title: Selective pharmacologic inhibition of murine and human IL-12-dependent Th1 differentiation and IL-12 signaling.
abstract: We have previously shown that lisofylline (LSF) inhibits murine Th1-mediated disease in vivo by blocking IL-12-induced differentiation of Th1 cells. The cellular and molecular mechanisms underlying this inhibition were further explored by testing LSF in several IL-12-responsive model systems in vitro. IL-12-dependent Th1 differentiation was abrogated by LSF and yielded effector T cells that were deficient in proinflammatory cytokine secretion, including IFN-gamma, IL-2, and TNF-alpha. The diminished Th1 phenotype resulted from both a lower frequency of IL-12-derived Th1 clones and a reduced capacity of individual clones to secrete IFN-gamma due to lower levels of IFN-gamma mRNA. The arrest in Th1 development resulted from a blockade of IL-12 signaling that preceded the Th0 to Th1 transition. Thus, LSF blocked IL-12-enhanced IFN-gamma production in anti-CD3-stimulated T cells and prevented IL-12-mediated repression of the transcription factor GATA-3. Lisofylline also inhibited IL-12-induced increases in STAT4 tyrosine phosphorylation, but did not block TCR signaling or inhibit acquisition of IL-12 responsiveness. These findings were extended to show that LSF also inhibits IL-12-dependent responses in human T cells. LSF, which has one asymmetric chiral center, was selectively inhibitory for IL-12 signaling compared with its S-enantiomer (1501-S) and the oxidized side chain analog, pentoxifylline. The results suggest that LSF may be useful as a modulator of Th1-mediated disease in humans.
authors.affiliation: Immunology Program, Cell Therapeutics, Inc., Seattle, WA 98119, USA.
authors.forename: M E
authors.initials: ME
authors.lastname: Coon
authors.forename: M
authors.initials: M
authors.lastname: Diegel
authors.forename: N
authors.initials: N
authors.lastname: Leshinsky
authors.forename: S J
authors.initials: SJ
authors.lastname: Klaus
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects / Q000276:immunology; D002478:Cells, Cultured; D016207:Cytokines / Q000096:biosynthesis; D006801:Humans; D007156:Immunologic Memory / Q000187:drug effects; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D018664:Interleukin-12 / Q000037:antagonists & inhibitors* / Q000502:physiology*; D007399:Interphase / Q000187:drug effects / Q000276:immunology; D008213:Lymphocyte Activation / Q000187:drug effects; D018655:Lymphocyte Count / Q000187:drug effects; D051379:Mice; D008807:Mice, Inbred BALB C; D010431:Pentoxifylline / Q000031:analogs & derivatives* / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects* / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D018417:Th1 Cells / Q000166:cytology* / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D014157:Transcription Factors / Q000096:biosynthesis / Q000378:metabolism / Q000502:physiology
chemical_list: D016207:Cytokines; D007166:Immunosuppressive Agents; D014157:Transcription Factors; D018664:Interleukin-12; C025189:lisofylline; D010431:Pentoxifylline