Type 1 diabetes (T1D) in non-obese diabetic (NOD) mice may be favored by immune dysregulation leading to the hyporesponsiveness of regulatory T cells and activation of effector T-helper type 1 (Th1) cells. The immunoregulatory activity of natural killer T (NKT) cells is well documented, and both interleukin (IL)-4 and IL-10 secreted by NKT cells have important roles in mediating this activity. NKT cells are less frequent and display deficient IL-4 responses in both NOD mice and individuals at risk for T1D (ref. 8), and this deficiency may lead to T1D (refs. 1,6-9). Thus, given that NKT cells respond to the alpha-galactosylceramide (alpha-GalCer) glycolipid in a CD1d-restricted manner by secretion of Th2 cytokines, we reasoned that activation of NKT cells by alpha-GalCer might prevent the onset and/or recurrence of T1D. Here we show that alpha-GalCer treatment, even when initiated after the onset of insulitis, protects female NOD mice from T1D and prolongs the survival of pancreatic islets transplanted into newly diabetic NOD mice. In addition, when administered after the onset of insulitis, alpha-GalCer and IL-7 displayed synergistic effects, possibly via the ability of IL-7 to render NKT cells fully responsive to alpha-GalCer. Protection from T1D by alpha-GalCer was associated with the suppression of both T- and B-cell autoimmunity to islet beta cells and with a polarized Th2-like response in spleen and pancreas of these mice. These findings raise the possibility that alpha-GalCer treatment might be used therapeutically to prevent the onset and recurrence of human T1D.

The urate oxidase (Uox) gene encodes uricase that in the rodent liver degrades uric acid into allantoin, forming an obstacle for establishing stable mouse models of hyperuricemia. The loss of uricase in humans during primate evolution causes their vulnerability to hyperuricemia. Thus, we generated a Uox-knockout mouse model on a pure C57BL/6J background using the transcription activator-like effector nuclease (TALEN) technique. These Uox-knockout mice spontaneously developed hyperuricemia (over 420 μmol/l) with about 40% survival up to 62 weeks. Renal dysfunction (elevated serum creatinine and blood urea nitrogen) and glomerular/tubular lesions were observed in these Uox-knockout mice. Male Uox-knockout mice developed glycol-metabolic disorders associated with compromised insulin secretion and elevated vulnerability to streptozotocin-induced diabetes, whereas female mice developed hypertension accompanied by aberrant lipo-metabolism. Urate-lowering drugs reduced serum uric acid and improved hyperuricemia-induced disorders. Thus, uricase knockout provides a suitable mouse model to investigate hyperuricemia and associated disorders mimicking the human condition, suggesting that hyperuricemia has a causal role in the development of metabolic disorders and hypertension.

Dysregulation of autophagy in diabetic kidney disease (DKD) has been reported, but the underlying mechanism and its pathogenic role remain elusive. We show that autophagy was inhibited in DKD models and in human diabetic kidneys. Ablation of autophagy-related gene 7 (Atg7) from kidney proximal tubules led to autophagy deficiency and worse renal hypertrophy, tubular damage, inflammation, fibrosis, and albuminuria in diabetic mice, indicating a protective role of autophagy in DKD. Autophagy impairment in DKD was associated with the downregulation of unc-51-like autophagyactivating kinase 1 (ULK1), which was mediated by the upregulation of microRNA-214 (miR-214) in diabetic kidney cells and tissues. Ablation of miR-214 from kidney proximal tubules prevented a decrease in ULK1 expression and autophagy impairment in diabetic kidneys, resulting in less renal hypertrophy and albuminuria. Furthermore, blockade of p53 attenuated miR-214 induction in DKD, leading to higher levels of ULK1 and autophagy, accompanied by an amelioration of DKD. Compared with nondiabetic samples, renal biopsies from patients with diabetes showed induction of p53 and miR-214, associated with downregulation of ULK1 and autophagy. We found a positive correlation between p53/miR-214 and renal fibrosis, but a negative correlation between ULK1/LC3 and renal fibrosis in patients with diabetes. Together, these results identify the p53/ miR-214/ULK1 axis in autophagy impairment in diabetic kidneys, pinpointing possible therapeutic targets for DKD.

Highlights Ultraviolet C at a dose of 1.5 J/cm 2 to both sides is effective on some models of N95 s. Straps may require additional disinfection to decontaminate properly. SARS-CoV-2 decontamination does not apply to all hospital respiratory pathogens. N95 model and fit-testing following irradiation need to be considered for UVC decontamination.

CTLA-4 is a costimulatory molecule that negatively regulates T cell activation. Originally identified in murine CD8+ T cells, it has been found to be rapidly induced on human T cells. Furthermore, CTLA-4 is expressed on regulatory T cells (Tregs). Clinically, targeting CTLA-4 has clinical utility in the treatment of melanoma. Whether the expression of CTLA-4 is differentially regulated in CD8+ vs. CD4+ human T cells is unclear. Here we analyzed CTLA-4 in normal human CD4+ and CD8+ T cell subsets and show for the first time that CTLA-4 is expressed significantly higher in the CD4+ T cells than in CD8+ T cells. CTLA-4 is higher at the protein and the transcriptional level in CD4+ T cells. This increase is due to activation of the CTLA-4 promoter, which undergoes acetylation at the proximal promoter. Furthermore, we show that blocking CTLA-4 on CD4+ T cells permits greater proliferation in CD4+ vs. CD8+ cells. These findings demonstrate a differential regulation of CTLA-4 on CD4+ and CD8+ T cell subsets, which is likely important to the clinical efficacy for anti-CTLA-4 therapies. The findings hint to strategies to modulate CTLA-4 expression by targeting epigenetic transcription to alter the immune response.

As the sentinels of the immune system, dendritic cells (DCs) play a critical role in initiating and regulating antigen-specific immune responses. Cross-priming, a process that DCs activate CD8 T cells by cross-presenting exogenous antigens onto their MHCI (Major Histocompatibility Complex class I), plays a critical role in mediating CD8 T cell immunity as well as tolerance. Current DC vaccines have remained largely unsuccessful despite their ability to potentiate both effector and memory CD8 T cell responses. There are two major hurdles for the success of DC-based vaccines: tumor-mediated immunosuppression and the functional limitation of the commonly used monocyte-derived dendritic cells (MoDCs). Due to their resistance to tumor-mediated suppression as inert vesicles, DC-derived exosomes (DCexos) have garnered much interest as cell-free therapeutic agents. However, current DCexo clinical trials have shown limited clinical benefits and failed to generate antigen-specific T cell responses. Another exciting development is the use of naturally circulating DCs instead of in vitro cultured DCs, as clinical trials with both human blood cDC2s (type 2 conventional DCs) and plasmacytoid DCs (pDCs) have shown promising results. pDC vaccines were particularly encouraging, especially in light of promising data from a recent clinical trial using a human pDC cell line, despite pDCs being considered tolerogenic and playing a suppressive role in tumors. However, how pDCs generate anti-tumor CD8 T cell immunity remains poorly understood, thus hindering their clinical advance. Using a pDC-targeted vaccine model, we have recently reported that while pDC-targeted vaccines led to strong cross-priming and durable CD8 T cell immunity, cross-presenting pDCs required cDCs to achieve cross-priming in vivo by transferring antigens to cDCs. Antigen transfer from pDCs to bystander cDCs was mediated by pDC-derived exosomes (pDCexos), which similarly required cDCs for cross-priming of antigen-specific CD8 T cells. pDCexos thus represent a new addition in our arsenal of DC-based cancer vaccines that would potentially combine the advantage of pDCs and DCexos.

MicroRNAs are small noncoding RNAs that are produced endogenously and have emerged as important regulators in pathophysiological conditions such as development and tumorigenesis. Very little is known about the regulation of microRNAs in renal diseases, including acute kidney injury (AKI). In this study, we examined the regulation of microRNA-34a (miR-34a) in experimental models of cisplatin-induced AKI and nephrotoxicity. By Northern blot and real-time polymerase chain reaction analyses, we detected an induction of miR-34a in vitro during cisplatin treatment of mouse proximal tubular cells and also in vivo during cisplatin nephrotoxicity in C57BL/6 mice. In cultured cells, miR-34a was induced within a few hours. In mice, miR-34a induction was detectable in renal tissues after 1 d of cisplatin treatment and increased to approximately four-fold of control at d 3. During cisplatin treatment, p53 was activated. Inhibition of p53 with pifithrin-α abrogated the induction of miR-34a during cisplatin treatment of proximal tubular cells. In vivo, miR-34a induction by cisplatin was abrogated in p53-deficient mice, a result that further confirms a role for p53 in miR-34a induction during cisplatin nephrotoxicity. Functionally, antagonism of miR-34a with specific antisense oligonucleotides increased cell death during cisplatin treatment. Collectively, the results suggest that miR-34a is induced via p53 during cisplatin nephrotoxicity and may play a cytoprotective role for cell survival.

BackgroundMicroRNAs (miRNAs) serve as important regulators of inflammatory and immune responses and are implicated in several immune disorders including gouty arthritis. The expression of miR-146a is upregulated in the peripheral blood mononuclear cells of patients with inter-critical gout when compared to normouricemic and hyperuricemic controls and those patients with acute gout flares. However, the role of miR-146a in the development of gout remains unknown. Here, we used miR-146a knockout (KO) mice to test miR-146a function in a monosodium urate (MSU)-induced gouty arthritis model.MethodsThe footpad or ankle joint of miR-146a KO and wild-type (WT) mice were injected with an MSU suspension to induce acute gouty arthritis. Bone marrow-derived macrophages (BMDMs) were stimulated with MSU and the gene expression of miR-146a; interleukin 1 beta (IL-1β); tumor necrosis factor-α (TNF-α); and the NACHT, LRR and PYD domains-containing protein 3 (NALP3) inflammasome was evaluated. TNF-α and IL-1β protein levels in BMDMs were assessed by fluorescence-activated cell sorting and western blot analyses. Gene and protein levels of TNF receptor-associated factor 6 (TRAF6) and IL-1 receptor-associated kinase (IRAK1), the targets of miR-146a, were also measured.ResultsSignificantly increased paw swelling and index and ankle joint swelling were observed in miR-146a KO mice compared to WT controls after MSU treatment. MiR-146a expression in BMDMs from WT mice was dramatically upregulated at 4 h following MSU stimulation. Additionally, the expression of IL-1β, TNF-α, and NALP3 was higher in BMDMs from miR-146a KO mice after exposure to MSU crystals compared to those from WT mice. Consistent with the observed gene expression, the IL-1β and TNF-α proteins were upregulated in miR-146a KO mice. Additionally quantitative RT-PCR and western blot demonstrated that TRAF6 and IRAK1 were dramatically upregulated in BMDMs from miR-146 KO mice compared to those from WT mice.ConclusionsCollectively, these observations suggest that miR-146a provides negative feedback regulation of gouty arthritis development and lack of miR-146a enhances gouty arthritis via upregulation of TRAK6, IRAK-1, and the NALP3 inflammasome function.