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1.
Curr Neurol Neurosci Rep ; 23(9): 507-520, 2023 09.
Article in English | MEDLINE | ID: mdl-37589918

ABSTRACT

PURPOSE OF REVIEW: Autologous haematopoietic stem cell transplantation (AHSCT) is increasingly considered a treatment option for patients with multiple sclerosis (MS), an autoimmune demyelinating and degenerative disease of the central nervous system (CNS). AHSCT persistently suppresses inflammation and improves the disease course in large proportions of patients with relapsing-remitting (RR) MS. Aim of this article is to review the relevant new knowledge published during the last 3 years. RECENT FINDINGS: Laboratory studies reported confirmatory and new insights into the immunological and biomarker effects of AHSCT. Retrospective clinical studies confirmed excellent outcomes in RRMS, showing possible superior effectiveness over standard therapies and suggesting a possible benefit in early secondary progressive (SP) MS with inflammatory features. New data on risks of infertility and secondary autoimmunity were also reported. Further evidence on the high effectiveness and acceptable safety of AHSCT strengthens its position as a clinical option for aggressive RRMS. Further research is needed to better define its role in treatment-naïve and progressive forms of MS, ideally within randomised clinical trials (RCTs).


Subject(s)
Hematopoietic Stem Cell Transplantation , Multiple Sclerosis, Chronic Progressive , Multiple Sclerosis, Relapsing-Remitting , Multiple Sclerosis , Humans , Multiple Sclerosis/therapy , Retrospective Studies
2.
Science ; 376(6594): eabd5926, 2022 05 13.
Article in English | MEDLINE | ID: mdl-35549409

ABSTRACT

Aging is associated with increased prevalence of axonal injuries characterized by poor regeneration and disability. However, the underlying mechanisms remain unclear. In our experiments, RNA sequencing of sciatic dorsal root ganglia (DRG) revealed significant aging-dependent enrichment in T cell signaling both before and after sciatic nerve injury (SNI) in mice. Lymphotoxin activated the transcription factor NF-κB, which induced expression of the chemokine CXCL13 by neurons. This in turn recruited CXCR5+CD8+ T cells to injured DRG neurons overexpressing major histocompatibility complex class I. CD8+ T cells repressed the axonal regeneration of DRG neurons via caspase 3 activation. CXCL13 neutralization prevented CXCR5+CD8+ T cell recruitment to the DRG and reversed aging-dependent regenerative decline, thereby promoting neurological recovery after SNI. Thus, axonal regeneration can be facilitated by antagonizing cross-talk between immune cells and neurons.


Subject(s)
Aging , Axons , CD8-Positive T-Lymphocytes , Ganglia, Spinal , Nerve Regeneration , Neurons , Sciatic Nerve , Aging/metabolism , Animals , Axons/physiology , CD8-Positive T-Lymphocytes/metabolism , Ganglia, Spinal/metabolism , Mice , Neurons/metabolism , Sciatic Nerve/injuries , Sciatic Nerve/physiology
3.
Front Immunol ; 12: 813957, 2021.
Article in English | MEDLINE | ID: mdl-35178046

ABSTRACT

Multiple sclerosis (MS) is a central nervous system (CNS) disorder, which is mediated by an abnormal immune response coordinated by T and B cells resulting in areas of inflammation, demyelination, and axonal loss. Disease-modifying treatments (DMTs) are available to dampen the inflammatory aggression but are ineffective in many patients. Autologous hematopoietic stem cell transplantation (HSCT) has been used as treatment in patients with a highly active disease, achieving a long-term clinical remission in most. The rationale of the intervention is to eradicate inflammatory autoreactive cells with lympho-ablative regimens and restore immune tolerance. Immunological studies have demonstrated that autologous HSCT induces a renewal of TCR repertoires, resurgence of immune regulatory cells, and depletion of proinflammatory T cell subsets, suggesting a "resetting" of immunological memory. Although our understanding of the clinical and immunological effects of autologous HSCT has progressed, further work is required to characterize the mechanisms that underlie treatment efficacy. Considering that memory B cells are disease-promoting and stem-like T cells are multipotent progenitors involved in self-regeneration of central and effector memory cells, investigating the reconstitution of B cell compartment and stem and effector subsets of immunological memory following autologous HSCT could elucidate those mechanisms. Since all subjects need to be optimally protected from vaccine-preventable diseases (including COVID-19), there is a need to ensure that vaccination in subjects undergoing HSCT is effective and safe. Additionally, the study of vaccination in HSCT-treated subjects as a means of evaluating immune responses could further distinguish broad immunosuppression from immune resetting.


Subject(s)
Autoimmunity , Hematopoietic Stem Cell Transplantation , Immune Tolerance , Immunologic Memory , Lymphocyte Subsets/immunology , Multiple Sclerosis, Chronic Progressive/surgery , Multiple Sclerosis, Relapsing-Remitting/surgery , Adaptive Immunity , Hematopoietic Stem Cell Transplantation/adverse effects , Humans , Immunity, Innate , Lymphocyte Subsets/metabolism , Multiple Sclerosis, Chronic Progressive/immunology , Multiple Sclerosis, Chronic Progressive/metabolism , Multiple Sclerosis, Relapsing-Remitting/immunology , Multiple Sclerosis, Relapsing-Remitting/metabolism , Phenotype , Transplantation, Autologous , Treatment Outcome
4.
Pharmacol Res ; 113(Pt A): 313-319, 2016 11.
Article in English | MEDLINE | ID: mdl-27616551

ABSTRACT

Monocytes are believed to be involved in the immunopathogenesis of multiple sclerosis (MS). The aim of this study was to investigate their role in MS and their immunomodulation by the endocannabinoid system (ECS), a novel target for the treatment of this disease. We compared the level of cytokine production from monocytes in healthy subjects and MS patients upon stimulation with viral or bacterial Toll-like receptors (TLR) and we evaluated the ECS immunomodulatory role in these cells. Here we show that MS monocytes produced more TNF-α, IL-12 and IL-6 following activation of TLR2/4 with LPS or of TLR5 with flagellin, as opposed to TLR7/8 stimulation with R848. Furthermore AEA, the main endocannabinoid, suppressed cytokine production and release from healthy monocytes upon stimulation with both bacterial and viral TLR receptors but not in cells from MS patients, where its immunosuppressive activity was TLR7/8-dependent. Altered expression levels of key ECS members in MS monocytes paralleled these data. Our data disclose a distinct immunomodulatory effect of AEA and an alteration of AEA-related members of the ECS in monocytes from MS patients that involves viral but not bacterial TLR. These findings not only may help to better understand the role of monocytes in MS immunopathogenesis but also could be of help to exploit new endocannabinoid-based drugs that target innate immune cells.


Subject(s)
Arachidonic Acids/therapeutic use , Endocannabinoids/therapeutic use , Lipids/therapeutic use , Monocytes/drug effects , Multiple Sclerosis/drug therapy , Polyunsaturated Alkamides/therapeutic use , Toll-Like Receptor 2/metabolism , Toll-Like Receptor 4/metabolism , Adult , Endocannabinoids/metabolism , Female , Humans , Immunologic Factors/therapeutic use , Immunosuppressive Agents/therapeutic use , Interleukin-12/metabolism , Interleukin-6/metabolism , Male , Monocytes/metabolism , Multiple Sclerosis/metabolism , Signal Transduction/drug effects , Tumor Necrosis Factor-alpha/metabolism
5.
Immunology ; 146(2): 251-63, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26095162

ABSTRACT

The p38 mitogen-activated protein kinase cascade is required for the induction of a T helper type 17 (Th17) -mediated autoimmune response, which underlies the development and progression of several autoimmune diseases, such as experimental autoimmune encephalomyelitis, the animal model of multiple sclerosis (MS). However, the contribution of p38 phosphorylation to human Th cell differentiation has not been clarified. Here we demonstrate that the p38 signalling pathway is implicated in the generation of Th17 lymphocytes from human CD4(+)  CD27(+)  CD45RA(+) naive T cells, both in healthy donors and in patients affected by the relapsing-remitting form of MS. Our data also indicate that p38 activation is essential for interleukin-17 release from central memory lymphocytes and committed Th17 cell clones. Furthermore, CD4(+) T cells isolated from individuals with relapsing-remitting MS display an altered responsiveness of the p38 cascade, resulting in increased p38 phosphorylation upon stimulation. These findings suggest that the p38 signalling pathway, by modulating the Th17 differentiation and response, is involved in the pathogenesis of MS, and open new perspectives for the use of p38 inhibitors in the treatment of Th17-mediated autoimmune diseases.


Subject(s)
Cell Differentiation , Lymphocyte Activation , MAP Kinase Signaling System , Multiple Sclerosis, Relapsing-Remitting/enzymology , Th17 Cells/enzymology , p38 Mitogen-Activated Protein Kinases/metabolism , Adenosine Triphosphatases/metabolism , Adult , Case-Control Studies , Cation Transport Proteins/metabolism , Cells, Cultured , Copper-Transporting ATPases , Enzyme Activation , Eukaryotic Initiation Factor-4E/metabolism , Female , Humans , Interleukin-17/metabolism , Interleukins/metabolism , Middle Aged , Multiple Sclerosis, Relapsing-Remitting/immunology , Phenotype , Phosphorylation , Th17 Cells/immunology
6.
Nat Commun ; 6: 6886, 2015 Apr 16.
Article in English | MEDLINE | ID: mdl-25881002

ABSTRACT

ATM kinase preserves genomic stability by acting as a tumour suppressor. However, its identification as a component of several signalling networks suggests a dualism for ATM in cancer. Here we report that ATM expression and activity promotes HER2-dependent tumorigenicity in vitro and in vivo. We reveal a correlation between ATM activation and the reduced time to recurrence in patients diagnosed with invasive HER2-positive breast cancer. Furthermore, we identify ATM as a novel modulator of HER2 protein stability that acts by promoting a complex of HER2 with the chaperone HSP90, therefore preventing HER2 ubiquitination and degradation. As a consequence, ATM sustains AKT activation downstream of HER2 and may modulate the response to therapeutic approaches, suggesting that the status of ATM activity may be informative for the treatment and prognosis of HER2-positive tumours. Our findings provide evidence for ATM's tumorigenic potential revising the canonical role of ATM as a pure tumour suppressor.


Subject(s)
Ataxia Telangiectasia Mutated Proteins/genetics , Breast Neoplasms/genetics , Carcinogenesis/genetics , Carcinoma/genetics , Receptor, ErbB-2/genetics , Adult , Aged , Aged, 80 and over , Animals , Ataxia Telangiectasia Mutated Proteins/metabolism , Breast Neoplasms/metabolism , Carcinoma/metabolism , Case-Control Studies , Cell Line, Tumor , Female , HEK293 Cells , HSP90 Heat-Shock Proteins/metabolism , Humans , Immunohistochemistry , In Vitro Techniques , MCF-7 Cells , Mice , Mice, Transgenic , Middle Aged , Neoplasm Transplantation , Proto-Oncogene Proteins c-akt/metabolism , Receptor, ErbB-2/metabolism , Young Adult
7.
Biochim Biophys Acta ; 1852(3): 462-72, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25483710

ABSTRACT

Olaparib (AZD-2281, Ku-0059436) is an orally bioavailable and well-tolerated poly(ADP-ribose) polymerase (PARP) inhibitor currently under investigation in patients with solid tumors. To study the clinical potential of olaparib as a single-agent for the treatment of acute myeloid leukemia (AML) patients, we analyzed the in vitro sensitivity of AML cell lines and primary blasts. Clinically achievable concentrations of olaparib were able to induce cell death in the majority of primary AML case samples (88%) and tested cell lines. At these concentrations, olaparib preferentially killed leukemic blasts sparing normal lymphocytes derived from the same patient and did not substantially affect the viability of normal bone marrow and CD34-enriched peripheral blood cells obtained from healthy donors. Most primary AML analyzed were characterized by low BRCA1 mRNA level and undetectable protein expression that likely contributed to explain their sensitivity to olaparib. Noteworthy, while PARP1 over-expression was detected in blasts not responsive to olaparib, phosphorylation of the histone H2AFX (γH2AX) was associated with drug sensitivity. As to genetic features of tested cases the highest sensitivity was shown by a patient carrying a 11q23 deletion. The high sensitivity of AML blasts and the identification of biomarkers potentially able to predict response and/or resistance may foster further investigation of olaparib monotherapy for AML patients unfit to conventional chemotherapy.


Subject(s)
BRCA1 Protein/metabolism , Biomarkers, Tumor/metabolism , Enzyme Inhibitors/pharmacology , Histones/metabolism , Leukemia, Myeloid, Acute/drug therapy , Phthalazines/pharmacology , Piperazines/pharmacology , Poly(ADP-ribose) Polymerase Inhibitors , BRCA1 Protein/genetics , Biomarkers, Tumor/genetics , Chromosome Deletion , Drug Screening Assays, Antitumor , Female , Gene Expression Regulation, Neoplastic/drug effects , HL-60 Cells , Histones/genetics , Humans , Leukemia, Myeloid, Acute/genetics , Leukemia, Myeloid, Acute/metabolism , Leukemia, Myeloid, Acute/pathology , Male , Poly (ADP-Ribose) Polymerase-1 , Poly(ADP-ribose) Polymerases/genetics , Poly(ADP-ribose) Polymerases/metabolism , U937 Cells
8.
Ann Neurol ; 73(5): 626-36, 2013 May.
Article in English | MEDLINE | ID: mdl-23447381

ABSTRACT

OBJECTIVE: The immunopathogenesis of multiple sclerosis (MS) has always been thought to be driven by chronically activated and autoreactive Th-1 and Th-17 cells. Recently, dendritic cells (DCs) have also been thought to significantly contribute to antigenic spread and to maturation of adaptive immunity, and have been linked with disease progression and exacerbation. However, the role of DCs in MS pathogenesis remains poorly understood. METHODS: We compared the level of cytokine production by myeloid DCs (mDCs) and plasmacytoid DCs (pDCs) in healthy subjects and MS patients, following in vitro stimulation of Toll-like receptors 7/8. We also evaluated the effect of the main endocannabinoid, anandamide (AEA), in these DC subsets and correlated cytokine levels with defects in the endocannabinoid system. RESULTS: mDCs obtained from MS patients produce higher levels of interleukin-12 and interleukin-6, whereas pDCs account for lower levels of interferon-α compared to healthy subjects. AEA significantly inhibited cytokine production from healthy mDCs and pDCs, as well as their ability to induce Th-1 and Th-17 lineages. Moreover, we found that in MS only pDCs lack responsiveness to cytokine inhibition induced by AEA. Consistently, this specific cell subset expresses higher levels of the anandamide hydrolase fatty acid amide hydrolase (FAAH). INTERPRETATION: Our data disclose a distinct immunomodulatory effect of AEA in mDCs and pDCs from MS patients, which may reflect an alteration of the expression of FAAH, thus forming the basis for the rational design of new endocannabinoid-based immunotherapeutic agents targeting a specific cell subset.


Subject(s)
Arachidonic Acids , Cannabinoid Receptor Agonists , Dendritic Cells/immunology , Endocannabinoids , Multiple Sclerosis/pathology , Myeloid Cells/immunology , Polyunsaturated Alkamides , Adolescent , Adult , Aged , Amidohydrolases/genetics , Amidohydrolases/metabolism , Cell Differentiation/drug effects , Cells, Cultured , Cytokines/genetics , Cytokines/metabolism , Dendritic Cells/drug effects , Female , Gene Expression Regulation/drug effects , Gene Expression Regulation/immunology , Humans , Male , Middle Aged , Myeloid Cells/drug effects , RNA, Messenger/metabolism , Receptor, Cannabinoid, CB2/genetics , Receptor, Cannabinoid, CB2/metabolism , Toll-Like Receptor 7/genetics , Toll-Like Receptor 7/metabolism , Toll-Like Receptor 8/genetics , Toll-Like Receptor 8/metabolism , Young Adult
9.
J Proteomics ; 75(4): 1440-53, 2012 Feb 02.
Article in English | MEDLINE | ID: mdl-22146475

ABSTRACT

The Ubiquitin-Proteasome System (UPS) and the Autophagy-Lysosome Pathways (ALP) are key mechanisms for cellular homeostasis sustenance and protein clearance. A wide number of Neurodegenerative Diseases (NDs) are tied with UPS impairment and have been also described as proteinopathies caused by aggregate-prone proteins, not efficiently removed by proteasome. Despite the large knowledge on proteasome biological role, molecular mechanisms associated with its impairment are still blur. We have pursued a comprehensive proteomic investigation to evaluate the phenotypic rearrangements in protein repertoires associated with a UPS blockage. Different functional proteomic approaches have been employed to tackle UPS impairment impact on human NeuroBlastoma (NB) cell lines responsive to proteasome inhibition by Epoxomicin. 2-Dimensional Electrophoresis (2-DE) separation combined with Mass Spectrometry and Shotgun Proteomics experiments have been employed to design a thorough picture of protein profile. Unsupervised meta-analysis of the collected proteomic data revealed that all the identified proteins relate each other in a functional network centered on beta-estradiol. Moreover we showed that treatment of cells with beta-estradiol resulted in aggregate removal and increased cell survival due to activation of the autophagic pathway. Our data may provide the molecular basis for the use of beta-estradiol in neurodegenerative disorders by induction of protein aggregate removal.


Subject(s)
Brain Neoplasms/metabolism , Estradiol/metabolism , Neuroblastoma/metabolism , Proteasome Endopeptidase Complex/metabolism , Proteomics/methods , Ubiquitin/metabolism , Autophagy , Cell Line, Tumor , Electrophoresis, Gel, Two-Dimensional/methods , Gene Expression Regulation, Neoplastic , Humans , Lysosomes/metabolism , Mass Spectrometry/methods , Models, Biological , Neurodegenerative Diseases/metabolism
10.
J Cell Sci ; 124(Pt 20): 3450-63, 2011 Oct 15.
Article in English | MEDLINE | ID: mdl-21984814

ABSTRACT

The apoptotic protease activating factor 1 (Apaf1) is the main component of the apoptosome, and a crucial factor in the mitochondria-dependent death pathway. Here we show that Apaf1 plays a role in regulating centrosome maturation. By analyzing Apaf1-depleted cells, we have found that Apaf1 loss induces centrosome defects that impair centrosomal microtubule nucleation and cytoskeleton organization. This, in turn, affects several cellular processes such as mitotic spindle formation, cell migration and mitochondrial network regulation. As a consequence, Apaf1-depleted cells are more fragile and have a lower threshold to stress than wild-type cells. In fact, we found that they exhibit low Bcl-2 and Bcl-X(L) expression and, under apoptotic treatment, rapidly release cytochrome c. We also show that Apaf1 acts by regulating the recruitment of HCA66, with which it interacts, to the centrosome. This function of Apaf1 is carried out during the cell life and is not related to its apoptotic role. Therefore, Apaf1 might also be considered a pro-survival molecule, whose absence impairs cell performance and causes a higher responsiveness to stressful conditions.


Subject(s)
Apoptotic Protease-Activating Factor 1/metabolism , Carrier Proteins/metabolism , Centrosome/metabolism , Mitochondria/metabolism , Spindle Apparatus/metabolism , Animals , Antigens, Neoplasm/metabolism , Apoptotic Protease-Activating Factor 1/genetics , Cell Death/genetics , Cell Movement/genetics , Cell Survival/genetics , Cells, Cultured , Centrosome/ultrastructure , Cytoskeleton/metabolism , Mice , Mice, Knockout , Protein Binding , Protein Transport/genetics
11.
PLoS One ; 5(1): e8688, 2010 Jan 14.
Article in English | MEDLINE | ID: mdl-20098669

ABSTRACT

BACKGROUND: Anandamide (AEA) is an endogenous lipid mediator that exerts several effects in the brain as well as in peripheral tissues. These effects are mediated mainly by two types of cannabinoid receptors, named CB(1)R and CB(2)R, making AEA a prominent member of the "endocannabinoid" family. Also immune cells express CB(1) and CB(2) receptors, and possess the whole machinery responsible for endocannabinoid metabolism. Not surprisingly, evidence has been accumulated showing manifold roles of endocannabinoids in the modulation of the immune system. However, details of such a modulation have not yet been disclosed in primary human T-cells. METHODOLOGY/SIGNIFICANCE: In this investigation we used flow cytometry and ELISA tests, in order to show that AEA suppresses proliferation and release of cytokines like IL-2, TNF-alpha and INF-gamma from activated human peripheral T-lymphocytes. However, AEA did not exert any cytotoxic effect on T-cells. The immunosuppression induced by AEA was mainly dependent on CB(2)R, since it could be mimicked by the CB(2)R selective agonist JWH-015, and could be blocked by the specific CB(2)R antagonist SR144528. Instead the selective CB(1)R agonist ACEA, or the selective CB(1)R antagonist SR141716, were ineffective. Furthermore, we demonstrated an unprecedented immunosuppressive effect of AEA on IL-17 production, a typical cytokine that is released from the unique CD4+ T-cell subset T-helper 17. CONCLUSIONS/SIGNIFICANCE: Overall, our study investigates for the first time the effects of the endocannabinoid AEA on primary human T-lymphocytes, demonstrating that it is a powerful modulator of immune cell functions. In particular, not only we clarify that CB(2)R mediates the immunosuppressive activity of AEA, but we are the first to describe such an immunosuppressive effect on the newly identified Th-17 cells. These findings might be of crucial importance for the rational design of new endocannabinoid-based immunotherapeutic approaches.


Subject(s)
Arachidonic Acids/pharmacology , Cell Proliferation/drug effects , Cytokines/metabolism , Polyunsaturated Alkamides/pharmacology , Receptor, Cannabinoid, CB2/metabolism , T-Lymphocytes/drug effects , Base Sequence , Camphanes/pharmacology , DNA Primers , Endocannabinoids , Enzyme-Linked Immunosorbent Assay , Flow Cytometry , Humans , Microscopy, Confocal , Piperidines/pharmacology , Pyrazoles/pharmacology , Receptor, Cannabinoid, CB2/agonists , Reverse Transcriptase Polymerase Chain Reaction , Rimonabant , T-Lymphocytes/metabolism
12.
Neurol Sci ; 30(6): 531-4, 2009 Dec.
Article in English | MEDLINE | ID: mdl-19768368

ABSTRACT

The endocannabinoid system (ECS) is involved in the pathophysiology of multiple sclerosis (MS), and relief from pain and spasticity has been reported in MS patients self-medicating with marijuana. A cannabis-based medication containing Delta(9)-tetrahydrocannabinol and cannabidiol (Sativex) has been approved in some countries for the treatment of MS-associated pain. The effects of this pharmaceutical preparation on other clinically relevant aspects of MS pathophysiology, however, are still unclear. In 20 MS patients, we measured the effects of Sativex on clinically measured spasticity and on neurophysiological and laboratory parameters that correlate with spasticity severity or with the modulation of the ECS. Sativex failed to affect spasticity and stretch reflex excitability. This compound also failed to affect the synthesis and the degradation of the endocannabinoid anandamide, as well as the expression of both CB1 and CB2 cannabinoid receptors in various subpopulations of peripheral lymphocytes.


Subject(s)
Cannabinoids/therapeutic use , Multiple Sclerosis/drug therapy , Plant Extracts/therapeutic use , Adult , Arachidonic Acids/metabolism , Cannabidiol , Dronabinol , Drug Combinations , Endocannabinoids , Female , Humans , Lymphocytes/drug effects , Lymphocytes/metabolism , Male , Middle Aged , Multiple Sclerosis/complications , Multiple Sclerosis/physiopathology , Muscle Spasticity/drug therapy , Muscle Spasticity/etiology , Muscle Spasticity/physiopathology , Pain/drug therapy , Pain/etiology , Pain/physiopathology , Polyunsaturated Alkamides/metabolism , Receptor, Cannabinoid, CB1/metabolism , Receptor, Cannabinoid, CB2/metabolism , Reflex, Stretch/drug effects , Treatment Outcome , Young Adult
13.
Mol Immunol ; 46(13): 2524-32, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19535144

ABSTRACT

The most promising approach in Alzheimer disease immunotherapy is represented by amyloid beta derivatives with low intrinsic neurotoxicity and minimal overall T cell responses. To avoid toxicity and autoimmune response, we have designed a new class of Abeta derivatives through segmentation of the original Abeta[1-42] peptide and application of the glycine substitution modification technology. Abeta[1-16], Abeta[13-28] and Abeta[25-42] fragments were selected in order to retain the major immunogenic sites of the Abeta[1-42] peptide. All peptides showed comparable immunogenicity, and raised antibodies were all able to cross-recognize both Abeta[1-42] and Abeta[1-40] synthetic amyloid forms. Polyclonal antibodies produced against the simplified variants were able to recognize the parent peptide, but not the opposite simplified forms, in strict agreement with the model of independent surfaces of recognition. All Abeta simplified derivatives showed reduced fibrillogenic properties, thus underlining that the introduction of glycine residues in alternating positions allows to obtain modified peptides maintaining the main immunogenic properties of the parent peptides, but with reduced ability to adopt a beta-sheet conformation and therefore a much lower risk of toxicity in humans. In addition, in vitro studies on peripheral blood mononuclear cells (PBMCs) from healthy donors showed that only the Abeta[13-28]+G peptide failed to induce IFN-gamma production, thus suggesting that this molecule could represent a good candidate for potentially safer vaccine therapy to reduce amyloid burden in Alzheimer's disease instead of using toxic Abeta[1-42].


Subject(s)
Amyloid beta-Peptides/immunology , Oligopeptides/immunology , Peptide Fragments/immunology , Amino Acid Sequence , Amyloid/chemistry , Amyloid/immunology , Amyloid beta-Peptides/chemistry , Animals , Antibodies/immunology , Antibody Specificity/immunology , Cell Line , Cells, Cultured , Cross Reactions/immunology , Enzyme-Linked Immunosorbent Assay , Flow Cytometry , Humans , Immunization , Immunoglobulin G/immunology , Interferon-gamma/metabolism , Leukocytes, Mononuclear/cytology , Leukocytes, Mononuclear/drug effects , Leukocytes, Mononuclear/immunology , Lymphocyte Activation/drug effects , Lymphocyte Activation/immunology , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Molecular Sequence Data , Oligopeptides/chemical synthesis , Oligopeptides/pharmacology , Peptide Fragments/pharmacology , T-Lymphocytes/cytology , T-Lymphocytes/immunology , T-Lymphocytes/metabolism
14.
J Neurosci ; 29(11): 3442-52, 2009 Mar 18.
Article in English | MEDLINE | ID: mdl-19295150

ABSTRACT

Neurodegeneration is the irremediable pathological event occurring during chronic inflammatory diseases of the CNS. Here we show that, in experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis, inflammation is capable in enhancing glutamate transmission in the striatum and in promoting synaptic degeneration and dendritic spine loss. These alterations occur early in the disease course, are independent of demyelination, and are strongly associated with massive release of tumor necrosis factor-alpha from activated microglia. CNS invasion by myelin-specific blood-borne immune cells is the triggering event, and the downregulation of the early gene Arc/Arg3.1, leading to the abnormal expression and phosphorylation of AMPA receptors, represents a culminating step in this cascade of neurodegenerative events. Accordingly, EAE-induced synaptopathy subsided during pharmacological blockade of AMPA receptors. Our data establish a link between neuroinflammation and synaptic degeneration and calls for early neuroprotective therapies in chronic inflammatory diseases of the CNS.


Subject(s)
Encephalomyelitis, Autoimmune, Experimental/pathology , Nerve Degeneration/pathology , Synapses/pathology , Animals , Cell Line, Transformed , Encephalomyelitis, Autoimmune, Experimental/genetics , Encephalomyelitis, Autoimmune, Experimental/metabolism , Female , Inflammation/genetics , Inflammation/metabolism , Inflammation/pathology , Mice , Mice, Inbred C57BL , Nerve Degeneration/genetics , Nerve Degeneration/metabolism , Receptors, AMPA/genetics , Receptors, AMPA/metabolism , Synapses/genetics , Synapses/metabolism
15.
Mol Biol Cell ; 19(8): 3576-88, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18550800

ABSTRACT

Cytochrome c release from mitochondria promotes apoptosome formation and caspase activation. The question as to whether mitochondrial permeabilization kills cells via a caspase-independent pathway when caspase activation is prevented is still open. Here we report that proneural cells of embryonic origin, when induced to die but rescued by apoptosome inactivation are deprived of cytosolic cytochrome c through proteasomal degradation. We also show that, in this context, those cells keep generating ATP by glycolysis for a long period of time and that they keep their mitochondria in a depolarized state that can be reverted. Moreover, under these conditions, such apoptosome-deficient cells activate a Beclin 1-dependent autophagy pathway to sustain glycolytic-dependent ATP production. Our findings contribute to elucidating what the point-of-no-return in apoptosis is. They also help in clarifying the issue of survival of apoptosome-deficient proneural cells under stress conditions. Unraveling this issue could be highly relevant for pharmacological intervention and for therapies based on neural stem cell transfer in the treatment of neurological disorders.


Subject(s)
Apoptosis , Apoptosomes/metabolism , Autophagy , Cytochromes c/metabolism , Gene Expression Regulation , Proteasome Endopeptidase Complex/metabolism , Adenosine Triphosphate/metabolism , Animals , Apoptosis Regulatory Proteins , Beclin-1 , Caspases/metabolism , Cell Survival , Enzyme Activation , Glycolysis , Mice , Models, Biological , Proteins/metabolism
16.
Blood ; 111(2): 829-37, 2008 Jan 15.
Article in English | MEDLINE | ID: mdl-17932249

ABSTRACT

Ataxia telangiectasia (A-T) is a rare cancer-predisposing genetic disease, caused by the lack of functional ATM kinase, a major actor of the double strand brakes (DSB) DNA-damage response. A-T patients show a broad and diverse phenotype, which includes an increased rate of lymphoma and leukemia development. Fas-induced apoptosis plays a fundamental role in the homeostasis of the immune system and its defects have been associated with autoimmunity and lymphoma development. We therefore investigated the role of ATM kinase in Fas-induced apoptosis. Using A-T lymphoid cells, we could show that ATM deficiency causes resistance to Fas-induced apoptosis. A-T cells up-regulate FLIP protein levels, a well-known inhibitor of Fas-induced apoptosis. Reconstitution of ATM kinase activity was sufficient to decrease FLIP levels and to restore Fas sensitivity. Conversely, genetic and pharmacologic ATM kinase inactivation resulted in FLIP protein up-regulation and Fas resistance. Both ATM and FLIP are aberrantly regulated in Hodgkin lymphoma. Importantly, we found that reconstitution of ATM kinase activity decreases FLIP protein levels and restores Fas sensitivity in Hodgkin lymphoma-derived cells. Overall, these data identify a novel molecular mechanism through which ATM kinase may regulate the immune system homeostasis and impair lymphoma development.


Subject(s)
Apoptosis , CASP8 and FADD-Like Apoptosis Regulating Protein/metabolism , Cell Cycle Proteins/metabolism , DNA-Binding Proteins/metabolism , Hodgkin Disease/metabolism , Lymphocytes/metabolism , Protein Serine-Threonine Kinases/metabolism , Tumor Suppressor Proteins/metabolism , fas Receptor/metabolism , Animals , Apoptosis/genetics , Ataxia Telangiectasia , Ataxia Telangiectasia Mutated Proteins , Autoimmunity/genetics , CASP8 and FADD-Like Apoptosis Regulating Protein/genetics , Cell Cycle Proteins/antagonists & inhibitors , Cell Cycle Proteins/genetics , Cell Line, Tumor , DNA Breaks, Double-Stranded , DNA-Binding Proteins/antagonists & inhibitors , DNA-Binding Proteins/genetics , Hodgkin Disease/genetics , Hodgkin Disease/pathology , Homeostasis/genetics , Humans , Leukemia/genetics , Leukemia/metabolism , Leukemia/pathology , Lymphocytes/pathology , Protein Serine-Threonine Kinases/antagonists & inhibitors , Protein Serine-Threonine Kinases/genetics , Tumor Suppressor Proteins/antagonists & inhibitors , Tumor Suppressor Proteins/genetics , fas Receptor/genetics
17.
J Immunol ; 174(10): 6144-52, 2005 May 15.
Article in English | MEDLINE | ID: mdl-15879110

ABSTRACT

Vitamin D is a steroid hormone that, in addition to its well-characterized role in calcium/phosphate metabolism, has been found to have regulatory properties for immune system function. The nuclear vitamin D receptor is widely expressed in tissues, but has also been shown to be regulated by hormones, growth factors, and cytokines. In this study we show that activation of human Vdelta2Vgamma9 T cells by nonpeptidic monoalkyl phosphates such as isopentenyl pyrophosphate leads to the up-regulation of the vitamin D receptor via a pathway that involves the classical isoforms of protein kinase C. We further show that this receptor is active by demonstrating that the ligand 1alpha,25-dihydroxyvitamin D3 (vitD3) significantly inhibits in a dose-dependent fashion phospholigand-induced gammadelta T cell expansion, IFN-gamma production, and CD25 expression. We also show that vitD3 negatively regulates signaling via Akt and ERK and, at high concentrations, potentiates Ag-induced cell death. As such, these data provide further support for the immunoregulatory properties of vitamin D, and suggest that the ability of vitD3 to negatively regulate the proinflammatory activity of gammadelta T cells may contribute to the protection this vitamin affords against inflammatory and autoimmune disorders dependent upon Th1-type responses.


Subject(s)
Adjuvants, Immunologic/physiology , Cholecalciferol/pharmacology , Gene Expression Profiling , Hemiterpenes/metabolism , Organophosphorus Compounds/metabolism , Receptors, Antigen, T-Cell, gamma-delta/genetics , T-Lymphocyte Subsets/immunology , T-Lymphocyte Subsets/metabolism , Transcription, Genetic/immunology , Cell Death/drug effects , Cell Death/immunology , Cells, Cultured , Cholecalciferol/metabolism , Extracellular Signal-Regulated MAP Kinases/physiology , Gene Expression Profiling/methods , Growth Inhibitors/metabolism , Growth Inhibitors/pharmacology , Hemiterpenes/pharmacology , Humans , Interferon-gamma/biosynthesis , Interleukin-2/physiology , Isoenzymes/physiology , Ligands , Lymphocyte Activation/drug effects , Lymphocyte Activation/immunology , Oligonucleotide Array Sequence Analysis/methods , Organophosphorus Compounds/pharmacology , Protein Kinase C/physiology , Receptors, Antigen, T-Cell, gamma-delta/biosynthesis , Receptors, Antigen, T-Cell, gamma-delta/metabolism , Receptors, Antigen, T-Cell, gamma-delta/physiology , Receptors, Calcitriol/biosynthesis , Receptors, Interleukin-2/biosynthesis , Signal Transduction/drug effects , Signal Transduction/immunology , T-Lymphocyte Subsets/drug effects
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