Interleukin-2-induced DNA synthesis and immunoglobulin secretion by resting human tonsillar B cells: effects of protein kinase C activation.
Responses to interleukin-2 (IL-2) of high-density human tonsillar B lymphocytes were examined in 20 microliters hanging drop microcultures. DNA synthesis and secretion of IgM and IgG were induced by IL-2 alone. Activation of calcium-dependent protein kinase C (PKC) with phorbol 12,13-dibutyrate and ionomycin increased IL-2 driven DNA synthesis yet reduced IL-2 driven secretion of IgM and IgG. Forskolin, which increases cAMP, had no effect on the responses to IL-2. Intrinsic IL-6 played no role in IL-2-induced DNA synthesis but was partially responsible for the secretion of immunoglobulin. These data show that pre-activation of the high-density human tonsillar B lymphocyte is not a prerequisite for IL-2-driven responses. They also show an asymmetry between the growth and differentiation induced by IL-2. This is reflected by opposite modulation on activation of PKC and by the role of the autocrine factor, IL-6.
Franz
A
A
Immunodeficiency Diseases Research Group, Clinical Research Centre, Harrow, U.K.
Bryant
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A
Farrant
J
J
D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D002478:Cells, Cultured; D005576:Colforsin / Q000494:pharmacology; D004247:DNA / Q000096:biosynthesis; D004789:Enzyme Activation; D006801:Humans; D007074:Immunoglobulin G / Q000378:metabolism; D007075:Immunoglobulin M / Q000378:metabolism; D007376:Interleukin-2 / Q000037:antagonists & inhibitors / Q000276:immunology*; D015850:Interleukin-6 / Q000276:immunology; D015759:Ionomycin / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000276:immunology*; D014066:Palatine Tonsil / Q000166:cytology / Q000276:immunology*; D015240:Phorbol 12,13-Dibutyrate / Q000494:pharmacology; D011493:Protein Kinase C / Q000378:metabolism*
D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007376:Interleukin-2; D015850:Interleukin-6; D005576:Colforsin; D015240:Phorbol 12,13-Dibutyrate; D015759:Ionomycin; D004247:DNA; D011493:Protein Kinase C