ABSTRACT
Interleukin-6 (IL-6) has been identified as a 26-kD secreted protein that stimulates B cells to produce antibodies. Later, IL-6 was revealed to have various functions that overlap with other IL-6 family cytokines and use the common IL-6 signal transducer gp130. IL-6 stimulates cells through multiple pathways, using both membrane and soluble IL-6 receptors. As indicated by the expanding market for IL-6 inhibitors, it has become a primary therapeutic target among IL-6 family cytokines. Here, we revisit the discovery of IL-6; discuss insights regarding the roles of this family of cytokines; and highlight recent advances in our understanding of regulation of IL-6 expression.
Subject(s)
Interleukin-6/history , Animals , Genetic Pleiotropy , History, 20th Century , Humans , Interleukin-6/genetics , Interleukin-6/metabolism , MicroRNAs/genetics , MicroRNAs/metabolism , Models, Biological , Mutation/genetics , Receptors, Interleukin-6/genetics , Receptors, Interleukin-6/metabolismABSTRACT
In the late 1960s, the essential role of T cells in antibody production was reported. This led to our hypothesis that T-cell-derived soluble factors would have to be involved in the activation of B cells. The factor that induced B cells to produce immunoglobulins was initially named B-cell stimulatory factor-2. In 1986, we successfully cloned the complementary DNA encoding B-cell stimulatory factor-2, now known as IL-6. At the same time, IFN-beta2 and a 26-kDa protein found in fibroblasts were independently cloned and found to be identical to IL-6. Later, a hybridoma/plasmacytoma growth factor and a hepatocyte-stimulating factor were also proven to be the same molecule as IL-6. Now, we know that IL-6 is a pleiotropic cytokine with a wide range of biological activities in immune regulation, hematopoiesis, inflammation and oncogenesis. Since the discovery of IL-6, we have further clarified its activities, the IL-6R system and the IL-6 signal transduction mechanism. On the basis of the findings, a new therapeutic approach to block the actions of IL-6 by use of a humanized anti-IL-6R antibody has been proven to be therapeutically effective for rheumatoid arthritis, systemic juvenile idiopathic arthritis and Castleman's disease. In this review, I discuss the history of IL-6 research as a paradigm of progress from basic science to clinical applications.
Subject(s)
Interleukin-6/immunology , Animals , B-Lymphocytes/immunology , History, 20th Century , History, 21st Century , Humans , Interleukin-6/history , Research/historyABSTRACT
This essay summarizes my 40 years of research in immunology. As a young physician, I encountered a patient with Waldenström's macroglobulinemia, and this inspired me to study the structure of IgM. I began to ask how antibody responses are regulated. In the late 1960s, the essential role of T cells in antibody production had been reported. In search of molecules mediating T cell helper function, I discovered activities in the culture supernatant of T cells that induced proliferation and differentiation of B cells. This led to my life's work: studying one of those factors, interleukin-6 (IL-6). To my surprise, IL-6 turned out to play additional roles, including myeloma growth factor and hepatocyte-stimulating factor activities. More importantly, it was involved in a number of diseases, such as rheumatoid arthritis and Castleman's disease. I feel exceptionally fortunate that my work not only revealed the framework of cytokine signaling, including identification of the IL-6 receptor, gp130, NF-IL6, STAT3, and SOCS-1, but also led to the development of a new therapy for chronic inflammatory diseases.