Involvement of gp130/interleukin‐6 receptor transducing component in interleukin‐11 receptor

Abstract

The recently cloned interleukin (IL)‐11 displays many biological properties in common with those reported for IL‐6. In order to analyze the nature and the functionality of the IL‐11 receptor we developed a proliferative assay using the human multifactor‐dependent cell line TF1. We showed that a blocking monoclonal antibody GPX7 raised against the gp130/IL‐6 receptor transducing subunit was also able to inhibit the IL‐11‐triggered TF1 line proliferation. In addition, involvement of gp130 in IL‐11 signaling was demonstrated by an induction of the transducing protein phosphorylation in response to IL‐11, as observed for IL‐6. In contrast, the blocking monoclonal antibody B‐R6, which recognized the gp80/IL‐6 binding subunit, failed to interfere with the IL‐11 proliferative signal in the TF1 cell line. Similarly, we did not observe any competition between IL‐6 and IL‐11 for a putative common binding site on the cell surface. These results suggest that the IL‐11 binding component is different from the gp80/IL‐6 receptor. In conclusion, IL‐11, along with IL‐6, leukemia inhibitory factor, oncostatin M and ciliary neurotrophic factor, belongs to the same family of cytokines, using gp130 as a transducing protein.