Nonmyelinating Schwann cells maintain hematopoietic stem cell hibernation in the bone marrow niche.

Hematopoietic stem cells (HSCs) reside and self-renew in the bone marrow (BM) niche. Overall, the signaling that regulates stem cell dormancy in the HSC niche remains controversial. Here, we demonstrate that TGF-ß type II receptor-deficient HSCs show low-level Smad activation and impaired long-term repopulating activity, underlining the critical role of TGF-ß/Smad signaling in HSC maintenance. TGF-ß is produced as a latent form by a variety of cells, so we searched for those that express activator molecules for latent TGF-ß. Nonmyelinating Schwann cells in BM proved responsible for activation. These glial cells ensheathed autonomic nerves, expressed HSC niche factor genes, and were in contact with a substantial proportion of HSCs. Autonomic nerve denervation reduced the number of these active TGF-ß-producing cells and led to rapid loss of HSCs from BM. We propose that glial cells are components of a BM niche and maintain HSC hibernation by regulating activation of latent TGF-ß.

Functional calcium-responsive parathyroid glands generated using single-step blastocyst complementation.

Patients with permanent hypoparathyroidism require lifelong replacement therapy to avoid life-threatening complications, The benefits of conventional treatment are limited, however. Transplanting a functional parathyroid gland (PTG) would yield better results. Parathyroid gland cells generated from pluripotent stem cells in vitro to date cannot mimic the physiological responses to extracellular calcium that are essential for calcium homeostasis. We thus hypothesized that blastocyst complementation (BC) could be a better strategy for generating functional PTG cells and compensating loss of parathyroid function. We here describe generation of fully functional PTGs from mouse embryonic stem cells (mESCs) with single-step BC. Using CRISPR-Cas9 knockout of Glial cells missing2 (Gcm2), we efficiently produced aparathyroid embryos for BC. In these embryos, mESCs differentiated into endocrinologically mature PTGs that rescued Gcm2-/- mice from neonatal death. The mESC-derived PTGs responded to extracellular calcium, restoring calcium homeostasis on transplantation into mice surgically rendered hypoparathyroid. We also successfully generated functional interspecies PTGs in Gcm2-/- rat neonates, an accomplishment with potential for future human PTG therapy using xenogeneic animal BC. Our results demonstrate that BC can produce functional endocrine organs and constitute a concept in treatment of hypoparathyroidism.

Generation of rat pancreas in mouse by interspecific blastocyst injection of pluripotent stem cells.

The complexity of organogenesis hinders in vitro generation of organs derived from a patient's pluripotent stem cells (PSCs), an ultimate goal of regenerative medicine. Mouse wild-type PSCs injected into Pdx1(-/-) (pancreatogenesis-disabled) mouse blastocysts developmentally compensated vacancy of the pancreatic "developmental niche," generating almost entirely PSC-derived pancreas. To examine the potential for xenogenic approaches in blastocyst complementation, we injected mouse or rat PSCs into rat or mouse blastocysts, respectively, generating interspecific chimeras and thus confirming that PSCs can contribute to xenogenic development between mouse and rat. The development of these mouse/rat chimeras was primarily influenced by host blastocyst and/or foster mother, evident by body size and species-specific organogenesis. We further injected rat wild-type PSCs into Pdx1(-/-) mouse blastocysts, generating normally functioning rat pancreas in Pdx1(-/-) mice. These data constitute proof of principle for interspecific blastocyst complementation and for generation in vivo of organs derived from donor PSCs using a xenogenic environment.

Regulatory T cells and immune tolerance.

Regulatory T cells (Tregs) play an indispensable role in maintaining immunological unresponsiveness to self-antigens and in suppressing excessive immune responses deleterious to the host. Tregs are produced in the thymus as a functionally mature subpopulation of T cells and can also be induced from naive T cells in the periphery. Recent research reveals the cellular and molecular basis of Treg development and function and implicates dysregulation of Tregs in immunological disease.

Interspecies organogenesis generates autologous functional islets.

Islet transplantation is an established therapy for diabetes. We have previously shown that rat pancreata can be created from rat pluripotent stem cells (PSCs) in mice through interspecies blastocyst complementation. Although they were functional and composed of rat-derived cells, the resulting pancreata were of mouse size, rendering them insufficient for isolating the numbers of islets required to treat diabetes in a rat model. Here, by performing the reverse experiment, injecting mouse PSCs into Pdx-1-deficient rat blastocysts, we generated rat-sized pancreata composed of mouse-PSC-derived cells. Islets subsequently prepared from these mouse-rat chimaeric pancreata were transplanted into mice with streptozotocin-induced diabetes. The transplanted islets successfully normalized and maintained host blood glucose levels for over 370 days in the absence of immunosuppression (excluding the first 5 days after transplant). These data provide proof-of-principle evidence for the therapeutic potential of PSC-derived islets generated by blastocyst complementation in a xenogeneic host.

Dual-antigen targeted iPSC-derived chimeric antigen receptor-T cell therapy for refractory lymphoma.

We generated dual-antigen receptor (DR) T cells from induced pluripotent stem cells (iPSCs) to mitigate tumor antigen escape. These cells were engineered to express a chimeric antigen receptor (CAR) for the antigen cell surface latent membrane protein 1 (LMP1; LMP1-CAR) and a T cell receptor directed to cell surface latent membrane protein 2 (LMP2), in association with human leucocyte antigen A24, to treat therapy-refractory Epstein-Barr virus-associated lymphomas. We introduced LMP1-CAR into iPSCs derived from LMP2-specific cytotoxic T lymphocytes (CTLs) to generate rejuvenated CTLs (rejTs) active against LMP1 and LMP2, or DRrejTs. All DRrejT-treated mice survived >100 days. Furthermore, DRrejTs rejected follow-up inocula of lymphoma cells, demonstrating that DRrejTs persisted long-term. We also demonstrated that DRrejTs targeting CD19 and LMP2 antigens exhibited a robust tumor suppressive effect and conferred a clear survival advantage. Co-operative antitumor effect and in vivo persistence, with unlimited availability of DRrejT therapy, will provide powerful and sustainable T cell immunotherapy.

Grass Cutting Robot for Inclined Surfaces in Hilly and Mountainous Areas.

Grass cutting is necessary to prevent grass from diverting essential nutrients and water from crops. Usually, in hilly and mountainous areas, grass cutting is performed on steep slopes with an inclination angle of up to 60° (inclination gradient of 173%). However, such grass cutting tasks are dangerous owing to the unstable positioning of workers. For robots to perform these grass cutting tasks, slipping and falling must be prevented on inclined surfaces. In this study, a robot based on stable propeller control and four-wheel steering was developed to provide stable locomotion during grass cutting tasks. The robot was evaluated in terms of locomotion for different steering methods, straight motion on steep slopes, climbing ability, and coverage area. The results revealed that the robot was capable of navigating uneven terrains with steep slope angles. Moreover, no slipping actions that could have affected the grass cutting operations were observed. We confirmed that the proposed robot is able to cover 99.95% and 98.45% of an area on a rubber and grass slope, respectively. Finally, the robot was tested on different slopes with different angles in hilly and mountainous areas. The developed robot was able to perform the grass cutting task as expected.

PDGF Receptors and Signaling Are Required for 3D-Structure Formation and Differentiation of Human iPSC-Derived Hepatic Spheroids.

Human iPSC-derived liver organoids (LO) or hepatic spheroids (HS) have attracted widespread interest, and the numerous studies on them have recently provided various production protocols. However, the mechanism by which the 3D structures of LO and HS are formed from the 2D-cultured cells and the mechanism of the LO and HS maturation remain largely unknown. In this study, we demonstrate that PDGFRA is specifically induced in the cells that are suitable for HS formation and that PDGF receptors and signaling are required for HS formation and maturation. Additionally, in vivo, we show that the localization of PDGFRα is in complete agreement with mouse E9.5 hepatoblasts, which begin to form the 3D-structural liver bud from the single layer. Our results present that PDGFRA play important roles for 3D structure formation and maturation of hepatocytes in vitro and in vivo and provide a clue to elucidate the hepatocyte differentiation mechanism.

[A Case of Long-Term Remission with Surgical Therapy and Chemoradiotherapy for a Rapidly Increasing Large Cell Neuroendocrine Carcinoma(LCNEC)].

BACKGROUND: Large cell neuroendocrine carcinoma(LCNEC)is a relatively rare disease classified as a subtype of neuroendocrine tumor. LCNEC has clinical and histological similarities to small cell lung cancer, both of which have a similarly poor prognosis. There are also unclear points regarding treatment. CASE: 43-years-old, male. He had repeated intermittent fever from 1 month before the consultation. Cough appeared 4 days before the consultation, and the family doctor pointed out an abnormal shadow in the right lung field, and the patient was referred. Blood test showed increased CRP 1.34 mg/dL and mild inflammatory response. Chest CT showed an increased tumor with a major axis of 16 cm in the right thoracic cavity compared to 6 months ago. FDG-PET showed accumulation of SUVmax 11.83 in the same area. A CT-guided needle biopsy was performed, and although tumor cell hyperplasia of like a plasma cells was suspected, but most of them were coagulative necrotic images and could not be diagnosed. After hospitalization, fever continued and the general condition became poor, so surgery was performed for the purpose of diagnostic treatment. Preoperatively, Interventional Radiology was used to embolize the tumor-feeding blood vessels. Intrathoracic tumor resection and partial upper and lower lobe resection were performed under thoracotomy. Postoperative histopathological examination revealed that large round to polyhedron tumor cells proliferated in sheet-like or intercellular binding sparsely, and synaptophysin was positive, which was a diagnosis of large cell neuroendocrine cell carcinoma. The general condition improved promptly after the operation, and the patient was discharged 14 days after the operation without any complications. After discharge, 4 courses of adjuvant chemotherapy (CDDP plus CPT-11)were performed. Six months after the operation, the disseminated nodule recurred in the right thoracic cavity. Chemotherapy(CBDCA plus PTX plus BEV)and radiation therapy were performed and the patient was in remission. It has been 5 years since the operation and has not recurred. SUMMARY: We report a case of rapidly increasing LCNEC with long-term remission by surgical treatment and chemoradiotherapy, with some review of the literature.

In vitro antibacterial activity of OPS-2071 against Gram-positive and Gram-negative enteropathogenic bacteria.

BACKGROUND: Enteric infections are a major public health issue in developing countries. Antimicrobial resistance is also a problem for enteric infection. OPS-2071 is a novel quinolone antibiotic with low oral absorption and potent antibacterial activity against Clostridioides difficile. OBJECTIVES: This study was conducted to confirm the antimicrobial activity of OPS-2071 against major enteropathogenic bacteria and to evaluate the risk of emergence of drug resistance. METHODS: The antibacterial activity was evaluated by the agar dilution method. The inhibitory activity against DNA gyrase and topoisomerase IV was determined by supercoiling assay and decatenation assay, respectively. The mutant prevention concentration and frequency of spontaneous resistance were determined by inoculation on drug-containing agar. RESULTS: Compared with the reference drugs, the antibacterial activity of OPS-2071 was more potent against Gram-positive bacteria and Campylobacter jejuni, including quinolone-resistant strains. Against other Gram-negative bacteria, OPS-2071 was comparable to existing quinolones. The inhibitory activities against DNA gyrase with quinolone-resistant mutations closely correlated with the antibacterial activity. Spontaneous resistance to OPS-2071 was not observed in Staphylococcus aureus and Escherichia coli and was lower than that of existing quinolones and higher than that of azithromycin in C. jejuni. The mutant prevention concentration of OPS-2071 was lower than that of tested compounds in S. aureus and C. jejuni and slightly higher than that of existing quinolones in E. coli. CONCLUSIONS: The broad and potent in vitro antibacterial activity and lower risk of drug resistance suggested that OPS-2071 may be useful for enteric infections caused by major pathogens including quinolone-resistant Campylobacter.

Evaluation of additional gastrectomy after noncurative endoscopic submucosal dissection for early gastric cancer.

BACKGROUND: Performing additional surgery after noncurative endoscopic submucosal dissection (ESD) for early gastric cancer is controversial. Our aims are to clarify the risk factors for lymph node metastasis (LNM) and local residual cancer (RC) after noncurative ESD and to determine recommendations for additional treatment. METHODS: Of the 1483 patients who underwent ESD for early gastric cancer between January 2012 and April 2020, we retrospectively analyzed 151 patients diagnosed as having a lesion not meeting the curative criteria after ESD. Of these patients, 100 underwent additional gastrectomy, and 51 were observed without surgery. RESULTS: Surgical specimens showed LNM in 14 patients (14.0%) and local RC in 7 (7.0%). However, 81 patients (81.0%) had neither of these malignancies. Multivariate analysis revealed that a positive lymphatic invasion (P = 0.035) and an undifferentiated type (P = 0.047) were independent risk factors for LNM, whereas a positive horizontal margin (P = 0.010) was an independent risk factor for local RC. Furthermore, the prevalence of LNM was significantly higher in patients with both positive lymphatic and vascular invasions. In the additional gastrectomy group, 3 patients (3.0%) had recurrences, and 2 patients (2.0%) who had distant recurrences died of gastric cancer. In the observation group, recurrence was observed in 3 patients (5.9%). One patient (2.0%) who had liver metastasis died of gastric cancer. Of the 2 patients (3.9%) who had local recurrences, one underwent additional ESD, and the other without additional ESD died of other disease. The 5-year overall survival rates in the additional gastrectomy and observation groups were 87.4% and 73.8%, respectively (log-rank test, P = 0.008). CONCLUSION: Following noncurative ESD for early gastric cancer, we recommend an additional gastrectomy with lymph node dissection for patients with lymphovascular invasion and/or undifferentiated type. Careful follow-ups without additional surgery may be acceptable for patients with advanced age, severe comorbidity, or no lymphovascular invasion.

Human-to-Human Position Estimation System Using RSSI in Outdoor Environment.

Methods to prevent collisions between people to avoid traffic accidents are receiving significant attention. To measure the position in the non-line-of-sight (NLOS) area, which cannot be directly visually recognized, position-measuring methods use wireless-communication-type GPS and propagation characteristics of radio signals, such as received signal strength indication (RSSI). However, conventional position estimation methods using RSSI require multiple receivers, which decreases the position estimation accuracy, owing to the presence of surrounding buildings. This study proposes a system to solve this challenge using a receiver and position estimation method based on RSSI MAP simulation and particle filter. Moreover, this study utilizes BLE peripheral/central functions capable of advertising as the transmitter/receiver. By using the advertising radio waves, our method provides a framework for estimating the position of unspecified transmitters. The effectiveness of the proposed system is evaluated in this study through simulations and experiments in actual environments. We obtained an error average of the distance to be 1.6 m from the simulations, which shows the precision of the proposed method. In the actual environment, the proposed method showed an error average of the distance to be 3.3 m. Furthermore, we evaluated the accuracy of the proposed method when both the transmitter and receiver are in motion, which can be considered as a moving person in the outdoor NLOS area. The result shows an error of 4.5 m. Consequently, we concluded that the accuracy was comparable when the transmitter is stationary and when it is moving. Compared with conventional path loss, the model can measure distances of 3 m to 10 m, whereas the proposed method can estimate the "position" with the same accuracy in an outdoor environment. In addition, it can be expected to be used as a collision avoidance system that confirms the presence of strangers in the NLOS area.

[A Case of Preoperative Diagnosis of Intraductal Papillary Tumor with Good Course after Surgical Resection].

BACKGROUND: Intraductal papillary neoplasm of bile duct(IPNB)is a papillary tumor that develops in the bile duct inside and outside the liver, and is a relatively new disease concept recognized as a precancerous/early cancer lesion of bile duct cancer. CASE: A 74-year-old woman. A nearby doctor pointed out liver dysfunction in a medical examination, and he was introduced for the purpose of detailed examination. No subjective symptoms were observed. The blood sampling test showed no increase in tumor markers. Abdominal CT/MRI examination and abdominal echo examination showed multiple nodules from the origin of the left intrahepatic bile duct and intrahepatic bile duct dilation predominantly on the left side. No other findings indicating metastasis were found, including the PET-CT test. Endoscopic retrograde cholangiography revealed a poorly contrast-enhanced area in the B3 region, and intraluminal ultrasonography confirmed a mass that coincided with the poorly contrast-enhanced area and grew papillary. No tumor growth was observed in the other branches or common bile ducts, but all ducts were filled with suspended matter, which was thought to be mucus. Histopathological examination of the tumor biopsy revealed atypical epithelium with papillary structure and moderate nuclear atypia. A diagnosis of intraductal papillary tumor was made, and left hepatic lobectomy was performed. Postoperative histopathological examination revealed a complex papillary growth of highly dysplastic mucus-producing epithelium similar to the pancreatic duct/bile duct epithelium, and no obvious infiltrative growth. The postoperative course was uneventful, and the patient was discharged 16 days after the operation. Currently, 6 months after the operation, he is outpatient without recurrence. We report a case of intraductal papillary tumor that had a favorable course after surgical resection in the preoperative diagnosis, with some review of the literature.

Xanthogranulomatous cholecystitis: a review of 31 patients.

BACKGROUND: Xanthogranulomatous cholecystitis (XGC) is a rare inflammatory gallbladder disease which is difficult to diagnose and treat; XGC may be confused with gallbladder cancer. The present study aimed to evaluate the clinical and radiological features and surgical outcomes, with the aim to determine the appropriate treatment approaches for XGC. METHODS: This retrospective study analyzed the clinical characteristics, intraoperative findings, and postoperative outcomes of 31 patients (2.0%) who were diagnosed with XGC based on histopathological findings among 1513 patients who underwent cholecystectomy at our hospital between January 2010 and July 2019. RESULTS: Preoperative ultrasonography and computed tomography findings indicated acute cholecystitis, chronic cholecystitis, and suspicious XGC in 26 (83.9%) patients with thickening of the gallbladder wall and suspicious gallbladder cancer in 5 (16.1%) patients. Abdominal pain and jaundice were observed in 18 (58.1%) patients and 5 (16.1%) patients, respectively. Biliary drainage before surgery was performed in 21 (67.7%) patients. Laparoscopic cholecystectomy, which was performed in 23 (74.2%) patients, was converted to open cholecystectomy in 12 (52.2%) of these 23 patients. Among the patients with other diseases treated during the study period, laparoscopic cholecystectomy was performed in 1377 patients and converted to open surgery in 71 (5.2%) patients. Five patients with suspicious gallbladder cancer underwent open surgery. In these patients, intraoperative frozen section analysis was useful in distinguishing between XGC and gallbladder cancer and was important in avoiding unnecessarily extended surgery. CONCLUSION: Laparoscopic cholecystectomy for XGC is possible, but often difficult due to severe inflammation. The frequency of conversion to open surgery is higher in patients with XGC than those with other forms of cholecystitis. XGC may resemble gallbladder cancer based on the diagnostic imaging findings, and intraoperative frozen section analysis is essential to avoid unnecessarily extended surgery.

Impact of left ventricular ejection fraction and preoperative hemoglobin level on perioperative adverse cardiovascular events in noncardiac surgery.

The prediction of a perioperative adverse cardiovascular event (PACE) is an important clinical issue in the medical management of patients undergoing noncardiac surgery. Although several predictors have been reported, simpler and more practical predictors of PACE have been needed. The aim of this study was to investigate the predictors of PACE in noncardiac surgery. We retrospectively analyzed 723 patients who were scheduled for elective noncardiac surgery and underwent preoperative examinations including 12-lead electrocardiography, transthoracic echocardiography, and blood test. PACE was defined as cardiac death, non-fatal myocardial infarction, unstable angina, congestive heart failure, arrhythmia attack that needs emergency treatment (rapid atrial fibrillation, ventricular tachycardia, and bradycardia), acute pulmonary embolism, asystole, pulseless electrical activity, or stroke during 30 days after surgery. PACE occurred in 54 (7.5%) of 723 patients. High-risk operation (11% vs. 3%, p = 0.003) was more often seen, left ventricular ejection fraction (LVEF) (55 ± 8% vs. 60 ± 7%, p = 0.001) and preoperative hemoglobin level (11.8 ± 2.2 g/dl vs. 12.7 ± 2.0 g/dl, p = 0.001) were lower in patients with PACE compared to those without PACE. By multivariate logistic regression analysis, high-risk operation (odds ratio (OR): 7.05, 95% confidence interval (CI) 2.16-23.00, p = 0.001), LVEF (OR 1.06, every 1% decrement, 95% CI 1.03-1.09, p = 0.001), and preoperative hemoglobin level (OR 1.22, every 1 g/dl decrement, 95% CI 1.07-1.39, p = 0.003) were identified as independent predictors of PACE. Receiver operating characteristic analysis demonstrated that LVEF of 58% (sensitivity = 80%, specificity = 61%, area under the curve (AUC) = 0.723) and preoperative hemoglobin level of 12.2 g/dl (sensitivity = 63%, specificity = 64%, AUC = 0.644) were optimal cut-off values for predicting PACE. High-risk operation, reduced LVEF, and reduced preoperative hemoglobin level were independently associated with PACE in patients undergoing noncardiac surgery.

Timely intubation with early prediction of respiratory exacerbation in acute traumatic cervical spinal cord injury.

BACKGROUND: Early routine intubation in motor-complete cervical spinal cord injury (CSCI) above the C5 level is a conventional protocol to prevent unexpected respiratory exacerbation (RE). However, in the context of recent advances in multidisciplinary respiratory management, the absolute indication for intubation in patients with CSCI based on initial neurologic assessment is controversial because of the drawbacks of intubation. This study aimed to redetermine the most important predictor of RE following CSCI after admission without routine intubation among patients admitted with motor-complete injury and/or injury above the C5 level to ensure timely intubation. METHODS: We performed a retrospective review of patients with acute traumatic CSCI admitted to our hospital without an initial routine intubation protocol from January 2013 to December 2017. CSCI patients who developed RE (defined as unexpected emergent intubation for respiratory resuscitation) were compared with those who did not. Baseline characteristics and severity of trauma data were collected. Univariate analyses were performed to compare treatment data and clinical outcomes between the two groups. Further, multivariate logistic regression was performed with clinically important independent variables: motor-complete injury, neurologic level above C5, atelectasis, and copious airway secretion (CAS). RESULTS: Among 58 patients with CSCI, 35 (60.3%) required post-injury intubation and 1 (1.7%) died during hospitalization. Thirteen (22.4%) had RE 3.5 days (mean) post-injury; 3 (37.5%) of eight patients with motor-complete CSCI above C5 developed RE. Eleven of the 27 (40.7%) patients with motor-complete injury and five of the 22 (22.7%) patients with neurologic injury above C5 required emergency intubation at RE. Three of the eight CSCI patients with both risk factors (motor-complete injury above C5) resulted in emergent RE intubation (37.5%). CAS was an independent predictor for RE (odds ratio 7.19, 95% confidence interval 1.48-42.72, P = 0.0144) in multivariate analyses. CONCLUSION: Timely intubation post-CSCI based on close attention to CAS during the acute 3-day phase may prevent RE and reduce unnecessary invasive airway control even without immediate routine intubation in motor-complete injury above C5.

[A Case of Lung Adenocarcinoma with Pulmonary Hypertrophic Osteoarthropathy].

BACKGROUND: Hypertrophic osteoarthropathy(HOA)is a syndrome that has three signs, the digital finger, periosteal neoplasia of the iliac bone, and arthritis. Among them, the secondary 1 associated with lung disease is called pulmonary hypertrophic osteoarthropathy(PHO). It is reported that many of the underlying diseases are associated with primary lung cancer, but in Japan, this is a rare condition with about 0.2 to 5.0%. CASE: A 68-year-old man. The patient was complaining of an arthralgia, and treated by the department of rheumatology. The thoracic CT scan for a screening pointed out a tumor in the right lower lobe, and referred to the department of surgery. Blood test showed CEA 21.8 ng/mL and LH 10.2 mIU/mL, FSH 23.1 mIU/mL. Chest CT showed a lung mass measuring 6.5×3.5 cm in the right lower lobe, and tracheobronchial lymph- node swelling. Bone scintigraphy showed abnormal accumulations in the long bones. We performed right lower lobectomy by thoracoscope. The pathological results were adenocarcinoma, G2, pT3, pN1, pm0, pl1, Ly1, V1, stage ⅢA. The arthralgia was relieved early after surgery. The patient recovered uneventfully and was discharged after the operation. Adjuvant chemotherapy was started, he was been well without recurrence.

Long-term eradication of extranodal natural killer/T-cell lymphoma, nasal type, by induced pluripotent stem cell-derived Epstein-Barr virus-specific rejuvenated T cells in vivo.

Functionally rejuvenated induced pluripotent stem cell (iPSC)-derived antigen-specific cytotoxic T lymphocytes (CTL) are expected to be a potent immunotherapy for tumors. When L-asparaginase-containing standard chemotherapy fails in extranodal natural killer/T-cell lymphoma, nasal type (ENKL), no effective salvage therapy exists. The clinical course then is miserable. We demonstrate prolonged and robust eradication of ENKL in vivo by Epstein-Barr virus-specific iPSC-derived antigen-specific CTL, with iPSC-derived antigen-specific CTL persisting as central memory T cells in the mouse spleen for at least six months. The anti-tumor response is so strong that any concomitant effect of the programmed cell death 1 (PD-1) blockade is unclear. These results suggest that long-term persistent Epstein-Barr virus-specific iPSC-derived antigen-specific CTL contribute to a continuous anti-tumor effect and offer an effective salvage therapy for relapsed and refractory ENKL.

Theoretical modeling reveals that regulatory T cells increase T-cell interaction with antigen-presenting cells for stable immune tolerance.

The immune system in tolerance maintains cell diversity without responding to self-antigens. Foxp3-expressing CD25+CD4+ regulatory T cells (Tregs) inhibit T-cell activation through various molecular mechanisms. However, several key questions are still not resolved, including how Tregs control the immune response on the basis of their self-skewed T-cell receptor repertoire and how Tregs avoid impeding relevant immunity against pathogens. Here, we show that Tregs promote the proliferation of conventional T cells in the presence of excessive co-stimulation when murine T cells are stimulated in vitro with allogeneic antigen-presenting cells (APCs). Antigen-specific Tregs increase the number of cells interacting with dendritic cells (DCs) by increasing the number of viable DCs and the expression of adhesion molecules on DCs. Theoretical simulations and mathematical models representing the dynamics of T-APC interaction and T-cell numbers in a lymph node indicate that Tregs reduce the dissociation probability of T cells from APCs and increase the new association. These functions contribute to tolerance by enhancing the interaction of low-affinity T cells with APCs. Supporting the theoretical analyses, we found that reducing the T-cell numbers in mice increases the ratio of specific T cells among CD4+ T cells after immunization and effectively induces autoimmune diabetes in non obese diabetes mice. Thus, as a critical function, antigen-specific Tregs stabilize the immune state, irrespective of it being tolerant or responsive, by augmenting T-APC interaction. We propose a novel regulation model in which stable tolerance with large heterogeneous populations proceeds to a specific immune response through a transient state with few populations.

Characterization of the Subventricular-Thalamo-Cortical Circuit in the NP-C Mouse Brain, and New Insights Regarding Treatment.

Gliosis in Niemann-Pick type C (NP-C) disease is characterized by marked changes in microglia and astrocytes. However, the gliosis onset and progression in NP-C has not been systematically studied, nor has the mechanism underlying this finding. Here, we found early gliosis in the subventricular zone (SVZ) of NP-C mice. Neural progenitor damage by Npc1 mutation suppressed vascular endothelial growth factor (VEGF) expression and further induced microglia activation followed by astrogliosis. Interestingly, excessive astrogliosis in the SVZ induced neural progenitor retention and/or migration into thalamus via astrocyte-derived VEGF, resulting in acceleration of thalamic and cortical gliosis through thalamo-cortical pathways. Transplantation of VEGF-overexpressing neural stem cells into the SVZ improved whole-brain pathology of NP-C mice. Overall, our data provide a new pathological perspective on NP-C neural pathology, revealing abnormalities in the subventricular-thalamo-cortical circuit of NP-C mouse brain and highlighting the importance of the SVZ microenvironment as a therapeutic target for NP-C disease.