Affiliations: Department of Clinical (Viro-)Immunology, Central Laboratory of the Netherlands Red Cross Blood Transfusion Service and Laboratory for Clinical and Experimental Immunology, University of Amsterdam, Amsterdam, The Netherlands
Note: [] Address reprint requests to Dr. René A. W. van Lier, Department of Clinical (Viro-)Immunology, Central Laboratory of the Netherlands Red Cross Blood Transfusion Service, P.O.B. 9406, 1006 AK Amsterdam, The Netherlands. Dr. van Lier is a fellow of the Royal Dutch Academy of Arts and Sciences.
Note: [] Dr. Jochems' present address is Hospital de la Princesa, Departamento de biologia molecular, Diego de León 62, 28007 Madrid, Spain.
Abstract: To study the role of interleukin (IL)-6 as a growth and differentiation factor for Epstein-Barr virus (EBV)-transformed B lymphocytes, we transfected the cDNA coding for human IL-6 in a monoclonal IgG1 -secreting EBV B cell line. Two independent clones were selected that constitutively secreted high amounts of IL-6. These clones showed enhanced levels of IL-6 and tumor necrosis factor a secretion when compared to non-IL-6 transfected controls. Moreover, they could efficiently be recovered from low cell density cultures in limiting dilutions when plated on a feeder layer of heterologous EBV B cells. IL-6-induced phenotypical changes comprised a significant rise in immunoglobulin secretion levels and enhanced membrane expression of CD25 (the β chain of the IL-2 receptor) and of the B cell differentiation antigen CD40. IL-6-dependent down modulation of CD38 and of the adhesion structure VLA4 were also observed. Our data support the notion that IL-6 can serve as an growth and differentiation factor for EBV B cells.
