ProtoNK™ cell technology is the heart of our work here at HebeCell. The process of producing NK cells indefinitely is simple, but the results and possibilities are limitless.
HebeCell’s ProtoNKTM is the trademark name for the human natural killer (NK) cells derived from human pluripotent stem cells (eg. human embryonic or induced pluripotent stem cells, abbreviated as hESCs or hiPSCs) using HebeCell’s proprietary feeder-free 3D bioreactor based manufacture process. The prefix prot-, or proto-, comes from Greek and has the basic meaning “first formed.” A prototype is something that serves as a model or inspiration for those that come later.
The principle of HebeCell’s methodology is to mimic the natural developmental process of hematopoiesis in human body through formation and subsequent in vitro development of hematopoietic organoids. The hematopoietic organoids, similar to human in vivo hematopoiesis, will undergo several waves of the hematopoiesis process generating hematopoietic cells of primitive, definitive, lymphoid phenotypes. HebeCell’s ProtoNKTM cells are exclusively generated from the 3rd wave of hematopoiesis in the organoids producing highly pure CD56+CD3- NK cells.
HebeCell’s ProtoNKTM cells are predominately CD56+bright and display better or comparable cytotoxic activity in vitro with NK92 cell line and peripheral blood NK cells. In addition to expressing common NK activating and inhibitory receptors, ProtoNKTM has a high percentage of CD56+/CD8+ (CD8alpha-alpha) population which is highly correlated with their cytotoxicity against target cells.
In summary, ProtoNKTM cells are developmentally identical to natural formed NK cells developing in the human body without artificial manipulation, e.g. involvement of engineered feeder cells or genetic modification of hematopoietic genes. More specifically, ProtoNKTM cells are not expanded though co-culture using artificial antigen presenting cells and are similar, if not identical, to primary NK cells.
HebeCell PSC-NK Platform
We start with a small sample of white blood cells from a young, healthy donor. We convert these cells into induced pluripotent stem cells (iPS cells) or with human embryonic stem cells (hES Cells). They can also transform into any type of cell in the human body. We then suspend the PSCs in a liquid solution (i.e. the culture medium) so that they can reproduce in a three-dimensional space within a bioreactor. This provides far more room for growth than traditional petri dish models. Bioreactors use magnetically activated agitators to break up clumps of cells, ensuring even, controlled growth and development.
We can efficiently convert the PSCs into natural killer (NK) cells by switching the culture medium within the bioreactor. This is the most important step in the process because it provides a stable, reliable way to produce an enormous number of NK cells in a relatively short amount of time. The number of NK cells produced is limited only by the size of the bioreactor, which is inexpensive to manufacture and operate. Many bioreactors can operate within the same facility to save power and maximize efficiency. In the HebeCell labs alone, we have produced billions of healthy, viable NK cells in under three months. NK cells can be easily stored for future use in standard cryogenic freezers, several of which we have in our lab. Stored cells such are thought to have a shelf life of more than twenty years.
Each sphere is composed of thousands of stem cells that express green fluorescence protein (GFP)
NK cells are unique because they can target and kill specific types of cells — in this case, cancer cells. Importantly, our NK cells are allogeneic, which means that they can be used to treat any patient. This drastically reduces the time, effort, and cost required to produce therapies for specific patients. It also means that older patients, whose own NK cells have been damaged by the aging process, can take advantage of younger, healthier cells that will have a better chance of fighting disease.
NK cells use a special protein, perforin, and a special enzyme, granzyme, to penetrate the cell membranes of cancer cells, causing apoptosis (cell death). HebeCell’s NK cells are specifically programmed to target only cancer cells and leave other cells alone.
Other Patented HebeCell Technologies
Retinal photoreceptor progenitors
Macular degeneration, the leading cause of blindness in adults worldwide, is caused by the death of certain cells within the retina. HebeCell scientists have developed a process to engineer iPS cells into retinal photoreceptor progenitors, or RPRPs, to produce young, functioning photosensitive cells that can replace dead or dying ones. RPRPs also show promise for treating other vision-related issues, including retinitis pigmentosa.
Nanoproteins
Certain proteins, called neurotrophic factors, support the life and function of macular retinal cells. These proteins, however, are very fragile and can only survive for a few days in the human body. Your body needs to produce them continuously, because failure to do so causes retinal cells to die, resulting in macular degeneration. HebeCell scientists have shown that a single injection of nanoproteins — neurotrophic factors embedded in tiny nanoparticles that last for months — can keep retinal cells alive for far longer, reducing the effects of macular degeneration.