ISSN:
0021-9541
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Medicine
Notes:
The inhibitory effect of phorbol dibutyrate (PDB) on B-cell stimulation was evaluated using a model in which activation is induced by modest doses of antiimmunoglobulin antibody (anti-lg) and progression to DNA synthesis is induced by cytochalasin. PDB preferentially inhibited anti-lg-induced activation and did so during brief (2 hr) preincubation with anti-lg. Activation was inhibited whether PDB was added before or shortly after anti-lg. Since activation for cytochalasin responsiveness appears to be mediated by Ca2+, the effect of PDB on the anti-lg-induced rise in intracellular Ca2+ was evaluated. PDB (and other phorbol esters that activate protein kinase C) inhibited the rise in Ca2+ normally associated with anti-lg treatment; moreover, PDB reversed an established anti-lg-induced Ca2+ response. These data suggest that phorbol esters inhibit B-cell activation by interfering with the elevated levels of intracellular Ca2+ produced by cross-linking of surface immunoglobulin by anti-lg. This could represent a “feedback inhibition” type of response, but it remains to be seen if this occurs under physiological conditions of protein kinase C activation.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jcp.1041290313
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