Differentiated Cells Derived from Hematopoietic Stem Cells and Their Applications in Translational Medicine.

Hematopoietic stem cells (HSCs) and their development are one of the most widely studied model systems in mammals. In adults, HSCs are predominantly found in the bone marrow, from where they maintain homeostasis. Besides bone marrow and mobilized peripheral blood, cord blood is also being used as an alternate allogenic source of transplantable HSCs. HSCs from both autologous and allogenic sources are being applied for the treatment of various conditions like blood cancers, anemia, etc. HSCs can further differentiate to mature blood cells. Differentiation process of HSCs is being extensively studied so as to obtain a large number of pure populations of various differentiated cells in vitro so that they can be taken up for clinical trials. The ability to generate sufficient quantity of clinical-grade specialized blood cells in vitro would take the field of hematology a step ahead in translational medicine.

Establishment of human iPSC line from patient of Indian ethnicity carrying homozygous CD8/9 (+G) beta thalassemia mutation.

This study shows generation of iPSCs from peripheral blood mononuclear cells (PBMNCs) of a male patient having homozygous CD 8/9 (+G) beta thalassemia (major) mutation. Cells were nucleofected with episomal vectors containing Oct4, Sox2, L-Myc, Lin28, Klf4 and p53DD (dominant negative p53 mutation). Cell line exhibited presence of pluripotency markers by immunofluorescence, flow-cytometry and PCR. The plasmids were lost from cells by subsequent passages, observed by PCR. Karyotype analysis demonstrated a stable genome. The cells had capability to differentiate into three-germ lineages in vitro. This iPSC line can be used as a tool for drug design and gene therapy studies.

Catalase incorporation in freezing mixture leads to improved recovery of cryopreserved iPSC lines.

Among the various types of stem cells, induced pluripotent stem cells (iPSCs) have gained much attention due to their pluripotent nature. iPSCs help us to understand the processes that regulate pluripotency and specialization. However, in order to use them in various applications in regenerative medicine, their efficient cryopreservation and recovery after the freezing injury is critical. Here we have used an antioxidant catalase, as an additive to the conventional freezing mixture containing 50% FBS and 10% DMSO. The hiPSCs were frozen as aggregates by using a programmable freezer and then stored in liquid nitrogen at -196 °C. It was seen that catalase improved the revival efficiency by reducing the late apoptotic populations and increasing the live cell fraction. Catalase also retained the pluripotent nature of iPSCs in a better way post revival. This improvement could be attributed to reduction of total ROS and apoptosis, which are the two main factors that cause damage during freezing. Our data suggest that catalase could be a useful additive while freezing hiPSCs.

Improved neural differentiation of normal and abnormal induced pluripotent stem cell lines in the presence of valproic acid.

During the generation of induced pluripotent stem cell (iPSC) lines from cord blood CD34+ cells, a line having complete trisomy of Chromosome 1 and deletion of q23 to qTer of Chromosome 11 was accidentally developed in our lab. The abnormality was consistently detected even at higher passages. These chromosomal anomalies are known to manifest neurological developmental defects. In order to examine if such defects occur during in vitro differentiation of the cell line, we set up a protocol for neural differentiation. Valproic acid (VPA) was earlier reported by us to enhance neural differentiation of placental mesenchymal stem cells. Here, we induced normal and abnormal iPSC lines to neural lineage with/without VPA. Neural differentiation was observed in all four sets, but for both the iPSCs lines, VPA sets performed better. The characteristics tested were morphology, neural filament length, detection of neural markers, and electrophysiology. In summary, the karyotypically abnormal line exhibited efficient neural differentiation. This iPSC line may serve as a useful tool to study abnormalities associated with trisomy 1 and deletion of q23 to qTer of Chromosome 11.

Development and characterization of human iPSC line NCCSi004-A from umbilical cord blood (UCB) derived CD34+cells obtained from donor belonging to Indian ethnic population.

Here we report the reprogramming of CD34+ cells obtained from UCB of a healthy donor female child belonging to the Indian ethnic population. These CD34+cells were subjected to nucleofection for delivery of episomal vectors expressing Oct4, Sox2, L-Myc, Lin28, Klf4 and p53DD (negative mutation in p53). The iPSC colonies expressed pluripotency markers as detected by PCR, immunofluorescence and flow-cytometry. The removal of plasmid was confirmed by its absence in cells at higher passages. Karyotype analysis revealed a stable genome. The property of in vitro differentiation to tri-lineage was confirmed by expression of markers by immunofluorescence.

Compromised functionality of monocyte-derived dendritic cells in multiple myeloma patients may limit their use in cancer immunotherapy.

Dendritic cells (DCs) have the potential to elicit long-lasting anti-tumour immune responses. Most of the clinical trials of anti-cancer DC vaccines are based on monocyte-derived DCs (Mo-DCs). However, their outcomes have shown limited promise especially in multiple myeloma (MM) patients. Here, we investigated whether in vitro generated Mo-DCs from MM patients (MM-DCs) possess impaired functionality, thus contributing to the limited success of DC vaccines. We generated MM-DCs and compared them with DCs from healthy donors (HD-DCs). The yield of DCs in MM was 3.5 fold lower than in HD sets. However morphology, phenotype, antigen uptake and allo-T cell stimulation were comparable. Migration and secretion of IL12p70 and IFN-γ (in DC-T cell co-cultures) were significantly reduced in MM-DCs. Thus, MM-DCs were compromised in functionality. This impairment could be attributed to autocrine secretion of IL6 by MM-monocytes and activation of their P38 MAPK pathway. This indicates a need to look for alternative sources of DCs.

Derivation of human iPSC line NCCSi002-A from umbilical cord blood (UCB) CD34+cells of donor from Indian ethnicity.

We discuss the reprogramming of CD34+ cells isolated from UCB of a healthy female child of Indian ethnicity. The CD34+cells were nucleofected using episomal vectors expressing Oct4, Sox2, L-Myc, Klf4, Lin28 and p53DD (negative mutation in p53). The colonies were stained for alkaline phosphatase and evaluated for pluripotency marker expression by PCR, immunofluorescence and flow-cytometry. The safety of cells was confirmed by absence of plasmid in subsequent passages by PCR. G-banded karyotype demonstrated a stable genome. The ability of tri-lineage differentiation was confirmed by specific marker expression by immunofluorescence invitro and teratoma formation invivo.

Establishment of human iPSC line NCCSi003-A from CD34+cells of peripheral blood collected during apheresis of healthy donor from Indian ethnicity.

We present generation of iPSCs from CD34+ cells isolated from peripheral blood, collected during apheresis of a healthy female individual. We nucleofected the CD34+cells by episomal vectors containing Oct4, Sox2, L-Myc, Lin28, Klf4 and p53DD (dominant negative mutation in p53). The resultant colonies showed cobble-stone appearance and stained positive for alkaline phosphatase. The colonies demonstrated presence of pluripotency markers by immunofluorescence, flow-cytometry and PCR. The plasmids were lost from cells subsequently during passages as assessed by PCR. Karyotype analysis demonstrated a stable genome. The cells had capability to differentiate to cells from all three-germ lineages in vitro.

Generation and characterization of human iPSC line from CD34+ cells isolated from umbilical cord blood belonging to Indian origin.

We describe here the reprogramming of CD34+ cells isolated from umbilical cord blood obtained after full term delivery of a healthy female child of Indian origin. The cells were nucleofected by episomal vectors expressing Oct4, Sox2, L-Myc, Klf4, Lin28 and p53DD (negative mutation in p53). Colonies were identified by alkaline phosphatase staining and characterized for expression of pluripotency markers at protein level by immunofluorescence, flow cytometry and at transcript level by PCR. Genomic stability of the cell line was checked by G-banded karyotype. The ability to differentiate to endoderm, mesoderm and ectoderm in vitro was confirmed by immunofluorescence staining.

Valproic acid enhances the neural differentiation of human placenta derived-mesenchymal stem cells in vitro.

Mesenchymal stem cells (MSCs) are known to express a wide range of markers belonging to all the three lineages: mesodermal, ectodermal and endodermal. Therefore, the possibility of their transdifferentiation towards a neural lineage has been an aspect of active research. In the present study, MSCs were isolated from human placental tissue (P-MSC) and subjected them to neural differentiation. It was found that the P-MSCs differentiated towards neural lineage in appropriate differentiation conditions. However, when a histone deacetylase (HDAC) inhibitor - valproic acid (VPA) - was incorporated in the medium, there was a further increase in their neural differentiation potential. The increase in the number of neurites and neural lineage specific markers was notable. The VPA-treated cells showed a significantly elevated membrane potential compared with the cells grown in only differentiation medium. When the molecular mechanism was studied, the enhancement in the neuronal lineage specification was caused by the inhibition of bone morphogenetic protein (BMP) 2 and an increase in BMP4 under both conditions. The target of VPA (HDAC2) was reduced in the VPA set, whereas HDAC1 remained unchanged. Concurrent reduction in the levels of Stat3 was observed, leading to an upregulation of ßIII tubulin, which is a neuronal lineage-specific marker. The components of Notch signalling (i.e. decreased notch 1 and increased notch 3) also supported differentiation towards the neuronal lineage. Thus, the VPA treated P-MSCs can serve as an alternative source for deriving neural cells for use in both research and in clinics. Copyright © 2016 John Wiley & Sons, Ltd.