Contributions
Abstract: EP1658
Type: ePoster
Abstract Category: Therapy - disease modifying - 26 Immunomodulation/Immunosuppression
Introduction: The mode of action of dimethylfumarate (DMF), an immunomodulatory treatment for relapsing-remitting multiple sclerosis (RRMS), has not yet been fully elucidated. While in-vitro experiments and animal studies suggest effects on immune cell survival, cytokine secretion and oxidative stress response, a proof from human ex-vivo studies is lacking.
Methods: Blood samples were collected from twenty well-characterized RRMS patients at baseline and after 3, 6 and 12 months of DMF treatment and an age- and gender-matched cohort of healthy individuals at 0 and 3 months. Peripheral blood mononuclear cells (PBMCs) were separated and cryopreserved for flow cytometry and immunoassays. Leukocyte subpopulations and cytokine secretion ex-vivo and upon in-vitro stimulation were recorded. T cells were assessed for their levels of reactive oxygen species (ROS) and their proliferative capacity. Response of monocyte activation markers as well as NFkB and MAPK pathways to DMF was analysed.
Results: Upon DMF treatment all lymphocyte subpopulations dropped significantly over the course of 12 months with cytotoxic and effector T cells being affected most drastically. In vitro DMF treatment lead to increased lymphocyte cell death which was potentiated by oxidative stress. In line with this result a significant increase of cytosolic ROS levels after 3 months treatment was detected. DMF inhibited proliferation of T cells in-vitro (CD8>CD4).Interestingly, this anti-proliferative effect decreased under treatment. While in-vitro stimulation with DMF resulted in an increased secretion of pro- and anti-inflammatory cytokines, no according longitudinal effects were observed. In-vitro DMF treatment reduced NFkB (p65) translocation to the nucleus. Consistent with this result the activation of antigen presenting cells (APCs) was decreased both in-vitro and ex-vivo.
Conclusion: This study translates knowledge from in-vitro and animal studies on DMF into the clinical setting. Our data suggest that DMF not only alters lymphocyte composition but also has profound effects on proliferation. In addition it also acts on innate immunity by reducing the activation status of APCs by reducing NFkB activation.
Disclosure: This study was supported by an Investigator Initiated Trial grant from Biogen.
Tobias Derfuss received speaker fees, research support, travel support, and/or served on Advisory Boards or Steering Committees of Novartis Pharma, Merck Serono, Biogen, Teva, Bayer-Schering, GeNeuro, Mitsubishi Pharma, MedDay, Roche, and Genzyme.
Raija LP Lindberg has received research support from the Swiss MS Society, Swiss National Science Foundation, European FP6 and IMI JU programs, Roche Postdoc Fellowship Program (RPF-program), unrestricted research grants from Novartis and Biogen.
Ludwig Kappos' institution (University Hospital Basel) received in the last 3 years and used exclusively for research support: steering committee for and consulting fees from Actelion, Addex, Bayer HealthCare, Biogen, Biotica, Genzyme, Lilly, Merck, Mitsubishi, Novartis, Ono, Pfizer, Receptos, Sanofi-Aventis, Santhera, Siemens, Teva, UCB and Xenoport; speaker fees: Bayer HealthCare, Biogen, Merck, Novartis, Sanofi-Aventis and Teva; support of educational activities from Bayer HealthCare, Biogen, CSL Behring, Genzyme, Merck, Novartis, Sanofi-Aventis and Teva; royalties from Neurostatus Systems GmbH; grants from Bayer HealthCare, Biogen, the European Union, Merck, Novartis, Roche, Roche Research Foundations, the Swiss Multiple Sclerosis Society and the Swiss National Research Foundation.
Martin Diebold, Claudia Sievers and Nicholas Sanderson declare no personal conflict of interest
Abstract: EP1658
Type: ePoster
Abstract Category: Therapy - disease modifying - 26 Immunomodulation/Immunosuppression
Introduction: The mode of action of dimethylfumarate (DMF), an immunomodulatory treatment for relapsing-remitting multiple sclerosis (RRMS), has not yet been fully elucidated. While in-vitro experiments and animal studies suggest effects on immune cell survival, cytokine secretion and oxidative stress response, a proof from human ex-vivo studies is lacking.
Methods: Blood samples were collected from twenty well-characterized RRMS patients at baseline and after 3, 6 and 12 months of DMF treatment and an age- and gender-matched cohort of healthy individuals at 0 and 3 months. Peripheral blood mononuclear cells (PBMCs) were separated and cryopreserved for flow cytometry and immunoassays. Leukocyte subpopulations and cytokine secretion ex-vivo and upon in-vitro stimulation were recorded. T cells were assessed for their levels of reactive oxygen species (ROS) and their proliferative capacity. Response of monocyte activation markers as well as NFkB and MAPK pathways to DMF was analysed.
Results: Upon DMF treatment all lymphocyte subpopulations dropped significantly over the course of 12 months with cytotoxic and effector T cells being affected most drastically. In vitro DMF treatment lead to increased lymphocyte cell death which was potentiated by oxidative stress. In line with this result a significant increase of cytosolic ROS levels after 3 months treatment was detected. DMF inhibited proliferation of T cells in-vitro (CD8>CD4).Interestingly, this anti-proliferative effect decreased under treatment. While in-vitro stimulation with DMF resulted in an increased secretion of pro- and anti-inflammatory cytokines, no according longitudinal effects were observed. In-vitro DMF treatment reduced NFkB (p65) translocation to the nucleus. Consistent with this result the activation of antigen presenting cells (APCs) was decreased both in-vitro and ex-vivo.
Conclusion: This study translates knowledge from in-vitro and animal studies on DMF into the clinical setting. Our data suggest that DMF not only alters lymphocyte composition but also has profound effects on proliferation. In addition it also acts on innate immunity by reducing the activation status of APCs by reducing NFkB activation.
Disclosure: This study was supported by an Investigator Initiated Trial grant from Biogen.
Tobias Derfuss received speaker fees, research support, travel support, and/or served on Advisory Boards or Steering Committees of Novartis Pharma, Merck Serono, Biogen, Teva, Bayer-Schering, GeNeuro, Mitsubishi Pharma, MedDay, Roche, and Genzyme.
Raija LP Lindberg has received research support from the Swiss MS Society, Swiss National Science Foundation, European FP6 and IMI JU programs, Roche Postdoc Fellowship Program (RPF-program), unrestricted research grants from Novartis and Biogen.
Ludwig Kappos' institution (University Hospital Basel) received in the last 3 years and used exclusively for research support: steering committee for and consulting fees from Actelion, Addex, Bayer HealthCare, Biogen, Biotica, Genzyme, Lilly, Merck, Mitsubishi, Novartis, Ono, Pfizer, Receptos, Sanofi-Aventis, Santhera, Siemens, Teva, UCB and Xenoport; speaker fees: Bayer HealthCare, Biogen, Merck, Novartis, Sanofi-Aventis and Teva; support of educational activities from Bayer HealthCare, Biogen, CSL Behring, Genzyme, Merck, Novartis, Sanofi-Aventis and Teva; royalties from Neurostatus Systems GmbH; grants from Bayer HealthCare, Biogen, the European Union, Merck, Novartis, Roche, Roche Research Foundations, the Swiss Multiple Sclerosis Society and the Swiss National Research Foundation.
Martin Diebold, Claudia Sievers and Nicholas Sanderson declare no personal conflict of interest