune disease (multiple sclerosis and auto-immune encephalitis) in humans and in rats.