Thymocyte Development of Humanized Mice Is Promoted by Interactions with Human-Derived Antigen Presenting Cells upon Immunization.

Immune responses in humanized mice are generally inefficient without co-transplantation of human thymus or HLA transgenes. Previously, we generated humanized mice via the intra-bone marrow injection of CD133+ cord blood cells into irradiated adult immunodeficient mice (IBMI-huNSG mice), which could mount functional immune responses against HTLV-1, although the underlying mechanisms were still unknown. Here, we investigated thymocyte development in IBMI-huNSG mice, focusing on the roles of human and mouse MHC restriction. IBMI-huNSG mice had normal developmental profiles but aberrant thymic structures. Surprisingly, the thymic medulla-like regions expanded after immunization due to enhanced thymocyte expansion in association with the increase in HLA-DR+ cells, including CD205+ dendritic cells (DCs). The organ culture of thymus from immunized IBMI-huNSG mice with a neutralizing antibody to HLA-DR showed the HLA-DR-dependent expansion of CD4 single positive thymocytes. Mature peripheral T-cells exhibited alloreactive proliferation when co-cultured with human peripheral blood mononuclear cells. Live imaging of the thymus from immunized IBMI-huNSG mice revealed dynamic adhesive contacts of human-derived thymocytes and DCs accompanied by Rap1 activation. These findings demonstrate that an increase in HLA-DR+ cells by immunization promotes HLA-restricted thymocyte expansion in humanized mice, offering a unique opportunity to generate humanized mice with ease.

Mouse Models for HTLV-1 Infection and Adult T Cell Leukemia.

Adult T cell leukemia (ATL) is an aggressive hematologic disease caused by human T cell leukemia virus type 1 (HTLV-1) infection. Various animal models of HTLV-1 infection/ATL have been established to elucidate the pathogenesis of ATL and develop appropriate treatments. For analyses employing murine models, transgenic and immunodeficient mice are used because of the low infectivity of HTLV-1 in mice. Each mouse model has different characteristics that must be considered before use for different HTLV-1 research purposes. HTLV-1 Tax and HBZ transgenic mice spontaneously develop tumors, and the roles of both Tax and HBZ in cell transformation and tumor growth have been established. Severely immunodeficient mice were able to be engrafted with ATL cell lines and have been used in preclinical studies of candidate molecules for the treatment of ATL. HTLV-1-infected humanized mice with an established human immune system are a suitable model to characterize cells in the early stages of HTLV-1 infection. This review outlines the characteristics of mouse models of HTLV-1 infection/ATL and describes progress made in elucidating the pathogenesis of ATL and developing related therapies using these mice.

Vaccination with short-term-cultured autologous PBMCs efficiently activated STLV-1-specific CTLs in naturally STLV-1-infected Japanese monkeys with impaired CTL responses.

A small proportion of human T-cell leukemia virus type-1 (HTLV-1)-infected individuals develop adult T-cell leukemia/lymphoma, a chemotherapy-resistant lymphoproliferative disease with a poor prognosis. HTLV-1-specific cytotoxic T lymphocytes (CTLs), potential anti-tumor/virus effectors, are impaired in adult T-cell leukemia/lymphoma patients. Here, using Japanese monkeys naturally infected with simian T-cell leukemia/T-lymphotropic virus type-1 (STLV-1) as a model, we demonstrate that short-term-cultured autologous peripheral blood mononuclear cells (PBMCs) can serve as a therapeutic vaccine to activate such CTLs. In a screening test, STLV-1-specific CTL activity was detectable in 8/10 naturally STLV-1-infected monkeys. We conducted a vaccine study in the remaining two monkeys with impaired CTL responses. The short-term-cultured PBMCs of these monkeys spontaneously expressed viral antigens, in a similar way to PBMCs from human HTLV-1 carriers. The first monkey was subcutaneously inoculated with three-day-cultured and mitomycin C (MMC)-treated autologous PBMCs, and then boosted with MMC-treated autologous STLV-1-infected cell line cells. The second monkey was inoculated with autologous PBMC-vaccine alone twice. In addition, a third monkey that originally showed a weak STLV-1-specific CTL response was inoculated with similar autologous PBMC-vaccines. In all three vaccinated monkeys, marked activation of STLV-1-specific CTLs and a mild reduction in the STLV-1 proviral load were observed. Follow-up analyses on the two monkeys vaccinated with PBMCs alone indicated that STLV-1-specific CTL responses peaked at 3-4 months after vaccination, and then diminished but remained detectable for more than one year. The significant reduction in the proviral load and the control of viral expression were associated with CTL activation but also diminished 6 and 12 months after vaccination, respectively, suggesting the requirement for a booster. The vaccine-induced CTLs in these monkeys recognized epitopes in the STLV-1 Tax and/or Envelope proteins, and efficiently killed autologous STLV-1-infected cells in vitro. These findings indicated that the autologous PBMC-based vaccine could induce functional STLV-1-specific CTLs in vivo.

Preoperative Serum Cortisol Level Is Predictive of Weight Loss After Laparoscopic Sleeve Gastrectomy in Men with Severe Obesity but Not Women.

BACKGROUND: Bariatric surgery is an effective treatment for severe obesity and its associated medical problems. Preoperative factors that predict postoperative weight loss remain to be fully characterized, however. METHODS: Anthropometric and laboratory data were collected retrospectively for severely obese patients who underwent laparoscopic sleeve gastrectomy (LSG) between April 2016 and July 2019 at our hospital. Preoperative factors that predicted weight loss at 1 year after LSG were investigated. RESULTS: A total of 122 subjects (45 men and 77 women) underwent LSG. The mean ± SD age and body mass index at surgery were 44.4 ± 10.4 years and 40.7 ± 6.7 kg/m2. The percent total weight loss (%TWL) was 27.0 ± 8.6 among all subjects, 26.4 ± 8.0 among men, and 27.4 ± 8.9 among women, with no significant difference between the sexes. The %TWL showed a significant inverse correlation with serum cortisol level in men and with age and the visceral/subcutaneous fat area ratio in women. Multivariable regression analysis revealed the presence of type 2 diabetes and the serum cortisol concentration to be negatively associated with %TWL among all subjects and men, respectively. Receiver operating characteristic curve analysis identified an optimal cutoff of 10 µg/dL for prediction of a %TWL of ≥ 25 in men by serum cortisol level. CONCLUSIONS: Serum cortisol concentration was identified as a predictor for postoperative weight loss in men. Our results may thus help inform the decision to perform LSG or more effective surgical procedures in men with severe obesity.

Identification and characterization of a novel enhancer in the HTLV-1 proviral genome.

Human T-cell leukemia virus type 1 (HTLV-1) is a retrovirus that causes adult T-cell leukemia/lymphoma (ATL), a cancer of infected CD4+ T-cells. There is both sense and antisense transcription from the integrated provirus. Sense transcription tends to be suppressed, but antisense transcription is constitutively active. Various efforts have been made to elucidate the regulatory mechanism of HTLV-1 provirus for several decades; however, it remains unknown how HTLV-1 antisense transcription is maintained. Here, using proviral DNA-capture sequencing, we found a previously unidentified viral enhancer in the middle of the HTLV-1 provirus. The transcription factors, SRF and ELK-1, play a pivotal role in the activity of this enhancer. Aberrant transcription of genes in the proximity of integration sites was observed in freshly isolated ATL cells. This finding resolves certain long-standing questions concerning HTLV-1 persistence and pathogenesis. We anticipate that the DNA-capture-seq approach can be applied to analyze the regulatory mechanisms of other oncogenic viruses integrated into the host cellular genome.

Caspase-1 initiates apoptosis in the absence of gasdermin D.

Caspase-1 activated in inflammasomes triggers a programmed necrosis called pyroptosis, which is mediated by gasdermin D (GSDMD). However, GSDMD-deficient cells are still susceptible to caspase-1-mediated cell death. Therefore, here, we investigate the mechanism of caspase-1-initiated cell death in GSDMD-deficient cells. Inflammasome stimuli induce apoptosis accompanied by caspase-3 activation in GSDMD-deficient macrophages, which largely relies on caspase-1. Chemical dimerization of caspase-1 induces pyroptosis in GSDMD-sufficient cells, but apoptosis in GSDMD-deficient cells. Caspase-1-induced apoptosis involves the Bid-caspase-9-caspase-3 axis, which can be followed by GSDME-dependent secondary necrosis/pyroptosis. However, Bid ablation does not completely abolish the cell death, suggesting the existence of an additional mechanism. Furthermore, cortical neurons and mast cells exhibit little or low GSDMD expression and undergo apoptosis after oxygen glucose deprivation and nigericin stimulation, respectively, in a caspase-1- and Bid-dependent manner. This study clarifies the molecular mechanism and biological roles of caspase-1-induced apoptosis in GSDMD-low/null cell types.

Fat-specific protein 27α inhibits autophagy-dependent lipid droplet breakdown in white adipocytes.

AIMS/INTRODUCTION: Fat-specific protein 27 (FSP27) α is the major isoform of FSP27 in white adipose tissue (WAT), and is essential for large unilocular lipid droplet (LD) formation in white adipocytes. In contrast, FSP27ß is abundantly expressed in brown adipose tissue (BAT), and plays an important role in small multilocular LD formation. In FSP27 KO mice in which FSP27α and ß are both depleted, WAT is characterized by multilocular LD formation, and by increased mitochondrial abundance and energy expenditure, whereas BAT conversely manifests large oligolocular LDs and reduced energy expenditure. MATERIALS AND METHODS: We investigated the effects of autophagy in WAT and BAT of wild type (WT) and FSP27 knockout (KO) mice. In addition, we examined the effects of FSP27α and FSP27ß to the induction of autophagy in COS cells. RESULTS: Food deprivation induced autophagy in BAT of WT mice, as well as in WAT of FSP27 KO mice, suggesting that enhanced autophagy is characteristic of adipocytes with small multilocular LDs. Pharmacological inhibition of autophagy attenuated the fasting-induced loss of LD area in adipocytes with small multilocular LDs (BAT of WT mice and WAT of FSP27 KO mice), without affecting that in adipocytes with large unilocular or oligolocular LDs (WAT of WT mice or in BAT of FSP27 KO mice). Overexpression of FSP27α inhibited autophagy induction by serum deprivation in COS cells, whereas that of FSP27ß had no such effect. CONCLUSIONS: The present results thus showed that FSP27α inhibits autophagy and might thereby contribute to the energy-storage function of WAT.

Effects of exenatide and liraglutide on postchallenge glucose disposal in individuals with normal glucose tolerance.

PURPOSE: Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are categorized as short- or long-acting types, but information regarding differences in the effects of these two types on postprandial glucose disposal has been limited. We have now investigated the effects of exenatide and liraglutide (short- and long-acting GLP-1RAs, respectively) on glucose disposal during an oral glucose tolerance test (OGTT). METHODS: Fourteen healthy volunteers with normal glucose tolerance underwent three OGTTs, which were performed without pharmacological intervention or after a single administration of exenatide or liraglutide at 30 min and 10 h, respectively, before test initiation. The three OGTTs were performed with intervals of at least 7 days between successive tests and within a period of 2 months. RESULTS: Exenatide, but not liraglutide, markedly decelerated the peak of both plasma glucose and serum insulin levels during the OGTT, with the peaks of both glucose and insulin concentrations occurring at 150 min after test initiation with exenatide compared with 30 min in the control condition or with liraglutide. Exenatide and liraglutide reduced the area under the curve for plasma glucose levels during the OGTT by similar extents, whereas that for serum insulin levels was reduced only by exenatide. CONCLUSIONS: Our results suggest that exenatide decelerates the increase in plasma glucose levels through inhibition of glucose absorption and that it exerts an insulin-sparing action after glucose challenge.

Characterization of Innate and Adaptive Immune Responses in PYNOD-Deficient Mice.

PYNOD (also called NLRP10) is a member of the nucleotide-binding domain and leucine-rich repeat containing family. Many members of this family play important roles in the activation and/or regulation of immune and inflammatory responses. We previously showed that PYNOD inhibits the IL-1ß secretion in response to microbial infection in PYNOD-transgenic mice. In this study, we generated PYNOD-knockout (KO) mice and further investigated PYNOD's role in the innate and adaptive immune responses. Similar to wild-type macrophages, PYNOD-KO macrophages produced IL-1ß and induced pyroptosis, a caspase-1-dependent programmed cell death, in response to various inflammasome activators and microbial infection. In addition, the PYNOD deficiency did not significantly affect the proliferation or cytokine production of T cells, the delayed-type hypersensitivity responses, the anti-tumor immunity, the Ag-specific Ab production, the cytotoxicity of NK cells, or the maturation, Ag-presenting capacity, or elicited migration of dendritic cells. Furthermore, the steady-state skin self-antigen transport to regional lymph nodes was not impaired in PYNOD-KO mice, suggesting that PYNOD is dispensable for steady-state dendritic cell migration. These results suggested that PYNOD is dispensable for the regulation of innate and adaptive immune responses in mice, unless PYNOD's expression is highly induced under certain conditions.

Cell death-inducing DNA fragmentation factor A-like effector A and fat-specific protein 27ß coordinately control lipid droplet size in brown adipocytes.

Adipose tissue stores neutral lipids and is a major metabolic organ involved in regulating whole-body energy homeostasis. Triacylglycerol is stored as unilocular large lipid droplets (LDs) in white adipocytes and as multilocular small LDs in brown adipocytes. Proteins of the cell death-inducing DNA fragmentation factor A-like effector (Cide) family include CideA, CideB, and fat-specific protein of 27 (FSP27). Of these, FSP27 has been shown to play a crucial role in the formation of unilocular large LDs in white adipocytes. However, the mechanisms by which brown adipocytes store small and multilocular LDs remain unclear. An FSP27 isoform, FSP27ß, was recently identified. We herein report that CideA and FSP27ß are mainly expressed in brown adipose tissue and that FSP27ß overexpression inhibits CideA-induced LD enlargements in a dose-dependent manner in COS cells. Furthermore, RNAi-mediated FSP27ß depletion resulted in enlarged LDs in HB2 adipocytes, which possess the characteristics of brown adipocytes. Brown adipocytes in FSP27-knock-out mice that express CideA, but not FSP27ß, had larger and fewer LDs. Moreover, we confirmed that FSP27ß and CideA form a complex in brown adipose tissue. Our results suggest that FSP27ß negatively regulates CideA-promoted enlargement of LD size in brown adipocytes. FSP27ß appears to be responsible for the formation of small and multilocular LDs in brown adipose tissue, a morphology facilitating free fatty acid transport to mitochondria adjacent to LDs for oxidation in brown adipocytes.

Evaluation of metabolic parameters and body composition in Japanese patients with type 2 diabetes mellitus who were administered tofogliflozin for 48 weeks.

Sodium glucose cotransporter 2 inhibitors are unique antihyperglycemic agents that cause osmotic diuresis and calorie loss to urine. We previously reported that administration of tofogliflozin, a sodium glucose cotransporter 2 inhibitor, for 8 weeks decreased fat-free mass without affecting fat mass. We thus investigated the impact of tofogliflozin on metabolic parameters and body composition for 48 weeks in Japanese patients with type 2 diabetes mellitus. This single-arm open-label study enrolled 20 patients. Patients received tofogliflozin 20 mg once daily for 48 weeks. At week 48, changes in metabolic parameters and body composition from baseline were evaluated. Two patients discontinued administration due to adverse events during the first 8 weeks; however, no other adverse events occurred after that period. Seventeen patients completed the 48 weeks of administration of tofogliflodin. Body weight and body mass index decreased during the treatment period. Hemoglobin A1c decreased from 7.8% to 7.1%. The degree of improvement in hemoglobin A1c was correlated with body mass index, fat mass, and plasma glucose level at baseline. As for body composition, fat mass decreased without any change in fat-free mass (including total body water, extracellular water, and intracellular water). Red blood cell count and hematocrit increased, while the estimated glomerular filtration rate decreased. ALT and γ-GTP decreased and the decrease in γ-GTP was correlated with the loss of fat mass. In conclusion, our study clearly suggests that the body weight reduction caused by tofogliflozin administration for 48 weeks was almost entirely due to fat mass dissipation.

Multiple Salivary Cortisol Measurements Are a Useful Tool to Optimize Metyrapone Treatment in Patients with Cushing's Syndromes Treatment: Case Presentations.

Measuring salivary cortisol is both convenient and non-invasive for patients; however, its usefulness as a marker for monitoring medical therapy has not yet been established. The aim of this study was to assess the utility of multiple salivary cortisol measurements in patients with Cushing's syndrome (CS) during medical therapy. Six patients with CS (three with cortisol-secreting adrenocortical adenoma and three with ACTH-secreting pituitary adenoma) were recruited. Samples for morning serum cortisol, urinary free cortisol (UFC), and multiple salivary cortisol levels were collected before and during metyrapone treatment. The area under the curve (AUC) and mean value (MV) of daily salivary cortisol levels were calculated. In five out of six patients, UFC were normalized; however, multiple salivary cortisol measurements revealed an impaired diurnal cortisol rhythm in these patients. To verify the usefulness of multiple salivary cortisol measurements, we performed a prospective case study of a patient in whom the excess secretion of cortisol was not controlled (UFC 211 µg/day) with 2,250 mg/day in four divided doses of metyrapone. Multiple measurements of salivary cortisol revealed that cortisol levels elevated before the next administration. Accordingly, we shortened the interval by increasing the number of administration from four to five times per day, with a slight increment of daily dose of 2,500 mg. These optimizations resulted in a drastic improvement of diurnal pattern as well as UFC level (101 µg/day). Changes in both the MV and AUC of salivary cortisol levels were more correlated with those in UFC levels (Correlation coefficient 0.75, p = 0.007, and 0.70, p = 0.017) than those in the morning serum cortisol levels (0.42, p = 0.200), indicating that multiple salivary cortisol measurements reflect more precisely the excess secretion of cortisol. Our preliminary data suggest that multiple salivary cortisol measurements can be a useful tool to visualize the diurnal cortisol rhythm and to determine the dose and timing of metyrapone during the treatment in patients with CS.

Impact of the 8-week Administration of Tofogliflozin for Glycemic Control and Body Composition in Japanese Patients with Type 2 Diabetes Mellitus.

Objective The adverse effects of selective sodium-glucose co-transporter 2 (SGLT2) inhibitors generally appear within about two or three months after treatment initiation in Japan. Therefore, we investigated the impact of tofogliflozin, a class of SGLT2 inhibitors, on glycemic control and body composition during this period in Japanese patients with type 2 diabetes mellitus. Methods This single-arm open-label study enrolled 20 patients. Patients received tofogliflozin 20 mg once daily for 8 weeks. At week 8, changes from baseline in body weight, serum metabolic markers, and body composition were evaluated. Results A total of 17 patients completed the 8-week administration of tofogliflodin. No serious adverse events were noted. Hemoglobin A1c (HbA1c) decreased significantly, from 7.8% to 7.3% with 8-week administration of tofogliflozin. Both the body weight and body mass index (BMI) also decreased. In addition, a decreased renal function of the boundary zone and hemoconcentration were detected. As for body composition, the free fat mass, total body water, extracellular water and intracellular water were all decreased significantly. Interestingly, the amount of fat mass did not change. The degree of improvement in HbA1c was correlated with the baseline fat mass and BMI. Conclusion An eight-week administration of tofogliflozin improved glycemic control and reduced the body weight and free fat mass in type 2 diabetic patients without affecting the fat mass. In this period, the hematocrit level and renal function should be monitored to guard against hemoconcentration and renal impairment, respectively.

Negatively-charged residues in the polar carboxy-terminal region in FSP27 are indispensable for expanding lipid droplets.

FSP27 has an important role in large lipid droplet (LD) formation because it exchanges lipids at the contact site between LDs. In the present study, we clarify that the amino-terminal domain of FSP27 (amino acids 1-130) is dispensable for LD enlargement, although it accelerates LD growth. LD expansion depends on the carboxy-terminal domain of FSP27 (amino acids 131-239). Especially, the negative charge of the acidic residues (D215, E218, E219 and E220) in the polar carboxy-terminal region (amino acids 202-239) is essential for the enlargement of LD. We propose that the carboxy-terminal domain of FSP27 has a crucial role in LD expansion, whereas the amino-terminal domain only has a supportive role.

Effects of insulin degludec and insulin glargine on day-to-day fasting plasma glucose variability in individuals with type 1 diabetes: a multicentre, randomised, crossover study.

AIMS/HYPOTHESIS: We compared the effects of insulin degludec (IDeg; Des(B30)LysB29(γ-Glu Nε-hexadecandioyl) human insulin) and insulin glargine (IGlar; A21Gly,B31Arg,B32Arg human insulin) on the day-to-day variability of fasting plasma glucose (FPG) levels in individuals with type 1 diabetes treated with basal-bolus insulin injections. METHODS: The effects of basal-bolus insulin therapy for 4 weeks with either IDeg or IGlar as the basal insulin in adult C-peptide-negative outpatients with type 1 diabetes were investigated in an open-label, multicentre, randomised, crossover trial. Randomisation was conducted using a centralised allocation process. The primary endpoints were the SD and CV of FPG during the final week of each treatment period. Secondary endpoints included serum glycoalbumin level, daily dose of insulin, intraday glycaemic variability and frequency of severe hypoglycaemia. RESULTS: Thirty-six randomised participants (17 in the IDeg/IGlar and 19 in the IGlar/IDeg groups) were recruited, and data for 32 participants who completed the trial were analysed. The mean (7.74 ± 1.76 vs 8.56 ± 2.06 mmol/l; p = 0.04) and SD (2.60 ± 0.97 vs 3.19 ± 1.36 mmol/l; p = 0.03) of FPG were lower during IDeg treatment than during IGlar treatment, whereas the CV did not differ between the two treatments. The dose of IDeg was smaller than that of IGlar (11.0 ± 5.2 vs 11.8 ± 5.6 U/day; p < 0.01), but other secondary endpoints did not differ between the treatments. CONCLUSIONS/INTERPRETATION: IDeg yielded a lower FPG level and smaller day-to-day variability of FPG at a lower daily dose compared with IGlar in participants with type 1 diabetes. IDeg serves as a good option for basal insulin in the treatment of type 1 diabetes. TRIAL REGISTRATION: University Hospital Medical Information Network 000009965. FUNDING: This research recieved no specific grant from any funding agency in the public, commercial or not-for-profit sectors.

Median-lower normal levels of serum thyroxine are associated with low triiodothyronine levels and body temperature in patients with central hypothyroidism.

OBJECTIVE: Although it has been recommended that serum free thyroxine (FT4) levels should be targeted to middle-upper normal levels during levothyroxine (l-T4) replacement therapy in patients with central hypothyroidism (CeH), the rationale has not been clarified. METHODS: A retrospective single-center study enrolled 116 patients with hypothyroidism (CeH, n=32; total thyroidectomy (Tx), n=22; primary hypothyroidism (PH), n=33; and control benign thyroid nodule (C), n=29). The patients had received L-T4 therapy at the Kobe University Hospital between 2003 and 2013. They were stratified according to serum FT4 level (≥ 1.10 or <1.10 ng/dl), and body temperature (BT), serum free triiodothyronine (FT3) levels, FT3/FT4 ratio, and lipid profiles were compared. The effect of GH replacement therapy on thyroid function was also analyzed. RESULTS: FT3 levels and FT3/FT4 ratios were significantly lower in patients with CeH than in patients with PH (P<0.05) or C (P<0.05). In patients with FT4 <1.10 ng/dl, BT was significantly lower in patients with CeH (P=0.002) and Tx (P=0.005) than in patients with PH, whereas no differences were found in patients with FT4 ≥ 1.10 ng/dl. In patients with CeH, FT3 levels were higher in those with GH replacement therapy (P=0.018). CONCLUSION: In CeH, patients with median-lower normal levels of serum FT4 exhibited lower serum FT3 levels and lower BT. These results support the target levels of serum FT4 as middle-upper normal levels during l-T4 replacement therapy in patients with CeH.

AP-1 is involved in ICOS gene expression downstream of TCR/CD28 and cytokine receptor signaling.

It has been proposed that sustained ICOS expression in chronic inflammatory immune conditions, such as autoimmunity and allergy, contributes to symptom exacerbation. Therefore modulation of ICOS gene expression could be a potential therapeutic strategy for such immune diseases. However, the precise molecular mechanisms controlling ICOS gene expression remain poorly understood. In this study, we explored transcription factors involving in ICOS gene expression and examined their roles in a physiological situation. Microarray analysis revealed that one AP-1 molecule, Fos-related antigen-2 (Fra2), was highly correlated with ICOS expression. Ectopic expression of Fra2 and other AP-1 molecules upregulated ICOS expression on T cells. We identified an AP-1-responsive site (AP1-RE) within the ICOS promoter region and demonstrated AP-1 actually binds to AP1-RE upon TCR/CD28 stimulation. Meanwhile, we found several cytokines could upregulate ICOS expression on both naïve and effector T cells in a manner independent of TCR/CD28 stimulation. These cytokine stimuli induced AP-1 binding to AP1-RE. Together, our results indicate AP-1 transcription factors are involved in ICOS gene expression downstream of both TCR/CD28 signaling and cytokine receptor signaling, and suggest AP-1 activation via cytokine receptor signaling may be one of the mechanisms maintaining high level ICOS expression in chronic inflammatory immune responses.

IL-15-high-responder developing NK cells bearing Ly49 receptors in IL-15-/- mice.

In mice lacking IL-15, NK cell development is arrested at immature stages, providing an opportunity to investigate the earliest developing NK cells that would respond to IL-15. We show in this study that immature NK cells were present in the spleen as well as bone marrow (BM) and contained IL-15-high-responder cells. Thus, mature NK cells were generated more efficiently from IL-15(-/-) than from control donor cells in radiation BM chimeras, and the rate of IL-15-induced cell division in vitro was higher in NK cells in the spleen and BM from IL-15(-/-) mice than in those from wild-type mice. Phenotypically, NK cells developed in IL-15(-/-) mice up to the minor but discrete CD11b(-)CD27(+)DX5(hi)CD51(dull)CD127(dull)CD122(hi) stage, which contained the majority of Ly49G2(+) and D(+) NK cells both in the spleen and BM. Even among wild-type splenic NK cells, IL-15-induced proliferation was most prominent in CD11b(-)DX5(hi) cells. Notably, IL-15-mediated preferential expansion (but not conversion from Ly49(-) cells) of Ly49(+) NK cells was observed in vitro only for NK cells in the spleen. These observations indicated the uneven distribution of NK cells of different developing stages with variable IL-15 responsiveness in these lymphoid organs. Immature NK cells in the spleen may contribute, as auxiliaries to those in BM, to the mature NK cell compartment through IL-15-driven extramarrow expansion under steady-state or inflammatory conditions.

Cervical epidural abscess presenting with Brown-Sequard syndrome in a patient with type 2 diabetes.

An 80-year-old woman with type 2 diabetes was admitted due to right-handed muscle weakness. The patient presented with Brown-Sequard syndrome, with complete paralysis of the right lower limb along with a loss of pain and temperature sensations in the left lower limb. Magnetic resonance imaging revealed a cervical epidural abscess, and accompanying edema or inflammation of the right side of the spinal cord at the C5 level. She underwent drainage and evacuation of the spinal abscess, followed by intravenous antibiotic administration. These interventions ameliorated the neurological deficits. The present case suggests the importance of epidural abscess as a rare pathogenetic cause of Brown-Sequard syndrome in type 2 diabetes.