| Abstract: | The interleukin-6-(IL-6)-alpha dependent B-cell heterohybridomas were obtained by the fusion of X65.Ag8.653 cells with spleen cells from August rats immunized with lipopolysaccharide E. coli. One of these hybridomas (D6C8) was found to be most dependent on IL-6 for its surviving and growth. Human recombinant IL-1 beta and tumor necrosis factor-alpha could not induce the in vitro growth of this cell line. Presence of elevated level of IL-6 was demonstrated in the sera of patients with rheumatoid arthritis. A specific and sensitive detection of the IL-6 activity in test samples makes it possible to study the presence and role of IL-6 in various immunological disorders. |
