Background-Experimental data suggest that bone marrow-derived cells may contribute to the healing of myocardial infarction (MI). For this reason, we analyzed 10 patients who were treated by intracoronary transplantation of autologous, mononuclear bone marrow cells (BMCs) in addition to standard therapy after MI. Methods and Results-After standard therapy for acute MI, 10 patients were transplanted with autologous mononuclear BMCs via a balloon catheter placed into the infarct-related artery during balloon dilatation (percutaneous transluminal coronary angioplasty). Another 10 patients with acute MI were treated by standard therapy alone. After 3 months of follow-up, the infarct region (determined by left ventriculography) had decreased significantly within the cell therapy group (from 30Ϯ13 to 12Ϯ7%, Pϭ0.005) and was also significantly smaller compared with the standard therapy group (Pϭ0.04). Likewise, infarction wall movement velocity increased significantly only in the cell therapy group (from 2.0Ϯ1.1 to 4.0Ϯ2.6 cm/s, Pϭ0.028). Further cardiac examinations (dobutamine stress echocardiography, radionuclide ventriculography, and catheterization of the right heart) were performed for the cell therapy group and showed significant improvement in stroke volume index, left ventricular end-systolic volume and contractility (ratio of systolic pressure and end-systolic volume), and myocardial perfusion of the infarct region. Conclusions-These results demonstrate for the first time that selective intracoronary transplantation of autologous, mononuclear BMCs is safe and seems to be effective under clinical conditions. The marked therapeutic effect may be attributed to BMC-associated myocardial regeneration and neovascularization.

Here a new, intrinsically pluripotent, CD45-negative population from human cord blood, termed unrestricted somatic stem cells (USSCs) is described. This rare population grows adherently and can be expanded to 1015 cells without losing pluripotency. In vitro USSCs showed homogeneous differentiation into osteoblasts, chondroblasts, adipocytes, and hematopoietic and neural cells including astrocytes and neurons that express neurofilament, sodium channel protein, and various neurotransmitter phenotypes. Stereotactic implantation of USSCs into intact adult rat brain revealed that human Tau-positive cells persisted for up to 3 mo and showed migratory activity and a typical neuron-like morphology. In vivo differentiation of USSCs along mesodermal and endodermal pathways was demonstrated in animal models. Bony reconstitution was observed after transplantation of USSC-loaded calcium phosphate cylinders in nude rat femurs. Chondrogenesis occurred after transplanting cell-loaded gelfoam sponges into nude mice. Transplantation of USSCs in a noninjury model, the preimmune fetal sheep, resulted in up to 5% human hematopoietic engraftment. More than 20% albumin-producing human parenchymal hepatic cells with absence of cell fusion and substantial numbers of human cardiomyocytes in both atria and ventricles of the sheep heart were detected many months after USSC transplantation. No tumor formation was observed in any of these animals.

Human multipotent mesenchymal stromal cells (MSCs) exhibit multilineage differentiation potential, support hematopoiesis, and inhibit proliferation and effector function of various immune cells. On the basis of these properties, MSC are currently under clinical investigation in a range of therapeutic applications including tissue repair and immune-mediated disorders such as graft-versus-host-disease refractory to pharmacological immunosuppression. Although initial clinical results appear promising, there are significant concerns that application of MSC might inadvertently suppress antimicrobial immunity with an increased risk of infection. We demonstrate here that on stimulation with inflammatory cytokines human MSC exhibit broad-spectrum antimicrobial effector function directed against a range of clinically relevant bacteria, protozoal parasites and viruses. Moreover, we identify the tryptophan catabolizing enzyme indoleamine 2,3-dioxygenase (IDO) as the underlying molecular mechanism. We furthermore delineate significant differences between human and murine MSC in that murine MSC fail to express IDO and inhibit bacterial growth. Conversely, only murine but not human MSC express inducible nitric oxide synthase on cytokine stimulation thus challenging the validity of murine in vivo models for the preclinical evaluation of human MSC. Collectively, our data identify human MSC as a cellular immunosuppressant that concurrently exhibits potent antimicrobial effector function thus encouraging their further evaluation in clinical trials.

These results demonstrate that functional and metabolic regeneration of infarcted and chronically avital tissue can be realized in humans by bone marrow mononuclear cell transplantation.

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BackgroundPrimary mesenchymal stem cells (MSCs) are fraught with aging-related shortfalls. Human-induced pluripotent stem cell (iPSC)-derived MSCs (iMSCs) have been shown to be a useful clinically relevant source of MSCs that circumvent these aging-associated drawbacks. To date, the extent of the retention of aging-hallmarks in iMSCs differentiated from iPSCs derived from elderly donors remains unclear.MethodsFetal femur-derived MSCs (fMSCs) and adult bone marrow MSCs (aMSCs) were isolated, corresponding iPSCs were generated, and iMSCs were differentiated from fMSC-iPSCs, from aMSC-iPSCs, and from human embryonic stem cells (ESCs) H1. In addition, typical MSC characterization such as cell surface marker expression, differentiation capacity, secretome profile, and trancriptome analysis were conducted for the three distinct iMSC preparations—fMSC-iMSCs, aMSC-iMSCs, and ESC-iMSCs. To verify these results, previously published data sets were used, and also, additional aMSCs and iMSCs were analyzed.ResultsfMSCs and aMSCs both express the typical MSC cell surface markers and can be differentiated into osteogenic, adipogenic, and chondrogenic lineages in vitro. However, the transcriptome analysis revealed overlapping and distinct gene expression patterns and showed that fMSCs express more genes in common with ESCs than with aMSCs. fMSC-iMSCs, aMSC-iMSCs, and ESC-iMSCs met the criteria set out for MSCs. Dendrogram analyses confirmed that the transcriptomes of all iMSCs clustered together with the parental MSCs and separated from the MSC-iPSCs and ESCs. iMSCs irrespective of donor age and cell type acquired a rejuvenation-associated gene signature, specifically, the expression of INHBE, DNMT3B, POU5F1P1, CDKN1C, and GCNT2 which are also expressed in pluripotent stem cells (iPSCs and ESC) but not in the parental aMSCs. iMSCs expressed more genes in common with fMSCs than with aMSCs. Independent real-time PCR comparing aMSCs, fMSCs, and iMSCs confirmed the differential expression of the rejuvenation (COX7A, EZA2, and TMEM119) and aging (CXADR and IGSF3) signatures. Importantly, in terms of regenerative medicine, iMSCs acquired a secretome (e.g., angiogenin, DKK-1, IL-8, PDGF-AA, osteopontin, SERPINE1, and VEGF) similar to that of fMSCs and aMSCs, thus highlighting their ability to act via paracrine signaling.ConclusionsiMSCs irrespective of donor age and cell source acquire a rejuvenation gene signature. The iMSC concept could allow circumventing the drawbacks associated with the use of adult MSCs und thus provide a promising tool for use in various clinical settings in the future.Electronic supplementary materialThe online version of this article (10.1186/s13287-019-1209-x) contains supplementary material, which is available to authorized users.

The CMRF-44 and CD83 (HB15) antigens are associated with functional maturation and activation of blood dendritic cells (DC). We describe the expression of these antigens on freshly isolated epidermal Langerhans cells and dermal DC as well as the distribution of CD83+/ CMRF-44++-activated DC within sections of normal human skin. Fresh Langerhans cells were prepared by standard techniques and large numbers of enriched (25%-55%), viable dermal DC were obtained using an improved collagenase treatment protocol with density gradient enrichment. Freshly isolated Langerhans cells and dermal DC had similar costimulator and activation antigen expression, and both stimulated moderate levels of allogeneic T lymphocyte proliferation as determined in the 7 d mixed leukocyte reaction. In situ labeling of DC within skin sections revealed a population of CD83 and CMRF-44 positive dermal cells of which most (approximately 75%) were in intimate contact with CD3+ T lymphocytes, especially in the adnexal regions. In contrast, only 25%-30% of the more numerous CD1a++ dermal DC population were directly apposed to T lymphocytes. The CMRF-44++ dermal DC population stimulated an allogeneic mixed leukocyte reaction, confirming their identity as DC. These data, plus comparative data obtained for migratory dermal DC, suggest that only a small proportion of dermal DC have been triggered to a more advanced state of differentiation or activation. The striking association of the activated dermal DC population with T lymphocytes suggests that communication between these two cell types in situ may occur early in the immune response to cutaneous antigen.

Immunotherapy of malignant diseases based on dendritic cells (DCs) pulsed with tumor antigens is a promising approach. Therefore, there is a demand for large-scale, clinical-grade ex vivo generation of DCs. Here, a procedure is presented that combines monocyte selection and tissue culture in closed systems under current good manufacturing practice conditions. Leukocytes from three patients with urologic cancers were collected by leukapheresis and subjected to immunomagnetic enrichment. From leukapheresis products containing 1.6 +/- 0.2 x 1010 (mean +/- SEM) leukocytes with a frequency of CD14+ monocytes of 18.7 +/- 2.3%, monocytes were enriched to 94.3 +/- 2.2%. CD14+ cell recovery was 67.0 +/- 4.7%. After 6 days of culture in Teflon bags in X-Vivo 15 medium supplemented with autologous plasma, GM-CSF, and IL-4, cells showed an immature DC phenotype and efficient antigen uptake. Following an additional 3 days of culture in the presence of GM-CSF, IL-4, IL-1beta, IL-6, TNFalpha, and PGE(2), cells (82.0 +/- 5.8% CD83+) displayed a mature DC morphology and phenotype, including expression of CD11b, CD11c, CD18, CD25, CD40, CD54, CD58, CD80, CD86, HLA class I, and HLA-DR as well as expression of CCR7 but not CCR5. The mature DC phenotype remained stable for at least 5 days in the absence of cytokines. Yield of DC was 14.0 +/- 4.7% and viability was 91.9 +/- 3.5%. Mature DCs effectively clustered with naive T cells and potently induced allogeneic T-cell proliferation and IL-2 and IFNgamma but not IL-4 production. Thus, this procedure allows large-scale generation of stably mature, Th1 responses inducing DCs under cGMP conditions in a closed system from cancer patients and is therefore well suited for immunotherapy.