Generation and comprehensive characterization of induced pluripotent stem cells for translational research.

Induced pluripotent stem cells (iPSCs) hold immense potential in disease modeling, drug discovery and regenerative medicine. Despite advances in reprogramming methods, generation of clinical-grade iPSCs remains a challenge. Reported here is the first off-the-shelf reprogramming kit, CTS CytoTune-iPS 2.1, specifically designed for clinical and translational research. Workflow gaps were identified, and methods developed were used to consistently generate iPSC from multiple cell types. Resulting clones were subjected to characterization that included confirmation of pluripotency, preservation of genomic integrity and authentication of cell banks via an array of molecular methods including high resolution microarray and next-generation sequencing. Development of integrated xeno-free workflows combined with comprehensive characterization offers generation of high-quality iPSCs that are suited for clinical and translational research.

Strengthening the links between mapping, planning and global engagement for disease elimination: lessons learnt from trachoma.

BACKGROUND: Trachoma is the leading infectious cause of blindness. Until recently, reliable data on the global extent of the disease, detailed plans for elimination, and government, donor and partner engagement were all inadequate. METHODS: The trachoma community undertook a systematic, three-pronged strategy to map trachoma district by district, develop national-level trachoma elimination plans, and create a framework for governments, donors and partners to convene and coordinate in support of trachoma elimination.  RESULT: There has been a frame-shift in internal and external perceptions of the global trachoma programme, from being an effort working towards disease control in focussed geographical areas, to one in the process of achieving worldwide disease elimination. Multiple factors contributed to the successful implementation of mapping, planning, and cross-sectional engagement of governments, partners and donors. CONCLUSIONS: Elimination of trachoma is possible if the right combination of factors is in place. Planning for success is a critical first step. Some remaining challenges must still be addressed if the elimination targets are to be successfully attained.

The Global Trachoma Mapping Project: Methodology of a 34-Country Population-Based Study.

PURPOSE: To complete the baseline trachoma map worldwide by conducting population-based surveys in an estimated 1238 suspected endemic districts of 34 countries. METHODS: A series of national and sub-national projects owned, managed and staffed by ministries of health, conduct house-to-house cluster random sample surveys in evaluation units, which generally correspond to "health district" size: populations of 100,000-250,000 people. In each evaluation unit, we invite all residents aged 1 year and older from h households in each of c clusters to be examined for clinical signs of trachoma, where h is the number of households that can be seen by 1 team in 1 day, and the product h × c is calculated to facilitate recruitment of 1019 children aged 1-9 years. In addition to individual-level demographic and clinical data, household-level water, sanitation and hygiene data are entered into the purpose-built LINKS application on Android smartphones, transmitted to the Cloud, and cleaned, analyzed and ministry-of-health-approved via a secure web-based portal. The main outcome measures are the evaluation unit-level prevalence of follicular trachoma in children aged 1-9 years, prevalence of trachomatous trichiasis in adults aged 15 + years, percentage of households using safe methods for disposal of human feces, and percentage of households with proximate access to water for personal hygiene purposes. RESULTS: In the first year of fieldwork, 347 field teams commenced work in 21 projects in 7 countries. CONCLUSION: With an approach that is innovative in design and scale, we aim to complete baseline mapping of trachoma throughout the world in 2015.

Integration of water, sanitation, and hygiene for the prevention and control of neglected tropical diseases: a rationale for inter-sectoral collaboration.

Improvements of water, sanitation, and hygiene (WASH) infrastructure and appropriate health-seeking behavior are necessary for achieving sustained control, elimination, or eradication of many neglected tropical diseases (NTDs). Indeed, the global strategies to fight NTDs include provision of WASH, but few programs have specific WASH targets and approaches. Collaboration between disease control programs and stakeholders in WASH is a critical next step. A group of stakeholders from the NTD control, child health, and WASH sectors convened in late 2012 to discuss opportunities for, and barriers to, collaboration. The group agreed on a common vision, namely "Disease-free communities that have adequate and equitable access to water and sanitation, and that practice good hygiene." Four key areas of collaboration were identified, including (i) advocacy, policy, and communication; (ii) capacity building and training; (iii) mapping, data collection, and monitoring; and (iv) research. We discuss strategic opportunities and ways forward for enhanced collaboration between the WASH and the NTD sectors.

Generation of induced pluripotent stem cells with CytoTune, a non-integrating Sendai virus.

One of the major obstacles in generating induced pluripotent stem cells for research or downstream applications is the potential modifications of cellular genome as a result of using integrating viruses during reprogramming. Another major disadvantage of reprogramming cells with integrating vectors is that silencing and activation of transgenes are unpredictable, which may affect terminal differentiation potential and increase the risk of using iPSC-derived cells. Here we describe a protocol for the generation of induced pluripotent stem cells using a non-integrating RNA virus, Sendai virus, to efficiently generate transgene-free iPSCs starting with different cell types as well as in feeder-free conditions.

Generation of human-induced pluripotent stem cells (hiPSCs) using episomal vectors on defined Essential 8™ Medium conditions.

Human-induced pluripotent stem cells (iPSCs) are an important potential source of cells for regenerative medicine due to their inherent ability to differentiate into all cell types of the three germ layers. Generation of iPSCs with a non-integrating reprogramming method and in culture conditions that are completely absent of animal proteins will be ideal for such regenerative and cell therapy applications. Here we describe a method to generate non-integrating iPSCs using the Episomal iPSC Reprogramming Vectors.

Site-specific integration in human ESC using Jump-In™ TI™ technology.

Engineering of human embryonic stem cells (hESC) offers a great potential tool for the study of human gene function. There are many techniques that can be used to engineer human cells, but most are lacking in either specificity or efficiency. Jump-In™ TI™ technology utilizes two bacteriophage recombinases (PhiC31 and R4) to specifically, efficiently, and stably introduce genetic elements into the genome of human ESCs. The techniques described here allow the user to first deliver a targeting site to a defined locus, and second to deliver the genetic elements of interest to that targeting site, allowing for stable, single copy integration into the genome. These integrated elements show high levels of expression in the pluripotent state, as well as in multiple differentiated lineages.

Enhancing community knowledge and health behaviors to eliminate blinding trachoma in Mali using radio messaging as a strategy.

The National Blindness Prevention Program in Mali has broadcast messages on the radio about trachoma as part of the country's trachoma elimination strategy since 2008. In 2011, a radio impact survey using multi-stage cluster sampling was conducted in the regions of Kayes and Segou to assess radio listening habits, coverage of the broadcasts, community knowledge and behavior specific to trachoma and facial cleanliness of children. Radio access and listening were high, with 60% of respondents having heard a message on the radio about trachoma. The majority of respondents knew about trachoma, its root causes, its impact on health and prevention measures. Additionally, 66% reported washing their children's faces more than or equal to twice/day and 94% reported latrine disposal of feces. A high percentage of persons who gave a positive response to knowledge and behavior questions reported hearing the trachoma messages on the radio with 60% reporting that the radio is where they learned about trachoma. There was no significant difference in facial cleanliness when comparing children whose primary caregiver had/had not heard the trachoma messages. Next steps include revising the current messages to include more focused behavior change messaging and to engage in a more robust use of community radios.

Generation of human-induced pluripotent stem cells by a nonintegrating RNA Sendai virus vector in feeder-free or xeno-free conditions.

The generation of induced pluripotent stem cells (iPSCs) from somatic cells has enabled the possibility of providing unprecedented access to patient-specific iPSC cells for drug screening, disease modeling, and cell therapy applications. However, a major obstacle to the use of iPSC for therapeutic applications is the potential of genomic modifications caused by insertion of viral transgenes in the cellular genome. A second concern is that reprogramming often requires the use of animal feeder layers and reagents that contain animal origin products, which hinder the generation of clinical-grade iPSCs. Here, we report the generation of iPSCs by an RNA Sendai virus vector that does not integrate into the cells genome, providing transgene-free iPSC line. In addition, reprogramming can be performed in feeder-free condition with StemPro hESC SFM medium and in xeno-free (XF) conditions. Generation of an integrant-free iPSCs generated in xeno-free media should facilitate the safe downstream applications of iPSC-based cell therapies.

The role of nutrition in integrated programs to control neglected tropical diseases.

There are strong and direct relationships between undernutrition and the disease caused by infectious organisms, including the diverse pathogens labeled as neglected tropical diseases (NTDs). Undernutrition increases the risk of infection, the severity of disease and the risk that children will die, while the physical damage, loss of appetite, and host responses during chronic infection can contribute substantially to undernutrition. These relationships are often synergistic. This opinion article examines the role of nutrition in controlling NTDs and makes the point that mass drug treatment--the major strategy currently proposed to control several diseases--is crucial to controlling disease and transmission, but is only the start of the process of physical recovery. Without adequate energy and nutrients to repair damaged tissues or recover lost growth and development, the benefits of treatment may not be evident quickly; the effects of control programs may be not appreciated by beneficiaries; while vulnerability to reinfection and disease may not be reduced. There is substantial potential for nutritional interventions to be added to large-scale programs to deliver drug treatments and thereby contribute, within a broad strategy of public health interventions and behavior change activities, to controlling and preventing NTDs in populations, and to restoring their health.

Implementing preventive chemotherapy through an integrated National Neglected Tropical Disease Control Program in Mali.

BACKGROUND: Mali is endemic for all five targeted major neglected tropical diseases (NTDs). As one of the five 'fast-track' countries supported with the United States Agency for International Development (USAID) funds, Mali started to integrate the activities of existing disease-specific national control programs on these diseases in 2007. The ultimate objectives are to eliminate lymphatic filariasis, onchocerciasis and trachoma as public health problems and to reduce morbidity caused by schistosomiasis and soil-transmitted helminthiasis through regular treatment to eligible populations, and the specific objectives were to achieve 80% program coverage and 100% geographical coverage yearly. The paper reports on the implementation of the integrated mass drug administration and the lessons learned. METHODOLOGY/PRINCIPAL FINDINGS: The integrated control program was led by the Ministry of Health and coordinated by the national NTD Control Program. The drug packages were designed according to the disease endemicity in each district and delivered through various platforms to eligible populations involving the primary health care system. Treatment data were recorded and reported by the community drug distributors. After a pilot implementation of integrated drug delivery in three regions in 2007, the treatment for all five targeted NTDs was steadily scaled up to 100% geographical coverage by 2009, and program coverage has since been maintained at a high level: over 85% for lymphatic filariasis, over 90% for onchocerciasis and soil-transmitted helminthiasis, around 90% in school-age children for schistosomiasis, and 76-97% for trachoma. Around 10 million people have received one or more drug packages each year since 2009. No severe cases of adverse effects were reported. CONCLUSIONS/SIGNIFICANCE: Mali has scaled up the drug treatment to national coverage through integrated drug delivery involving the primary health care system. The successes and lessons learned in Mali can be valuable assets to other countries starting up their own integrated national NTD control programs.

Applications of quantitative polymerase chain reaction protein assays during reprogramming.

The capability to reprogram human somatic cells to induced pluripotent stem cells (iPSCs) has opened a new area of biology and provides unprecedented access to patient-specific iPSCs for drug screening, disease models, and transplantation therapies. Although the process of obtaining iPSC lines is technically simple, reprogramming is a slow and inefficient process consisting of a largely uncharacterized chain of molecular events. To date, researchers have reported a wide range of reprogramming efficiencies, from <0.01% to >1%, depending on the specific reprogramming factors used, the mode of delivery of the reprogramming factors, properties of the starting cells, and culture conditions. We have applied a quantitative polymerase chain reaction methodology, TaqMan Protein Assays to directly quantify the kinetics, and cellular levels of crucial transcription factors during the reprogramming process. Further, we have used the assays to ascertain the threshold levels of reprogramming protein factors required to generate iPSC colonies, to characterize the protein expression signatures of different iPSC lines, and to rapidly identify iPS versus non-iPSC colonies based on expression of pluripotency markers. These data demonstrate that TaqMan Protein Assays can be used as tools to dissect and gain greater understanding of the mechanisms guiding reprogramming and to further characterize individual established iPSC lines.

Chromatin insulator elements block transgene silencing in engineered human embryonic stem cell lines at a defined chromosome 13 locus.

Lineage reporters of human embryonic stem cell (hESC) lines are useful for differentiation studies and drug screening. Previously, we created reporter lines driven by an elongation factor 1 alpha (EF1α) promoter at a chromosome 13q32.3 locus in the hESC line WA09 and an abnormal hESC line BG01V in a site-specific manner. Expression of reporters in these lines was maintained in long-term culture at undifferentiated state. However, when these cells were differentiated into specific lineages, reduction in reporter expression was observed, indicating transgene silencing. To develop an efficient and reliable genetic engineering strategy in hESCs, we used chromatin insulator elements to flank single-copy transgenes and integrated the combined expression constructs via PhiC31/R4 integrase-mediated recombination technology to the chromosome 13 locus precisely. Two copies of cHS4 double-insulator sequences were placed adjacent to both 5' and 3' of the promoter reporter constructs. The green fluorescent protein (GFP) gene was driven by EF1α or CMV early enhancer/chicken ß actin (CAG) promoter. In the engineered hESC lines, for both insulated CAG-GFP and EF1α-GFP, constitutive expression at the chromosome 13 locus was maintained during prolonged culture and in directed differentiation assays toward diverse types of neurons, pancreatic endoderm, and mesodermal progeny. In particular, described here is the first normal hESC fluorescent reporter line that robustly expresses GFP in both the undifferentiated state and throughout dopaminergic lineage differentiation. The dual strategy of utilizing insulator sequences and integration at the constitutive chromosome 13 locus ensures appropriate transgene expression. This is a valuable tool for lineage development study, gain- and loss-of-function experiments, and human disease modeling using hESCs.

The epidemiology of trachoma in the five northern districts of Sierra Leone.

PURPOSE: In 2008, a trachoma prevalence survey was conducted in the five northern districts of Sierra Leone to determine if and where specific components of the SAFE strategy (Surgery, Antibiotics, Face washing, Environmental change) should be initiated. METHODS: A cross-sectional survey at district level was implemented using two-stage random cluster sampling: probability proportionate sampling was used to select villages in the first stage and compact segment sampling of households in the second stage. Both eyes of 16,780 individuals were examined using the World Health Organization simplified trachoma grading system. Data were also collected on village- and household-level behavior and environmental factors related to trachoma. RESULTS: Prevalence of trachomatous inflammation-follicular (TF) in children aged 1-9 years was highest in Kambia at 3.52% (95% Confidence Interval (CI): 2.28-4.75%), while the prevalence of trachomatous trichiasis (TT) in persons over 15 years of age was highest in Port Loko at 0.27% (95% CI: 0.03-0.50%). Across all districts, the percentage of households reporting washing children's faces less than once per day was very low, while latrine coverage and accessible and safe water sources were not highly prevalent. CONCLUSIONS: In all districts but Koinadugu, TT prevalence was greater than the WHO elimination threshold, indicating the need for 1,016 TT surgeries to prevent blindness. District TF prevalence rates did not warrant mass antibiotic distribution. Although not required given the low prevalence of TF, we recommend the construction of 35,941 household latrines and provision of water sources within a 30-minute walk roundtrip for 17,551 households to bring Sierra Leone closer to reaching Millennium Development Goal 7.

Neglected tropical disease control in post-war Sierra Leone using the Onchocerciasis Control Programme as a platform.

Strategic investments in the control of neglected tropical diseases (NTD) spearheaded by the US Government, the British Government and other bilateral donors such as foundations and key pharmaceutical partners have enabled the treatment of millions of people for the five targeted debilitating diseases (lymphatic filariasis, onchocerciasis, schistosomiasis, soil-transmitted helminthiasis and trachoma), paving the way for the potential elimination as public health problems of some of these diseases. Like many other countries, Sierra Leone has a high burden of these major NTDs. Despite the fragile infrastructure of a health system emerging from a devastating 10-year civil war, the country has successfully implemented the National NTD Control Programme, reaching national coverage in 2010. The NTD Control Programme uses the existing Onchocerciasis Control Programme as a platform and involves primary health workers. The programme has provided extensive training opportunities to health workers at national, district and community levels. The country currently has 31 161 trained community volunteers treating a population of five million people. It is shown that the investments in NTD control are not only to control NTDs but also to strengthen health systems, particularly at the primary level, through extensive capacity building of frontline health workers and community-directed distributors.

Control of neglected tropical diseases needs a long-term commitment.

BACKGROUND: Neglected tropical diseases are widespread, particularly in sub-Saharan Africa, affecting over 2 billion individuals. Control of these diseases has gathered pace in recent years, with increased levels of funding from a number of governmental or non-governmental donors. Focus has currently been on five major 'tool-ready' neglected tropical diseases (lymphatic filariasis, onchocerciasis, schistosomiasis, soil-transmitted helminthiasis and trachoma), using a package of integrated drug delivery according to the World Health Organization guidelines for preventive chemotherapy. DISCUSSION: Success in controlling these neglected tropical diseases has been achieved in a number of countries in recent history. Experience from these successes suggests that long-term sustainable control of these diseases requires: (1) a long-term commitment from a wider range of donors and from governments of endemic countries; (2) close partnerships of donors, World Health Organization, pharmaceutical industries, governments of endemic countries, communities, and non-governmental developmental organisations; (3) concerted action from more donor countries to provide the necessary funds, and from the endemic countries to work together to prevent cross-border disease transmission; (4) comprehensive control measures for certain diseases; and (5) strengthened primary healthcare systems as platforms for the national control programmes and capacity building through implementation of the programmes. CONCLUSIONS: The current level of funding for the control of neglected tropical diseases has never been seen before, but it is still not enough to scale up to the 2 billion people in all endemic countries. While more donors are sought, the stakeholders must work in a coordinated and harmonised way to identify the priority areas and the best delivery approaches to use the current funds to the maximum effect. Case management and other necessary control measures should be supported through the current major funding streams in order to achieve the objectives of the control of these diseases. For a long-term and sustainable effort, control of neglected tropical diseases should also be integrated into national primary healthcare systems.

hESC engineering by integrase-mediated chromosomal targeting.

Bacteriophage recombinases can target specific loci in human embryonic stem cells (hESCs) at high efficiency allowing for long-term expression of transgenes. In this chapter, we describe a retargeting system where phiC31 integrase is used to deliver a chromosomal target for a second integrase, R4. The engineered hESC line can be adapted for complex element assembly using Multisite Gateway technology. Retargeted clones show sustained expression and appropriate regulation of the transgenes over long-term culture and upon differentiation. The system described here represents a method to rapidly assemble complex plasmid-based assay systems, controllably insert them into the hESC genome, and have them actively express in pluripotent as well as in differentiated lineages there from.

A targeted neuroglial reporter line generated by homologous recombination in human embryonic stem cells.

In this study, we targeted Olig2, a basic helix-loop-helix transcription factor that plays an important role in motoneuron and oligodendrocyte development, in human embryonic stem cell (hESC) line BG01 by homologous recombination. One allele of Olig2 locus was replaced by a green fluorescent protein (GFP) cassette with a targeting efficiency of 5.7%. Targeted clone R-Olig2 (like the other clones) retained pluripotency, typical hESC morphology, and a normal parental karyotype 46,XY. Most importantly, GFP expression recapitulated endogenous Olig2 expression when R-Olig2 was induced by sonic hedgehog and retinoic acid, and GFP-positive cells could be purified by fluorescence-activated cell sorting. Consistent with previous reports on rodents, early GFP-expressing cells appeared biased to a neuronal fate, whereas late GFP-expressing cells appeared biased to an oligodendrocytic fate. This was corroborated by myoblast coculture, transplantation into the rat spinal cords, and whole genome expression profiling. The present work reports an hESC reporter line generated by homologous recombination targeting a neural lineage-specific gene, which can be differentiated and sorted to obtain pure neural progenitor populations.