- Email: [email protected]
Plasmacytoid dendritic cells induce an immunoregulatory T helper 9 profile in multiple sclerosis
Abstracts
show that in mice deficient in IFN-gamma-producing T cells, the CP was not activated, and recruitment of inflammation-resolving monocytederived macrophages to the spinal cord parenchyma was limited. We further demonstrate that monocyte-derived macrophages locally regulated recruitment of thymic-derived Foxp3+ regulatory T (Treg) cells to the injured spinal cord parenchyma at the subacute/chronic phase. These two inflammation-resolving populations, monocyte-derived macrophages and Tregs, were found to be pivotal and non-redundant in their activities at distinct stages of the recovery process. Importantly, an ablation protocol that resulted in reduced Tregs at the subacute/chronic stage interfered with tissue remodeling, in contrast to Treg transient ablation, restricted to the 4 day-period before the injury, which favored repair. The enhanced functional recovery observed following such a controlled decrease of Tregs suggests that reduced systemic immunosuppression at the time of the insult can enhance CNS repair. Overall, we established that sequential participation of immune cells, including Th1 cells, infiltrating resolving mo-MΦ and regulatory T cells, is needed for recovery from CNS injury. Our results further highlight the delicate spatial and temporal dynamics of the effector and regulatory/resolving cells, the balance of which is pivotal for the CNS repair process. doi:10.1016/j.jneuroim.2014.08.555
378 NR4A2 controls pathogenic “switched” Th17 cells in the CNS during autoimmune inflammation Ben Raveney, Shinji Oki, Takashi Yamamura National Institute of Neuroscience, NCNP, Tokyo, Japan We previously reported that NR4A2 (Nurr1) is highly upregulated in peripheral blood T cells from patients with multiple sclerosis (MS). Further, NR4A2 is specifically expressed by pathogenic Th17 cells infiltrating the central nervous system (CNS) during experimental autoimmune encephalomyelitis (EAE), the murine model of MS. NR4A2 is not observed in T cells in secondary lymphoid tissues during EAE, but instead it is first observed in CNS T cells. We now reveal that NR4A2 can be induced in T cells by stimulation with a population of antigen presenting cells (APC) isolated from the CNS during EAE that are also highly efficient inducers of Th1 and Th17 cells. Thus we suggest that NR4A2 expression in EAE may result from activation in the specialized target organ milieu in EAE leading to pathogenic T cell differentiation in situ. To investigate the role of NR4A2 in subsequent pathogenic mechanisms, we have generated mice with a T cell-specific NR4A2 deficiency. Such mice are protected from acute clinical EAE induction, despite infiltration of activated T cells into the CNS. These infiltrating T cells are non-pathogenic as they cannot induce passive EAE upon transfer, and a lack of NR4A2 leads to reduced IL-17 production, but increased interferon (IFN)-gamma production. Intriguingly, pathogenic CNS T cells from control mice had a high proportion of IFN-gammasecreting T cells that expressed the Th17 transcription factor RORgamma-t, but despite NR4A2-deficient mice had a high number of IFNgamma-producing T cells, they lacked ROR-gamma-t+IFN-gamma+ CNS T cells. In vitro, control IL-17-producing T cells were able to secrete IFN-gamma upon restimulation with CNS APC, but NR4A2-deficient Th17 cells had a reduced ability to switch to IFN-gamma production. The critical role of NR4A2 in Th17 switching appears to be associated with modulating the strength of T cell receptor signals and so controls T cell differentiation. Our results suggest that different stages of autoimmune inflammation may be mediated by distinct populations of IL-17secreting T cells and the development of these T cell populations results from signals from within the CNS environment. The pathogenicity of
207
these potent “switched” Th17 cells seems to be controlled by NR4A2dependent mechanisms. Thus, NR4A2 might prove an effective target to manipulate early/acute inflammation during autoimmune disease. doi:10.1016/j.jneuroim.2014.08.556
486 CD8 T cell recruitment in the normal aging CNS Rodney Ritzel, Anita Patel, Josh Crapser, Louise Mccullough University of Connecticut Health Center, University of Connecticut Health Center, Farmington, United States Introduction: Aging is associated with an increase in basal inflammatory processes in the CNS and an overall decline in cognitive function and recovery following injury. Whereas the effect of aging on the peripheral immune system has been well studied, less is known regarding the role of immune privilege in the normal aging CNS. Although an increased presence of leukocyte recruitment in the aging brain has been reported, to date, no systematic analysis of these populations has been performed. Herein, we examined the effect of aging on leukocyte recruitment into the CNS. Methods: Young (8–12 wks) and aged (18–22 mos) wildtype C57Bl/6 mice were sacrificed, perfused, and brains were processed for flow cytometry using a Percoll gradient. Intracellular cytokine staining was performed using fixation/permeabilization following 8 hr of in vivo incubation. For immunohistochemistry, harvested brains were snap frozen, sectioned on a cryostat and fixed using paraformaldehyde. Results: Despite no observed change in blood brain barrier permeability, aging was associated with compromised immune privilege in the brain and spinal cord as evidenced by a three-fold increase in the number of CD45hi leukocytes, primarily composed of conventional CD8+ T cells. CD8 T cells in the aged brain expressed significantly higher levels of the adhesion molecules required for CNS entry, LFA-1 (p b 0.001) and VLA-4 (p b 0.001), compared to those in the blood. Intravascular labeling and immunohistochemical staining revealed the presence of parenchymal CD8+ T cells in several regions of the brain including the choroid plexus and meninges. These cells were identified as effector/memory (CD44+CD62L−) cells and expressed markers associated with TCR activation. Further we show that this population of CNS-specific CD8 T cells is defined by IL-17A production and has a unique pattern of TCR vBeta repertoire usage suggesting that entry into the CNS may be antigen-driven. Conclusion: Taken together, we have identified a unique population of age-related, CNS-specific CD8 T cells that implicate a role for autoimmunity in the CNS. More studies will be required to ascertain the functional significance of this cell population. doi:10.1016/j.jneuroim.2014.08.557
548 Plasmacytoid dendritic cells induce an immunoregulatory T helper 9 profile in multiple sclerosis Gabriella Ruoccoa, Silvia Rossib, Caterina Mottab, Giulia Macchiarulob, Francesca Barbierib, Marco De Bardia, Giovanna Borsellinoa, Maria Grazia Grassoc, Serena Ruggierid, Claudio Gasperinid, Roberto Furlane, Diego Centonzeb, Luca Battistinia, Elisabetta Volpea a
Neuroimmunology Unit, Santa Lucia Foundation, Rome, Italy; Neuroimmunology and Synaptic Plasticity Laboratory Units, Department of Neuroscience, Santa Lucia Foundation, University Tor Vergata, Rome,
b
208
Abstracts
Italy; cMultiple Sclerosis Centre, Santa Lucia Foundation, Rome, Italy; d Department of Neuroscience “Lancisi”, San Camillo Hospital, Rome, Italy; e Neuroimmunology Unit, San Raffaele Scientific Institute, Milan, Italy Dendritic cells (DCs) are responsible for the differentiation of naive CD4 T cells into T helper (Th) cells, which orchestrate the consequent adaptive immune response. Distinct Th subsets with different functions have been described, such as Th1, Th2, Th9, Th17 and Th22. Autoimmune diseases and, particularly, multiple sclerosis (MS), are characterized by persistent inflammation generated by Th1 and Th17 cells. However, the role of human DCs in shaping adaptive Th cell response in MS has not been investigated. In this study, we compared the production of Th cytokines by naive T cells polarized with myeloid and plasmacytoid dendritic cells (mDCs and pDCs) in healthy donors (HD) and relapsing–remitting (RR) MS patients. We found that after stimulation mDCs are able to activate a Th17 immune response, while pDCs induce IL-10 production. Surprisingly, we found that stimulated pDCs from MS patients are also involved in the polarization of Th9 cells, which produce IL-9 and are known to be involved in allergic diseases. We investigated the potential role of pDCmediated IL-9 production in MS. We found that IL-9 activates STAT1 and STAT5 phosphorylation in Th17 cells and interferes with IL-17 production and IRF-4 expression by Th17-polarized cells. We measured IL-9 levels in the cerebrospinal fluid (CSF) of MS patients and found them to be inversely correlated with the severity of MS and with levels of IL-17 in the CSF. Moreover, we analysed CSF contents of IL-9 and we found that IL-9 is inversely correlated with indexes of inflammatory activity, neurodegeneration and disability progression of MS. Furthermore, high levels of IL-9 are associated with the absence of IL-17 in the CSF of RR-MS patients. In conclusion, these results suggest an important immunoregulatory role exerted by pDCs in driving the Th9 profile, which attenuate the exaggerated Th17 inflammatory response in MS. doi:10.1016/j.jneuroim.2014.08.558
the field most work on Treg was based identifying Foxp3+ Treg cell using just one antibody clone, and our impression is that some information has been lost. We observed in fact different percentages of Foxp3+ within CD4 + CD25hiCD39+ nTreg cells with the use of antiFoxp3 clones 259D, PCH101 or 150D (26.7 % vs 13.7% vs 25.7% respectively). Since different antibody clones recognize distinct portions of the Foxp3 protein, we speculate they are identifying different Foxp3 isoforms; accordingly, we observed different percentages of Foxp3+ within iTreg, depending on the antibody clone used. Autoimmune diseases such as Multiple Sclerosis (MS) arise from a general failure of immune-tolerance, and Treg cells are inevitably involved. We wondered whether the failure of immune-tolerance in MS patients is due to an identifiable peculiarity of the Foxp3 protein. Interestingly, based on the antibody clone used, we observed a lower iTreg polarization in MS patients compared to healthy donors (HD), but this is more evident with one antibody rather than other: PCH101: 23.6% (HD) vs 22.8% (MS); 259D: 49.1% (HD) vs 15.5% (MS). To confirm this data at the protein level, we performed western blotting (WB) using different anti-FoxP3 antibody clones, which revealed Foxp3 protein as doublet or triplet in nTreg and iTreg respectively. In conclusion, the coupled analysis with the use of Flow-Cytometry and WB with different antibodies can unveil differences between MS and HD that otherwise could be easily lost. Keywords: T-cells, Immunological mechanisms, mechanisms of CNS disease doi:10.1016/j.jneuroim.2014.08.559
33 Alpha-synuclein immunization, in the absence of alpha-synuclein over-expression or neural pathology, modifies microglia activation patterns and T cells' activation profiles Marina Romero-ramosa, Josefine Christiansena,b, Vanesa Sanchez-guajardob a
398 Is there a correlation between CD39 + CD25+ T lymphocytes and Foxp3 isoforms in Multiple Sclerosis? Manolo Sambuccia, Francesca Garganoa, Marco De Bardia, Claudio Gasperinib, Serena Ruggierib, Veronica De Rosac, Giuseppe Mataresed, Giovanna Borsellinoa, Luca Battistinia a
Neuroimmunology Unit, IRCCS Santa Lucia Foundation, Rome, Italy; Department of Neuroscience "Lancisi", San Camillo Hospital, Rome, Italy; c Laboratorio di Immunologia, Istituto di Endocrinologia e Oncologia Sperimentale, Consiglio Nazionale delle Ricerche (IEOS-CNR), Napoli, Italy; d Department of Medicine and Surgery, University of Salerno, “Baronissi Campus”, Salerno, Italy b
The regulatory circuit that controls immunological tolerance is clearly linked to the transcription factor Foxp3, the director of T regulatory cell (Treg) development. In human, the Foxp3 protein is expressed as three main isoforms: a “full length” isoform (FL), and at least an alternativesplicing product lacking exon 2 (Foxp3Delta2) or lacking both exon 2 and exon 7 (Foxp3Delta2Delta7). Foxp3 isoforms are probably different exon-coded proteins derived by a maturation process and their function and association with other regulatory cell markers in both natural (nTreg) and induced (iTreg) Treg are not clear. Our lab has previously shown a linear correlation between expression of Foxp3+ and CD39. In
CNS Disease Modeling Group, NEURODIN, Department of Biomedicine, Aarhus University, Aarhus, Denmark; bNeuroimmunology of Degenerative Disease Group, NEURODIN, Department of Biomedicine, Aarhus University, Aarhus, Denmark Alpha-synuclein (a-syn) mutations or accumulation has been associated with onset of Parkinson’s disease. At the same time, neuroinflammation has been shown to be an important factor during PD pathology and both T cells and IgG have been observed in postmortem PD brains. Furthermore, in animal models of PD Th17 T cells have been shown to contribute to pathology while Treg are protective. Immunological based therapies have shown that immunization with a-syn or transfer of a-syn specific IgG confers protection in animal models of PD. All together this implies that the adaptive immune system is able to act on the brain. We propose that this interaction is mediated by microglia as a result of the adaptive immune system recognizing a-syn. To elucidate these processes, we immunized mice with different forms (monomeric, nitrated or fibrillar) and doses of a-syn (15 & 100 μg), or with adjuvant alone, LPS or Abeta peptide as controls. Results show that depending on the dose of a-syn microglia acquire distinct phenotypes, even if there is no a-syn accumulation in brain. We have further observed that microgliosis depends on the type and dose of a-syn, as does IgG deposition on microglia and neurons. T cells express different CCR6 and CD103 in a Dopamine Receptor dependent way depending on dose of a-syn. Additionally T cells express different STAT patterns depending on the type of a-syn. These effects are specific of a-syn, as
show that in mice deficient in IFN-gamma-producing T cells, the CP was not activated, and recruitment of inflammation-resolving monocytederived macrophages to the spinal cord parenchyma was limited. We further demonstrate that monocyte-derived macrophages locally regulated recruitment of thymic-derived Foxp3+ regulatory T (Treg) cells to the injured spinal cord parenchyma at the subacute/chronic phase. These two inflammation-resolving populations, monocyte-derived macrophages and Tregs, were found to be pivotal and non-redundant in their activities at distinct stages of the recovery process. Importantly, an ablation protocol that resulted in reduced Tregs at the subacute/chronic stage interfered with tissue remodeling, in contrast to Treg transient ablation, restricted to the 4 day-period before the injury, which favored repair. The enhanced functional recovery observed following such a controlled decrease of Tregs suggests that reduced systemic immunosuppression at the time of the insult can enhance CNS repair. Overall, we established that sequential participation of immune cells, including Th1 cells, infiltrating resolving mo-MΦ and regulatory T cells, is needed for recovery from CNS injury. Our results further highlight the delicate spatial and temporal dynamics of the effector and regulatory/resolving cells, the balance of which is pivotal for the CNS repair process. doi:10.1016/j.jneuroim.2014.08.555
378 NR4A2 controls pathogenic “switched” Th17 cells in the CNS during autoimmune inflammation Ben Raveney, Shinji Oki, Takashi Yamamura National Institute of Neuroscience, NCNP, Tokyo, Japan We previously reported that NR4A2 (Nurr1) is highly upregulated in peripheral blood T cells from patients with multiple sclerosis (MS). Further, NR4A2 is specifically expressed by pathogenic Th17 cells infiltrating the central nervous system (CNS) during experimental autoimmune encephalomyelitis (EAE), the murine model of MS. NR4A2 is not observed in T cells in secondary lymphoid tissues during EAE, but instead it is first observed in CNS T cells. We now reveal that NR4A2 can be induced in T cells by stimulation with a population of antigen presenting cells (APC) isolated from the CNS during EAE that are also highly efficient inducers of Th1 and Th17 cells. Thus we suggest that NR4A2 expression in EAE may result from activation in the specialized target organ milieu in EAE leading to pathogenic T cell differentiation in situ. To investigate the role of NR4A2 in subsequent pathogenic mechanisms, we have generated mice with a T cell-specific NR4A2 deficiency. Such mice are protected from acute clinical EAE induction, despite infiltration of activated T cells into the CNS. These infiltrating T cells are non-pathogenic as they cannot induce passive EAE upon transfer, and a lack of NR4A2 leads to reduced IL-17 production, but increased interferon (IFN)-gamma production. Intriguingly, pathogenic CNS T cells from control mice had a high proportion of IFN-gammasecreting T cells that expressed the Th17 transcription factor RORgamma-t, but despite NR4A2-deficient mice had a high number of IFNgamma-producing T cells, they lacked ROR-gamma-t+IFN-gamma+ CNS T cells. In vitro, control IL-17-producing T cells were able to secrete IFN-gamma upon restimulation with CNS APC, but NR4A2-deficient Th17 cells had a reduced ability to switch to IFN-gamma production. The critical role of NR4A2 in Th17 switching appears to be associated with modulating the strength of T cell receptor signals and so controls T cell differentiation. Our results suggest that different stages of autoimmune inflammation may be mediated by distinct populations of IL-17secreting T cells and the development of these T cell populations results from signals from within the CNS environment. The pathogenicity of
207
these potent “switched” Th17 cells seems to be controlled by NR4A2dependent mechanisms. Thus, NR4A2 might prove an effective target to manipulate early/acute inflammation during autoimmune disease. doi:10.1016/j.jneuroim.2014.08.556
486 CD8 T cell recruitment in the normal aging CNS Rodney Ritzel, Anita Patel, Josh Crapser, Louise Mccullough University of Connecticut Health Center, University of Connecticut Health Center, Farmington, United States Introduction: Aging is associated with an increase in basal inflammatory processes in the CNS and an overall decline in cognitive function and recovery following injury. Whereas the effect of aging on the peripheral immune system has been well studied, less is known regarding the role of immune privilege in the normal aging CNS. Although an increased presence of leukocyte recruitment in the aging brain has been reported, to date, no systematic analysis of these populations has been performed. Herein, we examined the effect of aging on leukocyte recruitment into the CNS. Methods: Young (8–12 wks) and aged (18–22 mos) wildtype C57Bl/6 mice were sacrificed, perfused, and brains were processed for flow cytometry using a Percoll gradient. Intracellular cytokine staining was performed using fixation/permeabilization following 8 hr of in vivo incubation. For immunohistochemistry, harvested brains were snap frozen, sectioned on a cryostat and fixed using paraformaldehyde. Results: Despite no observed change in blood brain barrier permeability, aging was associated with compromised immune privilege in the brain and spinal cord as evidenced by a three-fold increase in the number of CD45hi leukocytes, primarily composed of conventional CD8+ T cells. CD8 T cells in the aged brain expressed significantly higher levels of the adhesion molecules required for CNS entry, LFA-1 (p b 0.001) and VLA-4 (p b 0.001), compared to those in the blood. Intravascular labeling and immunohistochemical staining revealed the presence of parenchymal CD8+ T cells in several regions of the brain including the choroid plexus and meninges. These cells were identified as effector/memory (CD44+CD62L−) cells and expressed markers associated with TCR activation. Further we show that this population of CNS-specific CD8 T cells is defined by IL-17A production and has a unique pattern of TCR vBeta repertoire usage suggesting that entry into the CNS may be antigen-driven. Conclusion: Taken together, we have identified a unique population of age-related, CNS-specific CD8 T cells that implicate a role for autoimmunity in the CNS. More studies will be required to ascertain the functional significance of this cell population. doi:10.1016/j.jneuroim.2014.08.557
548 Plasmacytoid dendritic cells induce an immunoregulatory T helper 9 profile in multiple sclerosis Gabriella Ruoccoa, Silvia Rossib, Caterina Mottab, Giulia Macchiarulob, Francesca Barbierib, Marco De Bardia, Giovanna Borsellinoa, Maria Grazia Grassoc, Serena Ruggierid, Claudio Gasperinid, Roberto Furlane, Diego Centonzeb, Luca Battistinia, Elisabetta Volpea a
Neuroimmunology Unit, Santa Lucia Foundation, Rome, Italy; Neuroimmunology and Synaptic Plasticity Laboratory Units, Department of Neuroscience, Santa Lucia Foundation, University Tor Vergata, Rome,
b
208
Abstracts
Italy; cMultiple Sclerosis Centre, Santa Lucia Foundation, Rome, Italy; d Department of Neuroscience “Lancisi”, San Camillo Hospital, Rome, Italy; e Neuroimmunology Unit, San Raffaele Scientific Institute, Milan, Italy Dendritic cells (DCs) are responsible for the differentiation of naive CD4 T cells into T helper (Th) cells, which orchestrate the consequent adaptive immune response. Distinct Th subsets with different functions have been described, such as Th1, Th2, Th9, Th17 and Th22. Autoimmune diseases and, particularly, multiple sclerosis (MS), are characterized by persistent inflammation generated by Th1 and Th17 cells. However, the role of human DCs in shaping adaptive Th cell response in MS has not been investigated. In this study, we compared the production of Th cytokines by naive T cells polarized with myeloid and plasmacytoid dendritic cells (mDCs and pDCs) in healthy donors (HD) and relapsing–remitting (RR) MS patients. We found that after stimulation mDCs are able to activate a Th17 immune response, while pDCs induce IL-10 production. Surprisingly, we found that stimulated pDCs from MS patients are also involved in the polarization of Th9 cells, which produce IL-9 and are known to be involved in allergic diseases. We investigated the potential role of pDCmediated IL-9 production in MS. We found that IL-9 activates STAT1 and STAT5 phosphorylation in Th17 cells and interferes with IL-17 production and IRF-4 expression by Th17-polarized cells. We measured IL-9 levels in the cerebrospinal fluid (CSF) of MS patients and found them to be inversely correlated with the severity of MS and with levels of IL-17 in the CSF. Moreover, we analysed CSF contents of IL-9 and we found that IL-9 is inversely correlated with indexes of inflammatory activity, neurodegeneration and disability progression of MS. Furthermore, high levels of IL-9 are associated with the absence of IL-17 in the CSF of RR-MS patients. In conclusion, these results suggest an important immunoregulatory role exerted by pDCs in driving the Th9 profile, which attenuate the exaggerated Th17 inflammatory response in MS. doi:10.1016/j.jneuroim.2014.08.558
the field most work on Treg was based identifying Foxp3+ Treg cell using just one antibody clone, and our impression is that some information has been lost. We observed in fact different percentages of Foxp3+ within CD4 + CD25hiCD39+ nTreg cells with the use of antiFoxp3 clones 259D, PCH101 or 150D (26.7 % vs 13.7% vs 25.7% respectively). Since different antibody clones recognize distinct portions of the Foxp3 protein, we speculate they are identifying different Foxp3 isoforms; accordingly, we observed different percentages of Foxp3+ within iTreg, depending on the antibody clone used. Autoimmune diseases such as Multiple Sclerosis (MS) arise from a general failure of immune-tolerance, and Treg cells are inevitably involved. We wondered whether the failure of immune-tolerance in MS patients is due to an identifiable peculiarity of the Foxp3 protein. Interestingly, based on the antibody clone used, we observed a lower iTreg polarization in MS patients compared to healthy donors (HD), but this is more evident with one antibody rather than other: PCH101: 23.6% (HD) vs 22.8% (MS); 259D: 49.1% (HD) vs 15.5% (MS). To confirm this data at the protein level, we performed western blotting (WB) using different anti-FoxP3 antibody clones, which revealed Foxp3 protein as doublet or triplet in nTreg and iTreg respectively. In conclusion, the coupled analysis with the use of Flow-Cytometry and WB with different antibodies can unveil differences between MS and HD that otherwise could be easily lost. Keywords: T-cells, Immunological mechanisms, mechanisms of CNS disease doi:10.1016/j.jneuroim.2014.08.559
33 Alpha-synuclein immunization, in the absence of alpha-synuclein over-expression or neural pathology, modifies microglia activation patterns and T cells' activation profiles Marina Romero-ramosa, Josefine Christiansena,b, Vanesa Sanchez-guajardob a
398 Is there a correlation between CD39 + CD25+ T lymphocytes and Foxp3 isoforms in Multiple Sclerosis? Manolo Sambuccia, Francesca Garganoa, Marco De Bardia, Claudio Gasperinib, Serena Ruggierib, Veronica De Rosac, Giuseppe Mataresed, Giovanna Borsellinoa, Luca Battistinia a
Neuroimmunology Unit, IRCCS Santa Lucia Foundation, Rome, Italy; Department of Neuroscience "Lancisi", San Camillo Hospital, Rome, Italy; c Laboratorio di Immunologia, Istituto di Endocrinologia e Oncologia Sperimentale, Consiglio Nazionale delle Ricerche (IEOS-CNR), Napoli, Italy; d Department of Medicine and Surgery, University of Salerno, “Baronissi Campus”, Salerno, Italy b
The regulatory circuit that controls immunological tolerance is clearly linked to the transcription factor Foxp3, the director of T regulatory cell (Treg) development. In human, the Foxp3 protein is expressed as three main isoforms: a “full length” isoform (FL), and at least an alternativesplicing product lacking exon 2 (Foxp3Delta2) or lacking both exon 2 and exon 7 (Foxp3Delta2Delta7). Foxp3 isoforms are probably different exon-coded proteins derived by a maturation process and their function and association with other regulatory cell markers in both natural (nTreg) and induced (iTreg) Treg are not clear. Our lab has previously shown a linear correlation between expression of Foxp3+ and CD39. In
CNS Disease Modeling Group, NEURODIN, Department of Biomedicine, Aarhus University, Aarhus, Denmark; bNeuroimmunology of Degenerative Disease Group, NEURODIN, Department of Biomedicine, Aarhus University, Aarhus, Denmark Alpha-synuclein (a-syn) mutations or accumulation has been associated with onset of Parkinson’s disease. At the same time, neuroinflammation has been shown to be an important factor during PD pathology and both T cells and IgG have been observed in postmortem PD brains. Furthermore, in animal models of PD Th17 T cells have been shown to contribute to pathology while Treg are protective. Immunological based therapies have shown that immunization with a-syn or transfer of a-syn specific IgG confers protection in animal models of PD. All together this implies that the adaptive immune system is able to act on the brain. We propose that this interaction is mediated by microglia as a result of the adaptive immune system recognizing a-syn. To elucidate these processes, we immunized mice with different forms (monomeric, nitrated or fibrillar) and doses of a-syn (15 & 100 μg), or with adjuvant alone, LPS or Abeta peptide as controls. Results show that depending on the dose of a-syn microglia acquire distinct phenotypes, even if there is no a-syn accumulation in brain. We have further observed that microgliosis depends on the type and dose of a-syn, as does IgG deposition on microglia and neurons. T cells express different CCR6 and CD103 in a Dopamine Receptor dependent way depending on dose of a-syn. Additionally T cells express different STAT patterns depending on the type of a-syn. These effects are specific of a-syn, as