Original article The capacity of connective tissue stromas to sustain myelopoiesis depends both upon the growth factors and the local intercellular environment Marcelo A. Carvalho a,b , Katia Arcanjo a,c,d , Luiz Claudio F. Silva d , Radovan Borojevic a,e * a Laboratório de Proliferação e Diferenciação Celular, Departamento de Histologia e Embriologia, Instituto de Ciências Biomédicas, Cidade Universitária, 21941-970, Rio de Janeiro, Brazil b Departamento de Bioquímica, Instituto de Química, Cidade Universitária, 21944-970 Rio de Janeiro, Brazil c Departamento de Biologia Celular, Universidade de Campinas, Cidade Universitária, 13083-970 Campinas, SP, Brazil d Laboratório de Tecido Conjuntivo, Departamento de Bioquímica Médica, Hospital Universitário Clementino Fraga Filho, Centro de Ciências de Saúde, Cidade Universitária, 21941-590 Rio de Janeiro, Brazil e Programa Avançado de Biologia Celular Aplicada à Medicina, Hospital Universitário Clementino Fraga Filho, Centro de Ciências de Saúde, Cidade Universitária, 21941-590, Rio de Janeiro, Brazil Received 22 October 2000; accepted 24 January 2001 In adults, haemopoiesis is located in the bone marrow, where it is tightly regulated by cytokines and by a physical association of haemopoietic progenitors with the stroma. However, in pathological situations, haemopoiesis can be partly or fully dislodged to peripheral tissues. It is not clear which are the requirements for a given peripheral stroma to sustain haemopoiesis. Using the growth factor-dependent cell line FDC-P1, we have compared the myelopoietic capacities of a murine bone marrow-derived cell line S17, a liver inflammatory granuloma-derived stroma (GR) that sustains haemopoiesis, and normal skin fibroblasts (SF) that sustain neither survival nor proliferation of myeloid cells. All three stromas expressed mRNA for major haemopoietins with the exception of IL-3. Despite the incapacity of SF to sustain FDC-P1 cells, the biologically active GM–CSF could be recovered from all the studied stromas by treatment with high-salt buffers that release non-covalently bound molecules from stroma cells. Glycosaminoglycans purified from stromas had distinct effect on the GM–CSF-mediated proliferation of FDC-P1 cells: those purified from S17 and GR cells were stimulatory, whereas those obtained from SF cells were slightly stimulatory at low concentration, but inhibitory at the higher ones. We conclude that the quality of the stroma pericellular glycoconjugates is determinant for the ability of a given stroma to sustain myelopoiesis, even when biologically active haemopoietins are locally produced. © 2000 Éditions scientifiques et médicales Elsevier SAS haemopoiesis / cytokines / glycosaminoglycans / FDC-P1 cells / S17 cells / liver connective tissue * Correspondence and reprints: fax: +55 21 562 6483. E-mail address: radovan@iq.ufrj.br (R. Borojevic). Biology of the Cell 92 (2000) 605-614 © 2000 Éditions scientifiques et médicales Elsevier SAS. All rights reserved S0248490001011133/FLA GM–CSF activity and glycosaminoglycans Carvalho et al.