The infusion of human fetal liver cells

Cadaveric Stem Cells: Their Research Potential and Limitations

In the era of growing interest in stem cells, the availability of donors for transplantation has become a problem. The isolation of embryonic and fetal cells raises ethical controversies, and the number of adult donors is deficient. Stem cells isolated from deceased donors, known as cadaveric stem cells (CaSCs), may alleviate this problem. So far, it was possible to isolate from deceased donors mesenchymal stem cells (MSCs), adipose delivered stem cells (ADSCs), neural stem cells (NSCs), retinal progenitor cells (RPCs), induced pluripotent stem cells (iPSCs), and hematopoietic stem cells (HSCs). Recent studies have shown that it is possible to collect and use CaSCs from cadavers, even these with an extended postmortem interval (PMI) provided proper storage conditions (like cadaver heparinization or liquid nitrogen storage) are maintained. The presented review summarizes the latest research on CaSCs and their current therapeutic applications. It describes the developments in thanatotranscriptome and scaffolding for cadaver cells, summarizes their potential applications in regenerative medicine, and lists their limitations, such as donor’s unknown medical condition in criminal cases, limited differentiation potential, higher risk of carcinogenesis, or changing DNA quality. Finally, the review underlines the need to develop procedures determining the safe CaSCs harvesting and use.

Study of Peripheral Mononuclear Cells and CD34 Levels as a Predictive Marker for Initiating Apheresis in Autologous Stem Cell Transplant

Background: Autologous HCT in multiple myeloma is done as upfront treatment in newly diagnosed transplant eligible patients after induction chemotherapy. In addition, it is standard for relapsed, aggressive non-Hodgkin lymphoma (NHL) and classical Hodgkin lymphoma (HL), and is curative in ~40% to 45% of patients. Over a decade, many efforts were made to find helpful parameters to predict an optimal time for initiating an efficient peripheral blood stem cell collection so that adequate stem cells are collected.  It has been well accepted that CD34+ cell count in peripheral blood before leukapheresis is the best parameter to predict CD34 cell yield. However, white blood cell count, mononuclear cell count, and other easily obtained parameters are still used to guide the clinical practice of peripheral blood stem cell mobilization and collection. 

Materials and Methods: In the present study, we analyzed the correlation between peripheral blood MNC and Apheresis CD34 levels and also between peripheral blood CD34 by flow cytometry and apheresis CD34 levels.

Results: We found that there was a statistically insignificant weak correlation between peripheral MNC and apheresis CD34. There was a statistically significant strong correlation between peripheral CD34 and apheresis CD34.

Conclusion: The results show that peripheral blood MNC was analogous indicating that no reliable prediction can be done for CD34 cells collected in apheresis while peripheral CD34 by flow cytometry is the strongest predictor for initiating stem cell collection.

Sources of Human Hematopoietic Stem Cells for Transplantation–A Review

Transplantation of hematopoietic stem cells provides a means of replacing a defective hematopoietic system in patients with a wide range of malignant and nonmalignant disorders that affect the blood forming tissue. The same procedure has also allowed dose-escalation of standard chemotherapy and radiotherapy in the treatment of malignant disease of nonhematological origin. Until recently, bone marrow has been the sole source of hematopoietic stem cells, but limitations of conventional bone marrow transplantation have stimulated a search for alternative sources and uses of stem cells. Fetal tissues (especially liver) are a recognized source of transplantable stem cells and offer the great advantage of reduced immunogenicity, potentially removing the problems of tissue type matching. Umbilical cord blood is also a rich source of stem cells and, although it contains alloreactive cells, it is readily available without special ethical constraints. Both fetal tissue and cord blood suffer the disadvantages of limited numbers of stem cells per donation, and there is much interest in the development of technologies for the safe and reliable expansion and/or pooling of stem and progenitor cells. The observation that small numbers of stem cells are found in the peripheral blood of adults has led to the exploitation of the blood as a further source of stem cells. The ability to mobilize these cells from the medullary compartment into the periphery by the use of chemotherapy and/or recombinant hematopoietic growth factors has enabled the collection of sufficient numbers of cells for transplantation purposes. All of these advances are increasing the options and the range of choices available to clinicians and patients in the arena of hematopoietic stem cell transplantation.

Peripheral blood stem cell versus bone marrow allotransplantation: does the source of hematopoietic stem cells matter?

Hematopoietic stem cells from 4 different sources have been or are being used for the reconstitution of lymphohematopoietic function after myeloablative, near-myeloablative, or nonmyeloablative treatment. Bone marrow (BM)-derived stem cells, introduced by E. D. Thomas in 1963, are considered the classical stem cell source. Fetal liver stem cell transplantation has been performed on a limited number of patients with aplastic anemia or acute leukemia, but only transient engraftment has been demonstrated. Peripheral blood as a stem cell source was introduced in 1981, and cord blood was introduced as a source in 1988. The various stem cell sources differ in their reconstitutive and immunogenic characteristics, which are based on the proportion of early pluripotent and self-renewing stem cells to lineage-committed late progenitor cells and on the number and characteristics of accompanying "accessory cells" contained in stem cell allografts.

An efficient method for the cryopreservation of fetal human liver hematopoeitic progenitor cells

The use of human hematopoietic progenitor cells (HPC) for transplantation requires efficient recovery methods and cryopreservation procedures. The purpose of this study was to determine cryopreservation techniques for fetal human liver (FHL) CD34(+) cells. We assessed FHL HPC recovery efficiency after freezing and thawing by viability testing, fluorescence-activated cell sorting analysis, and colony-forming ability under different conditions. We also determined optimal cell freezing concentrations and the effect of rate-controlled freezing on cell recovery. Lastly, cell recovery after varying freezing time periods was examined. Our results indicated that optimal cell recovery occurs when: A) cryopreservation medium consists of either 5% dimethylsulphoxide (DMSO) or 10% DMSO in combination with either 20% fetal bovine serum (FBS) or 70% FBS and when Iscove's modified Dulbecco's medium consists of not more than 10% DMSO; B) a rate-controlled freezing device container is used; C) CD34(+) cells are frozen at a concentration of 1 x 10(6)/ml, and D) a thawing temperature of 37 degrees C is used. These observations indicate that cryopreservation of FHL HPC is possible for up to 18 months in optimal conditions without losing hematopoietic activity.

Stimulation of adult human bone marrow by factors secreted by fetal liver hematopoietic cells: in vitro evaluation using semisolid clonal assay system

Fetal liver infusion (FLI) therapy has been used in various disorders, such as aplastic anemia, leukemia, metabolic disorders, etc., and has been shown to result in stimulation of autologous hematopoiesis in many cases. The aim of the present study was to elucidate the mechanism of stimulation of adult hematopoiesis by fetal liver hematopoietic cells (FLHC) and to identify the factors involved in the process using a clonal assay system in vitro. The effect of FLHC on the clonal growth of bone marrow cells was studied using a co-culture system consisting of mitomycin C-treated FLHC with 2 x 10(5) bone marrow (BM) mononuclear cells. It was observed that FLHC induced a two- to four-fold increase in the BM colony formation. A further increase in the number of FLHC did not, however, result in an equivalent fold increase in the colony formation, indicating that the number of cells in the BM population responsive to FLHC was perhaps the limiting factor. When the effect of fetal liver cell conditioned medium (FLCM) was examined in a similar fashion, it was observed that the FLCM showed a 1.5- to 4-fold increase in the colony formation when used at 1%-5% along with limiting amounts of growth factors. Higher concentrations of conditioned medium resulted in inhibitory responses. One of the principal factors responsible for the stimulatory activity of FLCM was shown to be transforming growth factor-beta1 (TGF-beta1), by a variety of experiments such as its quantitation in FLCM by enzyme-linked immunosorbent assay, antibody neutralization, and reconstruction experiments using purified TGF-beta1 and normal medium. In these reconstitution experiments, TGF-beta1 stimulated the colony formation when it was applied at 1-50 pg/ml, but at higher concentration it induced an inhibitory effect, mimicking the behavior earlier seen with FLCM. Our data strongly suggest that one of the mechanisms in stimulation of a recipient's hematopoiesis could be mediated by the action of TGF-beta1 secreted by infused FLHC and could provide a rational framework on which FLI therapy can be further evaluated.

Alternative sources of hematopoietic stem cells for bone marrow transplantation and rescue

Hematopoietic stem cells from sources other than medullary bone marrow are being used for experimental and clinical rescue following myeloablative therapy. In this paper we review the cells capable of bone marrow engraftment and the use of orthotopic, cadaveric, peripheral blood, umbilical cord blood, and fetal liver derived stem cells in transplantation.