ABSTRACT
The Hadassah hESC Research Center's aim is to be a supplier of clinical and research-grade human embryonic stem cell (hESC) lines. In 2012, we derived the first three entirely GMP-compliant and xeno-free, fully-characterised, feeder-dependent (human umbilical cord) hESC lines developed under cleanroom conditions. In 2018, we established four new GMP and xeno-free, feeder-independent MCB hESCs under GMP conditions using commercially available reagents, media and matrix. All cell lines were derived under Israeli Ministry of Health's National Ethics Committee for Genetic Research in Humans and the ethical considerations that guided the development of the hESCs strictly followed Israeli law. Hadassah has provided its clinical-grade hESC lines to commercial entities of which two are already in clinical trials, establishing Hadassah as a key provider of clinical-grade hESC lines.
Subject(s)
Cell Culture Techniques/methods , Embryonic Stem Cells/metabolism , Pluripotent Stem Cells/metabolism , Cell Differentiation , HumansABSTRACT
Clinically compliant human embryonic stem cells (hESCs) should be developed in adherence to ethical standards, without risk of contamination by adventitious agents. Here we developed for the first time animal-component free and good manufacturing practice (GMP)-compliant hESCs. After vendor and raw material qualification, we derived xeno-free, GMP-grade feeders from umbilical cord tissue, and utilized them within a novel, xeno-free hESC culture system. We derived and characterized three hESC lines in adherence to regulations for embryo procurement, and good tissue, manufacturing and laboratory practices. To minimize freezing and thawing, we continuously expanded the lines from initial outgrowths and samples were cryopreserved as early stocks and banks. Batch release criteria included DNA-fingerprinting and HLA-typing for identity, characterization of pluripotency-associated marker expression, proliferation, karyotyping and differentiation in-vitro and in-vivo. These hESCs may be valuable for regenerative therapy. The ethical, scientific and regulatory methodology presented here may serve for development of additional clinical-grade hESCs.
Subject(s)
Cell Culture Techniques/methods , Embryonic Stem Cells/cytology , Cell Culture Techniques/ethics , HumansABSTRACT
Undifferentiated human embryonic stem cells (hESCs) are currently propagated on a relatively small scale as monolayer colonies. Culture of hESCs as floating aggregates is widely used for induction of differentiation into embryoid bodies. Here we show that hESC lines can be derived from floating inner cell masses in suspension culture conditions that do not involve feeder cells or microcarriers. This culture system supports prolonged propagation of the pluripotent stem cells as floating clusters without their differentiation into embryoid bodies. HESCs cultivated as aggregates in suspension maintain the expression of pluripotency markers and can differentiate into progeny of the three germ layers both in vitro and in vivo. We further show the controlled differentiation of hESC clusters in suspension into neural spheres. These results pave the way for large-scale expansion and controlled differentiation of hESCs in suspension, which would be valuable in basic and applied research.
Subject(s)
Cell Culture Techniques/methods , Embryonic Stem Cells/cytology , Embryonic Stem Cells/physiology , Tissue Engineering/methods , Cell Differentiation , Cell Proliferation , Cells, Cultured , HumansABSTRACT
Dysfunction and loss of retinal pigment epithelium (RPE) leads to degeneration of photoreceptors in age-related macular degeneration and subtypes of retinitis pigmentosa. Human embryonic stem cells (hESCs) may serve as an unlimited source of RPE cells for transplantation in these blinding conditions. Here we show the directed differentiation of hESCs toward an RPE fate under defined culture conditions. We demonstrate that nicotinamide promotes the differentiation of hESCs to neural and subsequently to RPE fate. In the presence of nicotinamide, factors from the TGF-beta superfamily, which presumably pattern RPE development during embryogenesis, further direct RPE differentiation. The hESC-derived pigmented cells exhibit the morphology, marker expression, and function of authentic RPE and rescue retinal structure and function after transplantation to an animal model of retinal degeneration caused by RPE dysfunction. These results are an important step toward the future use of hESCs to replenish RPE in blinding diseases.
