Targeting mTOR and MAPK Pathways to Inhibit Naïve and Experienced Effector CD4 T Cells in...
1
T.110. T Cell Subsets in Unstimulated Peripheral Blood of Patients with Ankylosing Spondylitis: Tumor Necrosis Factor-alpha Blockers Decrease Th 1 and Th 17 Subpopulations Leonardo Limón-Camacho 1 , María Inés Vargas-Rojas 2 , Ruben Burgos-Vargas 3 , Luis Llorente 4 . 1 Universidad Nacional Autonoma de México, México City, Mexico; 2 Instituto Nacional de Enfermedades Respiratorias “Ismael Cosio Villegas,” Mexico; 3 Hospital General de México, Mexico; 4 Instituto Nacional de Ciencias Médicas y Nutrición “Salvador Zubiran,” Mexico With the description of new effector T cell, the role of Th 1 in the pathogenesis of autoimmune and inflammatory diseases is nowadays questionable. Previous reports have shown an increase in the Th 17 cells after stimulation in ankylosing spondylitis (AS), but it is important to determine whether there is a polarization of response in peripheral blood not subjected to stimulation in vitro. We studied 46 AS patients with juvenile-onset (60.9%) or adult-onset (39.1%) disease; 7 (15.2%) received TNF-α-blockers; and in 26 patients (54.2%), the BASDAI scored N 4, 20 rheumatoid arthritis (RA) patients (95% with DAS28 N 2.6) and 25 healthy controls (HC). Cytometry was used to analyze the surface phenotype of freshly isolated PBMCs. Th 1 , Th 2 , Th 17 , and Treg subsets were defined as CD3 + CD4 + IFN-γ + /CD3 + CD4 + IL- 4 + /CD3 + CD4 + IL-17A + /CD3 + CD4 + FOXP3 + . The percentage of Th 17 in AS was higher than in RA and HC (7.4±2.9% vs 1.4± 1.1%, P b 0.001, and 0.7 ± 0.2%, P b 0.0001). The proportion of Th 1 in AS and RA was similar, but higher than that of HC (4.0 ± 2.1%; 4.3 ± 2.4% vs 1.1 ± 0.3%, P b 0.0001). AS subgroup analyses found no differences between juvenile and adult onset disease and BASDAI score. Th 1 and Th 17 subsets in AS patients on TNF-α-blockers was lower in comparison with AS without such treatment (Th 1 0.7 ± 0.4% vs 4.0 ± 2.1%, P b 0.001; Th 17 0.8 ± 0.5% vs 7.4 ± 2.9%, P b 0.001) and similar to HC (Th 1 0.4 ± 0.2% vs 1.1 ± 0.3%; Th 17 0.9 ± 0.5% vs 0.7 ± 0.2%). Our data show an increase in the Th 17 in PBMCs without artificial stimuli which suggest an active role for Th 17 cell subset in the pathogenesis of AS. Furthermore, TNF-α- blockers seem to be able to diminish T cell subpopulations with a proinflammatory cytokine profile. doi:10.1016/j.clim.2010.03.210 T.111. Targeting mTOR and MAPK Pathways to Inhibit Naïve and Experienced Effector CD4 T Cells in Autoimmunity Jack Lin, Emily Stein, Michael Wong, Krishna Kalpathy, Leon Su, Paul Utz, William Robinson, Charles Fathman. Stanford University, Stanford, CA Activation of mTOR is a critical component of naive CD4 T cell proliferation and inhibition of mTOR by the small molecule rapamycin prevents proliferation. In contrast, experienced effector CD4 T cells have become refractory to rapamycin inhibition. While mTOR inhibition appeared insufficient to block effector CD4 T cell proliferation, PI3K inhibition was still effective. A common pathway through PI3K that intersects the mTOR pathway at the level of promoting protein translation is the MAPK/ERK pathway. Similar to rapamycin, MAPK inhibitors block naïve CD4 T-cell proliferation but were incapable of blocking effectors. However, the combination of both rapamycin and MAPK inhibitors could block effector cell proliferation. We showed that this inhibitory activity diminished ribosomal protein S6 phosphorylation, linking proliferation to protein translation activity. The mouse collagen-induced arthritis (CIA) model of rheumatoid arthritis in DBA/1 mice contains both naïve and effector pathogenic T cells. In vivo administration of both rapamycin and MAPK inhibitor decreased the incidence of clinical disease more so than either drug alone. These studies identify differential requirements for pathway utilization in the proliferation of naïve versus experienced effector T cells. Blocking either the mTOR or MAPK/ERK pathway alone is sufficient to inhibit naïve T cells while blocking both pathways is necessary to inhibit effector T cells. This distinction may be important in the context of autoimmunity as both naive and effector CD4 T cells are present upon disease detection, suggesting combinational therapy target- ing multiple pathways that converge upon pathogenic cellular processes may be necessary for successful treatment. doi:10.1016/j.clim.2010.03.211 T.112. IL-6 Plays an Essential Role in Multi-factors Associated Hepcidin Regulation: Anti-IL-6R Ab Therapy Improve Inflammatory Anemia in Multicentric Castleman's Disease (MCD) and Rheumatoid Arthritis (RA) Patients Soken-Nakazawa Song 1 , Naohisa Tomosugi 2 , Hiroshi Kawabata 3 , Takayuki Ishikawa 3 , Teppei Nishikawa 1 , Kazuyuki Yoshizaki 1 . 1 Osaka University, Osaka, Japan; 2 Kanazawa Medical University, Ishikawa, Japan; 3 Kyoto University, Kyoto, Japan Dysregulated production of hepcidin is implicated in anemia of inflammation (AI) and interleukin-6 (IL-6) is a major inducer of hepcidin production. Increased inflam- matory cytokines, especially IL-6 is response for pathogen- esis of MCD and RA. In this study, we study the role of hepcidin and IL-6 in AI patients with MCD or RA, by investigating the effect of tocilizumab, an anti-IL-6 receptor antibody, on the serum hepcidin and relationship between hepcidin and iron-related parameters. The mech- anism involving inflammatory anemia in MCD and RA was further analyzed in vitro by studying the transcriptional regulation of hepcidin in hepatoma-derived cell lines in the presence of cytokines, anti-cytokines antibodies, inhibitors of signal pathways, and hematopoietic factors. In results, our data showed that treatment with tocilizumab resulted in a rapid reduction of serum hepcidin-25 in MCD and RA patients. Although treatment with anti-TNF-α antibody also resulted in a decrease of serum hepcidin, compared to tocilizumab therapy, it decreased by a smaller margin. Furthermore, long-term reductions of hepcidin-25 were S69 Abstracts
Transcript of Targeting mTOR and MAPK Pathways to Inhibit Naïve and Experienced Effector CD4 T Cells in...
S69Abstracts
T.110. T Cell Subsets in Unstimulated PeripheralBlood of Patients with Ankylosing Spondylitis:Tumor Necrosis Factor-alpha Blockers Decrease Th1and Th17 SubpopulationsLeonardo Limón-Camacho1, María Inés Vargas-Rojas2,Ruben Burgos-Vargas3, Luis Llorente4. 1UniversidadNacional Autonoma de México, México City, Mexico;2Instituto Nacional de Enfermedades Respiratorias “IsmaelCosio Villegas,” Mexico; 3Hospital General de México,Mexico; 4Instituto Nacional de Ciencias Médicas y Nutrición“Salvador Zubiran,” Mexico
With the description of new effector T cell, the role of Th1in the pathogenesis of autoimmune and inflammatorydiseases is nowadays questionable. Previous reports haveshown an increase in the Th17 cells after stimulation inankylosing spondylitis (AS), but it is important to determinewhether there is a polarization of response in peripheralblood not subjected to stimulation in vitro. We studied 46 ASpatients with juvenile-onset (60.9%) or adult-onset (39.1%)disease; 7 (15.2%) received TNF-α-blockers; and in 26patients (54.2%), the BASDAI scored N4, 20 rheumatoidarthritis (RA) patients (95% with DAS28N2.6) and 25 healthycontrols (HC). Cytometry was used to analyze the surfacephenotype of freshly isolated PBMCs. Th1, Th2, Th17, andTreg subsets were defined as CD3+CD4+IFN-γ+/CD3+CD4+IL-4+/CD3+CD4+IL-17A+/CD3+CD4+FOXP3+. The percentage ofTh17 in AS was higher than in RA and HC (7.4±2.9% vs 1.4±1.1%, Pb0.001, and 0.7±0.2%, Pb0.0001). The proportion ofTh1 in AS and RA was similar, but higher than that of HC (4.0±2.1%; 4.3±2.4% vs 1.1±0.3%, Pb0.0001). AS subgroupanalyses found no differences between juvenile and adultonset disease and BASDAI score. Th1 and Th17 subsets in ASpatients on TNF-α-blockers was lower in comparison with ASwithout such treatment (Th1 0.7 ±0.4% vs 4.0 ±2.1%,Pb0.001; Th17 0.8±0.5% vs 7.4±2.9%, Pb0.001) and similarto HC (Th1 0.4±0.2% vs 1.1±0.3%; Th17 0.9±0.5% vs 0.7±0.2%). Our data show an increase in the Th17 in PBMCswithout artificial stimuli which suggest an active role for Th17cell subset in the pathogenesis of AS. Furthermore, TNF-α-blockers seem to be able to diminish T cell subpopulationswith a proinflammatory cytokine profile.
doi:10.1016/j.clim.2010.03.210
T.111. Targeting mTOR and MAPK Pathways toInhibit Naïve and Experienced Effector CD4 T Cellsin AutoimmunityJack Lin, Emily Stein, Michael Wong, Krishna Kalpathy, LeonSu, Paul Utz, William Robinson, Charles Fathman. StanfordUniversity, Stanford, CA
Activation of mTOR is a critical component of naive CD4 Tcell proliferation and inhibition of mTOR by the smallmolecule rapamycin prevents proliferation. In contrast,experienced effector CD4 T cells have become refractoryto rapamycin inhibition. While mTOR inhibition appearedinsufficient to block effector CD4 T cell proliferation, PI3K
inhibition was still effective. A common pathway throughPI3K that intersects the mTOR pathway at the level ofpromoting protein translation is the MAPK/ERK pathway.Similar to rapamycin, MAPK inhibitors block naïve CD4 T-cellproliferation but were incapable of blocking effectors.However, the combination of both rapamycin and MAPKinhibitors could block effector cell proliferation. We showedthat this inhibitory activity diminished ribosomal protein S6phosphorylation, linking proliferation to protein translationactivity. The mouse collagen-induced arthritis (CIA) model ofrheumatoid arthritis in DBA/1 mice contains both naïve andeffector pathogenic T cells. In vivo administration of bothrapamycin and MAPK inhibitor decreased the incidence ofclinical disease more so than either drug alone. These studiesidentify differential requirements for pathway utilization inthe proliferation of naïve versus experienced effector Tcells. Blocking either the mTOR or MAPK/ERK pathway aloneis sufficient to inhibit naïve T cells while blocking bothpathways is necessary to inhibit effector T cells. Thisdistinction may be important in the context of autoimmunityas both naive and effector CD4 T cells are present upondisease detection, suggesting combinational therapy target-ing multiple pathways that converge upon pathogeniccellular processes may be necessary for successfultreatment.
doi:10.1016/j.clim.2010.03.211
T.112. IL-6 Plays an Essential Role in Multi-factorsAssociated Hepcidin Regulation: Anti-IL-6R AbTherapy Improve Inflammatory Anemia inMulticentric Castleman's Disease (MCD) andRheumatoid Arthritis (RA) PatientsSoken-Nakazawa Song1, Naohisa Tomosugi2, HiroshiKawabata3, Takayuki Ishikawa3, Teppei Nishikawa1,Kazuyuki Yoshizaki1. 1Osaka University, Osaka, Japan;2Kanazawa Medical University, Ishikawa, Japan; 3KyotoUniversity, Kyoto, Japan
Dysregulated production of hepcidin is implicated inanemia of inflammation (AI) and interleukin-6 (IL-6) is amajor inducer of hepcidin production. Increased inflam-matory cytokines, especially IL-6 is response for pathogen-esis of MCD and RA. In this study, we study the role ofhepcidin and IL-6 in AI patients with MCD or RA, byinvestigating the effect of tocilizumab, an anti-IL-6receptor antibody, on the serum hepcidin and relationshipbetween hepcidin and iron-related parameters. The mech-anism involving inflammatory anemia in MCD and RA wasfurther analyzed in vitro by studying the transcriptionalregulation of hepcidin in hepatoma-derived cell lines in thepresence of cytokines, anti-cytokines antibodies, inhibitorsof signal pathways, and hematopoietic factors. In results,our data showed that treatment with tocilizumab resultedin a rapid reduction of serum hepcidin-25 in MCD and RApatients. Although treatment with anti-TNF-α antibody alsoresulted in a decrease of serum hepcidin, compared totocilizumab therapy, it decreased by a smaller margin.Furthermore, long-term reductions of hepcidin-25 were
