Cloning of complementary DNA encoding T-cell replacing factor and identity with B-cell growth factor II

• DOI: 10.1038/324070a0
• Publication Date: 2004-11-18T05:51:53Z
• Authors: Tatsuo Kinashi; Nobuyuki Harada; Eva Severinson; Toshizumi Tanabe; Paschalis Sideras; Mikio Konishi; Chihiro Azuma; Akira Tominaga; Susanne Bergstedt...; Masazumi Takahashi; Fumihiko Matsuda; Yoshio Yaoita; Kiyoshi Takatsu; Tasuku Honjo
• Keywords: Lymphokines; Base Sequence; DNA; DNA Restriction Enzymes; 3. Good health; Mice; 03 medical and health sciences; 0302 clinical medicine; Animals; Interleukin-4; Cloning, Molecular; Interleukin-5; Growth Substances

Proliferation and maturation of antigen-stimulated B cells are regulated by several soluble factors derived from macrophages and T cells. These soluble factors are functionally divided into two groups: B-cell growth factor (BCGF), thought to be involved in B-cell proliferation; and B-cell differentiation factor (BCDF), responsible for maturation of activated B cells into immunoglobulin-secreting cells. This classification needs to be re-examined in the light of the recent cloning of complementary DNA encoding IgG1 induction factor (interleukin-4, IL-4) from the 2.19 mouse T-cell line. Recombinant IL-4 has BCGF and BCDF activities and affects B cells, T cells and mast cells (refs 7, 8; our unpublished data). Another well-characterized B-cell factor is T-cell replacing factor (TRF), which, when secreted by the murine T-cell hybridoma B151K12, is defined by two activities: induction of IgM secretion by BCL1 leukaemic B-cell line; and induction of secondary anti-dinitrophenol (DNP) immunoglobulin G (IgG) synthesis in vitro by DNP-prime B cells. Although TRF from B151K12 was classified as BCDF, purified TRF has BCGF-II activity. To elucidate the molecular properties of TRF we isolated cDNA encoding TRF from the 2.19 T-cell line and report here the structure and multiple activities of this lymphokine.