Infusion Of Bone Marrow Cells Research Articles

Regulatory T-cell subset analysis and profile of interleukin (IL)-10, IL-17 and interferon-gamma cytokine-producing cells in kidney allograft recipients with donor cells infusion

This pilot study aimed to assess whether the perioperative infusion of donor bone marrow cells (DBMC) in renal allograft recipients can affect the appearance of peripheral regulatory T-cell subsets and the profile of cytokine-producing cells [interferon-gamma (IFN-γ), interleukin (IL)-17 and IL-10] 2 years after transplantation. Fresh blood samples were collected from 14 kidney recipients who received infusion and from 13 kidney recipients without infusion who served as controls at the end of the second post-transplantation year. Initially the percentages of CD4(+)CD25(+)FoxP3(+) T cells and CD3(+)CD8(+)CD28(-) T cells were quantified using flowcytometry. Thereafter, the frequencies of IL-10-, IL-17- and IFN-γ-producing cells were determined separately using the ELISPOT technique with peptides corresponding to mismatched donor HLA-DR molecules and phytohemagglutinin (PHA). The mean numbers of IFN-γ- and IL-17-producing cells in response to PHA were lower in infused patients than in controls (P = 0.02 and P = 0.18, respectively); however, an increased frequency of IL-10-producing cells was observed compared to controls (P = 0.07). Furthermore, the ratio of IL-10/IFN-γ-producing cells was significantly higher in the DBMC-infused group versus controls (P = 0.01). There was a negative correlation between the percentage of CD3(+)CD8(+)CD28(-)T cells and IL-17-producing cells in the infused group (r = -0.539, P = 0.04). The mean levels and the frequency of microchimerism within the first post-transplantation year were also significantly higher in infused patients than in controls (P = 0.007 and P = 0.001, respectively). Our findings suggest that DBMC infusion could partially stimulate the regulatory mechanisms against alloimmune responses in kidney allograft recipients

New directions in cardiac stem cell therapy: An update for clinicians

The emergence of cardiac stem cell therapy can be traced to late 2001, when studies in small animal models of myocardial infarction suggested that stem cells could engraft, proliferate, and regenerate myo-cardium. Subsequent animal laboratory studies showed improved cardiac function, perfusion and survival compared to controls (Figure 1). Within two years, the first clinical trials of stem cell therapy began to appear, and we now have several trials of intracoronary infusion of bone marrow cells with more than one year follow-up. Although this clinical therapy has proven to be safe, the magnitude of improvement in objective measures like ejection fraction has been modest, and the therapy has not entered clinical practice. In the absence of a large prospective randomized trial, the field has moved back to the laboratory. This manuscript aims to provide clinicians with a broad overview of this complex field by briefly reviewing the existing status of clinical myocardial regeneration therapy, then describing selected examples from the laboratory research approaches that may provide a platform for new and potentially increasingly effective clinical strategies.

Liver bioengineering: Current status and future perspectives

The present review aims to illustrate the strategies that are being implemented to regenerate or bioengineer livers for clinical purposes. There are two general pathways to liver bioengineering and regeneration. The first consists of creating a supporting scaffold, either synthetically or by decellularization of human or animal organs, and seeding cells on the scaffold, where they will mature either in bioreactors or in vivo. This strategy seems to offer the quickest route to clinical translation, as demonstrated by the development of liver organoids from rodent livers which were repopulated with organ specific cells of animal and/or human origin. Liver bioengineering has potential for transplantation and for toxicity testing during preclinical drug development. The second possibility is to induce liver regeneration of dead or resected tissue by manipulating cell pathways. In fact, it is well known that the liver has peculiar regenerative potential which allows hepatocyte hyperplasia after amputation of liver volume. Infusion of autologous bone marrow cells, which aids in liver regeneration, into patients was shown to be safe and to improve their clinical condition, but the specific cells responsible for liver regeneration have not yet been determined and the underlying mechanisms remain largely unknown. A complete understanding of the cell pathways and dynamics and of the functioning of liver stem cell niche is necessary for the clinical translation of regenerative medicine strategies. As well, it will be crucial to elucidate the mechanisms through which cells interact with the extracellular matrix, and how this latter supports and drives cell fate.

Effects of intracoronary delivery of allogenic bone marrow-derived stem cells expressing heme oxygenase-1 on myocardial reperfusion injury

Heme oxygenase-1 (HO-1) decreases apoptosis, inflammation and oxidative stress. The aim of the study was to investigate the effects of intracoronary infusion of allogenic bone marrow cells (BMC) overexpressing HO-1 in the porcine model of myocardial infarction (MI). MI was produced by balloon occlusion of a coronary artery. BMC were transduced with adenoviruses encoding for HO-1 (HO-1 BMC) or GFP (GFP-BMC) genes. Prior to reperfusion animals received HO-1 BMC, control BMC (unmodified or GFP-BMC) or placebo. Left ventricular (LV) ejection fraction (EF), shortening fraction (SF), end-systolic and end-diastolic diameters (EDD, ESD) were assessed by echocardiography before, 30 minutes (min) and 14 days after reperfusion. BMC significantly improved LVEF and SF early (30 min) after reperfusion as well as after 14 days. Early after reperfusion HO-1 BMC were significantly more effective than control BMC, but after 14 days, there were no differences. There were no effect of cells on LV remodelling and diastolic function. Both HO-1 BMC and control BMC significantly reduced the infarct size vs. placebo (17.2 ± 2.7 and 18.8 ± 2.5, respectively, vs. 27.5 ± 5.1, p= 0.02) in histomorphometry. HO-1-positive donor BMC were detected in the infarct border area in pigs receiving HO-1-cells. No significant differences in expression of inflammatory genes (SDF-1, TNF-α, IL-6, miR21, miR29a and miR133a) in the myocardium were found. In conclusion, intracoronary delivery of allogeneic BMC immediately prior to reperfusion improved the LVEF and reduced the infarct size. HO-1 BMC were not superior to control cells after 14 days, however, produced faster recovery of LVEF. Transplanted cells survived in the peri-infarct zone.

Splenectomy enhances the anti-fibrotic effect of bone marrow cell infusion and improves liver function in cirrhotic mice and patients

In 2003, we initiated a clinical trial to examine autologous bone marrow cell infusion (ABMi) therapy for cirrhotic patients and reported the clinical effect of the therapy. To analyze how splenectomy may potentiate the effects of bone marrow cell infusion on cirrhosis, we performed a mouse study and a clinical trial on patients with cirrhosis. In mice, we analyzed the effect of splenectomy on bone marrow cell infusion in four experimental groups (group A, splenectomy+bone marrow cell infusion+CCl(4); group B, sham operation+bone marrow cell infusion+CCl(4); group C, splenectomy+CCl(4); group D, sham operation+CCl(4)). In clinical, we compared the effect of splenectomy on ABMi therapy. We observed significantly increased average serum albumin levels and higher expression of green fluorescent protein (GFP), matrix metalloproteinase 9 (MMP9), and proliferating cell nuclear antigen in the livers of group A. We observed MMP9/GFP double-positive cells in the cirrhotic livers. A significant decrease in the liver fibrosis areas was observed in group A. Splenectomy enhanced the repopulation of bone marrow cells into the cirrhotic liver and improved the liver microenvironment via expression of MMP9 secreted from repopulating GFP-positive cells. Next, we performed a clinical trial to compare the effect of splenectomy on the efficacy of ABMi therapy. Cirrhotic patients who underwent splenectomy before ABMi therapy tended to have a greater improvement in liver function. ABMi therapy with splenectomy may be an effective therapeutic modality for cirrhosis.

Biologics and Donor Bone Marrow Cells for Targeted Immunomodulation in Vascularized Composite Allotransplantation: A Translational Trial in Swine

Introduction Bone marrow (BM) infusion following organ transplantation is a prerequisite for potential donor-antigen-specific tolerance induction. We developed a preclinical swine model to determine the optimal dose of BM cells to achieve microchimerism. Furthermore, induction therapy was optimized by augmenting the BM infusion with biologics in the form of costimulatory blockade: cytotoxic T-lymphocyte antigen 4 immunoglobulin (CTLA4-Ig). Materials and Methods Yucatan miniature swine ( n = 12) underwent total body and thymic irradiation for cytodepletion. Animal groups received 15, 30, or 60 million cells per kilogram of whole unmodified BM. The optimal dose of BM cell infusion (BMT) was then applied to subsequent experiments evaluating the addition of CTLA4lg. Group 1 (control) received no treatment. Group 2 received FK506 only; group 3 received irradiation, BMT, and FK506; group 4 received FK506 and CTLA4-lg. Results Microchimerism was established in all animals after BM cell infusion; at postoperative day 9, it was significantly increased for 60 million cells per kilogram ( P = .0001). Transplanted animals in group 1 rejected the allograft 5 to 8 days after transplantation. Group 2 rejected the allograft (skin and muscle) 30 to 32 days after transplantation (2 days after cessation of immunosuppression). Group 3 rejected the skin portion of the allograft at 50, 52, and 53 days posttransplant. Remaining allograft components (muscle, bone, nerve, vessel) survived indefinitely. Group 4 animals demonstrated significantly prolonged muscle survival beyond 150 days posttransplant; the skin component survived past 150 days in two of three animals. Skin and muscle histology in all long-term surviving animals were normal. Conclusions BM cell infusion with 60 million cells per kilogram results in stable levels of microchimerism. The addition of costimulatory blockade (CTLA4lg) prolonged allograft skin survival and overall graft survival. Such targeted immunomodulatory protocols might facilitate immune tolerance and eliminate the need for multidrug immunosuppression to maintain graft survival after vascularized composite allotransplantation.

Vascularized Bone Marrow Transplantation Model in Rats as an Alternative to Conventional Cellular Bone Marrow Transplantation: Preliminary Results

The aim of the study was to follow the development of microchimerism after allogeneic vascularized bone marrow transplantation (VBMT) versus conventional bone marrow transplantation (BMT). In one group, a VBMT model consisted of donor Brown Norway rat hind limb heterotopic transplanted on recipient Lewis rats. An intravenous infusion of donor bone marrow cells in suspension equivalent to that grafted in the vascularized femur limb was administered intravenously to recipient rats in the second group. Cellular microchimerism was investigated in recipients of VBMT versus BMT. Donor-derived cells could be detected in VBMT recipients at 30 and 60 days but not in recipients of intravenous suspension of BMC. VBMT provides a theoretical alternative to conventional cellular bone marrow transplantation by addressing crucial clinical problems such as failure of engraftment or graft-versus-host disease.

Ischemia induces P-selectin-mediated selective progenitor cell engraftment in the isolated-perfused heart

Clinical trials infusing Bone Marrow Cells (BMCs) into injured hearts have produced measureable improvements in cardiac performance, but were insufficient to improve patient outcomes. Low engraftment rates are cited as probable contributor to limited improvements. To understand the mechanisms that control myocardial engraftment of BMCs following ischemia-reperfusion injury, in isolated–perfused mouse hearts, stop-flow ischemia was followed by variable-duration reperfusion (0–60min) before addition of labeled syngenic BMCs to the perfusate. After a buffer-only wash, the heart was disaggregated. Retained BMCs (digest) and infused BMCs (aliquot) were compared by flow cytometry for c-kit and CD45 expression to determine the proportion of cell subtypes engrafted versus delivered (selectivity ratio). In these studies, a time-dependent selective retention of c-kit+ cells was apparent starting at 30min of reperfusion, at which time c-kit+/CD45+ BMCs showed a selectivity ratio of 18±2 (versus 2±1 in sham-ischemic controls). To study the underlying mechanism for this selective retention, neutralizing antibodies for P-selectin or L-selectin were infused into the heart preparation and incubated with BMCs prior to BMC infusion. Blocking P-selectin in ischemic hearts ablated selectivity for c-kit+/CD45+ BMCs at 30min reperfusion (selectivity ratio of 3±1) while selectivity persisted in the presence of L-selectin neutralization (selectivity ratio of 17±2). To corroborate this finding, a parallel plate flow chamber was used to study capture and rolling dynamics of purified c-kit+ versus c-kit- BMCs on various selectin molecules. C-kit+ BMCs interacted weakly with L-selectin substrates (0.03±0.01% adhered) but adhered strongly to P-selectin (0.28±0.04% adhered). C-kit- BMCs showed intermediate binding regardless of substrate (0.18±0.04% adhered on L-selectin versus 0.17±0.04% adhered on P-selectin). Myocardial ischemia–reperfusion stress induces selective engraftment of c-kit+ bone marrow progenitor cells via P-selectin activation.

TNFR1-mediated signaling is important to induce the improvement of liver fibrosis by bone marrow cell infusion

The importance of TNF-α signals mediated by tumor necrosis factor receptor type 1 (TNFR1) in inflammation and fibrosis induced by carbon tetrachloride (CCl4), and in post-injury liver regeneration including a GFP/CCl4 model developed as a liver repair model by bone marrow cell (BMC) infusion, was investigated. In mice in which TNFR1 was suppressed by antagonist administration or by knockout, liver fibrosis induced by CCl4 was significantly decreased. In these mice, intrahepatic macrophage infiltration and TGF-β1 expression were reduced and stellate cell activity was decreased; however, expression of MMP-9 was also decreased. With GFP-positive BMC (TNFR1 wild-type, WT) infusion in these mice, fibrosis proliferation, including host endogenous intrahepatic macrophage infiltration, TGF-β1 expression and stellate cell activity, increased significantly. There was no significant increase of MMP-9 expression. In this study, TNFR1 in hosts had a promoting effect on CCl4-induced hepatotoxicity and fibrosis, whereas BMC infusion in TNFR1 knockout mice enhanced host-derived intrahepatic inflammation and fibrosis proliferation. These findings differed from those in WT recipient mice, in which improvement in inflammation and fibrosis with BMC infusion had previously been reported. TNFR1-mediated signaling might be important to induce the improvement of liver fibrosis by bone marrow cell infusion.

401 Cardiac-resident bone marrow stem cells govern repair after infarction in aged mice

401 Cardiac-resident bone marrow stem cells govern repair after infarction in aged mice

MP-06.18 Augmentation of Chimerism by Donor Bone Marrow Cells Infusion in Kidney Allograft Recipients

MP-06.18 Augmentation of Chimerism by Donor Bone Marrow Cells Infusion in Kidney Allograft Recipients

Recovery of Microcirculation After Intracoronary Infusion of Bone Marrow Mononuclear Cells or Peripheral Blood Mononuclear Cells in Patients Treated by Primary Percutaneous Coronary Intervention: The Doppler Substudy of the Hebe Trial

In the present substudy of the Hebe trial, we investigated the effect of intracoronary bone marrow mononuclear cell (BMMC) and peripheral blood mononuclear cell (PBMC) therapy on the recovery of microcirculation in patients with reperfused ST-segment elevation myocardial infarction (STEMI). Several studies have suggested that cell therapy enhances neovascularization after STEMI. Paired Doppler flow measurements were available for 23 patients in the BMMC group, 18 in the PBMC group, and 19 in the control group. Coronary flow was assessed at 3 to 8 days after primary percutaneous coronary intervention (PCI) and repeated at 4-month follow-up, with intracoronary Doppler flow measurements. At baseline, the coronary flow velocity reserve was reduced in the infarct-related artery and improved over 4 months in all 3 groups. The increase of coronary flow velocity reserve did not significantly differ between the 2 treatment groups and the control group (BMMC group: 2.0 ± 0.5 to 3.1 ± 0.7; PBMC group: 2.2 ± 0.6 to 3.2 ± 0.8; control group: 2.0 ± 0.5 to 3.4 ± 0.9). Additionally, the decrease in hyperemic microvascular resistance index from baseline to 4-month follow-up was not statistically different between the 2 treatment groups and the control group. In STEMI patients treated with primary PCI in the Hebe trial, adjuvant therapy with BMMCs or PBMCs does not improve the recovery of microcirculation. Therefore, our data do not support the hypothesis of enhanced neovascularization after this mode of cell therapy. (Multicenter, randomised trial of intracoronary infusion of autologous mononuclear bone marrow cells or peripheral mononuclear blood cells after primary percutaneous coronary intervention [PCI]; ISRCTN95796863).

Human Umbilical Cord Blood-derived Stromal Cells, a New Resource in the Suppression of Acute Graft-versus-host Disease in Haploidentical Stem Cell Transplantation in Sublethally Irradiated Mice

Human umbilical cord blood-derived stromal cells (hUCBDSCs), a novel population isolated from CD34(+) cells by our laboratory, exerted an immunosuppressive effect on xenogenic T cells. This study aimed to investigate whether hUCBDSCs play a critical role in the suppression of acute graft-versus-host disease (aGVHD). The hUCBDSCs were co-cultured with splenocytes (SPCs) of donor C57BL/6 mice. The aGVHD in the recipient (B6×BALB/c) F1 mice was induced by the infusion of bone marrow cells and SPCs from donor mice following sublethal irradiation. The shift in vivo for hUCBDSCs was detected. The proliferation and cell cycle of SPCs were tested by cell counting kit-8 and flow cytometry, respectively. The expression of CD49b natural killer (NK) cells and CD3 T cells was detected by flow cytometry in co-culture and post-transplantation. IL-4, and IFN-γ were detected by ELISA in the serum of co-culture and post-transplantation. The survival time, body weight, clinical score, and histopathological score were recorded for mice post-transplantation. The hUCBDSCs promoted the proliferation of SPCs and significantly increased the ratio of the S and G(2)/M phase (p < 0.05). The hUCBDSCs significantly increased the expression of CD49b NK cells and IL-4 protein and decreased the expression of CD3 T cells and IFN-γ protein both in vitro and in vivo. The survival time of mice with co-transplantation of hUCBDSCs was significantly prolonged, and decreased clinical and histopathological scores were also observed. The hUCBDSCs were continually detected in the target organs of GVHD. These results suggest that hUCBDSCs possess the capability of suppressing aGVHD, possibly via their influence on CD3 T cells, NK cells, and cytokines.

Serum Levels of Interleukin (IL)-10, IL-17, Transforming Growth Factor (TGF)-β1, and Interferon-γ Cytokines and Expression Levels of IL-10 and TGF-β1 Genes in Renal Allograft Recipients After Donor Bone Marrow Cell Infusion

Background Cytokine storm generated by an alloimmune response after transplantation can lead to either graft survival or rejection. The aim of this study was to evaluate the serum levels of interleukin (IL)-10, IL-17, transforming growth factor (TGF)-β1, and interferon (IFN)-γ and expression levels of IL-10 and TGF-β1 in renal allograft recipients with or without donor bone marrow cell infusion (DBMI). Methods We retrospectively followed 28 living unrelated kidney recipients, including 14 with and 14 without DBMI infusion for 2 years. Also, 14 healthy subjects were included as a normal control group. PBMC gene expression analysis for mRNA levels of IL-10 and TGF-β1 cytokines relative to β-actin as a reference gene was performed using quantitative fluorescence real-time polymerase chain reaction at the end of 2 years posttransplantation. Also, serum levels of IL-10, TGF-β1, IFN-γ, and IL-17 in the 3 groups were measured by enzyme-linked immunosorbent assay at the same time. Results Both patient groups showed increased gene expression and serum content of IL-10 compared with normal controls. The expression levels were only significant between control patients and normal subjects ( P = .02). Serum levels of IFN-γ and IL-17 were higher in untreated patients compared with normal controls ( P = .03 and P = .07, respectively). DBMI patients showed significantly lower levels of serum TGF-β1 and IL-17 compared with normal subjects ( P = .05 and P = .06, respectively). Also, infused patients showed a positive correlation between circulating levels of IL-17 and IL-10 ( r = 0.692; P = .006), and an inverse correlation between serum creatinine and TGF-β1 levels ( r = −0.580; P = .03). Conclusion The decreased levels of inflammatory cytokines besides IL-10 with increased TGF-β1 levels and better allograft function with improved clinical outcomes were observed among infused patients, possibly indicating immunomodulatory effects of this approach in kidney allograft patients.

Human umbilical cord blood-derived stromal cells prevent graft-versus-host disease in mice following haplo-identical stem cell transplantation

Human umbilical cord blood-derived stromal cells (hUCBDSC) comprise a novel population of CD34(+) cells that has been isolated in our laboratory. They have been shown previously not only to be non-immunogenic but also to exert immunosuppressive effects on xenogenic T cells in vitro. This study investigated the role of hUCBDSC in immunomodulation in an acute graft-versus-host disease (GvHD) mouse model after haplo-identical stem cell transplantation. Acute GvHD was induced in recipient (B6 × BALB/c)F(1) mice by irradiation (750 cGy) followed by infusion of bone marrow cells and splenocytes from donor C57BL/6 mice. hUCBDSC were co-transplanted in the experimental group. The survival time, body weight and clinical and histopathologic scores were recorded after transplantation. The expression of surface markers [major histocompatibility complex (MHC) I, MHC II, CD80 and CD86] on CD11c(+) dendritic cells (DC), and the percentage of CD4(+) regulatory T cells (Treg), in the spleens of recipient mice were examined by flow cytometry. The survival time was significantly prolonged, and the clinical and histopathologic scores were reduced in mice co-transplanted with hUCBDSC. The expression levels of the surface markers on DC were significantly lower in mice transplanted with hUCBDSC compared with those without. The proportion of CD4(+) Treg in the spleen was also increased in mice transplanted with hUCBDSC. These results from a GvHD mouse model are in agreement with previous in vitro findings, suggesting that hUCBDSC possess immunosuppressive properties and may act via influencing DC and CD4(+) Treg.

Novel Findings for the Development of Drug Therapy for Various Liver Diseases: Current State and Future Prospects for Our Liver Regeneration Therapy Using Autologous Bone Marrow Cells for Decompensated Liver Cirrhosis Patients

We have developed an in vivo mouse model [the green fluorescent protein (GFP) / carbon tetrachloride (CCl4) model] and reported that infused GFP-positive bone marrow cells administered via a tail vein efficiently repopulated cirrhotic liver tissue under conditions of persistent liver damage induced by CCl4. Moreover, bone marrow cells infused into the liver improved liver function and ameliorated liver fibrosis with higher expression of matrix metalloproteinase 9 (MMP-9), consistent with improved survival rate. Based on these findings, we started a multicenter clinical trial of autologous bone marrow cell infusion (ABMi) therapy for decompensated liver cirrhosis patients and demonstrated the efficacy of this approach without unexpected complications. However, this therapy involves bone marrow aspiration under general anesthesia and is not indicated for patients for whom general anesthesia is difficult. We therefore aimed to develop a new liver regeneration therapy in which cells having a curative effect on liver cirrhosis are isolated and cultured from a small amount of autologous bone marrow aspirated under local anesthesia and infused back into the same subject. Herein, we present results for the GFP/CCl4 model and ABMi therapy and future prospects for a new liver regeneration therapy.

Intracoronary autologous mononucleated bone marrow cell infusion for acute myocardial infarction: results of the randomized multicenter BONAMI trial

Intracoronary administration of autologous bone marrow cells (BMCs) leads to a modest improvement in cardiac function, but the effect on myocardial viability is unknown. The aim of this randomized multicentre study was to evaluate the effect of BMC therapy on myocardial viability in patients with decreased left ventricular ejection fraction (LVEF) after acute myocardial infarction (AMI) and to identify predictive factors for improvement of myocardial viability. One hundred and one patients with AMI and successful reperfusion, LVEF ≤45%, and decreased myocardial viability (resting Tl201-SPECT) were randomized to either a control group (n = 49) or a BMC group (n = 52). Primary endpoint was improvement of myocardial viability 3 months after AMI. Baseline mean LVEF measured by radionuclide angiography was 36.3 ± 6.9%. Bone marrow cell infusion was performed 9.3 ± 1.7 days after AMI. Myocardial viability improved in 16/47 (34%) patients in the BMC group compared with 7/43 (16%) in the control group (P = 0.06). The number of non-viable segments becoming viable was 0.8 ± 1.1 in the control group and 1.2 ± 1.5 in the BMC group (P = 0.13). Multivariate analysis including major post-AMI prognostic factors showed a significant improvement of myocardial viability in BMC vs. control group (P = 0.03). Moreover, a significant adverse role for active smoking (P = 0.04) and a positive trend for microvascular obstruction (P = 0.07) were observed. Intracoronary autologous BMC administration to patients with decreased LVEF after AMI was associated with improvement of myocardial viability in multivariate-but not in univariate-analysis. A large multicentre international trial is warranted to further document the efficacy of cardiac cell therapy and better define a group of patients that will benefit from this therapy. URL: http://www.clinicaltrials.gov. Unique identifier NCT00200707.

Review Article: Current Status of Myocardial Regeneration: New Cell Sources and New Strategies

Clinical trials of stem cell therapy in cardiology are based upon a reasonably solid foundation in animal laboratory research. The most widely used cell source in clinical trials has been the patient's own reconstituted bone marrow cell (BMC) aspirate. Cell sources in human bone marrow include hematopoietic stem cells, mesenchymal progenitor cells, and other cell types with many desirable characteristics. In vitro, they can be induced to become typical sarcomeres with centrally positioned nuclei and abundant mitochondria and to express atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and contractile proteins including myosin heavy chain, myosin light chain, and alpha actin. Intracoronary BMC infusion significantly decreases infarct size, increases myocardial perfusion, and improves regional and global cardiac function. Meta-analyses of clinical trials of intracoronary autologous BMC infusion following acute myocardial infarction (MI) report that the mean absolute increase in ejection fraction (EF) is approximately 3% to 4%. This modest improvement in function appears to persist for 1 year. Some trials have shown that clinical events are reduced at 12 months, but others have reported no long-term clinical benefit, and the only 5-year follow-up suggests persistent benefit with decreased mortality, but also little evidence of significant myocardial regeneration in humans. These results have led to efforts to identify better cell sources and to create more conducive myocardial environment for cell proliferation. Among the cell types are skeletal myoblasts, cardiac stem cells, and induced pluripotent stem cells. Environmental modifiers are designed to increase cell survival, persistence, and proliferation.

Infusion of Lin − bone marrow cells results in multilineage macrochimerism and skin allograft tolerance in minimally conditioned recipient mice

Donor-specific immunological tolerance using high doses of donor bone marrow cells (BMC) has been demonstrated in mixed chimerism-based tolerance induction protocols; however, the development of graft versus host disease (GVHD) remains a risk. In the present study, we demonstrate that the infusion of low numbers of donor Lin − bone marrow cells (Lin − BMC) 7 days post allograft transplantation facilitates high level macrochimerism induction and graft tolerance. Full-thickness BALB/c skin allografts were transplanted onto C57BL/6 mice. Mice were treated with anti-CD4 and anti-CD8 mAbs on day 0, + 2, +5, +7 and +14 along with low dose busulfan on day + 5. A low dose of highly purified Lin − BMC from BALB/c donor mice was infused on day + 7. Chimerism and clonal cell deletion were evaluated using flow cytometry. Donor-specific tolerance was tested by donor and third-party skin grafting and mixed leukocyte reaction (MLR). Lin − BMC infusion with minimal immunosuppression led to stable, mixed, multilineage macrochimerism and long-term allograft survival (> 300 days). Mixed donor-recipient macrochimerism was observed. Donor-reactive T cells were clonally deleted and a 130% increase in CD4 +CD25 +Foxp3 + regulatory T cells (Tregs) was observed in the spleen. Tolerant mice subsequently accepted second donor, but not third-party (C3H), skin grafts and recipient splenocytes failed to react with allogeneic donor cells indicating donor-specific immunological tolerance was achieved. We conclude that the infusion of donor Lin − BMC without cytoreductive recipient conditioning can induce indefinite survival of skin allografts via mechanisms involving the establishment of a multilineage macrochimeric state principally through clonal deletion of alloreactive T cells and peripherally induced CD4 +Foxp3 + Tregs.

Autologous Bone Marrow Infusion Activates the Progenitor Cell Compartment in Patients with Advanced Liver Cirrhosis

Several clinical trials of bone marrow cell infusion in patients with liver cirrhosis (LC) have shown clinical improvement, despite conflicting results from animal models. We investigated serial pathological features and the clinical impact after autologous bone marrow infusion (ABMI) in patients with advanced LC. Ten patients with advanced LC due to chronic hepatitis B virus infection underwent ABMI. Serological tests, MRI, and liver biopsies were performed, and quality of life was assessed by a questionnaire. Median serum albumin and hemoglobin levels increased significantly after ABMI. All patients showed an improvement in quality of life, with no serious adverse events. Liver volume, measured by MRI, increased in 80% of the patients, and ascites decreased after ABMI. Child-Pugh scores were also significantly improved at 6 months after ABMI. In the serially biopsied livers, a gradually increasing activation of the hepatic progenitor cell (HPC) compartment, including HPC activation (ductular reaction) and HPC differentiation (intermediate hepatocyte), reached a peak after 3 months, with continued proliferation of hepatocytes, and returned to baseline levels after 6 months. There was no significant change in grade or stage of liver fibrosis or stellate cell activation after ABMI. ABMI is suggested to improve liver function and to activate the progenitor cell compartment. Although clinical improvement was sustained for more than 6 months, histological changes in the liver returned to baseline 6 months after ABMI. Further comparative studies are warranted.