Objective To evaluate the feasibility, safety, and immunological effects of intrathecal and intravenous administration of autologous mesenchymal stem cells (MSCs) (also called mesenchymal stromal cells ) in patients with multiple sclerosis (MS) and amyotrophic lateral sclerosis (ALS). Design A phase 1/2 open-safety clinical trial. Patients Fifteen patients with MS (mean [SD] Expanded Disability Status Scale [EDSS] score, 6.7 [1.0]) and 19 with ALS (mean [SD] Amyotrophic Lateral Sclerosis Functional Rating Scale [ALSFRS] score, 20.8 [8.0]) were enrolled. Intervention After culture, a mean (SD) of 63.2 × 10 6 (2.5 × 10 6 ) MSCs was injected intrathecally (n = 34) and intravenously (n = 14). In 9 cases, MSCs were magnetically labeled with the superparamagnetic iron oxide ferumoxides (Feridex). Main Outcome Measures The main outcome measure was the recording of side effects. Follow-up (≤25 months) included adverse events evaluation, neurological disability assessment by means of the EDSS, magnetic resonance imaging to exclude unexpected pathologies and track the labeled stem cells, and immunological tests to assess the short-term immunomodulatory effects of MSC transplantation. Results Twenty-one patients had injection-related adverse effects consisting of transient fever, and 15 reported headache. No major adverse effects were reported during follow-up. The mean ALSFRS score remained stable during the first 6 months of observation, whereas the mean (SD) EDSS score improved from 6.7 (1.0) to 5.9 (1.6). Magnetic resonance imaging visualized the MSCs in the occipital horns of the ventricles, indicating the possible migration of ferumoxides-labeled cells in the meninges, subarachnoid space, and spinal cord. Immunological analysis revealed an increase in the proportion of CD4 + CD25 + regulatory T cells, a decrease in the proliferative responses of lymphocytes, and the expression of CD40 + , CD83 + , CD86 + , and HLA-DR on myeloid dendritic cells at 24 hours after MSC transplantation. Conclusion Transplantation of MSCs in patients with MS and ALS is a clinically feasible and relatively safe procedure and induces immediate immunomodulatory effects. Trial Registration clinicaltrials.gov Identifier:NCT00781872

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Safety and immunological effects of mesenchymal stem cell transplantation in patients with multiple sclerosis and amyotrophic lateral sclerosis.

Summary Background More than half of patients with multiple sclerosis have progressive disease characterised by accumulating disability. The absence of treatments for progressive multiple sclerosis represents a major unmet clinical need. On the basis of evidence that mesenchymal stem cells have a beneficial effect in acute and chronic animal models of multiple sclerosis, we aimed to assess the safety and efficacy of these cells as a potential neuroprotective treatment for secondary progressive multiple sclerosis. Methods Patients with secondary progressive multiple sclerosis involving the visual pathways (expanded disability status score 5·5–6·5) were recruited from the East Anglia and north London regions of the UK. Participants received intravenous infusion of autologous bone-marrow-derived mesenchymal stem cells in this open-label study. Our primary objective was to assess feasibility and safety; we compared adverse events from up to 20 months before treatment until up to 10 months after the infusion. As a secondary objective, we chose efficacy outcomes to assess the anterior visual pathway as a model of wider disease. Masked endpoint analyses was used for electrophysiological and selected imaging outcomes. We used piecewise linear mixed models to assess the change in gradients over time at the point of intervention. This trial is registered with ClinicalTrials.gov, number NCT00395200. Findings We isolated, expanded, characterised, and administered mesenchymal stem cells in ten patients. The mean dose was 1·6×10 6 cells per kg bodyweight (range 1·1–2·0). One patient developed a transient rash shortly after treatment; two patients had self-limiting bacterial infections 3–4 weeks after treatment. We did not identify any serious adverse events. We noted improvement after treatment in visual acuity (difference in monthly rates of change −0·02 logMAR units, 95% CI −0·03 to −0·01; p=0·003) and visual evoked response latency (−1·33 ms, −2·44 to −0·21; p=0·020), with an increase in optic nerve area (difference in monthly rates of change 0·13 mm 2 , 0·04 to 0·22; p=0·006). We did not identify any significant effects on colour vision, visual fields, macular volume, retinal nerve fibre layer thickness, or optic nerve magnetisation transfer ratio. Interpretation Autologous mesenchymal stem cells were safely given to patients with secondary progressive multiple sclerosis in our study. The evidence of structural, functional, and physiological improvement after treatment in some visual endpoints is suggestive of neuroprotection. Funding Medical Research Council, Multiple Sclerosis Society of Great Britain and Northern Ireland, Evelyn Trust, NHS National Institute for Health Research, Cambridge and UCLH Biomedical Research Centres, Wellcome Trust, Raymond and Beverly Sackler Foundation, and Sir David and Isobel Walker Trust.

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Autologous mesenchymal stem cells for the treatment of secondary progressive multiple sclerosis: an open-label phase 2a proof-of-concept study

Objective To investigate the therapeutic potential of mesenchymal stromal cells (MSCs) in the chronic model of experimental autoimmune encephalomyelitis (EAE). Design Mesenchymal stromal cells were obtained from the bone marrow of naive C57BL and green fluorescent protein–transgenic mice and cultured with Eagle minimum essential medium/alpha medium after removal of adhering cells. Following 2 to 3 passages, MSCs were injected intraventricularly or intravenously into mice in which chronic EAE had been induced with myelin oligodendrocyte glycoprotein 35-55 peptide. Results In 8 separate experiments, the intravenously and intraventricularly injected green fluorescent protein–positive MSCs were attracted to the areas of central nervous system inflammation and expressed galactocerebroside, O4, glial fibrillary acidic protein, and β-tubulin type III. The clinical course of chronic EAE was ameliorated in MSC-treated animals (0% mortality; mean [SE] maximal EAE score, 1.76 [1.01] and 1.8 [0.46] in the intraventricular and intravenous groups, respectively, vs 13% and 21% mortality and 2.80 [0.79] and 3.42 [0.54] mean maximal score in the controls). A strong reduction in central nervous system inflammation, accompanied by significant protection of the axons (86%-95% intact axons vs 45% in the controls) was observed in the animals injected with MSCs (especially following intraventricular administration). Mesenchymal stromal cells injected intravenously were detected in the lymph nodes and exhibited systemic immunomodulatory effects, downregulating proliferation of lymphocytes in response to myelin antigens and mitogens. Mesenchymal stromal cells cultured with fibroblast growth factor and brain-derived neurotrophic factor in vitro acquired neuronal-lineage cell morphology and expressed β-tubulin type III, nestin glial fibrillary acidic protein, and O4. Conclusions Our results indicate that stem cells derived from bone marrow may provide a feasible and practical way for neuroprotection, immunomodulation, and possibly remyelination and neuroregeneration in diseases such as multiple sclerosis.

https://jamanetwork.com/journals/jamaneurology/articlepdf/795748/noc80004_753_761.pdf

Neuroprotection and immunomodulation with mesenchymal stem cells in chronic experimental autoimmune encephalomyelitis.

Tissue regeneration from transplanted mesenchymal stromal cells (MSC) either through transdifferentiation or cell fusion was originally proposed as the principal mechanism underlying their therapeutic action. However, several studies have now shown that both these mechanisms are very inefficient. The low MSC engraftment rate documented in injured areas also refutes the hypothesis that MSC repair tissue damage by replacing cell loss with newly differentiated cells. Indeed, despite evidence of preferential homing of MSC to the site of myocardial ischemia, exogenously administered MSC show poor survival and do not persist in the infarcted area. Therefore, it has been proposed that the functional benefits observed after MSC transplantation in experimental models of tissue injury might be related to the secretion of soluble factors acting in a paracrine fashion. This hypothesis is supported by pre-clinical studies demonstrating equal or even improved organ function upon infusion of MSC-derived conditioned medium (MSC-CM) compared with MSC transplantation. Identifying key MSC-secreted factors and their functional role seems a reasonable approach for a rational design of nextgeneration MSC-based therapeutics. Here, we summarize the major findings regarding both different MSC-mediated paracrine actions and the identification of paracrine mediators.

Paracrine Mechanisms of Mesenchymal Stem Cells in Tissue Repair

Mesenchymal stem cells (MSC) can be isolated from different adult tissues including bone marrow, adipose tissue, cord blood and placenta. MSCs modulate the immune function of the major immune cell populations involved in alloantigen recognition and elimination, including antigen presenting cells, T cells, B cells and natural killer cells. Many clinical trials are currently underway that employ MSCs to treat human immunological diseases. However, the molecular mechanism that mediates the immunosuppressive effect of MSCs is still unclear and the safety of using MSC in patient needs further confirmation. Here, we review the cytokines that activate MSCs and the soluble factors produced by MSCs, which allow them to exert their immunosuppressive effects. We review the mechanism responsible, at least in part, for the immune suppressive effects of MSCs and highlight areas of research required for a better understanding of MSC immune modulation.

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Immunosuppressive Properties of Mesenchymal Stem Cells

We investigated the ability of human bone marrow stromal cell (hBMSC) treatment to reduce axonal loss in experimental autoimmune encephalomyelitis (EAE) mice. EAE was induced in SJL/J mice by injection with proteolipid protein (PLP). Mice were injected intravenously with hBMSCs or PBS on the day of clinical onset, and neurological function was measured daily (score 0–5) until 45 weeks after onset. Mice were sacrificed at week 1, 10, 20, 34, and 45 after clinical onset. Bielshowsky silver was used to identify axons. Immunohistochemistry was performed to measure the expression of nerve growth factor (NGF) and MAB1281, a marker of hBMSCs. hBMSC treatment significantly reduced the mortality, the disease severity, and the number of relapses in EAE mice compared with PBS treatment. Axonal density and NGF+ cells in the EAE brain were significantly increased in the hBMSC group compared with the PBS group at 1, 10, 20, 34, and 45 weeks. Disease severity was significantly correlated with decreased axonal density and decreased NGF, and increased axonal density was significantly correlated with reduced loss of NGF expression after hBMSC treatment. Most of the NGF+ cells are brain parenchymal cells. Under 5% of MAB1281+ cells colocalized with NG2+, a marker of oligodendrocyte progenitor cells. Nearly 10% of MAB1281+ cells colocalized with GFAP, a marker of astrocytes, and MAP-2, a marker of neurons. Our findings indicate that hBMSCs improve functional recovery and may provide a potential therapy aimed at axonal protection in EAE mice, in which NGF may play a vital role. © 2006 Wiley-Liss, Inc.

Lori Noffsinger

Papers

Bone marrow stromal cells reduce axonal loss in experimental autoimmune encephalomyelitis mice

Gene Editing/Gene Therapies: IMPROVING GENETIC ENGINEERING OF ADOPTIVE CELL THERAPIES BY A NOVEL CULTURE MEDIA SUPPLEMENT