... required for ligand b inding as the presence of IL-11 and IL-11R-D2,3 issuf®cient to induce b iological activity [50]. The residuesresponsible for the ligand binding are mainly located in the D3, and ... the presence of twofold dilutions of IL-11(2 lgÁmL)1). After 7 days of cultu re, the number o fsurviving cells was determined by a c olorimetric assay of hexosaminidase. I n this assay, the ... the regulation of production of pro-in¯ammatory cytokinessuch as TNF-a,IL-1b,IFN-c and I L-12 by monocytes[55,56], and that the IL-11 receptor analysis on human celllines by ¯ow cytometry using monoclonal...