Interleukin 6 and its receptor in the immune response and hematopoiesis.
Interleukin 6 (IL-6) plays critical roles in the immune response and hematopoiesis. It is a potent B cell differentiation factor inducing antibody-forming plasma cells. It enhances interleukin 3-induced proliferation of hematopoietic stem cells. Furthermore, IL-6 induces maturation of megakaryocytes. In IL-6 transgenic mice, a massive polyclonal plasmacytosis and an increase in the number of mature megakaryocytes in the bone marrow were observed. The data indicated that deregulated expression of the IL-6 gene induced a polyclonal plasmacytosis and could be involved in the oncogenesis of plasma cell neoplasias. IL-6 receptor (IL-6R) was molecularly cloned and found to be an immunoglobulin superfamily having an MW of 80 kDa. Upon the binding of IL-6 to its 80 kDa IL-6R, a second non-binding molecule, gp130 was shown to associate with IL-6R. The complex of IL-6 and soluble IL-6R lacking both transmembrane and cytoplasmic domains could bind gp130 and transduce the signal. The results indicate that the IL-6R system consists of two polypeptide chains: one is an 80 kDa ligand-binding molecule and the other is a possible signal transducer, gp130.
Hirano
T
T
Division of Immunology, Osaka University, Japan.
Taga
T
T
Matsuda
T
T
Hibi
M
M
Suematsu
S
S
Tang
B
B
Murakami
M
M
Kishimoto
T
T
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D002471:Cell Transformation, Neoplastic; D003001:Cloning, Molecular; D004247:DNA / Q000096:biosynthesis; D015870:Gene Expression; D006410:Hematopoiesis / Q000235:genetics*; D006801:Humans; D007107:Immune System / Q000378:metabolism* / Q000473:pathology; D015850:Interleukin-6 / Q000235:genetics / Q000276:immunology* / Q000502:physiology; D051379:Mice; D008822:Mice, Transgenic; D009154:Mutation; D011971:Receptors, Immunologic / Q000235:genetics / Q000276:immunology* / Q000502:physiology; D019947:Receptors, Interleukin-6; D015398:Signal Transduction
D000911:Antibodies, Monoclonal; D015850:Interleukin-6; D011971:Receptors, Immunologic; D019947:Receptors, Interleukin-6; D004247:DNA