| 研究実績の概要 |
Recent evidence indicates that human megakaryocytes (MKs) represent a heterogeneous population, which includes an immune subset that is genetically programmed. However, the ontogeny of this heterogeneity in human MKs is not well understood. In this study, we sought to investigate the regulation of immune-biased MKs utilizing an immortalized MK cell line (imMKCLs), which is derived from human-induced pluripotent stem cells (iPSCs) and serves as a source of iPSC-derived platelets (iPSC-PLTs) used in clinical trials.
In 2022, we conducted a series of studies aimed at characterizing the immune properties of imMKCLs and elucidating the key regulators involved in immune-skewed imMKCLs. Specifically, we investigated the expression of several immune-related surface markers and found ICAM-1 and CD11b were expressed on imMKCLs. To identify potential factors involved in the lineage determination of immune-biased transcriptional signatures during imMKCL development, we conducted single-cell RNA-seq analysis using imMKCLs. Through gain-of-function and lentiviral-mediated forced expression studies, we identified let-7a-5p and its downstream target gene X as potential key regulators involved in immune-skewed imMKCL development. Unexpectedly, we discovered that the dysregulated immune properties/subsets of imMKCLs were closely linked with deficient proliferation and subsequently impaired PLT production.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
2: おおむね順調に進展している
理由
The task 1 and 2 listed in the proposal have been mostly achieved. The immune-skewed transcriptional signatures have been identified by bulk and single cell RNA sequencing analyses. Besides, further IPA analysis and loss-of-function trials enable the identification and validation of let-7 targets. However, other immune properties should be further studied, despite of expression of surface markers and transcriptional signatures.
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| 今後の研究の推進方策 |
In 2023, my research will focus primarily on conducting studies related to Task 3, which aims to identify transcriptional differences between MKs derived from iPSCs of COVID-19 patients with varying disease severity. To accomplish this, iPSCs from COVID-19 patients will be directly differentiated into MKs, and immortalized imMKCLs will also be established. To enrich immune subsets, let-7 microRNA switches will be utilized. These samples will be subjected to bulk RNA-seq analysis, and if necessary, scRNA-seq analysis will also be conducted.
The manuscript related to the regulation of immune MKs is expected to be submitted for publication within the current year.
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