Language：English   Publishing type：Research paper (scientific journal)  

A massive increase in the number of mature CD4+ T-cells in peripheral blood (PB) is a defining characteristic of acute type of adult T-cell leukemia (ATL). To date, the site of proliferation of ATL cells in the body has been unclear. In an attempt to address this question, we examined the expression of the proliferation marker, Ki-67, in freshly isolated ATL cells from PB and lymph nodes (LNs) of patients with various types of ATL. Our findings reveal that LN-ATL cells display higher expression of the Ki-67 antigen than PB-ATL cells in acute type patients. The gene expression of T-cell quiescence regulators such as Krüppel-like factor 2/6 and forkhead box protein 1 was substantially high in acute type PB-ATL cells. The expression of human telomerase reverse transcriptase, which is involved in T-cell expansion, was significantly low in PB-ATL cells from acute type patients, similar to that in normal resting T-cells. These findings suggest that ATL cells proliferate in the LNs rather than in PB.

DOI： 10.1038/s41417-022-00475-0

PubMed

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Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.bbrep.2021.100984

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Language：English  

Ras GTPase-activating proteins negatively regulate the Ras/Erk signaling pathway, thereby playing crucial roles in the proliferation, function, and development of various types of cells. In this study, we identified a novel Ras GTPase-activating proteins protein, RASAL3, which is predominantly expressed in cells of hematopoietic lineages, including NKT, B, and T cells. We established systemic RASAL3-deficient mice, and the mice exhibited a severe decrease in NKT cells in the liver at 8 weeks of age. The treatment of RASAL3-deficient mice with α-GalCer, a specific agonist for NKT cells, induced liver damage, but the level was less severe than that in RASAL3-competent mice, and the attenuated liver damage was accompanied by a reduced production of interleukin-4 and interferon-γ from NKT cells. RASAL3-deficient NKT cells treated with α-GalCer in vitro presented augmented Erk phosphorylation, suggesting that there is dysregulated Ras signaling in the NKT cells of RASAL3-deficient mice. Taken together, these results suggest that RASAL3 plays an important role in the expansion and functions of NKT cells in the liver by negatively regulating Ras/Erk signaling, and might be a therapeutic target for NKT-associated diseases.

DOI： 10.1002/eji.201444977

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Blackwell Publishing Ltd  

DOI： 10.1111/cas.12618

Scopus

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Publishing type：Research paper (scientific journal)   Publisher：American Society of Hematology  

<title>Key Points</title>
Interaction of HTLV-1 Tax with USP10 reduces arsenic-induced stress granule formation and enhances ROS production. USP10 controls sensitivities of leukemia cell lines to arsenic-induced apoptosis.

DOI： 10.1182/blood-2013-03-493718

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