Interleukin 11

Interleukin 11 (IL-11) is a is_associated_with::protein that in humans is encoded by the IL11 is_associated_with::gene.

IL-11 is a multifunctional is_associated_with::cytokine first isolated in 1990 from is_associated_with::bone marrow-derived stromal cells. It is a key regulator of multiple events in hematopoiesis, most notably the stimulation of is_associated_with::megakaryocyte maturation. It is also known under the names adipogenesis inhibitory factor (AGIF) and is_associated_with::oprelvekin.

The human IL-11 is_associated_with::gene, consisting of 5 is_associated_with::exons and 4 is_associated_with::introns, is located on is_associated_with::chromosome 19, and encodes a 23 kDa protein. IL-11 is a member of the IL-6-type cytokine family, distinguished based on their use of the common co-receptor gp130. Signal specificity is provided by the IL-11Rα subunit.

Downstream signalling
Signal transduction is initiated upon binding of IL-11 to IL-11Ralpha and gp130, facilitating the homodimerization of gp130 molecules. This permits gp130-associated is_associated_with::Janus kinases (JAK) to become activated and phosphorylate intracellular tyrosine residues on gp130.

Function
IL-11 has been demonstrated to improve is_associated_with::platelet recovery after chemotherapy-induced is_associated_with::thrombocytopenia, induce is_associated_with::acute phase proteins, modulate antigen-antibody responses, participate in the regulation of bone cell proliferation and differentiation and could be use as a therapeutic for is_associated_with::osteoporosis. IL-11 stimulates the growth of certain is_associated_with::lymphocytes and, in the murine model, stimulates an increase in the cortical thickness and strength of long bones. In addition to having is_associated_with::lymphopoietic/is_associated_with::hematopoietic and is_associated_with::osteotrophic properties, it has functions in many other tissues, including the brain, gut, testis and bone.

As a signaling molecule, interleukin 11 has a variety of functions associated with its receptor interleukin 11 receptor alpha; such functions include is_associated_with::placentation and to some extent of is_associated_with::decidualization. IL11 has been expressed to have a role during implantation of the blastocyst in the endometrium of the uterus; as the blastocyst is imbedded within the endometrium, the extravillous is_associated_with::trophoblasts will invade the maternal spiral arteries for stability and the transfer of essential life-sustaining elements via the maternal and fetal circulatory systems. This process is highly regulated due to detrimental consequences that can arise from aberrations of the placentation process: poor infiltration of the trophoblasts may result in is_associated_with::preeclampsia while severely invasive trophoblasts may resolve in is_associated_with::placenta accreta, increta or percreta; all defects which most likely would result in the early demise of the embryo and/or negative effects upon the mother. IL11 has been shown to be present in the decidua and chorionic villi to regulate the extent in which the placenta implants itself; regulations to ensure the well-being of the mother but also the normal growth and survival of the fetus. A murine knockout model has been produced for this particular gene, with initial studies involving IL11 role in bone pathologies but have since progressed to fertility research; further research utilizes endometrial and gestational tissue from humans.

Medical use
Interleukin 11 is manufactured using is_associated_with::recombinant DNA technology and is marketed as a protein therapeutic called is_associated_with::oprelvekin, for the prevention of severe thrombocytopenia in cancer patients.