Purification to homogeneity and characterization of human B-cell differentiation factor (BCDF or BSFp-2).
Human B-cell differentiation factor (BCDF) was purified to homogeneity by sequential filtration and chromatography of culture supernatants from TCL-Na1 cells on an AcA34 gel column and then on a Mono P column with fast protein liquid chromatography and reversed-phase HPLC. A 5300-fold enrichment in specific activity of BCDF with about 25% recovery was attained. The homogeneity of purified BCDF was evidenced by the following: (i) the specific activity was 1.7 X 10(7) units/mg of protein, (ii) only two bands, Mr 19,000 and 21,000, were identified by NaDodSO4/PAGE under reduced as well as nonreduced conditions, and (iii) BCDF activity was recovered from the gel after NaDodSO4/PAGE in the fractions corresponding to protein bands of Mr 19,000 or 21,000. Purified BCDF induced Ig secretion in Epstein-Barr virus-transformed cell lines; as little as 3 pM gave 50% of the maximum reaction achieved by 30-80 pM BCDF. Purified BCDF induced Ig production in activated B cells without any effect on cell growth. Purified BCDF did not show any activity of interleukin 1 or 2, B-cell stimulatory factor (BSF)p-1, B-cell growth factor II (BCGF-II), or interferon. Since BCDF was isolated and characterized as described, we propose that the BCDF that induces the final differentiation of B cells into high-rate Ig-secreting cells be designated BSFp-2.
T
T
Hirano
T
T
Taga
N
N
Nakano
K
K
Yasukawa
S
S
Kashiwamura
K
K
Shimizu
K
K
Nakajima
K H
KH
Pyun
T
T
Kishimoto
D000944:Antigens, Differentiation, B-Lymphocyte; D000954:Antigens, Surface / Q000302:isolation & purification*; D001402:B-Lymphocytes / Q000276:immunology*; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007136:Immunoglobulins / Q000032:analysis; D007372:Interferons / Q000032:analysis; D008970:Molecular Weight
D000944:Antigens, Differentiation, B-Lymphocyte; D000954:Antigens, Surface; D007136:Immunoglobulins; D007372:Interferons