Production of lymphotoxin by isolated human tonsillar B lymphocytes and B lymphocyte cell lines.
The expression of lymphotoxin (LT) mRNA and cytokine in human tonsillar B cells and B cell lines was examined by Northern blots and cytotoxicity assays, respectively. In tonsillar B cells, phorbol myristate acetate (PMA) or Staphylococcus aureus Cowan l (SAC) alone induced low levels of LT mRNA accumulation. However, SAC and anti-mu were strongly synergistic with PMA in this induction. Peak LT mRNA expression in tonsillar B cells stimulated by PMA plus SAC occurred between 48 and 72 h and was approximately half as much as that in PMA plus anti-CD3-stimulated T cells. Cyclosporine A was not effective in inhibiting LT mRNA accumulation by stimulated tonsillar B cells. A number of B cell lines could also be stimulated by PMA to express LT mRNA. Peak accumulation of LT mRNA in the cell line RPMI 1788 stimulated with PMA peaked about 8 h. A23187 in combination with PMA caused this accumulation to increase slightly and to peak earlier. The cytotoxic effects in the supernatants of stimulated B cells were contributed mostly by LT. The results indicate that tonsillar B cells are important in LT production and that there are important differences in the stimulation requirements for LT production and in LT mRNA expression kinetics between tonsillar B cells and B cell lines.
Sung
S S
SS
Immunology Program, Oklahoma Medical Research Foundation, Oklahoma City 73104.
Jung
L K
LK
Walters
J A
JA
Jeffes
E W
EW
Granger
G A
GA
Fu
S M
SM
D001402:B-Lymphocytes / Q000378:metabolism*; D015152:Blotting, Northern; D002460:Cell Line; D003601:Cytotoxicity Tests, Immunologic; D004587:Electrophoresis, Agar Gel; D005786:Gene Expression Regulation; D006801:Humans; D008233:Lymphotoxin-alpha / Q000096:biosynthesis*; D014066:Palatine Tonsil / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D008233:Lymphotoxin-alpha; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D013755:Tetradecanoylphorbol Acetate