PLATELET-ACTIVATING-FACTOR AND HEMATOPOIESIS .11. PLATELET-ACTIVATING-FACTOR HAS NO EFFECT ON THE PRODUCTION OF INTERLEUKIN-6 AND TUMOR-NECROSIS-FACTOR-ALPHA BY HUMAN BONE-MARROW STROMAL CELLS

PAF is a phospholipid mediator of inflammation which stimulates IL-6 p roduction by murine skin fibroblasts, Although PAF is present in human hone marrow, its role in haematopoiesis is unknown. We have assessed whether PAF stimulates IL-6 and TNF-alpha production by human bone mar row stromal cells (mostly fibroblast-like cells). We report that PAF ( 1 nM to 10 mu M) has no effect on the synthesis of IL-6 and TNF-alpha by human bone marrow stromal cells, This difference may be due to the widely accepted concept of ''tissue-specific fibroblasts'' The role of PAF in the regulation of human haematopoiesis remains to be elucidate d.