👤 Delger Bayarsaikhan

Hemophilia B is an inherited disorder caused by a mutation in the FIX gene, which results in insufficient blood clotting factor IX (FIX) production from hepatocytes. Currently, there are no treatments for hemophilia B patients. The patients should be continuously administrated with clotting factor concentrates 2-3 times a month to prevent bleeding. Therefore, this study aimed to develop an engineered FIX-secreting hepatocyte sheet that can release FIX for an extended period. Within this study, the engineered FIX-secreting hepatocyte sheet was developed by integrating two core technologies, including a gene editing platform to generate FIX-secreting cells and cell sheet technology to improve cell delivery efficacy. The human FIX gene was inserted into the APOC3 site of iPSCs by CRISPR/Cas9, which secretes the target protein after differentiation into hepatocytes. FIX-secreting hepatocyte sheets were obtained by temperature-responsive polymer grafted cell culture dishes (TRCD). Immunohistochemical and functional tests were performed for hepatocyte-like cells differentiated from FIX KI-iPSCs and wild-type iPSCs (WT-iPSCs). After validating the functional activity and secretion of FIX protein, the engineered hepatocyte-like cell sheets were transplanted to NOD/SCID mice for the in vivo experiments. The insertion of the human FIX gene into the APOC3 site demonstrated a significant increase in FIX secretion in hepatocyte-like cells differentiated from FIX KI-iPSCs compared with those obtained from WT-iPSCs. Among the iPSCs to hepatocyte differentiation stages, the hepatic endoderm stage was most suitable for seeding the cells on TRCD and generating cell sheets by temperature changes from 37 The engineered FIX-secreting cell sheets fabricated from functionally improved iPSCs with practical cell delivery tools could be a promising tool for clinically treating Hemophilia B. Show less

The generation and maintenance of memory T cells are regulated by various factors, including cytokines. Previous studies have shown that IL-27 is produced during the early acute phase of Plasmodium chabaudi chabaudi AS (Pcc) infection and inhibits the development of Th1-type memory CD4+ T cells. However, whether IL-27 acts directly on its receptor on Plasmodium-specific CD4+ T cells or indirectly via its receptor on other immune cells remains unclear. We aimed to determine the role of IL-27 receptor signaling in different immune cell types in regulating the generation and phenotype of memory CD4+ T cells during Plasmodium infection. We utilized Plasmodium-specific T-cell antigen receptor (TCR) transgenic mice, PbT-II, and Il27rα-/- mice to assess the direct and indirect effects of IL-27 signaling on memory CD4+ T-cell generation. Mice were transferred with PbT-II or Il27rα-/- PbT-II cells and infected with Pcc. Conditional knockout mice lacking the IL-27 receptor in T cells or dendritic cells were employed to discern the specific immune cell types involved in IL-27 receptor signaling. High levels of memory in PbT-II cells with Th1-shift occurred only when both PbT-II and host cells lacked the IL-27 receptor, suggesting the predominant inhibitory role of IL-27 signaling in both cell types. Furthermore, IL-27 receptor signaling in T cells limited the number of memory CD4+ T cells, while signaling in both T and dendritic cells contributed to the Th1 dominance of memory CD4+ T cells. These findings underscore the complex cytokine signaling network regulating memory CD4+ T cells during Plasmodium infection. Show less

Malaria infection elicits both protective and pathogenic immune responses, and IL-27 is a critical cytokine that regulate effector responses during infection. Here, we identified a critical window of CD4 Show less