三浦 康生

Abstract This study investigated the anti-tumor effects of andrographolide, a diterpene lactone derived from Andrographis paniculata , on T-cell acute lymphoblastic leukemia (T-ALL) cells. Andrographolide induced dose-dependent cytotoxicity and morphological changes in the T-ALL cell line Jurkat cells, including cell shrinkage and chromatin condensation. Mechanistically, andrographolide triggers apoptosis through reactive oxygen species (ROS) generation, mitochondrial membrane depolarization, and cytochrome c release. These effects were reversed by the ROS inhibitor N-acetyl-L-cysteine (NAC), indicating that andrographolide induces apoptosis through a ROS-dependent apoptotic pathway. In contrast, NAC treatment did not reverse cytarabine- and vincristine-induced apoptosis or the ROS-dependent apoptotic pathway in Jurkat cells. Intriguingly, andrographolide also induced ferroptosis, as evidenced by increased expression of the ferroptosis marker fatty acid-CoA ligase 4 and ultrastructural changes such as reduced mitochondrial area and disappearance of cristae. These effects were likewise reversed by NAC, further implicating ROS in the ferroptotic process. In MOLT-4 cells, where andrographolide suppressed viability, increased Annexin V positivity and ROS levels, and upregulated FACL4 expression in a NAC-sensitive manner. Unlike cytarabine and vincristine, andrographolide did not significantly alter cell cycle distribution. In conclusion, andrographolide induces both apoptosis and ferroptosis in T-ALL cells via ROS-dependent mechanisms that are distinct from those of conventional chemotherapeutic agents. These dual actions position andrographolide as a candidate for standalone or combination therapy in T-ALL.

Abstract Exposure to ionizing radiation can induce harmful biological effects on the human body, particularly in cases of high-dose γ-irradiation affecting the gastrointestinal tract, bone marrow, skin and lung. Such exposures lead to lethal outcomes as individuals experience a breakdown in their immune system’s ability to defend against pathogens, predisposing them to sepsis-induced multiple organ failures. Mesenchymal stromal/stem cells (MSCs) possess diverse biological characteristics, including immunomodulation, anti-inflammation and tissue regeneration. Off-the-shelf culture-expanded human bone marrow- or adipose tissue-derived MSCs are clinically available to treat graft-versus-host disease following hematopoietic cell transplantation and perianal fistulas in Crohn’s disease in Japan. While preclinical studies showcase encouraging outcomes in radiation-induced injuries, the effectiveness of MSC transplantation in addressing acute radiation syndrome affecting organs in irradiated individuals is limited. Recent studies have highlighted MSC-releasing extracellular vesicles as nanoparticle substances responsible for outlining the mechanism of action and have identified various components, including proteins and microRNA, that serve as functional molecules. MSC-releasing extracellular vesicle-based therapy emerges as a promising avenue, offering a potential solution to the challenges posed by radiation-induced injuries. However, further investigation is required, especially regarding whether MSC-releasing extracellular vesicles have regenerative effects on tissue-resident stem cells. These unresolved issues represent key aspects that need to be addressed to optimize the therapeutic potential of cell-based and extracellular vesicle-based MSC therapies for interventions in the context of radiation-induced injuries.

Extracellular vesicles (EVs) serve as an intrinsic system for delivering functional molecules within our body, playing significant roles in diverse physiological phenomena and diseases. Both native and engineered EVs are currently the subject of extensive research as promising therapeutics and drug delivery systems, primarily due to their remarkable attributes, such as targeting capabilities, biocompatibility, and low immunogenicity and mutagenicity. Nevertheless, their clinical application is still a long way off owing to multiple limitations. In this context, the Science Board of the Pharmaceuticals and Medical Devices Agency (PMDA) of Japan has conducted a comprehensive assessment to identify the current issues related to the quality and safety of EV-based therapeutic products. Furthermore, we have presented several examples of the state-of-the-art methodologies employed in EV manufacturing, along with guidelines for critical processes, such as production, purification, characterization, quality evaluation and control, safety assessment, and clinical development and evaluation of EV-based therapeutics. These endeavors aim to facilitate the clinical application of EVs and pave the way for their transformative impact in healthcare.

Abstract Cytopenia is a well-documented complication in the treatment of hematological malignancies with lenalidomide and pomalidomide. Although prior studies have highlighted direct effects on hematopoietic cells to explain this adverse effect, the involvement of hematopoietic-supportive stroma remains less understood. This study examined the effects of lenalidomide/pomalidomide on the expansion and differentiation of human CD34⁺ hematopoietic stem/progenitor cells (HSPCs) in vitro, in co-culture with human bone-marrow mesenchymal stromal/stem cells (MSCs). Our findings indicate that lenalidomide/pomalidomide increases the population of immature CD34⁺CD38⁻ cells while decreasing the number of mature CD34⁺CD38⁺ cells, suggesting a mechanism that inhibits early HSPC maturation. This effect persisted across myeloid, megakaryocytic, and erythroid lineages, with MSCs playing a key role in preserving immature progenitors and inhibiting their differentiation. Furthermore, in myeloid differentiation assays augmented by granulocyte-colony stimulating factor, lenalidomide/pomalidomide not only enhanced the presence of CD34⁺ cells with mature myeloid markers such as CD11b but also reduced the populations lacking CD34 yet positive for these markers, irrespective of MSC presence. Thus, while MSCs support the presence of these immature cell populations, they simultaneously inhibit their maturation. This finding provides novel mechanistic insights into lenalidomide- and pomalidomide-induced cytopenia, and could guide therapeutic strategies for its mitigation.

The treatment of human immunodeficiency virus (HIV-1) has evolved since the establishment of combination antiretroviral therapy (ART) in the 1990s, providing HIV-infected individuals with approaches that suppress viral replication, prevent acquired immunodeficiency syndrome (AIDS) throughout their lifetime with continuous therapy, and halt HIV transmission. However, despite the success of these regimens, the global HIV epidemic persists, prompting a comprehensive exploration of potential strategies for an HIV cure. Here, we offer a consolidated overview of cell-based therapies for HIV-1, focusing on CAR-T cell approaches, gene editing, and immune modulation. Persistent challenges, including CAR-T cell susceptibility to HIV infection, stability, and viral reservoir control, underscore the need for continued research. This review synthesizes current knowledge, highlighting the potential of cellular therapies to address persistent challenges in the pursuit of an HIV cure.

Abstract Background Relapsing polychondritis (RP) is a rare inflammatory disease characterized by recurrent inflammation and destruction of cartilaginous tissues. RP has characteristics of autoimmune disease and some reports have noted co-occurrence with autoimmune thyroid disease (AITD), consisting of Graves’ disease (GD) and Hashimoto thyroiditis (HT). However, there have been no detailed studies on the co-occurrence of RP and AITD. In this study, we aimed to determine whether patients with RP tend to be complicated with AITD. We also analyzed the clinical and genetic profiles of patients in whom these diseases co-occur. Methods We recruited 117 patients with RP and reviewed their medical records. Furthermore, we genotyped Human Leucocyte Antigen (HLA)-A, B Cw, DRB1, DQB1, and DPB1 alleles for 93 of the 117 patients. The prevalence of AITD among the patients with RP was compared with that among the general Japanese population. We also analyzed the clinical and genetic features of the patients with both RP and AITD. Results The prevalence of GD among the patients with RP was 4.3% (5 among 117 patients), significantly higher than that among Japanese (0.11%) (p = 2.44 × 10^–7, binomial test). RP patients with GD tended to have nasal involvement (p = 0.023) (odds ratio (OR) 2.58) and HLA-DPB1*02:02 (p = 0.035, OR 10.41). We did not find significant enrichment of HT in patients with RP. Conclusions Patients with RP appear to be at elevated risk of GD. Nasal involvement and HLA-DPB1*02:02 characterize the subset of RP patients with GD, which may guide attempts to characterize a distinct subtype of RP for precision medicine.

Abstract Objective HLA-DRB1 alleles, particularly the shared epitope (SE) alleles, are strongly associated with RA. Different genetic structures underlie the production of the various autoantibodies in RA. While extensive genetic analyses have been conducted to generate a detailed profile of ACPA, a representative autoantibody in RA, the genetic architecture underlying subfractions of RF other than IgM-RF, namely IgG-RF, known to be associated with rheumatoid vasculitis, is not well understood. Methods We enrolled a total of 743 RA subjects whose detailed autoantibody (IgG-RF, IgM-RF, and ACPA) data were available. We evaluated co-presence and correlations of the levels of these autoantibodies. We analysed associations between the presence or levels of the autoantibodies and HLA-DRB1 alleles for the 743 RA patients and 2008 healthy controls. Results We found both IgG-RF(+) and IgG-RF(–) RA subjects showed comparable associations with SE alleles, which was not observed for the other autoantibodies. Furthermore, there was a clear difference in SE allele associations between IgG-RF(+) and (–) subsets: the association with the IgG-RF(+) subsets was solely driven by HLA-DRB1*04:05, the most frequent SE allele in the Japanese population, while not only HLA-DRB1*04:05 but also HLA-DRB1*04:01, less frequent in the Japanese population but the most frequent SE allele in Europeans, were main drivers of the association in the IgG-RF(–) subset. We confirmed that these associations were irrespective of ACPA presence. Conclusion We found a unique genetic architecture for IgG-RF(–) RA, which showed a strong association with a SE allele not frequent in the Japanese population but the most frequent SE allele in Europeans. The findings could shed light on uncovered RA pathology.

SARS-CoV-2 infection has been reported to be associated with a positive direct antiglobulin test (DAT). In this study, an analysis of 40 consecutive coronavirus disease 2019 (COVID-19) cases from December 2020 to September 2021 in Japan revealed that patients of 70 years and over were predisposed to a positive DAT. DAT positivity was related to a decrease in the hemoglobin level. Anemia in DAT-positive COVID-19 patients was attributed to hemolysis, which was corroborated by high reticulocyte counts and an increase in the red blood cell distribution width. Human leukocyte antigen (HLA)-DRB1*12:01 and DRB1*12:02 were exclusively found in DAT-positive COVID-19 patients. In silico assays for the Spike protein of SARS-CoV-2 predicted several common core peptides that met the criteria for a B cell epitope and strong binding to both HLA-DRB1*12:01 and DRB1*12:02. Among these peptides, the amino acids sequence TSNFR, which is found within the S1 subunit of SARS-CoV-2 Spike protein, is shared by human blood group antigen Rhesus (Rh) CE polypeptides. In vitro analysis showed that the expression of HLA-DR in CD4+ T cells and CD8+ T cells from a DAT-positive patient was increased after pulsation with TSNFR-sequence-containing peptides. In summary, positive DAT is related to enhanced anemia and to HLA-DR12 in the Japanese population. A peptide sequence within SARS-CoV-2 Spike protein may act as an epitope for IgG binding to RBCs in DAT-positive COVID-19 patients.

A 43-year-old Japanese male, who had undergone open liver surgery for tumor resection, presented with decreased hemoglobin levels on Day 13 post-emergency-release transfusion of 16 units of Fy(a +) red blood cells. As the anemia was accompanied by increased lactate dehydrogenase, indirect bilirubin, and reticulocytes, as well as decreased haptoglobin, it was attributed to hemolysis. In the diagnostic workup for hemolytic reaction, the direct antiglobulin test result for IgG was positive and the antibody dissociated from the patient's peripheral red blood cells was identified as anti-Fya (titer, 4). The hemolytic reaction was transient (approximately 10 days), of moderate severity, and did not result in any obvious organ damage. However, a single compatible red blood cell transfusion of 2 units was required on Day 17 after the causative transfusion. Notably, HLA typing revealed that the patient carried the HLA-DRB1*04:03 allele, which has been implicated in immunogenicity and induction of anti-Fya response in Caucasian populations. In summary, this is the first documented case of definitive anti-Fya-mediated delayed hemolytic transfusion reaction associated with HLA-DRB1*04:03 in the Japanese population.

BACKGROUND: The anti-cyclic citrullinated peptide (CCP) antibody is a diagnostic biomarker of rheumatoid arthritis (RA). However, some non-RA connective tissue disease (CTD) patients also test positive for the anti-CCP antibody and, thus, may ultimately develop RA. We retrospectively investigated whether anti-CCP-positive non-RA CTD patients developed RA and attempted to identify factors that may differentiate RA-overlapping CTD from pure CTD. METHODS: In total, 842 CTD patients with a primary diagnosis that was not RA were selected from our CTD database as of December 2012. Anti-CCP antibody titers were obtained from a retrospective chart review or measured using stored sera. RA was diagnosed according to the 1987 revised American College of Rheumatology classification criteria. Thirty-three anti-CCP-positive non-RA CTD patients were retrospectively followed up for the development of RA. Bone erosions on the hands and feet were assessed by X-ray. Citrullination dependency was evaluated by an in-house ELISA, the HLA-DRB1 allele was typed, and the results obtained were then compared between RA-overlapping and non-RA anti-CCP-positive CTD patients. RESULTS: Two out of 33 anti-CCP-positive CTD patients (6.1%) developed RA during a mean follow-up period of 8.9 years. X-rays were examined in 27 out of the 33 patients, and only one (3.7%) showed bone erosions. The frequency of the HLA-DRB1 shared epitope (SE) and anti-CCP antibody titers were both significantly higher in anti-CCP-positive RA-overlapping CTD patients than in anti-CCP-positive non-RA CTD patients, while no significant differences were observed in citrullination dependency. CONCLUSIONS: Anti-CCP-positive non-RA CTD patients rarely developed RA. HLA-DRB1 SE and anti-CCP antibody titers may facilitate the differentiation of RA-overlapping CTD from anti-CCP-positive non-RA CTD.

Vitamin K2 in the form of menatetrenone has clinical benefits for osteoporosis and cytopenia. Given the dominant role of mesenchymal-osteolineage cells in the regulation of hematopoiesis, we investigated whether menatetrenone alters the hematopoiesis-supportive capability of human bone marrow mesenchymal stromal/stem cells (BM-MSCs). Menatetrenone up-regulated fibronectin protein expression in BM-MSCs without affecting their proliferation and differentiation capabilities. In addition, menatetrenone treatment of BM-MSCs enhanced generation of the CD34+ cell population in co-cultures through acceleration of the cell cycle. This effect was associated with cell-cell interactions mediated by VLA-4 and fibronectin. This proposal was supported by cytokine array and quantitative real-time PCR analyses, in which there were no significant differences between the expression levels of hematopoiesis-associated soluble factors in naïve and menatetrenone-treated BM-MSCs. Profiling of hematopoietic cells in co-cultures with menatetrenone-treated BM-MSCs demonstrated that they included significantly more CD34+CD38+ hematopoietic progenitor cells and cells skewed toward myeloid and megakaryocytic lineages than those in co-cultures with untreated BM-MSCs. Notably, myelodysplastic syndrome-derived cells were induced to undergo apoptosis when co-cultured with BM-MSCs, and this effect was enhanced by menatetrenone. Overall, our findings indicate that pharmacological treatment with menatetrenone bestows a unique hematopoiesis-supportive capability on BM-MSCs, which may contribute to the clinical improvement of cytopenia.

BACKGROUND: Despite recent progress in blood systems, transfusion errors can occur at any time from the moment of collection through to the transfusion of blood and blood products. This study investigated the actual statuses of blood transfusion errors at institutions of all sizes in Aichi prefecture. MATERIALS AND METHODS: We investigated 104 institutions that perform 98 % of the blood transfusions in Aichi prefecture, and investigated the errors (incidents/accidents) that occurred at these facilities over 6 months (April to September, 2017). Incident/accident data were collected from responses to questionnaires sent to each institution; these were classified according to the categories and risk levels. RESULTS: Ninety-seven of the 104 institutions (93.3 %) responded to the questionnaire; a total of 688 incidents/accidents were reported. Most (682 cases; 99.2 %), were classified as risk level 2; however, 6 were level 3 and over, which included problems with autologous transfusion and inventory control. Approximately one-half of the incidents/accidents (394 cases; 57.3 %), were related to verification and the actual administration of blood products at the bedside; more than half of these incidents/accidents occurred at large-volume institutions. Meanwhile, a high frequency of incidents/accidents related to transfusion examination and labeling of blood products was observed at small- or medium-sized institutions. The reasons for most of these errors were simple mistakes and carelessness by the medical staff. CONCLUSIONS: Our results emphasize the importance of education, operational training, and compliance instruction for all members of the medical staff despite advances in electronic devices meant to streamline transfusion procedures.

健常人骨髄由来の間葉系幹細胞(BM-MSC)に対して2Gy以上の高線量のγ線照射を行い、MSC機能に与える影響について検討した。その結果、2Gy以上のγ線照射によって多分化能やB細胞分化支持能が障害されることが明らかになった。今回の検討から、造血幹細胞移植の前処置として用いる全身照射がBM-MSCに対して長期的な影響を及ぼすことで、移植後長期生存者の晩期合併症を生じる可能性が示唆された。

大阪市で開催された第80回日本血液学会総会（総会長 松村到教授）において教育講演を行いました [Abstract #EL3-3D]. 平成30年10月14日

MSCの機能を薬物学的に機能賦活することで治療効果を増強させる（Pharmacological activation of MSC）私たちのこれまでの研究成果をまとめました。

凍結保存することでさい帯血からのMSC分離効率が約60%低下することを示しました。