bioRxiv Science⌕ Search

Biology subjects

Petrus-Reurer, S.

Publications and source records attributed to Petrus-Reurer, S..

4 recordsLinked to original sources

Immunogenicity of autologous and allogeneic human primary cholangiocyte organoids

Primary human cells cultured in 3D organoid format have great promise as potential regenerative cellular therapies, but their immunogenicity has not yet been fully characterized. In this study, we use in vitro co-cultures and in vivo humanized mouse experimental models to examine the human immune response to autologous and allogeneic primary cholangiocyte organoids (PCOs). Our data demonstrate that PCOs upregulate the expression of HLA-I and HLA-II in inflammatory conditions. The immune response to allogeneic PCOs is driven by both HLA-I and HLA-II and is substantially ameliorated by donor-recipient HLA matching. Autologous PCOs induce a low-level immune infiltration into the graft site, while allogeneic cells display evolving stages of immune rejection in vivo. Our findings have important implications for the design and clinical translation of autologous and allogeneic organoid cellular therapies. ONE-SENTENCE SUMMARYThe immune response to human primary cholangiocyte organoids is ameliorated by donor-recipient HLA matching.

immunology↗

Generation of functional hepatocytes by forward programming with nuclear receptors

Production of large quantities of hepatocytes remains a major challenge for a number of clinical applications in the biomedical field. Directed differentiation of human pluripotent stem cells (hPSC) into hepatocyte-like cells (HLCs) provides an advantageous solution and a number of protocols have been developed for this purpose. However, these methods usually follow different steps of liver development in vitro which is time consuming and requires complex culture conditions. In addition, HLCs lack the full repertoire of functionalities characterising primary hepatocytes. Here, we explore the interest of forward programming to generate hepatocytes from hPSCs and to bypass these limitations. This approach relies on the overexpression of 3 hepatocyte nuclear factors (HNF1A, HNF6 and FOXA3) in combination with different nuclear receptors expressed in the adult liver using the OPTi-OX platform. Forward programming allows for the rapid production of hepatocytes (FoP-Heps) with functional characteristics using a simplified process. We also uncovered that the overexpression of nuclear receptors such as RORc can enhance specific functionalities of FoP-Heps thereby validating its role in lipid/glucose metabolism. Together, our results show that forward programming could offer a versatile alternative to direct differentiation for generating hepatocytes in vitro.

developmental biology↗

Single-cell atlas of human liver development reveals pathways directing hepatic cell fates

The liver has been studied extensively due to the broad number of diseases affecting its vital functions. However, therapeutic advances, especially in regenerative medicine, are currently hampered by the lack of knowledge concerning human hepatic cell development. Here, we addressed this limitation by describing the developmental trajectories of different cell types comprising the human fetal liver at single-cell resolution. These transcriptomic analyses revealed that sequential cell-to-cell interactions direct functional maturation of hepatocytes, with non-parenchymal cells playing critical, supportive roles during organogenesis. We utilised this information to derive bipotential hepatoblast organoids and then exploited this novel model system to validate the importance of key signalling pathways and developmental cues. Furthermore, these insights into hepatic maturation enabled the identification of stage-specific transcription factors to improve the functionality of hepatocyte-like cells generated from human pluripotent stem cells. Thus, our study establishes a new platform to investigate the basic mechanisms of human liver development and to produce cell types for clinical applications.

developmental biology↗

Molecular profiling of retinal pigment epithelial cell differentiation for therapeutic use

Human embryonic stem cell-derived retinal pigment epithelial cells (hESC-RPE) are a promising cell source to treat age-related macular degeneration (AMD). Despite several ongoing clinical studies, detailed single cell mapping of the transient cellular and molecular dynamics from the pluripotent state to mature RPE has not been performed. Here we conduct single-cell transcriptomic analyses of 25,718 cells during differentiation as well as in embryonic and adult retina references, revealing differentiation progression through an un-expected initial cell diversification recapitulating early embryonic development before converging towards an RPE lineage. We also identified NCAM1 to track and capture an intermediate retinal progenitor with the potential to give rise to multiple neuroepithelial lineages. Finally, we profiled hESC-RPE cells after subretinal transplantation into the rabbit eye, uncovering robust in vivo maturation towards an adult state. Our detailed evaluation of hESC-RPE differentiation supports the development of safe and efficient pluripotent stem cell-based therapies for AMD.

developmental biology↗