Adenosine 3',5'-cyclic monophosphate modulates the mitogenic responses of murine B lymphocytes.
Adenosine 3',5'-cyclic monophosphate (cAMP) acts to inhibit a number of lymphocyte activities. The extent of this inhibition was tested by evaluating the effects of two cAMP-raising agents on B cell S phase entry induced by several different mitogenic regimens. It was found that both dibutyryl cAMP (dbcAMP) and isobutylmethylxanthine (IBMX) enhanced S phase entry induced by some regimens but inhibited S phase entry induced by others. The observed enhancing activity stands in contrast to the general notion of cAMP as being a "negative regulator," and it confirms that the observed inhibiting activity does not simply reflect cytotoxicity. Mitogenic regimens that appear to mimic each other, such as F(ab')2 fragments of goat anti-mouse immunoglobulin and the combination of a calcium ionophore and a phorbol ester, were distinguished by their responses to the addition of the two cAMP-raising agents. B cell responses were enhanced or inhibited even when dbcAMP was added 18-24 hr after the establishment of cultures. Cyclic AMP may regulate in a complex fashion S phase entry in cells of the immune system.
Cohen
D P
DP
Department of Microbiology, Boston University Medical Center, Massachusetts 02118.
Rothstein
T L
TL
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology*; D003994:Bucladesine / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects; D000242:Cyclic AMP / Q000502:physiology*; D015638:Cytochalasin D; D003572:Cytochalasins / Q000494:pharmacology; D004987:Ethers / Q000494:pharmacology; D007140:Immunoglobulin Fab Fragments / Q000276:immunology; D066298:In Vitro Techniques; D015759:Ionomycin; D051379:Mice; D008805:Mice, Inbred A; D013601:T-Lymphocytes / Q000166:cytology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D003572:Cytochalasins; D004987:Ethers; D007140:Immunoglobulin Fab Fragments; D015638:Cytochalasin D; D015759:Ionomycin; D003994:Bucladesine; D000242:Cyclic AMP; D013755:Tetradecanoylphorbol Acetate; D015056:1-Methyl-3-isobutylxanthine