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1.
Mult Scler Relat Disord ; 57: 103332, 2022 Jan.
Article in English | MEDLINE | ID: mdl-35158426

ABSTRACT

BACKGROUND: To date, no specific scales have been developed to explore the impact of neuromyelitis optica spectrum disorder (NMOSD)-related disability on quality of life (QoL). The Expanded Disability Status Scale (EDSS) and the EuroQol 5-dimensions (EQ-5D) have been used to assess disability and QoL, respectively, in patients with NMOSD. However, there is limited evidence surrounding their use in this condition. We compared EDSS and EQ-5D data across two clinical trials to quantify the relationship between disability and QoL in patients with NMOSD. METHODS: SAkuraSky (NCT02028884) and SAkuraStar (NCT02073279) were Phase 3, multicenter, randomized, international, double-blind, placebo-controlled, parallel-assignment studies of satralizumab, administered in combination with baseline immunosuppressants (SAkuraSky) or as monotherapy (SAkuraStar). EDSS and EQ-5D were assessed at baseline and at 24-week intervals thereafter. The relationship between disability and QoL was assessed by estimating EQ-5D utilities (UK tariff) for each incremental EDSS category. A repeated-measures linear model was used to regress health utilities on EDSS score-derived health states. RESULTS: Overall, 176 patients underwent at least one EDSS assessment and completed an EQ-5D survey and were included in this analysis. There was a clear association between mean EQ-5D score and EDSS score, with decreases in QoL being observed at each incremental increase in disability. The relationship between EDSS and EQ-5D score remained consistent across the different treatment groups. CONCLUSIONS: These results, generated from high-quality clinical trial data, demonstrated a strong and consistent relationship between disability and QoL in patients with NMOSD.


Subject(s)
Disabled Persons , Neuromyelitis Optica , Humans , Immunosuppressive Agents , Neuromyelitis Optica/drug therapy , Quality of Life , Surveys and Questionnaires
2.
Brain Sci ; 11(9)2021 Sep 21.
Article in English | MEDLINE | ID: mdl-34573267

ABSTRACT

There is increasing interest in the development and deployment of digital solutions to improve patient care and facilitate monitoring in medical practice, e.g., by remote observation of disease symptoms in the patients' home environment. Digital health solutions today range from non-regulated wellness applications and research-grade exploratory instruments to regulated software as a medical device (SaMD). This paper discusses the considerations and complexities in developing innovative, effective, and validated SaMD for multiple sclerosis (MS). The development of SaMD requires a formalised approach (design control), inclusive of technical verification and analytical validation to ensure reliability. SaMD must be clinically evaluated, characterised for benefit and risk, and must conform to regulatory requirements associated with device classification. Cybersecurity and data privacy are also critical. Careful consideration of patient and provider needs throughout the design and testing process help developers overcome challenges of adoption in medical practice. Here, we explore the development pathway for SaMD in MS, leveraging experiences from the development of Floodlight™ MS, a continually evolving bundled solution of SaMD for remote functional assessment of MS. The development process will be charted while reflecting on common challenges in the digital space, with a view to providing insights for future developers.

3.
J Med Econ ; 24(1): 581-588, 2021.
Article in English | MEDLINE | ID: mdl-33879033

ABSTRACT

BACKGROUND: This US claims-based study aimed to identify and characterize temporal trends in diagnostic pathways for patients likely to have neuromyelitis optica spectrum disorder (NMOSD). METHODS: Patients were identified from IBM MarketScan Commercial Databases if, within 1 year, they had two NMOSD claims separated by ≥ 60 days; two transverse myelitis (TM) or optic neuritis (ON) claims separated by ≥ 60 days, and one additional symptom (TM, ON, or area postrema syndrome); or one NMOSD claim and one additional symptom. The first NMOSD or TM/ON claim was the index date, and the second claim was the diagnosis date. Similar methodology was used in temporal trend and incidence and prevalence analyses. RESULTS: Among 1,901 patients with NMOSD, 34.2% were identified by two NMO claims, 53.2% by ON or TM +1 symptom, and 12.6% by one NMOSD claim +1 symptom. Anti-aquaporin-4 immunoglobin G (AQP4-IgG) autoantibody tests and magnetic resonance imaging was used for 23.0% and 71.9% of cases, respectively. Across cohorts, 21.4-49.1% had multiple sclerosis (MS) diagnosis claims prior to index date, and 37.3-60.6% had an MS diagnosis, 14.9-31.0% had MS disease-modifying therapy (DMT) claims and 6.3-44.8% had immunosuppressive therapy (IST) claims <1 year after diagnosis. Over time, there were slight changes in MS diagnosis claims, AQP4-IgG autoantibody testing, and DMT and IST use before and after NMOSD diagnosis. LIMITATIONS: This study is limited by the information available in US claims databases, which included the potential for misclassification of NMOSD based solely on claims codes and lack of reimbursement for AQP4-IgG testing by insurance companies. CONCLUSIONS: Among patients likely to have NMOSD, low AQP4-IgG testing rates, IST use, frequent MS diagnosis claims, and DMT use highlight the need for a diagnostic algorithm and timely treatment of NMOSD.


Subject(s)
Insurance , Multiple Sclerosis , Neuromyelitis Optica , Aquaporin 4 , Autoantibodies , Humans , Neuromyelitis Optica/drug therapy , Neuromyelitis Optica/epidemiology
4.
J Inorg Biochem ; 155: 92-100, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26684582

ABSTRACT

Five new mononuclear Pt(II) complexes with 5-perfluoroalkyl-1,2,4-oxadiazolyl-pyridine and 3-perfluoroalkyl-1,2,4-triazolyl-pyridine ligands are reported. The ligands 2-(5-perfluoroheptyl-1,2,4-oxadiazole-3yl)-pyridine (pfhop), 2-(5-perfluoropropyl)-1,2,4-oxadiazole-3yl)-pyridine (pfpop), 2-(3-perfluoroheptyl-1-methyl-1,2,4-triazole-5yl)-pyridine (pfhtp), 2-(3-perfluoropropyl-1-methyl-1,2,4-triazole-5yl)-pyridine (pfptp) and their complexes [PtCl2(pfhop)2]·1.5 DMSO (2a), [PtCl2(pfpop)2]·1.5 DMSO (3a), [PtCl2(pfhtp)2]·1.5 DMSO (4a), PtCl2(pfhtp) (4b), [PtCl2(pfptp)2]·1.5 DMSO (5a) have been synthesized and structurally characterized. The complexes 2a, 3a, 4a and 5a have the same chemical environment of Pt(II) where PtCl2 moieties coordinate two molecules of ligand via N1 atom of pyridine in the case of pfhop and pfpop, and N2 atom of 1,2,4-triazole in the case of pfhtp and pfptp. For 4b, pfhtp behaves as bidentate ligand, coordinating Pt(II) ion via N4 atom of triazole and N1 atom of pyridine. All complexes have been tested in vitro by 3-(4,5-dimethyl-2-thiazolyl)bromide-2,5-diphenyl-2H-tetrazolium (MTT) test on four tumor cell lines MCF-7 (human breast cancer), HepG2 (human hepatocellular carcinoma), HCT116 (human colorectal carcinoma). Compounds 2a and 4b showed a dose-dependent anti-proliferative effect against the three tumor cell lines whereas did not affect viability of intestinal normal-like differentiated Caco-2 cells. The cell death of HepG2, MCF-7 and HCT116 induced by the compounds, was considered to be apoptotic by measuring the exposure of phosphatidylserine to the outer membrane and observing the typical apoptotic morphological change by acridine orange (AO)/ethidium bromide (EB) staining.


Subject(s)
Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacology , Platinum Compounds/chemical synthesis , Pyridines/chemistry , Acridine Orange/chemistry , Antineoplastic Agents/chemistry , Apoptosis/drug effects , Cell Line, Tumor , Ethidium/chemistry , Fluorescent Dyes/chemistry , Humans , Ligands , Platinum Compounds/chemistry , Platinum Compounds/pharmacology , Proton Magnetic Resonance Spectroscopy , Spectrophotometry, Infrared
5.
Expert Rev Mol Med ; 14: e9, 2012 Apr 10.
Article in English | MEDLINE | ID: mdl-22490239

ABSTRACT

Opiates such as morphine and fentanyl, a major class of analgesics used in the clinical management of pain, exert their effects through the activation of opioid receptors. Opioids are among the most commonly prescribed and frequently abused drugs in the USA; however, the prolonged use of opiates often leads to the development of tolerance and addiction. Although blockade of opioid receptors with antagonists such as naltrexone and naloxone can lessen addictive impulses and facilitate recovery from overdose, systemic disruption of endogenous opioid receptor signalling through the use of these antagonistic drugs can have severe side effects. In the light of these challenges, current efforts have focused on identifying new therapeutic targets that selectively and specifically modulate opioid receptor signalling and function so as to achieve analgesia without the adverse effects associated with chronic opiate use. We have previously reported that opioid receptors interact with each other to form heteromeric complexes and that these interactions affect morphine signalling. Since chronic morphine administration leads to an enhanced level of these heteromers, these opioid receptor heteromeric complexes represent novel therapeutic targets for the treatment of pain and opiate addiction. In this review, we discuss the role of heteromeric opioid receptor complexes with a focus on mu opioid receptor (MOR) and delta opioid receptor (DOR) heteromers. We also highlight the evidence for altered pharmacological properties of opioid ligands and changes in ligand function resulting from the heteromer formation.


Subject(s)
Analgesics , Morphine Dependence , Naloxone/therapeutic use , Naltrexone/therapeutic use , Narcotic Antagonists/therapeutic use , Protein Multimerization/drug effects , Receptors, Opioid, delta , Receptors, Opioid, mu , Analgesia , Animals , Drug Antagonism , Drug Overdose , Humans , Morphine Dependence/drug therapy , Morphine Dependence/metabolism , Naloxone/antagonists & inhibitors , Naltrexone/antagonists & inhibitors , Pain/drug therapy , Pain/metabolism , Protein Structure, Quaternary , Receptors, Opioid, delta/agonists , Receptors, Opioid, delta/antagonists & inhibitors , Receptors, Opioid, delta/metabolism , Receptors, Opioid, mu/agonists , Receptors, Opioid, mu/antagonists & inhibitors , Receptors, Opioid, mu/metabolism , Signal Transduction/drug effects , United States
6.
PLoS One ; 7(3): e33961, 2012.
Article in English | MEDLINE | ID: mdl-22448282

ABSTRACT

Agents that activate cannabinoid receptor pathways have been tested as treatments for cachexia, nausea or neuropathic pain in HIV-1/AIDS patients. The cannabinoid receptors (CB(1)R and CB(2)R) and the HIV-1 co-receptors, CCR5 and CXCR4, all signal via Gαi-coupled pathways. We hypothesized that drugs targeting cannabinoid receptors modulate chemokine co-receptor function and regulate HIV-1 infectivity. We found that agonism of CB(2)R, but not CB(1)R, reduced infection in primary CD4+ T cells following cell-free and cell-to-cell transmission of CXCR4-tropic virus. As this change in viral permissiveness was most pronounced in unstimulated T cells, we investigated the effect of CB(2)R agonism on to CXCR4-induced signaling following binding of chemokine or virus to the co-receptor. We found that CB(2)R agonism decreased CXCR4-activation mediated G-protein activity and MAPK phosphorylation. Furthermore, CB(2)R agonism altered the cytoskeletal architecture of resting CD4+ T cells by decreasing F-actin levels. Our findings suggest that CB(2)R activation in CD4+ T cells can inhibit actin reorganization and impair productive infection following cell-free or cell-associated viral acquisition of CXCR4-tropic HIV-1 in resting cells. Therefore, the clinical use of CB(2)R agonists in the treatment of AIDS symptoms may also exert beneficial adjunctive antiviral effects against CXCR4-tropic viruses in late stages of HIV-1 infection.


Subject(s)
CD4-Positive T-Lymphocytes/immunology , Cannabinoids/pharmacology , HIV Infections/prevention & control , HIV Infections/virology , Receptor, Cannabinoid, CB2/agonists , Receptors, CXCR4/metabolism , CD4-Positive T-Lymphocytes/virology , Cells, Cultured , Chemokines/metabolism , HIV Infections/immunology , HIV-1/pathogenicity , Humans , Membrane Fusion , Receptor, Cannabinoid, CB1/agonists , Virus Replication
7.
PLoS One ; 7(1): e29805, 2012.
Article in English | MEDLINE | ID: mdl-22299025

ABSTRACT

Human CD4(+) T cells process and present functional class II MHC-peptide complexes, but the endogenous peptide repertoire of these non-classical antigen presenting cells remains unknown. We eluted and sequenced HLA-DR-bound self-peptides presented by CD4(+) T cells in order to compare the T cell-derived peptide repertoire to sequences derived from genetically identical B cells. We identified several novel epitopes derived from the T cell-specific proteome, including fragments of CD4 and IL-2. While these data confirm that T cells can present peptides derived from the T-cell specific proteome, the vast majority of peptides sequenced after elution from MHC were derived from the common proteome. From this pool, we identified several identical peptide epitopes in the T and B cell repertoire derived from common endogenous proteins as well as novel endogenous epitopes with promiscuous binding. These findings indicate that the endogenous HLA-DR-bound peptide repertoire, regardless of APC type and across MHC isotype, is largely derived from the same pool of self-protein.


Subject(s)
Antigen Presentation/physiology , Autoantigens/immunology , B-Lymphocytes/immunology , Histocompatibility Antigens Class II/immunology , T-Lymphocytes/immunology , Antigen Presentation/genetics , Antigen Presentation/immunology , Antigen-Antibody Complex/chemistry , Antigen-Antibody Complex/isolation & purification , B-Lymphocytes/metabolism , Blood Donors , CD4-Positive T-Lymphocytes/metabolism , Case-Control Studies , Cell Line, Transformed , HLA-DR Antigens/genetics , HLA-DR Antigens/immunology , HLA-DR Antigens/metabolism , Histocompatibility Antigens Class II/genetics , Histocompatibility Antigens Class II/metabolism , Humans , Models, Biological , Peptides/chemistry , Peptides/isolation & purification , Proteome/analysis , Proteome/immunology , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , T-Lymphocytes/metabolism , Tandem Mass Spectrometry
8.
J Immunol ; 186(6): 3317-26, 2011 Mar 15.
Article in English | MEDLINE | ID: mdl-21300823

ABSTRACT

Studying the activity of homogeneous regulatory T cell (Treg) populations will advance our understanding of their mechanisms of action and their role in human disease. Although isolating human Tregs exhibiting low expression of CD127 markedly increases purity, the resulting Treg populations are still heterogeneous. To examine the complexity of the Tregs defined by the CD127 phenotype in comparison with the previously described CD4(+)CD25(hi) subpopulations, we subdivided the CD25(hi) population of memory Tregs into subsets based on expression of CD127 and HLA-DR. These subsets exhibited differences in suppressive capacity, ability to secrete IL-10 and IL-17, Foxp3 gene methylation, cellular senescence, and frequency in neonatal and adult blood. The mature, short telomere, effector CD127(lo)HLA-DR(+) cells most strongly suppressed effector T cells within 48 h, whereas the less mature CD127(lo)HLA-DR(-) cells required 96 h to reach full suppressive capacity. In contrast, whereas the CD127(+)HLA-DR(-) cells also suppressed proliferation of effector cells, they could alternate between suppression or secretion of IL-17 depending upon the stimulation signals. When isolated from patients with multiple sclerosis, both the nonmature and the effector subsets of memory CD127(lo) Tregs exhibited kinetically distinct defects in suppression that were evident with CD2 costimulation. These data demonstrate that natural and not induced Tregs are less suppressive in patients with multiple sclerosis.


Subject(s)
CD2 Antigens/physiology , CD4 Antigens/biosynthesis , Interleukin-2 Receptor alpha Subunit/biosynthesis , Multiple Sclerosis/immunology , Multiple Sclerosis/pathology , T-Lymphocytes, Regulatory/immunology , T-Lymphocytes, Regulatory/pathology , Adult , Cell Differentiation/immunology , Cells, Cultured , Coculture Techniques , Fetal Blood/cytology , Fetal Blood/immunology , Fetal Blood/metabolism , Forkhead Transcription Factors/biosynthesis , Forkhead Transcription Factors/pharmacokinetics , Humans , Infant, Newborn , Interleukin-7 Receptor alpha Subunit/genetics , Interleukin-7 Receptor alpha Subunit/metabolism , Lymphocyte Activation/genetics , Lymphocyte Activation/immunology , Middle Aged , Multiple Sclerosis/metabolism , Signal Transduction/immunology , T-Lymphocyte Subsets/immunology , T-Lymphocyte Subsets/metabolism , T-Lymphocyte Subsets/pathology , T-Lymphocytes, Regulatory/metabolism , Young Adult
9.
Nat Rev Immunol ; 10(7): 490-500, 2010 Jul.
Article in English | MEDLINE | ID: mdl-20559327

ABSTRACT

Forkhead box P3 (FOXP3)(+) regulatory T (T(Reg)) cells are potent mediators of dominant self tolerance in the periphery. But confusion as to the identity, stability and suppressive function of human T(Reg) cells has, to date, impeded the general therapeutic use of these cells. Recent studies have suggested that human T(Reg) cells are functionally and phenotypically diverse. Here we discuss recent findings regarding human T(Reg) cells, including the ontogeny and development of T(Reg) cell subsets that have naive or memory phenotypes, the unique mechanisms of suppression mediated by T(Reg) cell subsets and factors that regulate T(Reg) cell lineage commitment. We discuss future studies that are needed for the successful therapeutic use of human T(Reg) cells.


Subject(s)
Forkhead Transcription Factors/immunology , T-Lymphocytes, Regulatory/immunology , Animals , Cell Differentiation , Forkhead Transcription Factors/metabolism , Humans , Immunologic Memory , Immunotherapy , Leukocyte Common Antigens/metabolism , Mice , Models, Immunological , Phenotype , Self Tolerance , T-Lymphocyte Subsets/cytology , T-Lymphocyte Subsets/immunology , T-Lymphocyte Subsets/metabolism , T-Lymphocytes, Regulatory/cytology , T-Lymphocytes, Regulatory/metabolism
10.
J Immunol ; 185(1): 46-54, 2010 Jul 01.
Article in English | MEDLINE | ID: mdl-20498357

ABSTRACT

The secretion of IL-9, initially recognized as a Th2 cytokine, was recently attributed to a novel CD4 T cell subset termed Th9 in the murine system. However, IL-9 can also be secreted by mouse Th17 cells and may mediate aspects of the proinflammatory activities of Th17 cells. Here we report that IL-9 is secreted by human naive CD4 T cells in response to differentiation by Th9 (TGF-beta and IL-4) or Th17 polarizing conditions. Yet, these differentiated naive cells did not coexpress IL-17 and IL-9, unless they were repeatedly stimulated under Th17 differentiation-inducing conditions. In contrast to the naive cells, memory CD4 T cells were induced to secrete IL-9 by simply providing TGF-beta during stimulation, as neither IL-4 nor proinflammatory cytokines were required. Furthermore, the addition of TGF-beta to the Th17-inducing cytokines (IL-1beta, IL-6, IL-21, IL-23) that induce memory cells to secrete IL-17, resulted in the marked coexpression of IL-9 in IL-17 producing memory cells. The proinflammatory cytokine mediating TGF-beta-dependent coexpression of IL-9 and IL-17 was identified to be IL-1beta. Moreover, circulating monocytes were potent costimulators of IL-9 production by Th17 cells via their capacity to secrete IL-1beta. Finally, to determine whether IL-9/IL-17 coproducing CD4 cells were altered in an inflammatory condition, we examined patients with autoimmune diabetes and demonstrated that these subjects exhibit a higher frequency of memory CD4 cells with the capacity to transition into IL-9(+)IL-17(+) cells. These data demonstrate the presence of IL-17(+)IL-9(+) CD4 cells induced by IL-1beta that may play a role in human autoimmune disease.


Subject(s)
Interleukin-17/biosynthesis , Interleukin-9/biosynthesis , T-Lymphocytes, Helper-Inducer/immunology , T-Lymphocytes, Helper-Inducer/metabolism , Transforming Growth Factor beta1/physiology , Adult , Cell Polarity/immunology , Cells, Cultured , Coculture Techniques , Diabetes Mellitus, Type 1/immunology , Diabetes Mellitus, Type 1/metabolism , Diabetes Mellitus, Type 1/pathology , Gene Expression Regulation/immunology , Humans , Immunohistochemistry , Inflammation Mediators/metabolism , Inflammation Mediators/physiology , Interleukin-9/genetics , Interleukin-9/metabolism , Middle Aged , Resting Phase, Cell Cycle/immunology , Young Adult
11.
J Immunol ; 183(2): 945-52, 2009 Jul 15.
Article in English | MEDLINE | ID: mdl-19553543

ABSTRACT

Although it has long been known that human CD4(+) T cells can express functional class II MHC molecules, the role of lysosomal proteases in the T cell class II MHC processing and presentation pathway is unknown. Using CD4(+) T cell clones that constitutively express class II MHC, we determined that cathepsin S is necessary for invariant chain proteolysis in T cells. CD4(+)HLA-DR(+) T cells down-regulated cathepsin S expression and activity 18 h after activation, thereby ceasing nascent class II MHC product formation. This blockade resulted in the loss of the invariant chain fragment CLIP from the cell surface, suggesting that-like professional APC-CD4(+) HLA-DR(+) cells modulate self-Ag presentation as a consequence of activation. Furthermore, cathepsin S expression and activity, and concordantly cell surface CLIP expression, was reduced in HLA-DR(+) CD4(+) T cells as compared with B cells both in vitro and ex vivo.


Subject(s)
Antigen Presentation , Antigens, Differentiation, B-Lymphocyte/metabolism , CD4-Positive T-Lymphocytes/immunology , Cathepsins/physiology , HLA-DR Antigens/immunology , Histocompatibility Antigens Class II/immunology , Autoantigens , B-Lymphocytes , Cathepsins/analysis , Cathepsins/genetics , Clone Cells , Down-Regulation , Histocompatibility Antigens Class II/metabolism , Humans , Lymphocyte Activation/immunology , Lysosomes/enzymology , Peptide Hydrolases/metabolism
12.
Blood ; 113(18): 4240-9, 2009 Apr 30.
Article in English | MEDLINE | ID: mdl-19171879

ABSTRACT

Although implicated in antagonistic functions, both regulatory T cells (Tregs) and Th17 effector cells play an important role in controlling autoimmune pathogenesis. Paradoxically, recent studies indicate that Tregs have the capacity to produce interleukin-17 (IL-17), although the ability of these cells to retain their suppressive function remains unknown. Here we report that human Tregs within the CD4(+)CD45RA(-)CD25(high)CCR6(+)HLA-DR(-)FoxP3(+) population produce IL-17 when activated in the presence of the proinflammatory cytokines IL-1beta and IL-6, whereas IL-17 secretion was inhibited by TGFbeta. To assess the ability of a single Treg to secrete IL-17 and to suppress in vitro immune function, we isolated clones from this population. We found that IL-17(+)/FoxP3(+) Treg clones retain suppressive function and exhibit the plasticity to secrete IL-17 or suppress depending on the nature of the stimulus provided. IL-17 production by these Treg clones was accompanied by sustained FoxP3 expression and concomitant, but reversible, loss of suppressive activity. Our data demonstrate that at the single cell level a subset of in vitro suppressive FoxP3(+) cells can be driven to secrete IL-17 under inflammatory conditions. These findings suggest a new mechanism by which inflammation can drive Tregs to secrete IL-17, thereby dampening suppression and promoting an inflammatory milieu.


Subject(s)
Immune Tolerance/physiology , Interleukin-17/biosynthesis , T-Lymphocytes, Regulatory/immunology , Antigens, CD/metabolism , Enzyme-Linked Immunosorbent Assay , Flow Cytometry , Forkhead Transcription Factors/metabolism , HLA-DR Antigens/metabolism , Humans , Interleukin-17/antagonists & inhibitors , Interleukin-1beta/pharmacology , Interleukin-6/pharmacology , Lymphocyte Activation/drug effects , Reverse Transcriptase Polymerase Chain Reaction , T-Lymphocytes/cytology , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , Transforming Growth Factor beta/pharmacology
13.
J Clin Immunol ; 28(6): 697-706, 2008 Nov.
Article in English | MEDLINE | ID: mdl-18763026

ABSTRACT

INTRODUCTION: Multiple sclerosis (MS) is a complex genetic disease characterized by chronic inflammation of the central nervous system (CNS). The pathology of MS is largely attributed to autoreactive effector T cells that penetrate the blood-brain barrier and become activated within the CNS. As autoreactive T cells are present in the blood of both patients with MS and healthy individuals, other regulatory mechanisms exist to prevent autoreactive T cells from causing immune disorders. Active suppression by regulatory T (Treg) cells plays a key role in the control of self-antigen-reactive T cells and the induction of peripheral tolerance in vivo. In particular, the importance of antigen-specific Treg cells in conferring genetic resistance to organ-specific autoimmunity and in limiting autoimmune tissue damage has been documented in many disease models including MS. RESULTS: We have found that the frequency of Tregs in MS patients is unchanged from controls, but their function measured in vitro may be diminished, correlating with impaired inhibitory activity in vivo. This review discusses the immunopathology of MS with particular focus given to regulatory T cells and their potential for the development of new therapies to treat this disease.


Subject(s)
Central Nervous System/immunology , Multiple Sclerosis/immunology , T-Lymphocytes, Cytotoxic/immunology , T-Lymphocytes, Regulatory/immunology , Animals , Autoimmunity , Central Nervous System/metabolism , Central Nervous System/pathology , Hepatitis A Virus Cellular Receptor 2 , Humans , Immunotherapy , Membrane Proteins/immunology , Membrane Proteins/metabolism , Multiple Sclerosis/pathology , Multiple Sclerosis/therapy , T-Lymphocytes, Cytotoxic/metabolism , T-Lymphocytes, Regulatory/metabolism , Toll-Like Receptors/immunology , Toll-Like Receptors/metabolism
14.
Eur J Immunol ; 38(4): 921-4, 2008 Apr.
Article in English | MEDLINE | ID: mdl-18395861

ABSTRACT

CD4+CD25+ regulatory T cells (Treg) appear to be critical in regulating immune responses to self-antigens. Treg deficiency is associated with several human autoimmune diseases. Although substantial progress has been made in the study of murine and human Treg, their fundamental mechanism of action remains unknown. In this review, we discuss the phenotype of human natural Treg, their functional mechanism, and their role in autoimmune disease.


Subject(s)
Autoimmunity/immunology , T-Lymphocytes, Regulatory/immunology , Animals , Autoimmune Diseases/immunology , Cell Membrane/immunology , Histocompatibility Antigens Class II/immunology , Humans , Signal Transduction/immunology
15.
J Immunol ; 180(5): 2876-85, 2008 Mar 01.
Article in English | MEDLINE | ID: mdl-18292509

ABSTRACT

Presentation of Ag by class II MHC is regulated by lysosomal proteases that not only destroy the class II invariant chain (Ii) chaperone but also generate the peptide Ag that is loaded onto the class II MHC dimer. We sought to determine the extent to which asparagine endopeptidase (AEP) influences human Ag and Ii processing. Our data confirm the constructive function of AEP in tetanus toxoid processing, but they are discordant with findings that suggest a destructive role for AEP in processing of the immunodominant myelin basic protein epitope. Furthermore, we observed no effect on invariant chain processing following AEP inhibition for several distinct allelic variants of human class II MHC products. We find that cysteine and aspartic proteases, as well as AEP, can act redundantly to initiate Ii processing. We detected considerable variation in lysosomal activity between different EBV-transformed B cell lines, but these differences do not result in altered regulation of invariant chain catabolism. We propose that, as for bound peptide Ag, the identity of the lysosomal enzyme that initiates invariant chain cleavage is dependent on the class II MHC allelic variants expressed.


Subject(s)
Antigens, Differentiation, B-Lymphocyte/metabolism , Aspartic Acid Endopeptidases/biosynthesis , Aspartic Acid Endopeptidases/genetics , Cysteine Endopeptidases/biosynthesis , Cysteine Endopeptidases/genetics , Gene Expression Regulation, Enzymologic/immunology , Histocompatibility Antigens Class II/metabolism , Lysosomes/enzymology , Amino Acid Sequence , Antigen Presentation/genetics , Antigen Presentation/immunology , Aspartic Acid Endopeptidases/antagonists & inhibitors , Aspartic Acid Endopeptidases/physiology , B-Lymphocytes/enzymology , B-Lymphocytes/immunology , B-Lymphocytes/metabolism , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/metabolism , Cell Line, Transformed , Clone Cells , Coculture Techniques , Cysteine Endopeptidases/physiology , Genetic Heterogeneity , HLA-D Antigens/genetics , HLA-D Antigens/metabolism , Humans , Molecular Sequence Data , Protease Inhibitors/metabolism , Protein Processing, Post-Translational/genetics
16.
J Virol ; 77(18): 10113-8, 2003 Sep.
Article in English | MEDLINE | ID: mdl-12941922

ABSTRACT

In an effort to develop an AIDS vaccine that elicits high-frequency cytotoxic-T-lymphocyte (CTL) responses with specificity for a diversity of viral epitopes, we explored two prototype multiepitope plasmid DNA vaccines in the simian-human immunodeficiency virus/rhesus monkey model to determine their efficiency in priming for such immune responses. While a simple multiepitope vaccine construct demonstrated limited immunogenicity in monkeys, this same multiepitope genetic sequence inserted into an immunogenic simian immunodeficiency virus gag DNA vaccine elicited high-frequency CTL responses specific for all of the epitopes included in the vaccine. Both multiepitope vaccine prototypes primed for robust epitope-specific CTL responses that developed following boosting with recombinant modified vaccinia virus Ankara vaccines expressing complete viral proteins. The natural hierarchy of immunodominance for these epitopes was clearly evident in the boosted monkeys. These studies suggest that multiepitope plasmid DNA vaccine-based prime-boost regimens can efficiently prime for CTL responses of increased breadth and magnitude, although they do not overcome predicted hierarchies of immunodominance.


Subject(s)
SAIDS Vaccines/immunology , T-Lymphocytes, Cytotoxic/immunology , Vaccines, DNA/immunology , AIDS Vaccines/immunology , Amino Acid Sequence , Animals , Epitopes , Macaca mulatta , Molecular Sequence Data , Plasmids , Vaccination , Vaccinia virus/genetics , Vaccinia virus/immunology
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