Generation of and characterization of anti-IL-11 antibodies using newly established Il11-deficient mice.

Interleukin (IL)-11 belongs to the members of the IL-6 family of cytokines and is involved in a variety of biological responses, including hematopoiesis, bone development, and carcinogenesis. However, the cellular sources of IL-11 and regulation of IL-11 expression under physiological and pathological conditions are not fully understood. One of the causes to prevent characterization of IL-11 in vivo is due to the lack of reliable antibodies that detect IL-11 by immunohistochemistry. Moreover, although mice lacking Il11ra have been generated and extensively characterized, Il11-deficient mice have not been characterized yet. Here we generated two anti-IL-11 antibodies that blocked biological activities of IL-11 and detected IL-11 by immunohistochemistry, respectively. One clone of anti-IL-11 antibodies blocked IL-11-, but not IL-6-induced cell proliferation and IL-11-induced phosphorylation of STAT3 of an IL-11-dependent cell line. Moreover, we used recently established Il11-deficient mice to test the specificity of anti-IL-11 antibodies for immunohistochemistry. Another clone of anti-IL-11 antibodies stained stromal cells surrounding tumors of the colon of wild-type, but not Il11-deficient mice following treatment with Azoxymethane plus dextran sulfate sodium. Together, these newly developed anti-IL-11 antibodies provide a better understanding of the functions of IL-11 in vivo under various physiological and pathological conditions.