Efficient Designer Nuclease-Based Homologous Recombination Enables Direct PCR Screening for Footprintless Targeted Human Pluripotent Stem Cells

SummaryGenetic engineering of human induced pluripotent stem cells (hiPSCs) via customized designer nucleases has been shown to be significantly more efficient than conventional gene targeting, but still typically depends on the introduction of additional genetic selection elements. In our study, we demonstrate the efficient nonviral and selection-independent gene targeting in human pluripotent stem cells (hPSCs). Our high efficiencies of up to 1.6% of gene-targeted hiPSCs, accompanied by a low background of randomly inserted transgenes, eliminated the need for antibiotic or fluorescence-activated cell sorting selection, and allowed the use of short donor oligonucleotides for footprintless gene editing. Gene-targeted hiPSC clones were established simply by direct PCR screening. This optimized approach allows targeted transgene integration into safe harbor sites for more predictable and robust expression and enables the straightforward generation of disease-corrected, patient-derived iPSC lines for research purposes and, ultimately, for future clinical applications

Generation of an induced pluripotent stem cell line (MHHi018-A) from a patient with Cystic Fibrosis carrying p.Asn1303Lys (N1303K) mutation

Cystic Fibrosis (CF) is a genetic disease caused by mutations in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene which encodes for a chloride ion channel regulating the balance of salt and water across secretory epithelia. Here we generated an iPSC line from a CF patient homozygous for the p.Asn1303Lys mutation, a Class II folding defect mutation. This iPSC line provides a useful resource for disease modeling and to investigate the pharmacological response to CFTR modulators in iPSC derived epithelia

Primate iPS cells as tools for evolutionary analyses

Induced pluripotent stem cells (iPSCs) are regarded as a central tool to understand human biology in health and disease. Similarly, iPSCs from non-human primates should be a central tool to understand human evolution, in particular for assessing the conservation of regulatory networks in iPSC models. Here, we have generated human, gorilla, bonobo and cynomolgus monkey iPSCs and assess their usefulness in such a framework. We show that these cells are well comparable in their differentiation potential and are generally similar to human, cynomolgus and rhesus monkey embryonic stem cells (ESCs). RNA sequencing reveals that expression differences among clones, individuals and stem cell type are all of very similar magnitude within a species. In contrast, expression differences between closely related primate species are three times larger and most genes show significant expression differences among the analyzed species. However, pseudogenes differ more than twice as much, suggesting that evolution of expression levels in primate stem cells is rapid, but constrained. These patterns in pluripotent stem cells are comparable to those found in other tissues except testis. Hence, primate iPSCs reveal insights into general primate gene expression evolution and should provide a rich source to identify conserved and species-specific gene expression patterns for cellular phenotypes

Derivation and characterization of sleeping beauty transposon-mediated porcine induced pluripotent stem cells

The domestic pig is an important large animal model for preclinical testing of novel cell therapies. Recently, we produced pluripotency reporter pigs in which the Oct4 promoter drives expression of the enhanced green fluorescent protein (EGFP). Here, we reprogrammed Oct4-EGFP fibroblasts employing the non-viral Sleeping Beauty transposon system to deliver the reprogramming factors Oct4, Sox2, Klf4 and cMyc. Successful reprogramming to a pluripotent state was indicated by changes in cell morphology and reactivation of the Oct4-EGFP reporter. The transposon-reprogrammed putative iPS cells showed long term proliferation in vitro over >40 passages, expressed transcription factors typical of embryonic stem cells, including OCT4, NANOG, SOX2, REX1, ESRRB, DPPA5 and UTF1 and surface markers of pluripotency, including SSEA-1 and TRA-1-60. In vitro differentiation resulted in derivatives of the three germ layers. Upon injection of putative iPS cells under the skin of immunodeficient mice, we observed teratomas in 3 of 6 cases. These results form the basis for in-depth studies towards the derivation of porcine iPS cells, which hold great promise for preclinical testing of novel cell therapies in the pig model

Systemic Type I IFN Inflammation in Human ISG15 Deficiency Leads to Necrotizing Skin Lesions

Most monogenic disorders have a primary clinical presentation. Inherited ISG15 deficiency, however, has manifested with two distinct presentations to date: susceptibility to mycobacterial disease and intracranial calcifications from hypomorphic interferon-II (IFN-II) production and excessive IFN-I response, respectively. Accordingly, these patients were managed for their infectious and neurologic complications. Herein, we describe five new patients with six novel ISG15 mutations presenting with skin lesions who were managed for dermatologic disease. Cellularly, we denote striking specificity to the IFN-I response, which was previously assumed to be universal. In peripheral blood, myeloid cells display the most robust IFN-I signatures. In the affected skin, IFN-I signaling is observed in the keratinocytes of the epidermis, endothelia, and the monocytes and macrophages of the dermis. These findings define the specific cells causing circulating and dermatologic inflammation and expand the clinical spectrum of ISG15 deficiency to dermatologic presentations as a third phenotype co-dominant to the infectious and neurologic manifestations.Fil: Martin Fernandez, Marta. Icahn School Of Medicine At Mount Sinai; Estados Unidos. King Saud University; Arabia SauditaFil: Bravo García Morato, María. Instituto de Investigacion del Hospital de la Paz.; EspañaFil: Gruber, Conor. Icahn School Of Medicine At Mount Sinai; Estados Unidos. King Saud University; Arabia SauditaFil: Murias Loza, Sara. Instituto de Investigacion del Hospital de la Paz.; EspañaFil: Malik, Muhammad Nasir Hayat. Twincore; Alemania. University Of Lahore; Países Bajos. Leibniz Universitat Hannover; Alemania. Helmholtz Gemeinschaft; AlemaniaFil: Alsohime, Fahad. King Saud University; Arabia SauditaFil: Alakeel, Abdullah. King Saud University; Arabia SauditaFil: Valdez, Rita. Gobierno de la Ciudad Autónoma de Buenos Aires. Hospital General de Agudos Doctor Cosme Argerich; ArgentinaFil: Buta, Sofija. Icahn School Of Medicine At Mount Sinai; Estados UnidosFil: Buda, Guadalupe. Bitgenia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Biología Celular e Histología; ArgentinaFil: Marti, Marcelo Adrian. Bitgenia; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Biología Celular e Histología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Larralde, Margarita. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos Mejía"; ArgentinaFil: Boisson, Bertrand. L'institut Des Maladies Génétiques Imagine; Francia. The Rockefeller University; Estados Unidos. Universite de Paris; FranciaFil: Feito Rodriguez, Marta. Instituto de Investigacion del Hospital de la Paz.; EspañaFil: Qiu, Xueer. Icahn School Of Medicine At Mount Sinai; Estados UnidosFil: Chrabieh, Maya. L'institut Des Maladies Génétiques Imagine; FranciaFil: Al Ayed, Mohammed. Najran University; Arabia SauditaFil: Al Muhsen, Saleh. King Saud University; Arabia SauditaFil: Desai, Jigar V.. National Institutes of Health; Estados UnidosFil: Ferre, Elise M.N.. National Institutes of Health; Estados UnidosFil: Rosenzweig, Sergio D.. National Institutes of Health; Estados UnidosFil: Amador-Borrero, Blanca. Icahn School Of Medicine At Mount Sinai; Estados UnidosFil: Bravo-Gallego, Luz Yadira. Instituto de Investigacion del Hospital de la Paz.; EspañaFil: Olmer, Ruth. Hannover Medical School; Alemania. German Center for Lung Research; AlemaniaFil: Merkert, Sylvia. Hannover Medical School; Alemania. German Center for Lung Research; AlemaniaFil: Bret, Montserrat. Instituto de Investigacion del Hospital de la Paz.; EspañaFil: Sood, Amika K.. University of North Carolina; Estados UnidosFil: Al-rabiaah, Abdulkarim. King Saud University; Arabia SauditaFil: Temsah, Mohamad Hani. King Saud University; Arabia SauditaFil: Halwani, Rabih. University of Sharjah; Emiratos Arabes UnidosFil: Hernandez, Michelle Marilyn. University of North Carolina; Estados UnidosFil: Pessler, Frank. Twincore; Alemania. Helmholtz Centre for Infection Research; AlemaniaFil: Casanova, Jean Laurent. The Rockefeller University; Estados Unidos. Necker Hospital for Sick Children; Francia. Howard Hughes Medical Institute; Estados Unidos. Universite de Paris; FranciaFil: Bustamante, Jacinta. The Rockefeller University; Estados Unidos. Necker Hospital for Sick Children; Francia. Universite de Paris; FranciaFil: Lionakis, Michail S.. National Institutes of Health; Estados UnidosFil: Bogunovic, Dusan. Icahn School Of Medicine At Mount Sinai; Estados Unido

Site-Specific Genome Engineering in Human Pluripotent Stem Cells

The possibility to generate patient-specific induced pluripotent stem cells (iPSCs) offers an unprecedented potential of applications in clinical therapy and medical research. Human iPSCs and their differentiated derivatives are tools for diseases modelling, drug discovery, safety pharmacology, and toxicology. Moreover, they allow for the engineering of bioartificial tissue and are promising candidates for cellular therapies. For many of these applications, the ability to genetically modify pluripotent stem cells (PSCs) is indispensable, but efficient site-specific and safe technologies for genetic engineering of PSCs were developed only recently. By now, customized engineered nucleases provide excellent tools for targeted genome editing, opening new perspectives for biomedical research and cellular therapies

Targeted genome engineering using designer nucleases: State of the art and practical guidance for application in human pluripotent stem cells

Within the last years numerous publications successfully applied sequence specific designer nucleases for genome editing in human PSCs. However, despite this abundance of reports together with the rapid development and improvement accomplished with the technology, it is still difficult to choose the optimal methodology for a specific application of interest. With focus on the most suitable approach for specific applications, we present a practical guidance for successful gene editing in human PSCs using designer nucleases. We discuss experimental considerations, limitations and critical aspects which will guide the investigator for successful implementation of this technology

Generation of a gene-corrected isogenic control iPSC line from cystic fibrosis patient-specific iPSCs homozygous for p.Phe508del mutation mediated by TALENs and ssODN

Cystic fibrosis (CF) is a monogenetic disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, which affects multiple organs. Human induced pluripotent stem cells (iPSCs) derived from CF patients and the generation of isogeneic gene-corrected control cell lines enable disease modelling, drug discovery or toxicological studies and therefore the development of CF patient-specific therapies. We have previously generated a hiPSC line from a CF patient homozygous for the p.Phe508del mutation. Here we used TALENs and single-stranded oligonucleotides to correct the mutated triplet in our CF-iPSC line

Generation of two human NRF2 knockout iPSC clones using CRISPR/Cas9 editing

The nuclear factor erythroid 2-related factor 2 (NFE2L2, known as NRF2) regulates the expression of antioxidative and anti-inflammatory proteins. In order to investigate its impact during viral infections and testing of antiviral compounds, we applied CRISPR/Cas9 editing to eliminate NRF2 in the human iPS cell line MHHi001-A and generated two NRF2 knockout iPSC clones MHHi001-A-6 and MHHi001-A-7. After differentiation into epithelia or endothelial cells, these cells are useful tools to examine the antiviral effects of activators of the NRF2 signaling pathway

An Improved Protocol for Targeted Differentiation of Primed Human Induced Pluripotent Stem Cells into HLA-G-Expressing Trophoblasts to Enable the Modeling of Placenta-Related Disorders

Abnormalities at any stage of trophoblast development may result in pregnancy-related complications. Many of these adverse outcomes are discovered later in pregnancy, but the underlying pathomechanisms are constituted during the first trimester. Acquiring developmentally relevant material to elucidate the disease mechanisms is difficult. Human pluripotent stem cell (hPSC) technology can provide a renewable source of relevant cells. BMP4, A83-01, and PD173074 (BAP) treatment drives trophoblast commitment of hPSCs toward syncytiotrophoblast (STB), but lacks extravillous trophoblast (EVT) cells. EVTs mediate key functions during placentation, remodeling of uterine spiral arteries, and maintenance of immunological tolerance. We optimized the protocol for a more efficient generation of HLA-Gpos EVT-like trophoblasts from primed hiPSCs. Increasing the concentrations of A83-01 and PD173074, while decreasing bulk cell density resulted in an increase in HLA-G of up to 71%. Gene expression profiling supports the advancements of our treatment regarding the generation of trophoblast cells. The reported differentiation protocol will allow for an on-demand access to human trophoblast cells enriched for HLA-Gpos EVT-like cells, allowing for the elucidation of placenta-related disorders and investigating the immunological tolerance toward the fetus, overcoming the difficulties in obtaining primary EVTs without the need for a complex differentiation pathway via naïve pluripotent or trophoblast stem cells