IN-VITRO CHARACTERIZATION OF A NOVEL AVIAN HEMATOPOIETIC GROWTH-FACTOR DERIVED FROM STROMAL CELLS

To better define the role of the Nomenclature chicken haemopoietic mic roenvironment in supporting haemopoiesis, a continuous cell line was g enerated by RSV transformation of avian spleen stromal cells (SSL-1). Supernatants from this line were found to contain haemopoietic growth factor activity as measured by the ability to induce proliferation and differentiation of precursor cells present in embryonic and post-hatc hed haemopoietic tissues. Comparison of cultures grown in the presence of cMGF and SSL-1 conditioned media (CM) revealed that both cytokine sources induced similar types of cell populations. Both sources suppor ted the proliferation of predominantly macrophage-like cells based on colony morphology, differential staining, non-specific esterase staini ng, and phagocytosis activity. Interestingly, SSL-1 does not express a ny message for cMGF, nor does it secrete any IL-2 or interferon activi ties suggesting that the growth factor activities seen in SSL-1 are no vel. Copyright (C) 1996 Elsevier Science Ltd.