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M9610732.TXT
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1996-01-30
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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).