       Document 0732
 DOCN  M9610732
 TI    A CD4+ T cell line-secreted factor, growth promoting for normal and
       leukemic B cells, identified as thioredoxin.
 DT    9601
 AU    Rosen A; Lundman P; Carlsson M; Bhavani K; Srinivasa BR; Kjellstrom G;
       Nilsson K; Holmgren A; Department of Cell Biology, Faculty of Health
       Sciences,; University of Linkoping, Sweden.
 SO    Int Immunol. 1995 Apr;7(4):625-33. Unique Identifier : AIDSLINE
       MED/96031360
 AB    In this study, a B cell growth stimulatory factor, constitutively
       secreted by a human CD4+ T cell hybridoma clone, MP6, has been purified
       and characterized. Serum-free 24 h culture media from MP6 cells were
       collected, concentrated by ultrafiltration and separated by gel
       chromatography. Fractions were analyzed for stimulatory activity using
       [3H]thymidine incorporation in normal and leukemic (B-CLL) B cells as
       target cells. Activity was present in a 12 kDa protein peak. Upon
       storage this lost activity indicating that the factor was sensitive to
       air oxidation, a well-known property of mammalian thioredoxins (Trxs).
       Treatment of the inactive fraction with dithiothreitol restored full
       activity. When culture medium was analyzed with a radioimmunoassay for
       human placenta Trx, the MP6 clone was shown to release 30-50 ng/ml per
       million cells during 24 h. The B cell stimulatory activity of the MP6
       medium was removed by Sepharose-bound anti-human placenta Trx IgG and
       activity was recovered by elution from the antibodies. Furthermore, MP6
       medium showed Trx activity with NADPH and Trx reductase using an insulin
       disulfide reduction assay. Starting from 5 l of serum-free MP6
       conditioned medium, the Trx was purified approximately 100,000-fold.
       After gel electrophoresis banding, the material was analyzed by peptide
       sequencing and a full length sequence of an 104 amino acid long protein
       was obtained. This Trx sequence was identical to the previously
       published sequence of human Trx from HTLV-1 transformed T cells, adult T
       cell leukemia-derived factor/Trx.(ABSTRACT TRUNCATED AT 250 WORDS)
 DE    Amino Acid Sequence  Antibodies  B-Lymphocytes/DRUG EFFECTS/*PHYSIOLOGY
       Cell Line  Cell-Free System  Chromatography, Affinity  Clone Cells
       Culture Media, Conditioned/ANALYSIS  Cytokines/ANALYSIS  CD4-Positive
       T-Lymphocytes/*METABOLISM  Drug Synergism  Growth
       Substances/BIOSYNTHESIS/*ISOLATION & PURIF/PHARMACOLOGY  Human
       Leukemia, B-Cell, Chronic/METABOLISM  Molecular Sequence Data
       Radioimmunoassay  Support, Non-U.S. Gov't
       Thioredoxin/IMMUNOLOGY/*ISOLATION & PURIF  JOURNAL ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).

