Jan A Nolta

Publications (47)302.91 Total impact

• Article: Generation of an HIV-1-resistant immune system with CD34(+) hematopoietic stem cells transduced with a triple-combination anti-HIV lentiviral vector.

  Jon E Walker, Rachel X Chen, Jeannine McGee, Catherine Nacey, Richard B Pollard, Mehrdad Abedi, Gerhard Bauer, Jan A Nolta, Joseph S Anderson
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  ABSTRACT: HIV gene therapy has the potential to offer an alternative to the use of current small-molecule antiretroviral drugs as a treatment strategy for HIV-infected individuals. Therapies designed to administer HIV-resistant stem cells to an infected patient may also provide a functional cure, as observed in a bone marrow transplant performed with hematopoietic stem cells (HSCs) homozygous for the CCR5-Δ32-bp allele. In our current studies, preclinical evaluation of a combination anti-HIV lentiviral vector was performed, in vivo, in humanized NOD-RAG1(-/-) IL2rγ(-/-) knockout mice. This combination vector, which displays strong preintegration inhibition of HIV-1 infection in vitro, contains a human/rhesus macaque TRIM5α isoform, a CCR5 short hairpin RNA (shRNA), and a TAR decoy. Multilineage hematopoiesis from anti-HIV lentiviral vector-transduced human CD34(+) HSCs was observed in the peripheral blood and in various lymphoid organs, including the thymus, spleen, and bone marrow, of engrafted mice. Anti-HIV vector-transduced CD34(+) cells displayed normal development of immune cells, including T cells, B cells, and macrophages. The anti-HIV vector-transduced cells also displayed knockdown of cell surface CCR5 due to the expression of the CCR5 shRNA. After in vivo challenge with either an R5-tropic BaL-1 or X4-tropic NL4-3 strain of HIV-1, maintenance of human CD4(+) cell levels and a selective survival advantage of anti-HIV gene-modified cells were observed in engrafted mice. The data provided from our study confirm the safety and efficacy of this combination anti-HIV lentiviral vector in a hematopoietic stem cell gene therapy setting for HIV and validates its potential application in future clinical trials.
  Journal of Virology 03/2012; 86(10):5719-29. · 5.40 Impact Factor
• Article: Long-term effects of intravitreal injection of GMP-grade bone-marrow-derived CD34+ cells in NOD-SCID mice with acute ischemia-reperfusion injury.

  Susanna S Park, Sergio Caballero, Gerhard Bauer, Bradley Shibata, Alan Roth, Paul G Fitzgerald, Krisztina I Forward, Ping Zhou, Jeannine McGee, David G Telander, Maria B Grant, Jan A Nolta
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  ABSTRACT: To determine long-term safety of intravitreal administration of good manufacturing practice (GMP)-grade human bone-marrow-derived CD34(+) cells in NOD-SCID (nonobese diabetic-severe combined immunodeficiency) mice with acute retinal ischemia-reperfusion injury, a model for retinal vasculopathy. Acute ischemia-reperfusion injury was induced in the right eye of adult NOD-SCID mice (n = 23) by transient elevation of intraocular pressure. Seven days later, 12 injured eyes and 5 normal contralateral eyes were injected each intravitreally with 5 × 10(4) CD34(+) cells isolated under GMP conditions from a healthy human donor bone marrow using an immunomagnetic cell isolation system. The remaining 11 injured eyes were not treated and served as controls. Mice were euthanized 1 day, 4 months, and 8 months later. Both eyes were enucleated and examined by immunohistochemical analysis and hematoxylin and eosin staining. Among mice followed for 8 months, electroretinography (ERG) was performed on both eyes before euthanization. All major organs were examined grossly and histologically after serial sectioning. Immunohistochemical staining 4 months after injection showed detectable CD34(+) cells in the retinal vasculature. ERG at 8 months after CD34(+) cell injection showed signals that were similar in untreated eyes. Histology of the enucleated eyes injected with CD34(+) cells showed no intraocular tumor or abnormal tissue growth after 8 months. Histologic analysis of all major organs showed no abnormal proliferation of human cells. Intravitreal administration of GMP-grade human bone-marrow-derived CD34(+) cells appears to be well tolerated long-term in eyes with acute retinal ischemic injury. A clinical trial will start to further explore this therapy.
  Investigative ophthalmology & visual science 01/2012; 53(2):986-94. · 3.43 Impact Factor
• Source

  Available from: Abid Jan

  Article: Genetically engineered mesenchymal stem cells as a proposed therapeutic for Huntington's disease.

  Scott D Olson, Kari Pollock, Amal Kambal, Whitney Cary, Gaela-Marie Mitchell, Jeremy Tempkin, Heather Stewart, Jeannine McGee, Gerhard Bauer, Hyun Sook Kim, Teresa Tempkin, Vicki Wheelock, Geralyn Annett, Gary Dunbar, Jan A Nolta
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  ABSTRACT: There is much interest in the use of mesenchymal stem cells/marrow stromal cells (MSC) to treat neurodegenerative disorders, in particular those that are fatal and difficult to treat, such as Huntington's disease. MSC present a promising tool for cell therapy and are currently being tested in FDA-approved phase I-III clinical trials for many disorders. In preclinical studies of neurodegenerative disorders, MSC have demonstrated efficacy, when used as delivery vehicles for neural growth factors. A number of investigators have examined the potential benefits of innate MSC-secreted trophic support and augmented growth factors to support injured neurons. These include overexpression of brain-derived neurotrophic factor and glial-derived neurotrophic factor, using genetically engineered MSC as a vehicle to deliver the cytokines directly into the microenvironment. Proposed regenerative approaches to neurological diseases using MSC include cell therapies in which cells are delivered via intracerebral or intrathecal injection. Upon transplantation, MSC in the brain promote endogenous neuronal growth, encourage synaptic connection from damaged neurons, decrease apoptosis, reduce levels of free radicals, and regulate inflammation. These abilities are primarily modulated through paracrine actions. Clinical trials for MSC injection into the central nervous system to treat amyotrophic lateral sclerosis, traumatic brain injury, and stroke are currently ongoing. The current data in support of applying MSC-based cellular therapies to the treatment of Huntington's disease is discussed.
  Molecular Neurobiology 12/2011; 45(1):87-98. · 5.74 Impact Factor
• Article: Examination of mesenchymal stem cell-mediated RNAi transfer to Huntington's disease affected neuronal cells for reduction of huntingtin.

  Scott D Olson, Amal Kambal, Kari Pollock, Gaela-Marie Mitchell, Heather Stewart, Stefanos Kalomoiris, Whitney Cary, Catherine Nacey, Karen Pepper, Jan A Nolta
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  ABSTRACT: Huntington's disease (HD) is a fatal, autosomal dominant neurodegenerative disorder caused by an expanded trinucleotide (CAG) repeat in exon 1 of the huntingtin gene (Htt). This expansion creates a toxic polyglutamine tract in the huntingtin protein (HTT). Currently, there is no treatment for either the progression or prevention of the disease. RNA interference (RNAi) technology has shown promise in transgenic mouse models of HD by reducing expression of mutant HTT and slowing disease progression. The advancement of RNAi therapies to human clinical trials is hampered by problems delivering RNAi to affected neurons in a robust and sustainable manner. Mesenchymal stem cells (MSC) have demonstrated a strong safety profile in both completed and numerous ongoing clinical trials. MSC exhibit a number of innate therapeutic effects, such as immune system modulation, homing to injury, and cytokine release into damaged microenvironments. The ability of MSC to transfer larger molecules and even organelles suggested their potential usefulness as delivery vehicles for therapeutic RNA inhibition. In a series of model systems we have found evidence that MSC can transfer RNAi targeting both reporter genes and mutant huntingtin in neural cell lines. MSC expressing shRNA antisense to GFP were found to decrease expression of GFP in SH-SY5Y cells after co-culture when assayed by flow cytometry. Additionally MSC expressing shRNA antisense to HTT were able to decrease levels of mutant HTT expressed in both U87 and SH-SY5Y target cells when assayed by Western blot and densitometry. These results are encouraging for expanding the therapeutic abilities of both RNAi and MSC for future treatments of Huntington's disease.
  Molecular and Cellular Neuroscience 12/2011; 49(3):271-81. · 3.66 Impact Factor
• Article: Concise review: Induced pluripotent stem cell-derived mesenchymal stem cells: progress toward safe clinical products.

  Yunjoon Jung, Gerhard Bauer, Jan A Nolta
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  ABSTRACT: Adult stem cell therapies have provided success for more than 50 years, through reconstitution of the hematopoietic system using bone marrow, umbilical cord blood, and mobilized peripheral blood transplantation. Mesenchymal stem cell (MSC)-mediated therapy is a fast-growing field that has proven safe and effective in the treatment of various degenerative diseases and tissue injuries. Since the first derivation of embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs), there has been impressive progress toward developing safe clinical applications from PSCs. Recent successes in transgene-free iPSC reprogramming have brought attention to the potential of clinical applications of these pluripotent cells, but key hurdles must be overcome, which are discussed in this review. Looking to the future, it could be advantageous to derive MSC from iPSC or human ESC in cases where genetic engineering is needed, since in the PSCs, clones with "safe harbor" vector integration could be selected, expanded, and differentiated. Here, we describe the status of the progress of the use of MSC and PSCs in clinical trials and analyze the challenges that should be overcome before iPSC-derived MSC therapy can be used widely in the clinic.
  Stem Cells 09/2011; 30(1):42-7. · 7.78 Impact Factor
• Article: Effects on proliferation and differentiation of multipotent bone marrow stromal cells engineered to express growth factors for combined cell and gene therapy.

  Fernando A Fierro, Stefanos Kalomoiris, Claus S Sondergaard, Jan A Nolta
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  ABSTRACT: A key mechanism for mesenchymal stem cells/bone marrow stromal cells (MSCs) to promote tissue repair is by secretion of soluble growth factors (GFs). Therefore, clinical application could be optimized by a combination of cell and gene therapies, where MSCs are genetically modified to express higher levels of a specific factor. However, it remains unknown how this overexpression may alter the fate of the MSCs. Here, we show effects of overexpressing the growth factors, such as basic fibroblast growth factor (bFGF), platelet derived growth factor B (PDGF-BB), transforming growth factor β(1) (TGF-β(1) ), and vascular endothelial growth factor (VEGF), in human bone marrow-derived MSCs. Ectopic expression of bFGF or PDGF-B lead to highly proliferating MSCs and lead to a robust increase in osteogenesis. In contrast, adipogenesis was strongly inhibited in MSCs overexpressing PDGF-B and only mildly affected in MSCs overexpressing bFGF. Overexpression of TGF-β(1) blocked both osteogenic and adipogenic differentiation while inducing the formation of stress fibers and increasing the expression of the smooth muscle marker calponin-1 and the chondrogenic marker collagen type II. In contrast, MSCs overexpressing VEGF did not vary from control MSCs in any parameters, likely due to the lack of VEGF receptor expression on MSCs. MSCs engineered to overexpress VEGF strongly induced the migration of endothelial cells and enhanced blood flow restoration in a xenograft model of hind limb ischemia. These data support the rationale for genetically modifying MSCs to enhance their therapeutically relevant trophic signals, when safety and efficacy can be demonstrated, and when it can be shown that there are no unwanted effects on their proliferation and differentiation.
  Stem Cells 09/2011; 29(11):1727-37. · 7.78 Impact Factor
• Source

  Available from: Jian Wu

  Article: Decellularized liver matrix as a carrier for the transplantation of human fetal and primary hepatocytes in mice.

  Ping Zhou, Nataly Lessa, Daniel C Estrada, Ella B Severson, Shilpa Lingala, Mark A Zern, Jan A Nolta, Jian Wu
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  ABSTRACT: The transplantation of primary hepatocytes has been shown to augment the function of damaged livers and to bridge patients to liver transplantation. However, primary hepatocytes often have low levels of engraftment and survive for only a short time after transplantation. To explore the potential benefits of using decellularized liver matrix (DLM) as a carrier for hepatocyte transplantation, DLM from whole mouse livers was generated. Human fetal hepatocytes immortalized by telomerase reconstitution (FH-hTERTs) or primary human hepatocytes were infused into the DLM, which was then implanted into the omenta of immunodeficient nonobese diabetic/severe combined immunodeficient/interleukin-2 receptor γ-deficient mice or nonobese diabetic/severe combined immunodeficient/mucopolysaccharidosis type VII mice. The removal of endogenous cellular components and the preservation of the extracellular matrix proteins and vasculature were demonstrated in the resulting DLM. Bioluminescent imaging revealed that FH-hTERTs transduced with a lentiviral vector expressing firefly luciferase survived in the DLM for 8 weeks after peritoneal implantation, whereas the luciferase signal from FH-hTERTs rapidly declined in control mice 3 to 4 weeks after transplantation via splenic injection or omental implantation after Matrigel encapsulation. Furthermore, primary human hepatocytes that were reconstituted in the DLM not only survived 6 weeks after transplantation but also maintained their function, as demonstrated by messenger RNA levels of albumin and cytochrome P450 (CYP) subtypes (CYP3A4, CYP2C9, and CYP1A1) similar to the levels in freshly isolated human primary hepatocytes (hPHs). In contrast, when hPHs were transplanted into mice via splenic injection, they failed to express CYP3A4, although they expressed albumin. In conclusion, DLM provides an excellent environment for long-term survival and maintenance of the hepatocyte phenotype after transplantation.
  Liver Transplantation 04/2011; 17(4):418-27. · 3.39 Impact Factor
• Article: Characterization and in vivo testing of mesenchymal stem cells derived from human embryonic stem cells.

  William Gruenloh, Amal Kambal, Claus Sondergaard, Jeannine McGee, Catherine Nacey, Stefanos Kalomoiris, Karen Pepper, Scott Olson, Fernando Fierro, Jan A Nolta
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  ABSTRACT: Mesenchymal stem cells (MSCs) have been shown to contribute to the recovery of tissues through homing to injured areas, especially to hypoxic, apoptotic, or inflamed areas and releasing factors that hasten endogenous repair. In some cases genetic engineering of the MSC is desired, since they are excellent delivery vehicles. We have derived MSCs from the human embryonic stem cell (hESC) line H9 (H9-MSCs). They expressed CD105, CD90, CD73, and CD146, and lacked expression of CD45, CD34, CD14, CD31, and HLA-DR, the hESC pluripotency markers SSEA-4 and Tra-1-81, and the hESC early differentiation marker SSEA-1. Marrow-derived MSCs showed a similar phenotype. H9-MSCs did not form teratoma in our initial studies, whereas the parent H9 line did so robustly. H9-MSCs differentiated into bone, cartilage, and adipocytes in vitro, and displayed increased migration under hypoxic conditions. Finally, using a hindlimb ischemia model, H9-MSCs were shown to home to the hypoxic muscle, but not the contralateral limb, by 48 h after IV injection. In summary, we have defined methods for differentiation of hESCs into MSCs and have defined their characteristics and in vivo migratory properties.
  Tissue Engineering Part A 01/2011; 17(11-12):1517-25. · 4.64 Impact Factor
• Source

  Available from: Louisa Wirthlin

  Article: Mesenchymal stem cells for the treatment of neurodegenerative disease.

  Nanette Joyce, Geralyn Annett, Louisa Wirthlin, Scott Olson, Gerhard Bauer, Jan A Nolta
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  ABSTRACT: Mesenchymal stem cells/marrow stromal cells (MSCs) present a promising tool for cell therapy, and are currently being tested in US FDA-approved clinical trials for myocardial infarction, stroke, meniscus injury, limb ischemia, graft-versus-host disease and autoimmune disorders. They have been extensively tested and proven effective in preclinical studies for these and many other disorders. There is currently a great deal of interest in the use of MSCs to treat neurodegenerative diseases, in particular for those that are fatal and difficult to treat, such as Huntington's disease and amyotrophic lateral sclerosis. Proposed regenerative approaches to neurological diseases using MSCs include cell therapies in which cells are delivered via intracerebral or intrathecal injection. Upon transplantation into the brain, MSCs promote endogenous neuronal growth, decrease apoptosis, reduce levels of free radicals, encourage synaptic connection from damaged neurons and regulate inflammation, primarily through paracrine actions. MSCs transplanted into the brain have been demonstrated to promote functional recovery by producing trophic factors that induce survival and regeneration of host neurons. Therapies will capitalize on the innate trophic support from MSCs or on augmented growth factor support, such as delivering brain-derived neurotrophic factor or glial-derived neurotrophic factor into the brain to support injured neurons, using genetically engineered MSCs as the delivery vehicles. Clinical trials for MSC injection into the CNS to treat traumatic brain injury and stroke are currently ongoing. The current data in support of applying MSC-based cellular therapies to the treatment of neurodegenerative disorders are discussed.
  Regenerative Medicine 11/2010; 5(6):933-46. · 3.72 Impact Factor
• Article: Generation of HIV-1 resistant and functional macrophages from hematopoietic stem cell-derived induced pluripotent stem cells.

  Amal Kambal, Gaela Mitchell, Whitney Cary, William Gruenloh, Yunjoon Jung, Stefanos Kalomoiris, Catherine Nacey, Jeannine McGee, Matt Lindsey, Brian Fury, Gerhard Bauer, Jan A Nolta, Joseph S Anderson
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  ABSTRACT: Induced pluripotent stem cells (iPSCs) have radically advanced the field of regenerative medicine by making possible the production of patient-specific pluripotent stem cells from adult individuals. By developing iPSCs to treat HIV, there is the potential for generating a continuous supply of therapeutic cells for transplantation into HIV-infected patients. In this study, we have used human hematopoietic stem cells (HSCs) to generate anti-HIV gene expressing iPSCs for HIV gene therapy. HSCs were dedifferentiated into continuously growing iPSC lines with four reprogramming factors and a combination anti-HIV lentiviral vector containing a CCR5 short hairpin RNA (shRNA) and a human/rhesus chimeric TRIM5α gene. Upon directed differentiation of the anti-HIV iPSCs toward the hematopoietic lineage, a robust quantity of colony-forming CD133(+) HSCs were obtained. These cells were further differentiated into functional end-stage macrophages which displayed a normal phenotypic profile. Upon viral challenge, the anti-HIV iPSC-derived macrophages exhibited strong protection from HIV-1 infection. Here, we demonstrate the ability of iPSCs to develop into HIV-1 resistant immune cells and highlight the potential use of iPSCs for HIV gene and cellular therapies.
  Molecular Therapy 11/2010; 19(3):584-93. · 6.87 Impact Factor
• Article: Mesenchymal stem cells for the sustained in vivo delivery of bioactive factors.

  Todd Meyerrose, Scott Olson, Suzanne Pontow, Stefanos Kalomoiris, Yunjoon Jung, Geralyn Annett, Gerhard Bauer, Jan A Nolta
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  ABSTRACT: Mesenchymal stem cells (MSC) are a promising tool for cell therapy, either through direct contribution to the repair of bone, tendon and cartilage or as an adjunct therapy through protein production and immune mediation. They are an attractive vehicle for cellular therapies due to a variety of cell intrinsic and environmentally responsive properties. Following transplantation, MSC are capable of systemic migration, are not prone to tumor formation, and appear to tolerize the immune response across donor mismatch. These attributes combine to allow MSC to reside in many different tissue types without disrupting the local microenvironment and, in some cases, responding to the local environment with appropriate protein secretion. We describe work done by our group and others in using human MSC for the sustained in vivo production of supraphysiological levels of cytokines for the support of cotransplanted hematopoietic stem cells and enzymes that are deficient in animal models of lysosomal storage disorders such as MPSVII. In addition, the use of MSC engineered to secrete protein products has been reviewed in several fields of tissue injury repair, including but not limited to revascularization after myocardial infarction, regeneration of intervertebral disc defects and spine therapy, repair of stroke, therapy for epilepsy, skeletal tissue repair, chondrogenesis/knee and joint repair, and neurodegenerative diseases. Genetically engineered MSC have thus proven safe and efficacious in numerous animal models of disease modification and tissue repair and are poised to be tested in human clinical trials. The potential for these interesting cells to secrete endogenous or transgene products in a sustained and long-term manner is highly promising and is discussed in the current review.
  Advanced drug delivery reviews 10/2010; 62(12):1167-74. · 11.96 Impact Factor
• Article: shRNA-mediated decreases in c-Met levels affect the differentiation potential of human mesenchymal stem cells and reduce their capacity for tissue repair.

  Ivana Rosová, Daniel Link, Jan A Nolta
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  ABSTRACT: Mesenchymal stem cells/marrow stromal cells (MSC) are adult multipotent cells that can augment tissue repair. We previously demonstrated that culturing MSC in hypoxic conditions causes upregulation of the hepatocyte growth factor (HGF) receptor c-Met, allowing them to respond more robustly to HGF. MSC preconditioned in hypoxic environments contributed to restoration of blood flow after an ischemic injury more rapidly than MSC cultured in normoxic conditions. We now investigated the specific role of HGF/c-Met signaling in MSC function. An shRNA-mediated knockdown (KD) of c-Met in MSC did not alter their phenotypic profile, proliferation, or viability in vitro. However, we determined that while HGF/c-Met signaling does not play a role in the adipogenic differentiation of the cells, the disruption of this signaling pathway inhibited the ability of MSC to differentiate into the osteogenic and chondrogenic lineages. We next assessed the impact of c-Met KD on human MSC function in a xenogeneic hindlimb ischemia injury model. A 70% KD of c-Met in MSC resulted in a significant decrease in their capacity to regenerate blood flow to the ischemic limb, as compared to the MSC transduced with control shRNA. MSC with only a 60% KD of c-Met exhibited an intermediate capacity to restore blood flow, suggesting that MSC function is sensitive to the dosage of c-Met signaling. The current study highlights the significance of HGF/c-Met signaling in the capacity of MSC to restore blood flow after an ischemic injury and in their ability to differentiate into the osteogenic and chondrogenic lineages.
  Tissue Engineering Part A 04/2010; 16(8):2627-39. · 4.64 Impact Factor
• Source

  Available from: David A Hess

  Article: Human cord blood progenitors with high aldehyde dehydrogenase activity improve vascular density in a model of acute myocardial infarction.

  Claus S Sondergaard, David A Hess, Dustin J Maxwell, Carla Weinheimer, Ivana Rosová, Michael H Creer, David Piwnica-Worms, Attila Kovacs, Lene Pedersen, Jan A Nolta
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  ABSTRACT: Human stem cells from adult sources have been shown to contribute to the regeneration of muscle, liver, heart, and vasculature. The mechanisms by which this is accomplished are, however, still not well understood. We tested the engraftment and regenerative potential of human umbilical cord blood-derived ALDH(hi)Lin(-), and ALDH(lo)Lin(-) cells following transplantation to NOD/SCID or NOD/SCID beta2m null mice with experimentally induced acute myocardial infarction. We used combined nanoparticle labeling and whole organ fluorescent imaging to detect human cells in multiple organs 48 hours post transplantation. Engraftment and regenerative effects of cell treatment were assessed four weeks post transplantation. We found that ALDH(hi)Lin(-) stem cells specifically located to the site of injury 48 hours post transplantation and engrafted the infarcted heart at higher frequencies than ALDH(lo)Lin(-) committed progenitor cells four weeks post transplantation. We found no donor derived cardiomyocytes and few endothelial cells of donor origin. Cell treatment was not associated with any detectable functional improvement at the four week endpoint. There was, however, a significant increase in vascular density in the central infarct zone of ALDH(hi)Lin(-) cell-treated mice, as compared to PBS and ALDH(lo)Lin(-) cell-treated mice. CONCLUSIONS: Our data indicate that adult human stem cells do not become a significant part of the regenerating tissue, but rapidly home to and persist only temporarily at the site of hypoxic injury to exert trophic effects on tissue repair thereby enhancing vascular recovery.
  Journal of Translational Medicine 03/2010; 8:24. · 3.41 Impact Factor
• Article: Preintegration HIV-1 inhibition by a combination lentiviral vector containing a chimeric TRIM5 alpha protein, a CCR5 shRNA, and a TAR decoy.

  Joseph S Anderson, John Javien, Jan A Nolta, Gerhard Bauer
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  ABSTRACT: Human immunodeficiency virus (HIV) gene therapy offers a promising alternative approach to current antiretroviral treatments to inhibit HIV-1 infection. Various stages of the HIV life cycle including pre-entry, preintegration, and postintegration can be targeted by gene therapy to block viral infection and replication. By combining multiple highly potent anti-HIV transgenes in a single gene therapy vector, HIV-1 resistance can be achieved in transduced cells while prohibiting the generation of escape mutants. Here, we describe a combination lentiviral vector that encodes three highly effective anti-HIV genes functioning at separate stages of the viral life cycle including a CCR5 short hairpin RNA (shRNA) (pre-entry), a human/rhesus macaque chimeric TRIM5 alpha (postentry/preintegration), and a transactivation response element (TAR) decoy (postintegration). The major focus on designing this anti-HIV vector was to block productive infection of HIV-1 and to inhibit any formation of provirus that would maintain the viral reservoir. Upon viral challenge, potent preintegration inhibition of HIV-1 infection was achieved in combination vector-transduced cells in both cultured and primary CD34(+) hematopoietic progenitor cell (HPC)-derived macrophages. The generation of escape mutants was also blocked as evaluated by long-term culture of challenged cells. The ability of this combination anti-HIV lentiviral vector to prevent HIV-1 infection, in vitro, warrants further evaluation of its in vivo efficacy.
  Molecular Therapy 09/2009; 17(12):2103-14. · 6.87 Impact Factor
• Article: Revascularization of ischemic limbs after transplantation of human bone marrow cells with high aldehyde dehydrogenase activity.

  Benjamin J Capoccia, Debra L Robson, Krysta D Levac, Dustin J Maxwell, Sarah A Hohm, Marian J Neelamkavil, Gillian I Bell, Anargyros Xenocostas, Daniel C Link, David Piwnica-Worms, Jan A Nolta, David A Hess
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  ABSTRACT: The development of cell therapies to treat peripheral vascular disease has proven difficult because of the contribution of multiple cell types that coordinate revascularization. We characterized the vascular regenerative potential of transplanted human bone marrow (BM) cells purified by high aldehyde dehydrogenase (ALDH(hi)) activity, a progenitor cell function conserved between several lineages. BM ALDH(hi) cells were enriched for myelo-erythroid progenitors that produced multipotent hematopoietic reconstitution after transplantation and contained nonhematopoietic precursors that established colonies in mesenchymal-stromal and endothelial culture conditions. The regenerative capacity of human ALDH(hi) cells was assessed by intravenous transplantation into immune-deficient mice with limb ischemia induced by femoral artery ligation/transection. Compared with recipients injected with unpurified nucleated cells containing the equivalent of 2- to 4-fold more ALDH(hi) cells, mice transplanted with purified ALDH(hi) cells showed augmented recovery of perfusion and increased blood vessel density in ischemic limbs. ALDH(hi) cells transiently recruited to ischemic regions but did not significantly integrate into ischemic tissue, suggesting that transient ALDH(hi) cell engraftment stimulated endogenous revascularization. Thus, human BM ALDH(hi) cells represent a progenitor-enriched population of several cell lineages that improves perfusion in ischemic limbs after transplantation. These clinically relevant cells may prove useful in the treatment of critical ischemia in humans.
  Blood 04/2009; 113(21):5340-51. · 9.90 Impact Factor
• Article: Upregulation of Runx2 and Osterix during in vitro chondrogenesis of human adipose-derived stromal cells.

  Jason T Rich, Ivana Rosová, Jan A Nolta, Terence M Myckatyn, Linda J Sandell, Audrey McAlinden
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  ABSTRACT: The aim of this study was to create a gene expression profile to better define the phenotype of human adipose-derived stromal cells (HADSCs) during in vitro chondrogenesis, osteogenesis and adipogenesis. A novel aspect of this work was the analysis of the same subset of genes during HADSC differentiation into all three lineages. Chondrogenic induction resulted in increased mRNA expression of Sox transcription factors, COL2A1,COL10A1, Runx2, and Osterix. This is the first report demonstrating significant upregulation in expression of osteogenesis-related transcription factors Runx2 and Osterix by TGF-beta3 induction of HADSCs during in vitro chondrogenesis. These findings suggest that the commonly-used chondrogenic induction reagents promote differentiation suggestive of hypertrophic chondrocytes and osteoblasts. We conclude that alternative strategies are required to induce efficient articular chondrocyte differentiation in order for HADSCs to be of clinical use in cartilage tissue engineering.
  Biochemical and Biophysical Research Communications 08/2008; 372(1):230-5. · 2.48 Impact Factor
• Article: In vivo biosafety model to assess the risk of adverse events from retroviral and lentiviral vectors.

  Gerhard Bauer, Mo A Dao, Scott S Case, Todd Meyerrose, Louisa Wirthlin, Ping Zhou, Xiuli Wang, Phillip Herrbrich, Jesusa Arevalo, Susie Csik, Dianne C Skelton, Jon Walker, Karen Pepper, Donald B Kohn, Jan A Nolta
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  ABSTRACT: Serious adverse events in some human gene therapy clinical trials have raised safety concerns when retroviral or lentiviral vectors are used for gene transfer. We evaluated the potential for generating replication-competent retrovirus (RCR) and assessed the risk of occurrence of adverse events in an in vivo system. Human hematopoietic stem and progenitor cells (HSCs) and mesenchymal stem cells (MSCs) transduced with two different Moloney murine leukemia virus (MoMuLV)-based vectors were cotransplanted into a total of 481 immune-deficient mice (that are unable to reject cells that become transformed), and the animals were monitored for 18 months. Animals with any signs of illness were immediately killed, autopsied, and subjected to a range of biosafety studies. There was no detectable evidence of insertional mutagenesis leading to human leukemias or solid tumors in the 18 months during which the animals were studied. In 117 serum samples analyzed by vector rescue assay there was no detectable RCR. An additional 149 mice received HSCs transduced with lentiviral vectors, and were followed for 2-6 months. No vector-associated adverse events were observed, and none of the mice had detectable human immunodeficiency virus (HIV) p24 antigen in their sera. Our in vivo system, therefore, helps to provide an assessment of the risks involved when retroviral or lentiviral vectors are considered for use in clinical gene therapy applications.
  Molecular Therapy 08/2008; 16(7):1308-15. · 6.87 Impact Factor
• Article: Hypoxic preconditioning results in increased motility and improved therapeutic potential of human mesenchymal stem cells.

  Ivana Rosová, Mo Dao, Ben Capoccia, Daniel Link, Jan A Nolta
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  ABSTRACT: Mesenchymal stem cells (MSC) are adult multipotent cells found in bone marrow, adipose tissue, and other adult tissues. MSC have been shown to improve regeneration of injured tissues in vivo, but the mechanisms remain unclear. Typically, MSC are cultured under ambient, or normoxic, conditions (21% oxygen). However, the physiological niches for MSC in the bone marrow and other sites have much lower oxygen tension. When used as a therapeutic tool to repair tissue injuries, MSC cultured in standard conditions must adapt from 21% oxygen in culture to less than 1% oxygen in the ischemic tissue. We therefore examined the effects of preculturing human bone marrow-derived MSC in hypoxic conditions (1%-3% oxygen) to elucidate the best conditions that enhance their tissue regenerative potential. We demonstrated that MSC cultured in hypoxia activate the Akt signaling pathway while maintaining their viability and cell cycle rates. We also showed that MSC cultured in hypoxia induced expression of cMet, the major receptor for hepatocyte growth factor (HGF), and enhanced cMet signaling. MSC cultured in hypoxic conditions increased their migration rates. Since migration and HGF responsiveness are thought to be key mediators of MSC recruitment and/or activation in vivo, we next examined the tissue regenerative potential of MSC cultured under hypoxic conditions, using a murine hind limb ischemia model. We showed that local expression of HGF is increased in ischemic muscle in this model. Intra-arterial injection of MSC cultured in either normoxic or hypoxic conditions 24 hours after surgical induction of hind limb ischemia enhanced revascularization compared with saline controls. However, restoration of blood flow was observed significantly earlier in mice that had been injected with hypoxic preconditioned MSC. Collectively, these data suggest that preculturing MSC under hypoxic conditions prior to transplantation improves their tissue regenerative potential. Disclosure of potential conflicts of interest is found at the end of this article.
  Stem Cells 06/2008; 26(8):2173-82. · 7.78 Impact Factor
• Article: Lentiviral-transduced human mesenchymal stem cells persistently express therapeutic levels of enzyme in a xenotransplantation model of human disease.

  Todd E Meyerrose, Marie Roberts, Kevin K Ohlemiller, Carole A Vogler, Louisa Wirthlin, Jan A Nolta, Mark S Sands
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  ABSTRACT: Bone marrow-derived mesenchymal stem cells (MSCs) are a promising platform for cell- and gene-based treatment of inherited and acquired disorders. We recently showed that human MSCs distribute widely in a murine xenotransplantation model. In the current study, we have determined the distribution, persistence, and ability of lentivirally transduced human MSCs to express therapeutic levels of enzyme in a xenotransplantation model of human disease (nonobese diabetic severe combined immunodeficient mucopolysaccharidosis type VII [NOD-SCID MPSVII]). Primary human bone marrow-derived MSCs were transduced ex vivo with a lentiviral vector expressing either enhanced green fluorescent protein or the lysosomal enzyme beta-glucuronidase (MSCs-GUSB). Lentiviral transduction did not affect any in vitro parameters of MSC function or potency. One million cells from each population were transplanted intraperitoneally into separate groups of neonatal NOD-SCID MPSVII mice. Transduced MSCs persisted in the animals that underwent transplantation, and comparable numbers of donor MSCs were detected at 2 and 4 months after transplantation in multiple organs. MSCs-GUSB expressed therapeutic levels of protein in the recipients, raising circulating serum levels of GUSB to nearly 40% of normal. This level of circulating enzyme was sufficient to normalize the secondary elevation of other lysosomal enzymes and reduce lysosomal distention in several tissues. In addition, at least one physiologic marker of disease, retinal function, was normalized following transplantation of MSCs-GUSB. These data provide evidence that transduced human MSCs retain their normal trafficking ability in vivo and persist for at least 4 months, delivering therapeutic levels of protein in an authentic xenotransplantation model of human disease.
  Stem Cells 05/2008; 26(7):1713-22. · 7.78 Impact Factor
• Article: Widespread nonhematopoietic tissue distribution by transplanted human progenitor cells with high aldehyde dehydrogenase activity.

  David A Hess, Timothy P Craft, Louisa Wirthlin, Sarah Hohm, Ping Zhou, William C Eades, Michael H Creer, Mark S Sands, Jan A Nolta
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  ABSTRACT: Transplanted adult progenitor cells distribute to peripheral organs and can promote endogenous cellular repair in damaged tissues. However, development of cell-based regenerative therapies has been hindered by the lack of preclinical models to efficiently assess multiple organ distribution and difficulty defining human cells with regenerative function. After transplantation into beta-glucuronidase (GUSB)-deficient NOD/SCID/mucopolysaccharidosis type VII mice, we characterized the distribution of lineage-depleted human umbilical cord blood-derived cells purified by selection using high aldehyde dehydrogenase (ALDH) activity with CD133 coexpression. ALDH(hi) or ALDH(hi)CD133+ cells produced robust hematopoietic reconstitution and variable levels of tissue distribution in multiple organs. GUSB+ donor cells that coexpressed human leukocyte antigen (HLA-A,B,C) and hematopoietic (CD45+) cell surface markers were the primary cell phenotype found adjacent to the vascular beds of several tissues, including islet and ductal regions of mouse pancreata. In contrast, variable phenotypes were detected in the chimeric liver, with HLA+/CD45+ cells demonstrating robust GUSB expression adjacent to blood vessels and CD45-/HLA- cells with diluted GUSB expression predominant in the liver parenchyma. However, true nonhematopoietic human (HLA+/CD45-) cells were rarely detected in other peripheral tissues, suggesting that these GUSB+/HLA-/CD45- cells in the liver were a result of downregulated human surface marker expression in vivo, not widespread seeding of nonhematopoietic cells. However, relying solely on continued expression of cell surface markers, as used in traditional xenotransplantation models, may underestimate true tissue distribution. ALDH-expressing progenitor cells demonstrated widespread and tissue-specific distribution of variable cellular phenotypes, indicating that these adult progenitor cells should be explored in transplantation models of tissue damage.
  Stem Cells 04/2008; 26(3):611-20. · 7.78 Impact Factor