Allele Biotech Receives $200,000 Grant to Update Its mRNA Reprogramming Commercial Products and Services

On June 10, 2013 Allele received an SBIR award from the National Institute of Drug Abuse (NIDA/NIH) entitled “Revolutionary Technology for Efficient Derivation of Human iPSCs with Messenger RNA”. The goal of the proposed project is to provide to the biomedical research market an advanced reagent kit and services for highly efficient reprogramming of high quality human induced pluripotent stem cells (iPSCs). At the core of this kit is the Allele team’s recent development transcribed messenger RNA (mRNA). Compared to other reprogramming methods, such as lentivirus, Sendai virus, protein, small molecules or any combinations of these reagents, our new generation of the mRNA method often requires less than half the time while sometimes achieving “bulk conversion” efficiency.

While the Allele reprogramming technology was designed for clinical use as the process is feeder-free, xeno-free, chromosome integration-free, as well as without the need for cell splitting, PI, Dr. Jiwu Wang states, “Our purpose of executing the NIH-funded research it to make our method so easy that any researcher can integrate iPSC into his or her projects.” In addition to the extremely high efficiency, mRNA-generated iPSCs should also be more stable because there are no genetic alterations, more uniform among all clones as there is no clonal event, and ultimately suitable for future autologous cell therapy now that creating iPSCs from patient tissue cells should no longer be the rate-limiting steps.

Allele’s business model is to provide cGMP-grade iPSCs to pharmaceutical companies and perform large scale reprogramming by partnering first with university-affiliated hospitals. Great progress has been made in both directions, which has prompted the initiation of a cGMP unit within Allele’s newly acquired building in San Diego.

Autologous versus Allogeneic iPSCs in Immune Rejection

http://blog.allelebiotech.com/2013/04/1562/

The enthusiasm of using autologous induced pluripotent stem cells (iPSCs) for cell replacement therapy was dampened by a publication 2 years ago in Nature (Zhao et al, 2011), which suggested that even syngeneic (genetically identical) iPSCs could still invoke strong immune rejection because, as the authors in Yang Xu’s lab at UCSD explained, the iPSCs overexpress a number of tumor antigens possibly linked to genomic mistakes acquired during reprogramming. Embryonic stem cells (ESCs), on the other hand, did not show similar rejection problems in the same studies, indicating that the immune responses were due to somatic reprogramming.

If proven true, the iPSC-specific immune rejection would have been the biggest hurdle for any iPSC-inspired clinical plans. Naturally, a number of labs performed series of experiments that were aimed at addressing the concerns raised by Zhao et al. This month in Cell Stem Cell, researchers from Ashleigh Boyd’s lab at Boston University demonstrated that autologous (self) or syngeneic iPSCs or their derivatives were not rejected (Guha et al. 2013). These iPSCs behaved essentially the same as ESCs in transplantation settings. When immunogenicity was measured in vitro by monitoring T cell responses in co-culture, no immune response was observed either. In contrast, cells and tissues from allogeneic (genetically different) iPSCs were rejected immediately.

In light of this new publication and an earlier Nature paper (Araki et al. 2013), Kaneko and Yamanaka have commented that autologous iPSCs still seem to have a very good chance of being used in cell replacement therapy, pending, of course, additional research and trial results. In their Preview article in Cell Stem Cell (Kaneko and Yamanaka 2013) two points were particularly emphasized: 1) autologous iPSCs are preferred because of the lack of immune rejection; 2) iPSCs generated with footprint-free reprogramming technologies are preferred because the problems reported by Zhao et al 2011 might be correlated with the use of retroviral vectors (even though they also used episomal plasmid-reprogrammed iPSCs). We strongly support both of these points and believe that they point out the direction of future stem cell therapies.

However, we do not agree with the last statement by Kaneko and Yamanaka in that article stating that as a result of the cost and time required to generate iPSC lines from each patient in GMP facilities, iPSC lines from HLA homologous donors will be the choice going forward to clinical applications. First of all, HLA-matched iPSCs should be closer to allogeneic than to autologous iPSCs. From what we just learned in the last round of debates, the field should certainly go with autologous. Second, generating foot-print free iPSCs may already not be the rate-limiting step, even in GMP protocols, compared to downstream differentiations that are required using any pluripotent stem cells. We have shown that human fibroblasts can be reprogrammed in a completely feeder-free, xeno-free, passage-free process, using only mRNAs, in just over a week, achieving sometimes “bulk conversion”—converting nearly all cells within a well into iPSCs (Warren et al. 2012). We have drawn up a plan to establish cGMP protocols and to quickly apply autologous, footprint-free iPSCs to clinical programs through partnerships. The field can move at a faster speed, with all due scientific vigor and caution, if the best technology available is chosen for building the foundation.

Zhao, T., Z.N. Zhang, Z. Rong, and Y. Xu, Immunogenicity of induced pluripotent stem cells. Nature, 2011. 474(7350): p. 212-5.

Guha, P., et al., Lack of immune response to differentiated cells derived from syngeneic induced pluripotent stem cells. Cell Stem Cell, 2013. 12(4): p. 407-1
Kaneko, S. and S. Yamanaka, To Be Immunogenic, or Not to Be: That’s the iPSC Question. Cell Stem Cell, 2013. 12(4): p. 385-6.
Araki, R., et al., Negligible immunogenicity of terminally differentiated cells derived from induced pluripotent or embryonic stem cells. Nature, 2013. 494(7435): p. 100-4.
Warren, L., Y. Ni, J. Wang, and X. Guo, Feeder-free derivation of human induced pluripotent stem cells with messenger RNA. Sci Rep, 2012. 2: p. 657.