Ten years of iPSC: clinical potential and advances in vitro hematopoietic differentiation.

Ten years have passed since the first publication announcing the generation of induced pluripotent stem cells (iPSCs). Issues related to ethics, immune rejection, and cell availability seemed to be solved following this breakthrough. The development of iPSC technology allows advances in in vitro cell differentiation for cell therapy purpose and other clinical applications. This review provides a perspective on the iPSC potential for cell therapies, particularly for hematological applications. We discuss the advances in in vitro hematopoietic differentiation, the possibilities to employ iPSC in hematology studies, and their potential clinical application in hematologic diseases. The generation of red blood cells and functional T cells and the genome editing technology applied to mutation correction are also covered. We highlight some of the requirements and obstacles to be overcome before translating these cells from research to the clinic, for instance, iPSC variability, genotoxicity, the differentiation process, and engraftment. Also, we evaluate the patent landscape and compile the clinical trials in the field of pluripotent stem cells. Currently, we know much more about iPSC than in 2006, but there are still challenges that must be solved. A greater understanding of molecular mechanisms underlying the generation of hematopoietic stem cells is necessary to produce suitable and transplantable hematopoietic stem progenitor cells from iPSC.

Development of an Integrated Continuous Manufacturing Process for the rVSV-Vectored SARS-CoV-2 Candidate Vaccine.

The administration of viral vectored vaccines remains one of the most effective ways to respond to the ongoing novel coronavirus disease 2019 (COVID-19) pandemic. However, pre-existing immunity to the viral vector hinders its potency, resulting in a limited choice of viral vectors. Moreover, the basic batch mode of manufacturing vectored vaccines does not allow one to cost-effectively meet the global demand for billions of doses per year. To date, the exposure of humans to VSV infection has been limited. Therefore, a recombinant vesicular stomatitis virus (rVSV), which expresses the spike protein of SARS-CoV-2, was selected as the vector. To determine the operating upstream process conditions for the most effective production of an rVSV-SARS-CoV-2 candidate vaccine, a set of critical process parameters was evaluated in an Ambr 250 modular system, whereas in the downstream process, a streamlined process that included DNase treatment, clarification, and a membrane-based anion exchange chromatography was developed. The design of the experiment was performed with the aim to obtain the optimal conditions for the chromatography step. Additionally, a continuous mode manufacturing process integrating upstream and downstream steps was evaluated. rVSV-SARS-CoV-2 was continuously harvested from the perfusion bioreactor and purified by membrane chromatography in three columns that were operated sequentially under a counter-current mode. Compared with the batch mode, the continuous mode of operation had a 2.55-fold increase in space-time yield and a reduction in the processing time by half. The integrated continuous manufacturing process provides a reference for the efficient production of other viral vectored vaccines.

Induced Pluripotent Stem Cell for the Study and Treatment of Sickle Cell Anemia.

Sickle cell anemia (SCA) is a monogenic disease of high mortality, affecting millions of people worldwide. There is no broad, effective, and safe definitive treatment for SCA, so the palliative treatments are the most used. The establishment of an in vitro model allows better understanding of how the disease occurs, besides allowing the development of more effective tests and treatments. In this context, iPSC technology is a powerful tool for basic research and disease modeling, and a promise for finding and screening more effective and safe drugs, besides the possibility of use in regenerative medicine. This work obtained a model for study and treatment of SCA using iPSC. Then, episomal vectors were used for reprogramming peripheral blood mononuclear cells to obtain integration-free iPSC. Cells were collected from patients treated with hydroxyurea and without treatment. The iPSCP Bscd lines were characterized for pluripotent and differentiation potential. The iPSC lines were differentiated into HSC, so that we obtained a dynamic and efficient protocol of CD34+CD45+ cells production. We offer a valuable tool for a better understanding of how SCA occurs, in addition to making possible the development of more effective drugs and treatments and providing better understanding of widely used treatments, such as hydroxyurea.