Person: Kivisakk, Pia
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Kivisakk
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Pia
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Kivisakk, Pia
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Publication Alterations of the human gut microbiome in multiple sclerosis(Nature Publishing Group, 2016) Jangi, Sushrut; Gandhi, Roopali; Cox, Laura; Li, Ning; von Glehn, Felipe; Yan, Raymond; Patel, Bonny; Mazzola, Maria; Liu, Shirong; Glanz, Bonnie; Cook, Sandra; Tankou, Stephanie; Stuart, Fiona; Melo, Kirsy; Nejad, Parham; Smith, Kathleen; Topçuolu, Begüm D.; Holden, James; Kivisakk, Pia; Chitnis, Tanuja; De Jager, Philip; Quintana, Francisco; Gerber, Georg; Bry, Lynn; Weiner, HowardThe gut microbiome plays an important role in immune function and has been implicated in several autoimmune disorders. Here we use 16S rRNA sequencing to investigate the gut microbiome in subjects with multiple sclerosis (MS, n=60) and healthy controls (n=43). Microbiome alterations in MS include increases in Methanobrevibacter and Akkermansia and decreases in Butyricimonas, and correlate with variations in the expression of genes involved in dendritic cell maturation, interferon signalling and NF-kB signalling pathways in circulating T cells and monocytes. Patients on disease-modifying treatment show increased abundances of Prevotella and Sutterella, and decreased Sarcina, compared with untreated patients. MS patients of a second cohort show elevated breath methane compared with controls, consistent with our observation of increased gut Methanobrevibacter in MS in the first cohort. Further study is required to assess whether the observed alterations in the gut microbiome play a role in, or are a consequence of, MS pathogenesis.Publication Effect of Natalizumab Treatment on Circulating Plasmacytoid Dendritic Cells: A Cross-Sectional Observational Study in Patients with Multiple Sclerosis(Public Library of Science, 2014) Kivisakk, Pia; Francois, Katiana; Mbianda, Julvet; Gandhi, Roopali; Weiner, Howard; Khoury, SamiaObjectives: Dendritic cells (DCs) serve a critical role both in promoting and inhibiting adaptive immunity. The goal of this study was to investigate the effect of natalizumab (NTZ) treatment on DC numbers, phenotype, and function in patients with multiple sclerosis (MS). Methods: Frequency and phenotype of myeloid and plasmacytoid DCs (MDCs and PDCs, respectively) were analyzed in blood from two separate cohorts of untreated, interferon-treated, or NTZ-treated MS patients. In addition, PDCs were stimulated with CpG-containing oligonucleotides or co-cultured with homologous T cells in the presence or absence of NTZ in vitro to determine functional effects of NTZ treatment. Results: We observed that NTZ treatment was associated with a 25–50% reduction in PDC frequency in peripheral blood as compared to untreated MS patients, while the frequency of MDCs was unchanged. PDCs in NTZ-treated patients displayed a mature, activated phenotype with increased expression of HLA-DR, TLR9, CCR7, IL-6 and IL-12. In contrast, in vitro treatment with NTZ did not increase markers of PDC activation or their ability to induce T cell differentiation. Conclusion: Our study shows that NTZ treatment is associated with a reduced frequency of PDCs in the peripheral circulation, but that PDCs in NTZ-treated individuals display an activated phenotype. Taken together the data suggests that transmigration of activated PDCs is preferentially affected by blockade of integrin α4 leading to an increased frequency of activated PDCs in blood.Publication Identification of a novel mechanism of action of fingolimod (FTY720) on human effector T cell function through TCF-1 upregulation(BioMed Central, 2015) Mazzola, Maria; Raheja, Radhika; Murugaiyan, Gopal; Rajabi, Hasan; Kumar, Deepak; Pertel, Thomas; Regev, Keren; Griffin, Russell; Aly, Lilian; Kivisakk, Pia; Nejad, Parham; Patel, Bonny; Gwanyalla, Nguendab; Hei, Hillary; Glanz, Bonnie; Chitnis, Tanuja; Weiner, Howard; Gandhi, RoopaliBackground: Fingolimod (FTY720), the first oral treatment for multiple sclerosis (MS), blocks immune cell trafficking and prevents disease relapses by downregulation of sphingosine-1-phosphate receptor. We determined the effect of FTY720 on human T cell activation and effector function. Methods: T cells from MS patients and healthy controls were isolated to measure gene expression profiles in the presence or absence of FTY720 using nanostring and quantitative real-time polymerase chain reaction (qPCR). Cytokine protein expression was measured using luminex assay and flow cytometry analysis. Lentivirus vector carrying short hairpin RNA (shRNA) was used to knock down the expression of specific genes in CD4+ T cells. Chromatin immunoprecipitation was performed to assess T cell factor 1 (TCF-1) binding to promoter regions. Luciferase assays were performed to test the direct regulation of interferon gamma (IFN-γ) and granzyme B (GZMB) by TCF-1. Western blot analysis was used to assess the phosphorylation status of Akt and GSK3β. Results: We showed that FTY720 treatment not only affects T cell trafficking but also T cell activation. Patients treated with FTY720 showed a significant reduction in circulating CD4 T cells. Activation of T cells in presence of FTY720 showed a less inflammatory phenotype with reduced production of IFN-γ and GZMB. This decreased effector phenotype of FTY720-treated T cells was dependent on the upregulation of TCF-1. FTY720-induced TCF-1 downregulated the pathogenic cytokines IFN-γ and GZMB by binding to their promoter/enhancer regions and mediating epigenetic modifications. Furthermore, we observed that TCF-1 expression was lower in T cells from multiple sclerosis patients than in those from healthy individuals, and FTY720 treatment increased TCF-1 expression in multiple sclerosis patients. Conclusions: These results reveal a previously unknown mechanism of the effect of FTY720 on human CD4+ T cell modulation in multiple sclerosis and demonstrate the role of TCF-1 in human T cell activation and effector function. Electronic supplementary material The online version of this article (doi:10.1186/s12974-015-0460-z) contains supplementary material, which is available to authorized users.Publication Comprehensive evaluation of serum microRNAs as biomarkers in multiple sclerosis(Lippincott Williams & Wilkins, 2016) Regev, Keren; Paul, Anu; Healy, Brian; von Glenn, Felipe; Diaz-Cruz, Camilo; Gholipour, Taha; Mazzola, Maria; Raheja, Radhika; Nejad, Parham; Glanz, Bonnie; Kivisakk, Pia; Chitnis, Tanuja; Weiner, Howard; Gandhi, RoopaliObjective: To identify circulating microRNAs (miRNAs) linked to disease stage and disability in multiple sclerosis (MS). Methods: Sera from 296 participants including patients with MS, other neurologic diseases (Alzheimer disease and amyotrophic lateral sclerosis), and inflammatory diseases (rheumatoid arthritis and asthma) and healthy controls (HCs) were tested. miRNA profiles were determined using LNA (locked nucleic acid)-based quantitative PCR. Patients with MS were categorized according to disease stage and disability. In the discovery phase, 652 miRNAs were measured in sera from 26 patients with MS and 20 HCs. Following this, significant miRNAs (p < 0.05) from the discovery set were validated using quantitative PCR in 58 patients with MS, 30 HCs, and in 74 samples from other disease controls (Alzheimer disease, amyotrophic lateral sclerosis, asthma, and rheumatoid arthritis). Results: We validated 7 miRNAs that differentiate patients with MS from HCs (p < 0.05 in both the discovery and validation phase); miR-320a upregulation was the most significantly changing serum miRNA in patients with MS. We also identified 2 miRNAs linked to disease progression, with miR-27a-3p being the most significant. Ten miRNAs correlated with the Expanded Disability Status Scale of which miR.199a.5p had the strongest correlation with disability. Of the 15 unique miRNAs we identified in the different group comparisons, 12 have previously been reported to be associated with MS but not in serum. Conclusions: Our findings identify circulating serum miRNAs as potential biomarkers to diagnose and monitor disease status in MS. Classification of evidence: This study provides Class III evidence that circulating serum miRNAs can be used as biomarker for MS.Publication Dynamic regulation of serum aryl hydrocarbon receptor agonists in MS(Lippincott Williams & Wilkins, 2017) Rothhammer, Veit; Borucki, Davis M.; Garcia Sanchez, Maria Isabel; Mazzola, Maria; Hemond, Christopher C.; Regev, Keren; Paul, Anu; Kivisakk, Pia; Bakshi, Rohit; Izquierdo, Guillermo; Weiner, Howard; Quintana, FranciscoObjective: Several factors influence the clinical course of autoimmune inflammatory diseases such as MS and inflammatory bowel disease. Only recently, the complex interaction between the gut microbiome, dietary factors, and metabolism has started to be appreciated with regard to its potential to modulate acute and chronic inflammation. One of the molecular sensors that mediates the effects of these environmental signals on the immune response is the aryl hydrocarbon receptor (AHR), a ligand-activated transcription factor with key functions in immune cells. Methods: In this study, we analyzed the levels of AHR agonists in serum samples from patients with MS and healthy controls in a case-control study. Results: We detected a global decrease of circulating AHR agonists in relapsing-remitting MS patients as compared to controls. However, during acute CNS inflammation in clinically isolated syndrome or active MS, we measured increased AHR agonistic activity. Moreover, AHR ligand levels in patients with benign MS with relatively mild clinical impairment despite longstanding disease were unaltered as compared to healthy controls. Conclusions: Collectively, these data suggest that AHR agonists in serum are dynamically modulated during the course of MS. These findings may guide the development of biomarkers to monitor disease activity as well as the design of novel therapeutic interventions for MS.Publication Transcriptional signature of human pro-inflammatory TH17 cells identifies reduced IL10 gene expression in multiple sclerosis(Nature Publishing Group UK, 2017) Hu, Dan; Notarbartolo, Samuele; Croonenborghs, Tom; Patel, Bonny; Cialic, Ron; Yang, Tun-Hsiang; Aschenbrenner, Dominik; Andersson, Karin M.; Gattorno, Marco; Pham, Minh; Kivisakk, Pia; Pierre, Isabelle V.; Lee, Youjin; Kiani, Karun; Bokarewa, Maria; Tjon, Emily; Pochet, Nathalie; Sallusto, Federica; Kuchroo, Vijay; Weiner, HowardWe have previously reported the molecular signature of murine pathogenic TH17 cells that induce experimental autoimmune encephalomyelitis (EAE) in animals. Here we show that human peripheral blood IFN-γ+IL-17+ (TH1/17) and IFN-γ−IL-17+ (TH17) CD4+ T cells display distinct transcriptional profiles in high-throughput transcription analyses. Compared to TH17 cells, TH1/17 cells have gene signatures with marked similarity to mouse pathogenic TH17 cells. Assessing 15 representative signature genes in patients with multiple sclerosis, we find that TH1/17 cells have elevated expression of CXCR3 and reduced expression of IFNG, CCL3, CLL4, GZMB, and IL10 compared to healthy controls. Moreover, higher expression of IL10 in TH17 cells is found in clinically stable vs. active patients. Our results define the molecular signature of human pro-inflammatory TH17 cells, which can be used to both identify pathogenic TH17 cells and to measure the effect of treatment on TH17 cells in human autoimmune diseases.Publication Serum lipid antibodies are associated with cerebral tissue damage in multiple sclerosis(Ovid Technologies (Wolters Kluwer Health), 2016) Bakshi, Rohit; Yeste, Ada; Patel, B.; Tauhid, Shahamat; Tummala, Subhash; Rahbari, R.; Chu, Renxin; Regev, Keren; Kivisakk, Pia; Weiner, Howard; Quintana, FranciscoObjective: To determine whether peripheral immune responses as measured by serum antigen arrays are linked to cerebral MRI measures of disease severity in multiple sclerosis (MS). Methods: In this cross-sectional study, serum samples were obtained from patients with relapsing-remitting MS (n = 21) and assayed using antigen arrays that contained 420 antigens including CNS-related autoantigens, lipids, and heat shock proteins. Normalized compartment-specific global brain volumes were obtained from 3-tesla MRI as surrogates of atrophy, including gray matter fraction (GMF), white matter fraction (WMF), and total brain parenchymal fraction (BPF). Total brain T2 hyperintense lesion volume (T2LV) was quantified from fluid-attenuated inversion recovery images. Results: We found serum antibody patterns uniquely correlated with BPF, GMF, WMF, and T2LV. Furthermore, we identified immune signatures linked to MRI markers of neurodegeneration (BPF, GMF, WMF) that differentiated those linked to T2LV. Each MRI measure was correlated with a specific set of antibodies. Strikingly, immunoglobulin G (IgG) antibodies to lipids were linked to brain MRI measures. Based on the association between IgG antibody reactivity and each unique MRI measure, we developed a lipid index. This comprised the reactivity directed against all of the lipids associated with each specific MRI measure. We validated these findings in an additional independent set of patients with MS (n = 14) and detected a similar trend for the correlations between BPF, GMF, and T2LV vs their respective lipid indexes. Conclusions: We propose serum antibody repertoires that are associated with MRI measures of cerebral MS involvement. Such antibodies may serve as biomarkers for monitoring disease pathology and progression.