Potential Leukemic Cells Engraftment After Hematopoietic Stem Cell Transplantation From Unrelated Donors With Undiagnosed Chronic Leukemia.

BACKGROUND: Donor-related neoplasms are a potential complication of treatment strategies involving stem cell transplantation. Although mechanisms for detection of short-term complications after these procedures are well developed, complications with delayed onset, notably transmission of chronic diseases such as chronic myeloid leukemia (CML), have been difficult to assess. Consequently, we studied the potential of human CML cells to engraft hematopoietic tissues after intravenous implantation in mice. METHODS: Human peripheral blood cells, collected from CML patients presenting with moderately increased white blood cells count before treatment, were transplanted into sub-lethally irradiated, immunodeficient mice. Five weeks after transplantation the nuclear cells were isolated from the murine bone marrow, spleen, and peripheral blood and were used to quantitatively detect human CD45 antigen by flow cytometry; qRT-PCR was used to detect the BCR-ABL1 fusion gene, and the human or murine beta-glucuronidase housekeeping gene was used to examine human-murine chimerism. RESULTS: We found that all evaluated animals had donor chimerism at the selected interval after transplant and the presence of a specific BCR-ABL1 fusion gene transcript was also detected. CONCLUSIONS: Our results suggest that the risk of neoplasm transmission cannot be eliminated during hematopoietic stem cell transplantation from undiagnosed CML donors with borderline leukocytosis. The obtained data confirms the potential of leukemic cells to viably engraft the hematopoietic organs post-transplantation in an immunosuppressed recipient.

Morphologic Changes in the Dermis After the Single Administration of Autologous Fibroblastic Cells: A Preliminary Study.

BACKGROUND: Aging is a multifactorial process defined by an accumulation of damage in all tissues and organs, including the skin, throughout the lifespan of an individual. The reduction of both cellular and extracellular matrix components of the dermis during the aging process is followed by the alteration of the morphology of the skin tissue. This study was conducted to assess skin morphology in men before and 3 months after the intradermal injection of autologous fibroblastic cells. METHODS: Tissue biopsies were surgically obtained before and 3 months after the treatment with autogenously harvested fibroblasts expanded in vitro, as well as after injection of phosphate-buffered saline. The thickness of collagen fiber bundles and number of fibroblasts in the dermis were analyzed in morphometric studies. The morphologic evaluation, using different methods of staining has been performed to analyze of extracellular matrix proteins, including collagen and reticular fibers, fibrillin-1-rich microfibrils, elastic fibers, and hyaluronic acid. RESULTS: After administration of the cells, we found a noticeable increase in the number of fibroblasts within the dermis, a significant enlargement in diameter of the collagen fiber bundles, and an improvement in the density of reticular fibers, fibrillin-1-rich microfibrils, and elastic fibers compared with the initial, steady-state condition. CONCLUSIONS: The administration of autogenous fibroblasts could be an effective and safe adjunctive therapy to conventional health care treatment to prevent and reduce the age-related accumulation of dermal tissue damage.

Effects of growth hormone therapeutic supplementation on hematopoietic stem/progenitor cells in children with growth hormone deficiency: focus on proliferation and differentiation capabilities.

We investigated the direct effects of growth hormone (GH) replacement therapy (GH-RT) on hematopoiesis in children with GH deficiency (GHD) with the special emphasis on proliferation and cell cycle regulation. Peripheral blood (PB) was collected from sixty control individuals and forty GHD children before GH-RT and in 3rd and 6th month of GH-RT to measure hematological parameters and isolate CD34(+)-enriched hematopoietic progenitor cells (HPCs). Selected parameters of PB were analyzed by hematological analyzer. Moreover, collected HPCs were used to analyze GH receptor (GHR) and IGF1 expression, clonogenicity, and cell cycle activity. Finally, global gene expression profile of collected HPCs was analyzed using genome-wide RNA microarrays. GHD resulted in a decrease in several hematological parameters related to RBCs and significantly diminished clonogenicity of erythroid progenies. In contrast, GH-RT stimulated increases in clonogenic growth of erythroid lineage and RBC counts as well as significant up-regulation of cell cycle-propagating genes, including MAP2K1, cyclins D1/E1, PCNA, and IGF1. Likewise, GH-RT significantly modified GHR expression in isolated HPCs and augmented systemic IGF1 levels. Global gene expression analysis revealed significantly higher expression of genes associated with cell cycle, proliferation, and differentiation in HPCs from GH-treated subjects. (i) GH-RT significantly augments cell cycle progression in HPCs and increases clonogenicity of erythroid progenitors; (ii) GHR expression in HPCs is modulated by GH status; (iii) molecular mechanisms by which GH influences hematopoiesis might provide a basis for designing therapeutic interventions for hematological complications related to GHD.

Cells as vehicles for therapeutic genes to treat liver diseases.

Gene therapy involves the transfer of genetic sequences to tissues to obtain a curative effect. Effective gene transfer can be achieved by introducing the therapeutic gene into virus-like particles that facilitate the penetration of the transgene into the cells. However, direct injection of viral vectors may activate innate immunity leading to toxic effects. On the other hand, viral vectors frequently induce neutralizing antibodies, which limit the efficacy of repeated vector administration. Moreover, targeting of the transgene to the desired tissue is a goal that not always can be attained with current vectors. The use of cells as vehicles for therapeutic genes may offer solutions for these issues. Ex vivo transduction of specific cells with vectors encoding therapeutic genes followed by injection of the engineered cells to the patient will reduce the inherent toxicity of the vector while preventing the development of neutralizing antibodies. At the same time, this therapeutic approach can take advantage of the homing properties of the transduced cells to target transgene expression to the sites of interest. Thus, it has been shown that administration of dendritic cells engineered ex vivo with vectors encoding selected antigenic determinants or immunostimulatory molecules is an efficient means to elicit protective immune responses. Similarly, since endothelial progenitor cells (EPC) move to inflammed, ischemic or neoplastic tissues, the injection of EPC transduced ex vivo with appropriate therapeutic genes is an effective method to direct transgene expression to the lesions to be treated. Promising data in animal models of disease point to a future clinical application of this therapeutic strategy.