title: Activin in humoral immune responses.
abstract: The synthesis and secretion of activin A are stimulated in immune cells, including Th2 cells, B cells, peritoneal macrophages, dendritic cells, and mast cells, in response to their activation. The increased expression of activin A is regulated at the level of transcription. Activin A increases antigen-specific IgE production, promotes the differentiation of macrophages into the M2 phenotype, and stimulates the maturation of mast cells in an autocrine/paracrine fashion. The roles of activin A in Th2 cells, B cells, and peritoneal macrophages are distinct from those of TGF-β, which acts primarily as an immune suppressor. In contrast, the activities of activin A and TGF-β are similar in mast cells. These findings suggest the discrete regulation of immune responses by activin and TGF-β, two structurally related growth/differentiation factors.
authors.affiliation: Chemical Genomics Research Group, ASI, RIKEN, Hirosawa, Wako, Saitama, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Ogawa
authors.forename: Masayuki
authors.initials: M
authors.lastname: Funaba
mesh_terms: D028341:Activins / Q000378:metabolism*; D000818:Animals; D006801:Humans; D056724:Immunity, Humoral
chemical_list: D028341:Activins