The Comparison of Interleukin 6–Associated Immunosuppressive Effects of Human ESCs, Fetal-Type MSCs, and Adult-Type MSCs

Background: Although human embryonic stem cells (ESCs) and mesenchymal stem cells (MSCs) from various sources display immunomodulatory effects, direct comparisons among these classes of stem cells have not been reported.
Methods: Peripheral blood mononuclear cell suppression assays and carboxyfluorescein diacetate succinimidyl ester assays were used to assess the immunosuppressive effects of stem cells. Gene expression was measured using DNA microarrays. Enzyme-linked immunosorbent assays were used to determine interleukin (IL)-6 levels.
Results: We found that fetal-type MSCs proliferated significantly faster than adult-type MSCs. Compared with ESCs grown on feeder cells, ESCs grown in feeder cell–free conditions exhibited decreased immunosuppressive effects. The suppressive effects of ESCs were significantly stronger than those of MSCs, and the suppressive effects of fetal-type MSCs were significantly stronger than those of adult-type MSCs at each tested dose level. Analysis of gene expression by microarray and MetaCore pathway mapping revealed changes in eight different immune response pathways; we observed that IL-6 gene expression was highly significantly involved in all eight pathways. Significantly higher IL-6 elevation ratios (IL-6after:IL-6before) were found in ESCs compared with fetal-type MSCs, and these were also found in fetal-type MSCs compared with adult-type MSCs. Furthermore, IL-6 levels were found to correlate with cell dosages of MSCs and the suppressive effects.
Conclusions: The ease of obtaining fetal-type MSCs and their rapid proliferation make these cells ideal candidates for cell-based therapies, especially for diseases associated with immune responses, given the immunosuppressive effects of these cells. IL-6 might play an important role in the immunosuppressive effects of various stem cells (read more).

Induction Therapy With Autologous Mesenchymal Stem Cells in Living-Related Kidney Transplants (A Randomized Controlled Trial)

CONTEXT: Antibody-based induction therapy plus calcineurin inhibitors (CNIs) reduce acute rejection rates in kidney recipients; however, opportunistic infections and toxic CNI effects remain challenging. Reportedly, mesenchymal stem cells (MSCs) have successfully treated graft-vs-host disease.
OBJECTIVE: To assess autologous MSCs as replacement of antibody induction for patients with end-stage renal disease who undergo ABO-compatible, cross-match-negative kidney transplants from a living-related donor.
DESIGN, SETTING, AND PATIENTS: One hundred fifty-nine patients were enrolled in this single-site, prospective, open-label, randomized study from February 2008-May 2009, when recruitment was completed.
INTERVENTION: Patients were inoculated with marrow-derived autologous MSC (1-2 x 10(6)/kg) at kidney reperfusion and two weeks later. Fifty-three patients received standard-dose and 52 patients received low-dose CNIs (80% of standard); 51 patients in the control group received anti-IL-2 receptor antibody plus standard-dose CNIs.
MAIN OUTCOME MEASURES: The primary measure was 1-year incidence of acute rejection and renal function (estimated glomerular filtration rate [eGFR]); the secondary measure was patient and graft survival and incidence of adverse events.
RESULTS: Patient and graft survival at 13 to 30 months was similar in all groups. After 6 months, 4 of 53 patients (7.5%) in the autologous MSC plus standard-dose CNI group (95% CI, 0.4%-14.7%; P = .04) and 4 of 52 patients (7.7%) in the low-dose group (95% CI, 0.5%-14.9%; P = .046) compared with 11 of 51 controls (21.6%; 95% CI, 10.5%-32.6%) had biopsy-confirmed acute rejection. None of the patients in either autologous MSC group had glucorticoid-resistant rejection, whereas 4 patients (7.8%) in the control group did (95% CI, 0.6%-15.1%; overall P = .02). Renal function recovered faster among both MSC groups showing increased eGFR levels during the first month after surgery than the control group. Patients receiving standard-dose CNI had a mean difference of 6.2 mL/min per 1.73 m(2) (95% CI, 0.4-11.9; P=.04) and those in the low-dose CNI of 10.0 mL/min per 1.73 m(2) (95% CI, 3.8-16.2; P=.002). Also, during the 1-year follow-up, combined analysis of MSC-treated groups revealed significantly decreased risk of opportunistic infections than the control group (hazard ratio, 0.42; 95% CI, 0.20-0.85, P=.02)
CONCLUSION: Among patients undergoing renal transplant, the use of autologous MSCs compared with anti-IL-2 receptor antibody induction therapy resulted in lower incidence of acute rejection, decreased risk of opportunistic infection, and better estimated renal function at 1 year.
TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00658073 (read more).

Transplantation of an allogeneic vein bioengineered with autologous stem cells: a proof-of-concept study

Background : Extrahepatic portal vein obstruction can have severe health consequences. Variceal bleeding associated with this disorder causes upper gastrointestinal bleeding, leading to substantial morbidity and mortality. We report the clinical transplantation of a deceased donor iliac vein graft repopulated with recipient autologous stem cells in a patient with extrahepatic portal vein obstruction.
Methods : a 10 year old girl with extrahepatic portal vein obstruction was admitted to the Sahlgrenska University Hospital in Gothenburg, Sweden, for a bypass procedure between the superior mesenteric vein and the intrahepatic left portal vein (meso Rex bypass). A 9 cm segment of allogeneic donor iliac vein was decellularised and subsequently recellularised with endothelial and smooth muscle cells differentiated from stem cells obtained from the bone marrow of the recipient. This graft was used because the patient's umbilical vein was not suitable and other strategies (eg, liver transplantation) require lifelong immunosuppression.
Findings : The graft immediately provided the recipient with a functional blood supply (25—30 cm/s in the portal vein and 40 mL/s in the artery was measured intraoperatively and confirmed with ultrasound). The patient had normal laboratory values for 9 months. However, at 1 year the blood flow was low and, on exploration, the shunt was patent but too narrow due to mechanical obstruction of tissue in the mesocolon. Once the tissue causing the compression was removed the graft dilated. We therefore used a second stem-cell populated vein graft to lengthen the previous graft. After this second operation, the portal pressure was reduced from 20 mm Hg to 13 mm Hg and blood flow was 25—40 cm/s in the portal vein. With restored portal circulation the patient has substantially improved physical and mental function and growth. The patient has no anti-endothelial cell antibodies and is receiving no immunosuppressive drugs.
Interpretation : An acellularised deceased donor vein graft recellularised with autologous stem cells can be considered for patients in need of vascular vein shunts without the need for immunosuppression (read more).