Lingual epithelial cells, which constitute the filiform papillae of the tongue are thought to be an origin of the Tongue Cancer. And lingual tissues have one of the most rapid tissue turnover rates in the mammalian body. However, the mechanism of tissue maintenance and regeneration is not well known for these tissues. Here, we show that Bmi1- postitive cells within Cytokeratin14 and Cytokeratin5-positive cells are present in the base but not at the very bottom of the inter-papillary pit as a stem cell. And we demonstrated that one stem cell per inter-papillary pit survives longterm by using a multicolor lineage tracing method. The cells were found to usually be in a slow-growing or resting state; however, on irradiation-induced injury, the cells rapidly entered the cell cycle and regenerated tongue epithelium. The elimination of Bmi1-positive stem cells significantly suppressed the regeneration after irradiation injury. Then we show the establishment of a novel lingual epithelium organoid culture system using a three-dimensional matrix and growth factors in vitro. The organoids harvested at an early point in culture could be engrafted and maturate in the tongue of recipient mice. Taken together, these results suggest that Bmi1-positve cells are important for tissue maintenance and regeneration of the lingual epithelium.

Strategies to expand regulatory T cells (Treg)s hold therapeutic potential for ameliorating T cell-mediated inflammatory diseases. TCR signaling is partially dispensable for IL-2-induced Treg proliferation, as has been shown recently. In contrast, conventional T cells (Tconv)s require TCR signal activation for their proliferation. Therefore, we can expect that in conjunction with IL-2, pharmacological inhibition of TCR signaling may induce the expansion of Tregs while simultaneously inhibiting Tconv proliferation. We hereby demonstrate that costimulation but not TCR-mediated phospholipase Cγ (PLCγ) activation is required for the IL-2-induced Treg proliferation. Using Cyclosporine A (CSA) to inhibit TCR signaling and rapamycin to suppress costimulatory signaling pathways, we also demonstrate that while both agents attenuated antigen-specific Tconv proliferation, only CSA permitted IL-2-induced Treg expansion. Rapamycin, however, did increase the Treg:Tconv ratio due to its negative effects on Tconv survival. Importantly, CSA synergized with IL-2 in protection against experimental autoimmune encephalomyelitis (EAE). However, CSA abolished whereas rapamycin augmented the beneficial effect of IL-2 in graft-versus-host disease (GVHD). These differences could be potentially explained by the ability of rapamycin to promote inducible Treg generation and to allow TCR-enhanced Treg proliferation, processes that were inhibited by CSA but are important for GVHD protection. Thus, depending on the disease setting, different signaling pathways need to be targeted to increase the Treg:Tconv ratio for treatment of T cellmediated inflammatory disorders.

Accumulation of genetic aberrations causes mature B-cell lymphoma. Recent advances in high-throughput technology, including next generation sequencing, have made it possible for us to understand the landscape of genetic abnormalities in lymphoma; however, function-based synergistic analyses of candidate genes for lymphoma development have not been available, except for the transgenic mouse model. This type of functional analyses is essential to understand collaborative pathways leading to malignant transformation and is also important to provide a corroborative evidence for a rationale combination therapy. Therefore, we established an in vitro culture system that allowed multiple gene transduction into normal murine mature B-cells and in vivo transplantation model. In this review, we demonstrate how we explored the molecular mechanisms of B-cell lymphoma development and summarize the recent progress in molecular understandings of the B-cell lymphoma, along with future directions for lymphoma research.

We have recognized the appearance of NG2 antigen in MLL rearrangement-positive ALL. However, it is not clear why NG2 antigen appears in MLL rearrangement-positive ALL. The appearance of NG2 is not distinctive, but it is believed to be useful in MRD detection of MLL rearrangement-positive ALL. Using NG2, we are able to confirm the suspected connection with MLL-related ALL (case 1). And we tried to track the course of MRD in the ALL case (case 2). B cellprecursor acute lymphoblastic leukemia (BCPALL) was initially suspected in case 1. However, positive results for CD79a, CD19 and negative results for CD66c led us to use chondroitin sulfate proteoglycan-type neural-glial antigen 2 antibody (NG2 antibody), with a focus on negative CD10, positive CD15 and partially positive CD34 findings. Positive findings for NG2 confirmed the case 1 as mixed lineage leukemia (MLL)-related ALL. In addition, we confirmed the activity of an idioblast rate by visual observation and the positive rate of the MLL split signal. Tracking of the NG2 positive rate in the course of ALL was effective for the detection of MRD in the case 2.

Patient’s donor specific antibody (DSA) prior to transplantation is at a high risk of developing antibody mediated rejection (AMR) and show a lower rate of graft survival after transplantation. It is thought that graft failure can be prevented by early identification and removal of clinically harmful DSAs associated with AMR. In this study, we focused on and investigated the influences of factors affecting the results of flow cytometry crossmatch (FCXM) and of the types of measuring instruments used. As a requirement for investigation of the inter-instrument difference, it was decided that measurement should be performed at the same time on the same day. Measurement was performed after preparing the samples by washing once to 3 times after the primary antibody response, and adding the secondary antibody by the usual method. The correlation of the ratios between Canto and Calibur was investigated by using channel values, and a positive correlation was found; the correlation coefficient for T cells was R2 = 0.8237 and that for B cells was R2 = 0.8709. We performed analysis by changing the measurement method to the one using the channel values. As a result, a positive correlation was found. Molecules of equivalent soluble fluorochrome (MESF) was also measured by changing the method to that using the channel values, and a calibration curve was prepared. With the change of the measurement method, the calibration curve crossed with the longitudinal axis, which allowed lower values to be detected with a higher sensitivity.