title: Constitutive production of B cell differentiation factor-like activity by human T and B cell lines.
abstract: A lymphokine demonstrating human B cell differentiation factor (BCDF)-like activity was isolated from immature (MOLT-4f, CCRF-CEM and CCRF-HSDB-2) and mature (HUT-78) malignant human T lymphoid cell lines and from human B lymphoblastoid cell lines (BJAB and ALL-7031-B). All the cell lines were grown long term in serum-free medium. This BCDF-like activity has a molecular mass in the range of 40-60 kDa and stimulates immunoglobulin synthesis of cell lines capable of producing IgA (GM-1056), IgG (GM-1500 and CESS) and IgM (CBL#3). It was not produced by a myeloid cell line. We were only able to identify the differentiation activity produced by the T and B cell lines by using appropriate molecular mass fractions from the serum-free medium as controls. This BCDF-like activity is different from that of the human BCDF so far described as it has a higher molecular mass and is constitutively produced by malignant T lymphoid cell lines which are human T cell leukemia virus-I negative and by B lymphoblastoid cell lines.
mesh_terms: D000917:Antibody Formation / Q000187:drug effects; D001402:B-Lymphocytes / Q000502:physiology*; D002454:Cell Differentiation; D002460:Cell Line; D006133:Growth Substances / Q000096:biosynthesis*; D006801:Humans; D007073:Immunoglobulin E / Q000096:biosynthesis; D015847:Interleukin-4; D008213:Lymphocyte Activation; D008222:Lymphokines / Q000096:biosynthesis* / Q000494:pharmacology; D008970:Molecular Weight; D013601:T-Lymphocytes / Q000502:physiology*
chemical_list: D006133:Growth Substances; D008222:Lymphokines; D015847:Interleukin-4; D007073:Immunoglobulin E