Search

Background and Aim Mesenchymal stem cells [MSCs] have anti-inflammatory and anti-fibrotic properties and could be a potential therapy for Crohn’s disease [CD] strictures. In this phase I–II pilot trial, we assessed safety and efficacy of local MSC injection to treat CD strictures. Methods CD patients with a short [less than 5 cm in length] non-passable stricture accessible by ileocolonoscopy were included. Allogenic bone-marrow derived MSCs were injected in the four quadrants of the stricture. Adverse events and clinical scores were evaluated at each follow-up visit and endoscopy and magnetic resonance enterography were performed at baseline, Week [W]12 and W48. The main judgement criterion for efficacy was the complete [defined by the ability to pass the ileocolonoscope] or partial [defined by a diameter increase] resolution of the stricture at W12. Second efficacy criteria included assessment of the stricture at W48 and evolution of clinical scores at W12 and W48. Results We performed 11 MSC injections in 10 CD patients [three primary and seven anastomotic strictures; one stricture injected twice]. MSC injections were well tolerated but four hospitalisations for occlusion were reported. At W12, five patients presented a complete or partial resolution of the stricture [two complete and three partial]. Seven patients were re-evaluated at W48 [one dilated, one operated, and one lost to follow-up] and four patients had a complete resolution. The evolution of clinical scores between W0, W12, and W48 was not statistically significant. Conclusions MSCs injection in CD stricture was well tolerated and may offer a benefit.

Mesenchymal stromal cells (MSCs) exhibit anti-inflammatory and immune-regulatory properties, and preclinical studies suggest a potential benefit in solid organ transplantation. We report on the 1-year follow-up of an open-label phase I-II trial of a single infusion of third-party MSC post-kidney transplantation, in addition to standard immunosuppression. Ten kidney transplant recipients from deceased donors received third-party bone marrow MSCs (∼2 × 106/kg) on day 3 ± 2 post-transplant and were compared to 10 concurrent controls. No adverse effects were noted at MSC injection. One participant with a history of cardiac disease had a non-ST-elevation myocardial infarction approximately 3 hours after MSC infusion. Incidences of opportunistic infections and acute rejection were similar. At day 7 post-transplant, estimated glomerular filtration rate (eGFR) in MSC-treated recipients reached 48.6 ml/min/1.73m2, compared to 32.5 ml/min/1.73m2 in controls and 29.3 ml/min/1.73m2 in our overall cohort of kidney transplant recipients. No difference in eGFR was found at 1 year. MSC-treated recipients showed increased frequencies of regulatory T cells at day 30, with no significant change in B cell frequencies compared to concurrent controls. Four MSC-treated participants developed antibodies against MSC or shared kidney-MSC HLA, with only 1 with MFI >1500. A single infusion of third-party MSC following kidney transplantation appears to be safe, with one cardiac event of unclear relationship to the intervention. MSC therapy is associated with increased regulatory T cell proportion and with improved early allograft function. Long-term effects, including potential immunization against MSC, remain to be studied.

Background Intestinal fibrosis is a common complication of Crohn’s disease (CD) leading to progressive bowel stricture formation. Mesenchymal stem cells (MSCs), known for their immunomodulatory, anti-inflammatory and anti-fibrotic properties, could be a potential therapy in this frequently fibro-inflammatory condition. In this phase I–II open-label pilot trial, we aimed to assess safety and efficacy of local MSCs injection in CD strictures. Methods: CD patients with a non-passable stricture, length from 2 to 5 cm, accessible by ileocolonoscopy, but without intestinal obstruction, fistulas, or abscess, could be included. A total of 3X107 allogenic bone-marrow derived MSCs were equally injected in the 4 quadrants of the strictured bowel wall during an ileocolonoscopy. Adverse events and clinical scores (Crohn Disease Activity Index, Short Health Scale and Crohn Disease Obstructive Score) were evaluated at each follow-up visit (at week 4, 12, 24 and 48) while endoscopy was performed at baseline, W12 and W48. The main judgement criteria for efficacy was the complete (defined by the ability to pass the ileocolonoscope) or partial (defined by a diameter increase) resolution of the stricture at 12 weeks. Other efficacy criteria included complete or partial resolution of the stricture at 48 weeks as well as the evolution of clinical scores between weeks 0, 12 and 48. Results Between 2018 and 2020, we performed 11 local MSCs injections in 10 CD patients (6 female; aged to 38-65 years; median 45 years old; 70% were smoker). The strictures’ (3 primary, 7 anastomotic) location was as follows: 7 at an ileo-colonic or ileo-rectal anastomosis, 1 colonic and 2 of the ileocecal valve. MSCs injections were well tolerated but a total of 5 hospitalizations for occlusion were reported (2 secondary to a different stricture than the injected one) leading to a surgical resection for one patient and an endoscopic dilatation for another one. Neither intestinal perforation nor intra-abdominal fistula or abscess was reported. At 12 weeks, 5 patients (45%) presented a stricture improvement with a complete resolution for 2 and a partial resolution for 3. Of the 11 MSCs injections, 6 patients were re-evaluated at week 48 (2 patients still undergoing follow-up, 1 operated, 1 dilated, and 1 lost to follow-up), 4 patients had a complete resolution and 1 had a partial resolution. The evolution of clinical scores between weeks 0, 12 and 48 (Figure 1) was not statistically significant. Conclusion Local MSCs injection in non-passable CD stricture was well tolerated over the short term but several occlusions were reported in the follow-up. Combining the effects of MSCs with the proven effect of endoscopic balloon dilatation could possibly improve the outcome of CD stricture.

Poor graft function (PGF) is a rare but serious complication of hematopoietic cell transplantation (HCT). Boost of CD34+stem cells could be a therapeutic option but is not always feasible nor successfull. Due to their hematopoietic support properties and immune regulatory effects, multipotent mesenchymal stromal cells (MSC) could be considered a good candidate to help restore bone marrow (BM) niches homeostasis and facilitate hematopoiesis after HCT. Here, we conducted a multicenter prospective study to evaluate the efficacy of MSC perfusion to improve PGF after HCT. Thirty patients (median age 51y, range 11 to 70y) received a single IV administration of third-party donor BM-derived MSC (1-2 x 10 exp6/kg body weight) for PGF after allogeneic HCT (median 151 days after HCT, range 62- 430). PGF was defined as (1) at least one cytopenia (Hb < 80 g/L, absolute neutrophil count [ANC] The primary endpoint was response at day +90 after MSC administration. A significant decrease in RBC and platelet transfusion requirements was observed at day + 90 after MSC (median monthly frequencies of 0 and 0 vs. 5 and 4 before MSC, respectively, p ≤0.001). An increase in ANC was also noted (median 2.500 at day 90 vs. 1.767 x 10exp9/L before MSC, p= 0.04), with 2/5 patients with severe neutropenia having recovered an ANC > 0.5 x 10exp9/L. At day 90 post-MSC, 51.8% (95% CI, 33 - 70.7%) of patients resolved at least one of their cytopenias (overall response, OR) and 40.7% (95% CI, 22.2 - 59.3%) achieved a complete haematological recovery (CR: ANC >0.5 x 10exp9/L and transfusion independence). Corresponding response rates increased at day 180, with 69.2% (95% CI, 51.5 - 86.9%) OR and 61.5% (95% CI, 42.8 - 80.2%) CR, respectively. Overall survival at 1 year post-MSC was 70% (95% CI, 53.6 - 86.3%), with all but one of the d90-responders being alive (1 death to relapse of hematological malignancy). No severe adverse event related to MSC administration was reported during the 1-year follow-up. In conclusion , perfusion of BM-derived MSC from a third party donor appeared to be safe and to improve PGF after allogeneic HCT, although spontaneous amelioration cannot be excluded. Further (ideally comparative) studies are warranted to confirme our results. Disclosures Selleslag: Celyad: Other: Clinical trial research (no honoraria recieved); Novartis: Consultancy, Honoraria, Speakers Bureau.

Ischemia/reperfusion injury (IRI) represents a worldwide public health issue of increasing incidence. IRI may virtually affect all organs and tissues and is associated with significant morbidity and mortality. Particularly, the duration of blood supply deprivation has been recognized as a critical factor in stroke, hemorrhagic shock, or myocardial infarction, as well as in solid organ transplantation (SOT). Pathophysiologically, IRI causes multiple cellular and tissular metabolic and architectural changes. Furthermore, the reperfusion of ischemic tissues induces both local and systemic inflammation. In the particular field of SOT, IRI is an unavoidable event, which conditions both short- and long-term outcomes of graft function and survival. Clinically, the treatment of patients with IRI mostly relies on supportive maneuvers since no specific target-oriented therapy has been validated thus far. In the present review, we summarize the current literature on mesenchymal stromal cells (MSC) and their potential use as cell therapy in IRI. MSC have demonstrated immunomodulatory, anti-inflammatory, and tissue repair properties in rodent studies and in preliminary clinical trials, which may open novel avenues in the management of IRI and SOT.

Background aims. Transplantation is the gold standard procedure for treating acute and chronic end-stage liver diseases. Given the shortage of organs, the development of cellular sources other than human liver is urgent. The main objective of this project was to examine the effect of mesenchymal stromal cell (MSC) (bone marrow, umbilical cord and liver MSCs) intravenous injection on liver regeneration in a model of hepatic damage in NOD/SCID/IL non-obese diabetic/severe combined immunodeficient/Interleukin-2Rg(null) (NSG) mice. Methods. Mice received 3 intraperitoneal injections of CCl4 Carbon tetrachloride per week for 4 weeks. Forty-eight hours after the last injection of CCl4, mice received 500,000 MSCs or phosphate-buffered saline by intravenous injection. We examined hepatic damage by means of quantitative image analysis and blood enzyme analysis 24 h, 1 week or 8 weeks after MSC or phosphate-buffered saline injection. We also examined MSC homing by means of real-time polymerase chain reaction of human albumin. Results. We adapted a model of liver injury in immunodeficient mice. In this model, accumulation of collagen in newly formed scar septa was apparent up to 8 weeks after CCl4 treatment. Human albumin DNA was found in all organs tested. However, intravenous MSC injection, even after CXCR4 C-X-C chemokine receptor type 4 transduction and whatever the origin of MSCs, failed to improve liver damage. Conclusions. In this liver injury model, MSCs were propagated in various tissues, particularly filtering organs. For the treatment of hepatic damage, intravenous administration of moderate doses of MSCs does not appear to be effective. Yet, this adapted liver injury model is appropriate for investigating engraftment of human cells.

Background aims Graft-versus-host disease (GVHD) is a life-threatening complication of allogeneic hematopoietic cell transplantation caused by donor T cells reacting against host tissues. Previous studies have suggested that mesenchymal stromal cells (MSCs) could exert potent immunosuppressive effects. Methods The ability of human bone marrow derived MSCs to prevent xenogeneic GVHD in non-obese diabetic/severe combined immunodeficient (NOD/SCID) mice and in NOD/SCID/interleukin-2Rγ(null) (NSG) mice transplanted with human peripheral blood mononuclear cells (PBMCs) was assessed. Results Injection of 200 × 10 6 human PBMCs intraperitoneally (IP) into sub-lethally (3.0 Gy) irradiated NOD/SCID mice also given anti-asialo GM 1 antibodies IP 1 day prior and 8 days after transplantation induced lethal xenogeneic GVHD in all tested mice. Co-injection of 2 × 10 6 MSCs IP on day 0 did not prevent lethal xenogeneic GVHD induced by injection of human PBMCs. Similarly, injection of 30 × 10 6 human PBMCs IP into sub-lethally (2.5 Gy) irradiated NSG mice induced a lethal xenogeneic GVHD in all tested mice. Injection of 3 × 10 6 MSCs IP on days 0, 7, 14 and 21 did not prevent lethal xenogeneic GVHD induced by injection of human PBMCs. Conclusions Injection of MSCs did not prevent xenogeneic GVHD in these two humanized mice models.

Solid organ transplantation (SOT) currently represents the best therapeutic option in end-stage diseases caused by the irrevocable functional loss of an organ. Still, SOT is associated with immunological and non-immunological injuries, whose severity impacts on early functional recovery and long-term survival of the transplant. Current research focuses on the identification of innovative approaches to 1) attenuate ischemia/reperfusion-induced damage, 2) accelerate processes of tissue repair, and 3) induce in fine graft tolerance. Encouraging observations from both preclinical studies and clinical trials suggest that the administration of mesenchymal stromal cells at the time of SOT might be beneficial, as a result of theirs immunomodulatory, anti-inflammatory and regenerative properties.

SummaryBackground Inflammatory bowel diseases (IBD) are chronic relapsing diseases in which pro-inflammatory immune cells and cytokines induce intestinal tissue damage and disability. Mesenchymal stromal cells (MSCs) exert powerful immunomodulatory effects and stimulate tissue repair. Aim To review the current data on mesenchymal stromal cell therapy in IBD. Method We searched PubMed and ‘ClinicalTrials.gov’ databases using the terms ‘mesenchymal stromal cells’, ‘mesenchymal stem cell transplantation’, ‘inflammatory bowel diseases’, ‘Crohn disease’ and ‘colitis, ulcerative’. Additional publications were identified from individual article reference lists. Results MSCs include inhibition of Th1/Th17 lymphocytes and recruitment of regulatory T lymphocytes, induction of antigen-presenting cells into a regulatory-like profile, and stimulation of epithelial cell differentiation and proliferation. More than 200 patients with refractory fistulas have been treated with local injections of MSCs, resulting in complete response in more than half, and in overall response in approximately two thirds of patients. In refractory luminal Crohn's disease, 49 cases of systemic MSC infusions have been reported, while trials with autologous MSCs resulted in mitigated responses, studies using allogeneic MSCs were promising, with around 60% of patients experiencing a response and around 40% achieving clinical remission. Conclusions Mesenchymal stromal cells might represent a promising therapy for IBD, especially for Crohn's disease. There remain many unsolved questions concerning the optimal origin and source of mesenchymal stromal cells, dosage and modalities of administration. Moreover, mesenchymal stromal cells still need to prove their effectiveness compared with conventional treatments in randomised controlled trials.

The Hedgehog (Hh) signaling pathway plays an important role in human development. Abnormal activation of this pathway has been observed in several types of human cancers, such as the upper gastro-intestinal tract cancers. However, activation of the Hh pathway in colorectal cancers is controversial. We analyzed the expression of the main key members of the Hh pathway in 7 colon cancer cell lines in order to discover whether the pathway is constitutively active in these cells. We estimated the expression of SHH, IHH, PTCH, SMO, GLI1, GLI2, GLI3, SUFU and HHIP genes by RT-PCR. Moreover, Hh ligand, Gli3 and Sufu protein levels were quantified by western blotting. None of the cell lines expressed the complete set of Hh pathway members. The ligands were absent from Colo320 and HCT116 cells, Smo from Colo205, HT29 and WiDr. GLI1 gene was not expressed in SW480 cells nor were GLI2/GLI3 in Colo205 or Caco-2 cells. Furthermore the repressive form of Gli3, characteristic of an inactive pathway, was detected in SW480 and Colo320 cells. Finally treatment of colon cancer cells with cyclopamine, a specific inhibitor of the Hh pathway, did not downregulate PTCH and GLI1 genes expression in the colorectal cells, whereas it did so in PANC1 control cells. Taken together, these results indicate that the aberrant activation of the Hh signaling pathway is not common in colorectal cancer cell lines.

Acute kidney injury (AKI) represents a worldwide public health issue of increasing incidence, with a significant morbimortality. AKI treatment mostly relies on supportive manoeuvres in the absence of specific target-oriented therapy. The pathophysiology of AKI commonly involves ischaemia/reperfusion (I/R) events, which cause both immune and metabolic consequences in renal tissue. Similarly, at the time of kidney transplantation (KT), I/R is an unavoidable event which contributes to early graft dysfunction and enhanced graft immunogenicity. Mesenchymal stromal cells (MSCs) represent a heterogeneous population of adult, fibroblast-like multi-potent cells characterized by their ability to differentiate into tissues of mesodermal lineages. Because MSC have demonstrated immunomodulatory, anti-inflammatory and tissue repair properties, MSC administration at the time of I/R and/ or at later times has been hypothesized to attenuate AKI severity and to accelerate the regeneration process. Furthermore, MSC in KT could help prevent both I/R injury and acute rejection, thereby increasing graft function and survival. In this review, summarizing the encouraging observations in animal models and in pilot clinical trials, we outline the benefi to f MSC therapy in AKI and KT, and envisage their putative role in renal ischaemic conditioning.

Graft-versus-host disease (GVHD) remains a major limitation of allogeneic hematopoietic cell transplantation (allo-HCT). Despite major advances in the understanding of GVHD pathogenesis, standard GVHD prophylaxis regimens continue to be based on the combination of a calcineurin inhibitor with an antimetabolite, while first line treatments still rely on high-dose corticosteroids. Further, no second line treatment has emerged thus far in acute or chronic GVHD patients who failed to respond with corticosteroid treatment. After briefly reviewing current standards of GVHD prevention and treatment, this article will discuss recent approaches that might change GVHD prophylaxis/treatment for decades to come, with a special focus on recently developed immunoregulatory strategies based on infusion of mesenchymal stromal or regulatory T-cells, or injection of low-dose interleukin-2.

Background Multiple myeloma (MM) is a malignant plasma cell disorder with poor long-term survival and high recurrence rates. Despite evidence of graft-versus-myeloma (GvM) effects, the use of allogeneic hematopoietic stem cell transplantation (allo-SCT) remains controversial in MM. In the current study, we investigated the anti-myeloma effects of allo-SCT from B10.D2 mice into MHC-matched myeloma-bearing Balb/cJ mice, with concomitant development of chronic graft-versus-host disease (GvHD). Methods and results Balb/cJ mice were injected intravenously with luciferase-transfected MOPC315.BM cells, and received an allogeneic (B10.D2 donor) or autologous (Balb/cJ donor) transplant 30 days later. We observed a GvM effect in 94% of the allogeneic transplanted mice, as the luciferase signal completely disappeared after transplantation, whereas all the autologous transplanted mice showed myeloma progression. Lower serum paraprotein levels and lower myeloma infiltration in bone marrow and spleen in the allogeneic setting confirmed the observed GvM effect. In addition, the treated mice also displayed chronic GvHD symptoms. In vivo and in vitro data suggested the involvement of effector memory CD4 and CD8 T cells associated with the GvM response. The essential role of CD8 T cells was demonstrated in vivo where CD8 T-cell depletion of the graft resulted in reduced GvM effects. Finally, TCR Vβ spectratyping analysis identified Vβ families within CD4 and CD8 T cells, which were associated with both GvM effects and GvHD, whereas other Vβ families within CD4 T cells were associated exclusively with either GvM or GvHD responses. Conclusions We successfully established an immunocompetent murine model of graft-versus-myeloma. This is the first murine GvM model using immunocompetent mice that develop MM which closely resembles human MM disease and that are treated after disease establishment with an allo-SCT. Importantly, using TCR Vβ spectratyping, we also demonstrated the presence of GvM unique responses potentially associated with the curative capacity of this immunotherapeutic approach.

BACKGROUND: The availability of tyrosine kinase inhibitors (TKIs) has considerably changed the management of Philadelphia chromosome positive leukemia. The BCR-ABL inhibitor imatinib is also known to inhibit the tyrosine kinase of the stem cell factor receptor, c-Kit. Nilotinib is 30 times more potent than imatinib towards BCR-ABL in vitro. Studies in healthy volunteers and patients with chronic myelogenous leukemia or gastrointestinal stromal tumors have shown that therapeutic doses of nilotinib deliver drug levels similar to those of imatinib. The aim of this study was to compare the inhibitory effects of imatinib and nilotinib on proliferation, differentiation, adhesion, migration and engraftment capacities of human cord blood CD34(+) cells. DESIGN AND METHODS: After a 48-hour cell culture with or without TKIs, CFC, LTC-IC, migration, adhesion and cell cycle analysis were performed. In a second time, the impact of these TKIs on engraftment was assessed in a xenotransplantation model using NOD/SCID/IL-2Rγ (null) mice. RESULTS: TKIs did not affect LTC-IC frequencies despite in vitro inhibition of CFC formation due to inhibition of CD34(+) cell cycle entry. Adhesion of CD34(+) cells to retronectin was reduced in the presence of either imatinib or nilotinib but only at high concentrations. Migration through a SDF-1α gradient was not changed by cell culture in the presence of TKIs. Finally, bone marrow cellularity and human chimerism were not affected by daily doses of imatinib and nilotinib in a xenogenic transplantation model. No significant difference was seen between TKIs given the equivalent affinity of imatinib and nilotinib for KIT. CONCLUSIONS: These data suggest that combining non-myeloablative conditioning regimen with TKIs starting the day of the transplantation could be safe.