Immunoglobulin M oligoclonal bands: biomarker of targetable inflammation in primary progressive multiple sclerosis.

OBJECTIVE: To identify a biomarker distinguishing patients who, despite a primary progressive multiple sclerosis (PPMS) clinical course, may nonetheless benefit from immune therapy. METHODS: The presence or absence of both immunoglobulin (Ig) G and IgM oligoclonal bands (OCB) was blindly examined in paired cerebrospinal fluid (CSF) and serum samples from a large PPMS patient cohort, and related to clinical and imaging evidence of focal inflammatory disease activity. RESULTS: Using both cross-sectional samples and serial sampling in a subgroup of patients followed prospectively as part of the placebo-controlled OLYMPUS study of rituximab in PPMS, we found that the presence of CSF-restricted IgM OCB (but not of IgG OCB) is associated with an active inflammatory disease phenotype in PPMS patients. This finding was confirmed in an independent, multicenter validation cohort. INTERPRETATION: The presence of CSF IgM OCB may be a biomarker for a subset of PPMS patients with more active inflammatory disease, who may benefit from immune-directed treatments.

Diminished Th17 (not Th1) responses underlie multiple sclerosis disease abrogation after hematopoietic stem cell transplantation.

OBJECTIVE: To define changes in phenotype and functional responses of reconstituting T cells in patients with aggressive multiple sclerosis (MS) treated with ablative chemotherapy and autologous hematopoietic stem cell transplantation (HSCT). METHODS: Clinical and brain magnetic resonance imaging measures of disease activity were monitored serially in patients participating in the Canadian MS HSCT Study. Reconstitution kinetics of immune-cell subsets were determined by flow cytometry, whereas thymic function was assessed using T-cell receptor excision circle analyses as well as flow cytometry measurements of CD31+ recent thymic emigrants (RTEs). Functional assays were performed to track central nervous system-autoreactive antigen-specific T-cell responses, and the relative capacity to generate Th1, Th17, or Th1/17 T-cell responses. RESULTS: Complete abrogation of new clinical relapses and new focal inflammatory brain lesions throughout the 2 years of immune monitoring following treatment was associated with sustained decrease in naive T cells, in spite of restoration of both thymic function and release of RTEs during reconstitution. Re-emergence as well as in vivo expansion of autoreactive T cells to multiple myelin targets was evident in all patients studied. The reconstituted myelin-specific T cells exhibited the same Th1 and Th2 responses as preablation myelin-reactive T cells. In contrast, the post-therapy T-cell repertoire exhibited a significantly diminished capacity for Th17 responses. INTERPRETATION: Our results indicate that diminished Th17 and Th1/17 responses, rather than Th1 responses, are particularly relevant to the abrogation of new relapsing disease activity observed in this cohort of patients with aggressive MS following chemoablation and HSCT.

Elevated serum inflammatory markers in post-poliomyelitis syndrome.

OBJECTIVES: To determine (i) whether serum inflammatory markers TNFalpha, IL-1beta. IL-6, and leptin are increased in post-poliomyelitis syndrome (PPS) compared to healthy controls; and (ii) whether an association exists between elevated inflammatory markers and clinical parameters in PPS. The cause of PPS is unknown, but abnormal inflammatory responses have been implicated in several small studies. METHODS: Serum inflammatory markers were measured (by Luminex) in 51 PPS patients and 26 normal controls. Clinical parameters assessed included disease duration, muscle strength (Medical Research Council sumscore), fatigue (Fatigue Severity Scale and Multidimensional Fatigue Inventory), and pain (visual analog scale scores). RESULTS: In PPS, TNFalpha levels, as well as IL-6 and leptin were significantly increased compared to controls (Wilcoxon rank-sum test, p=0.03 for TNFalpha, p=0.03 for IL-6, p=0.01 for leptin). The elevated TNFalpha levels in PPS were associated with increased pain due to illness (Spearman correlation coefficient r=0.36, 95% C.I. 0.09 to 0.57) and specifically, with muscle pain (r=0.38, 95% C.I. 0.11 to 0.59). There were no correlations between inflammatory markers in PPS and joint pain, muscle strength, fatigue, or disease duration. CONCLUSIONS: Serum TNFalpha, IL-6 and leptin levels are abnormally increased in PPS patients. Elevated TNFalpha levels appear to be specifically associated with increased muscle pain.

Induction of antigen-specific tolerance in multiple sclerosis after immunization with DNA encoding myelin basic protein in a randomized, placebo-controlled phase 1/2 trial.

OBJECTIVE: To assess safety and immune modulation by BHT-3009, a tolerizing DNA vaccine encoding full-length human myelin basic protein, in patients with multiple sclerosis (MS). DESIGN: The study was a randomized, double-blind, placebo-controlled trial. Subjects receiving placebo were crossed over into an active arm after treatment unblinding. SETTING: The trial was conducted at 4 academic institutions within North America. Patients Thirty patients with relapsing-remitting or secondary progressive MS who were not taking any other disease-modifying drugs were enrolled in the trial. Further, the patients were required to have either 1 to 5 gadolinium-enhancing lesions on screening brain magnetic resonance imaging (MRI), a relapse in the previous 2 years, or disease worsening in the previous 2 years. INTERVENTIONS: BHT-3009 was administered as intramuscular injections at weeks 1, 3, 5, and 9 after randomization into the trial, with or without 80 mg of daily oral atorvastatin calcium in combination. Three dose levels of BHT-3009 were tested (0.5 mg, 1.5 mg, and 3 mg). MAIN OUTCOME MEASURES: The primary outcome measures were safety and tolerability of BHT-3009. Secondary outcome measures included the number and volume of gadolinium-enhanced lesions on MRI, relapses, and analysis of antigen-specific immune responses. RESULTS: BHT-3009 was safe and well tolerated, provided favorable trends on brain MRI, and produced beneficial antigen-specific immune changes. These immune changes consisted of a marked decrease in proliferation of interferon-gamma-producing, myelin-reactive CD4+ T cells from peripheral blood and a reduction in titers of myelin-specific autoantibodies from cerebral spinal fluid as assessed by protein microarrays. We did not observe a substantial benefit of the atorvastatin combination compared with BHT-3009 alone. CONCLUSION: In patients with MS, BHT-3009 is safe and induces antigen-specific immune tolerance with concordant reduction of inflammatory lesions on brain MRI.

Human Mesenchymal Stem Cells Impact Th17 and Th1 Responses Through a Prostaglandin E2 and Myeloid-Dependent Mechanism.

: Human mesenchymal stem cells (hMSCs) are being increasingly pursued as potential therapies for immune-mediated conditions, including multiple sclerosis. Although they can suppress human Th1 responses, they reportedly can reciprocally enhance human Th17 responses. Here, we investigated the mechanisms underlying the capacity of hMSCs to modulate human Th1 and Th17 responses. Human adult bone marrow-derived MSCs were isolated, and their purity and differentiation capacity were confirmed. Human venous peripheral blood mononuclear cells (PBMC) were activated, alone, together with hMSC, or in the presence of hMSC-derived supernatants (sups). Cytokine expression by CD4+ T-cell subsets (intracellular staining by fluorescence-activated cell sorting) and secreted cytokines (enzyme-linked immunosorbent assay) were then quantified. The contribution of prostaglandin E2 (PGE2) as well as of myeloid cells to the hMSC-mediated regulation of T-cell responses was investigated by selective depletion of PGE2 from the hMSC sups (anti-PGE2 beads) and by the selective removal of CD14+ cells from the PBMC (magnetic-activated cell sorting separation). Human MSC-secreted products could reciprocally induce interleukin-17 expression while decreasing interferon-γ expression by human CD4+ T cells, both in coculture and through soluble products. Pre-exposure of hMSCs to IL-1ß accentuated their capacity to reciprocally regulate Th1 and Th17 responses. Human MSCs secreted high levels of PGE2, which correlated with their capacity to regulate the T-cell responses. Selective removal of PGE2 from the hMSC supernatants abrogated the impact of hMSC on the T cells. Selective removal of CD14+ cells from the PBMCs also limited the capacity of hMSC-secreted PGE2 to affect T-cell responses. Our discovery of a novel PGE2-dependent and myeloid cell-mediated mechanism by which human MSCs can reciprocally induce human Th17 while suppressing Th1 responses has implications for the use of, as well as monitoring of, MSCs as a potential therapeutic for patients with multiple sclerosis and other immune-mediated diseases. SIGNIFICANCE: Although animal studies have generated a growing interest in the anti-inflammatory potential of mesenchymal stem cells (MSCs) for the treatment of autoimmune diseases, MSCs possess the capacity to both limit and promote immune responses. Yet relatively little is known about human-MSC modulation of human disease-implicated T-cell responses, or the mechanisms underlying such modulation. The current study reveals a novel prostaglandin E2-dependent and myeloid cell-mediated mechanism by which human MSCs can reciprocally regulate human Th17 and Th1 responses, with implications for the use of MSCs as a potential therapeutic for patients with multiple sclerosis and other immune-mediated diseases.

Type 2 monocyte and microglia differentiation mediated by glatiramer acetate therapy in patients with multiple sclerosis.

Glatiramer acetate (GA) therapy of patients with multiple sclerosis (MS) represents a unique setting in which in vivo Th2 deviation of T cells is consistently observed and associated with clinical benefit in a human autoimmune disease. We postulated that APCs are important targets of GA therapy and demonstrate that treatment of MS patients with GA reciprocally regulates the IL-10/IL-12 cytokine network of monocytes in vivo. We further show that Th1- or Th2-polarized GA-reactive T cells isolated from untreated or treated MS patients mediate type 1 and 2 APC differentiation of human monocytes, based on their ability to efficiently induce subsequent Th1 and Th2 deviation of naive T cells, respectively. These observations are extended to human microglia, providing the first demonstration of type 2 differentiation of CNS-derived APCs. Finally, we confirm that the fundamental capacity of polarized T cells to reciprocally modulate APC function is not restricted to GA-reactive T cells, thereby defining a novel and dynamic positive feedback loop between human T cell and APC responses. In the context of MS, we propose that GA therapy results in the generation of type 2 APCs, contributing to Th2 deviation both in the periphery and in the CNS of MS patients. In addition to extending insights into the therapeutic mode of action of GA, our findings revisit the concept of bystander suppression and underscore the potential of APCs as attractive targets for therapeutic immune modulation.