A retrospective analysis of gene fusions and treatment outcomes in pediatric acute megakaryoblastic leukemia without Down syndrome.

Not available.

CD3 downregulation identifies high-avidity human CD8 T cells.

CD8 T cells recognize infected and cancerous cells via their T-cell receptor (TCR), which binds peptide-MHC complexes on the target cell. The affinity of the interaction between the TCR and peptide-MHC contributes to the antigen sensitivity, or functional avidity, of the CD8 T cell. In response to peptide-MHC stimulation, the TCR-CD3 complex and CD8 co-receptor are downmodulated. We quantified CD3 and CD8 downmodulation following stimulation of human CD8 T cells with CMV, EBV, and HIV peptides spanning eight MHC restrictions, observing a strong correlation between the levels of CD3 and CD8 downmodulation and functional avidity, regardless of peptide viral origin. In TCR-transduced T cells targeting a tumor-associated antigen, changes in TCR-peptide affinity were sufficient to modify CD3 and CD8 downmodulation. Correlation analysis and generalized linear modeling indicated that CD3 downmodulation was the stronger correlate of avidity. CD3 downmodulation, simply measured using flow cytometry, can be used to identify high-avidity CD8 T cells in a clinical context.

A histone deacetylase network regulates epigenetic reprogramming and viral silencing in HIV-infected cells.

A long-lived latent reservoir of HIV-1-infected CD4 T cells persists with antiretroviral therapy and prevents cure. We report that the emergence of latently infected primary CD4 T cells requires the activity of histone deacetylase enzymes HDAC1/2 and HDAC3. Data from targeted HDAC molecules, an HDAC3-directed PROTAC, and CRISPR-Cas9 knockout experiments converge on a model where either HDAC1/2 or HDAC3 targeting can prevent latency, whereas all three enzymes must be targeted to achieve latency reversal. Furthermore, HDACi treatment targets features of memory T cells that are linked to proviral latency and persistence. Latency prevention is associated with increased H3K9ac at the proviral LTR promoter region and decreased H3K9me3, suggesting that this epigenetic switch is a key proviral silencing mechanism that depends on HDAC activity. These findings support further mechanistic work on latency initiation and eventual clinical studies of HDAC inhibitors to interfere with latency initiation.

C9orf72-ALS human iPSC microglia are pro-inflammatory and toxic to co-cultured motor neurons via MMP9.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by progressive motor neuron loss, with additional pathophysiological involvement of non-neuronal cells such as microglia. The commonest ALS-associated genetic variant is a hexanucleotide repeat expansion (HRE) mutation in C9orf72. Here, we study its consequences for microglial function using human iPSC-derived microglia. By RNA-sequencing, we identify enrichment of pathways associated with immune cell activation and cyto-/chemokines in C9orf72 HRE mutant microglia versus healthy controls, most prominently after LPS priming. Specifically, LPS-primed C9orf72 HRE mutant microglia show consistently increased expression and release of matrix metalloproteinase-9 (MMP9). LPS-primed C9orf72 HRE mutant microglia are toxic to co-cultured healthy motor neurons, which is ameliorated by concomitant application of an MMP9 inhibitor. Finally, we identify release of dipeptidyl peptidase-4 (DPP4) as a marker for MMP9-dependent microglial dysregulation in co-culture. These results demonstrate cellular dysfunction of C9orf72 HRE mutant microglia, and a non-cell-autonomous role in driving C9orf72-ALS pathophysiology in motor neurons through MMP9 signaling.

Aminobisphosphonates reactivate the latent reservoir in people living with HIV-1.

Antiretroviral therapy (ART) is not curative due to the existence of cellular reservoirs of latent HIV-1 that persist during therapy. Current research efforts to cure HIV-1 infection include "shock and kill" strategies to disrupt latency using small molecules or latency-reversing agents (LRAs) to induce expression of HIV-1 enabling cytotoxic immune cells to eliminate infected cells. The modest success of current LRAs urges the field to identify novel drugs with increased clinical efficacy. Aminobisphosphonates (N-BPs) that include pamidronate, zoledronate, or alendronate, are the first-line treatment of bone-related diseases including osteoporosis and bone malignancies. Here, we show the use of N-BPs as a novel class of LRA: we found in ex vivo assays using primary cells from ART-suppressed people living with HIV-1 that N-BPs induce HIV-1 from latency to levels that are comparable to the T cell activator phytohemagglutinin (PHA). RNA sequencing and mechanistic data suggested that reactivation may occur through activation of the activator protein 1 signaling pathway. Stored samples from a prior clinical trial aimed at analyzing the effect of alendronate on bone mineral density, provided further evidence of alendronate-mediated latency reversal and activation of immune effector cells. Decay of the reservoir measured by IPDA was however not detected. Our results demonstrate the novel use of N-BPs to reverse HIV-1 latency while inducing immune effector functions. This preliminary evidence merits further investigation in a controlled clinical setting possibly in combination with therapeutic vaccination.

Tailoring multifunctional anions to inhibit methanol absorption on a CsPbBr3 quantum dot surface for highly efficient semi-transparent photovoltaics.

Methyl acetate (MeOAc) is the most used antisolvent in the preparation of perovskite quantum dot (QD) films. However, the hydrolysis of MeOAc results in acetic acid and methanol (MeOH), and the decomposition of the perovskite occurs more easily under acidic and polar conditions. Herein, we report a facile and universal anion modification strategy to inhibit MeOH absorption on a perovskite QD surface and improve the photovoltaic performance of perovskite QD solar cells, which is implemented by incorporating a series of guanidinium salts containing different anions (guanidinium bromide (GuaBr), guanidinium thiocyanate (GuaSCN), and guanidinium acetate (GuaAc)). All anions play a positive role in inhibiting the absorption of MeOH on the QD surface, facilitating charge transfer between perovskite QDs and passivating the defects. Moreover, the regulation of surface chemistry can be optimized by rational tailoring of different anion species. The GuaAc-based devices deliver a PCE of 7.04%, which is the highest value among inorganic CsPbBr3 QD solar cells. More importantly, the CsPbBr3 QD solar cells exhibit high transparency over the entire visible spectrum region, indicating their promising application in solar windows.

Aminobisphosphonates reactivate the latent reservoir in people living with HIV-1.

Antiretroviral therapy (ART) is not curative due to the existence of cellular reservoirs of latent HIV-1 that persist during therapy. Current research efforts to cure HIV-1 infection include "shock and kill" strategies to disrupt latency using small molecules or latency-reversing agents (LRAs) to induce expression of HIV-1 enabling cytotoxic immune cells to eliminate infected cells. The modest success of current LRAs urges the field to identify novel drugs with increased clinical efficacy. Aminobisphosphonates (N-BPs) that include pamidronate, zoledronate, or alendronate, are the first-line treatment of bone-related diseases including osteoporosis and bone malignancies. Here, we show the use of N-BPs as a novel class of LRA: we found in ex vivo assays using primary cells from ART-suppressed people living with HIV-1 that N-BPs induce HIV-1 from latency to levels that are comparable to the T cell activator phytohemagglutinin (PHA). RNA sequencing and mechanistic data suggested that reactivation may occur through activation of the activator protein 1 signaling pathway. Stored samples from a prior clinical trial aimed at analyzing the effect of alendronate on bone mineral density, provided further evidence of alendronate-mediated latency reversal and activation of immune effector cells. Decay of the reservoir measured by IPDA was however not detected. Our results demonstrate the novel use of N-BPs to reverse HIV-1 latency while inducing immune effector functions. This preliminary evidence merits further investigation in a controlled clinical setting possibly in combination with therapeutic vaccination.

Human iPSC co-culture model to investigate the interaction between microglia and motor neurons.

Motor neuron diseases such as amyotrophic lateral sclerosis are primarily characterized by motor neuron degeneration with additional involvement of non-neuronal cells, in particular, microglia. In previous work, we have established protocols for the differentiation of iPSC-derived spinal motor neurons and microglia. Here, we combine both cell lineages and establish a novel co-culture of iPSC-derived spinal motor neurons and microglia, which is compatible with motor neuron identity and function. Co-cultured microglia express key identity markers and transcriptomically resemble primary human microglia, have highly dynamic ramifications, are phagocytically competent, release relevant cytokines and respond to stimulation. Further, they express key amyotrophic lateral sclerosis-associated genes and release disease-relevant biomarkers. This novel and authentic human model system facilitates the study of physiological motor neuron-microglia crosstalk and will allow the investigation of non-cell-autonomous phenotypes in motor neuron diseases such as amyotrophic lateral sclerosis.

Diminished Rbfox1 increases vascular constriction by dynamically regulating alternative splicing of CaV1.2 calcium channel in hypertension.

Calcium influx from depolarized CaV1.2 calcium channels triggers the contraction of vascular smooth muscle cells (VSMCs), which is important for maintaining vascular myogenic tone and blood pressure. The function of CaV1.2 channel can be subtly modulated by alternative splicing (AS), and its aberrant splicing involves in the pathogenesis of multiple cardiovascular diseases. The RNA-binding protein Rbfox1 is reported to regulate the AS events of CaV1.2 channel in the neuronal development, but its potential roles in vascular CaV1.2 channels and vasoconstriction remain undefined. Here, we detect Rbfox1 is expressed in rat vascular smooth muscles. Moreover, the protein level of Rbfox1 is dramatically decreased in the hypertensive small arteries from spontaneously hypertensive rats in comparison with normotensive ones from Wistar-Kyoto rats. In VSMCs, Rbfox1 could dynamically regulate the AS of CaV1.2 exons 9* and 33. By whole-cell patch clamp, we identify knockdown of Rbfox1 induces the hyperpolarization of CaV1.2 current-voltage relationship curve in VSMCs. Furthermore, siRNA-mediated knockdown of Rbfox1 increases the K+-induced constriction of rat mesenteric arteries. In summary, our results indicate Rbfox1 modulates vascular constriction by dynamically regulating CaV1.2 alternative exons 9* and 33. Therefore, our work elucidates the underlying mechanisms for CaV1.2 channels regulation and provides a potential therapeutic target for hypertension.

CD8 T Cell Virus Inhibition Assay Protocol.

The human immunodeficiency virus (HIV)-1 viral inhibition assay (VIA) measures CD8+ T cell-mediated inhibition of HIV replication in CD4+ T cells and is increasingly used for clinical testing of HIV vaccines and immunotherapies. Different VIAs that differ in length of CD8:CD4 T cell culture periods (6-13 days), purity of CD4 cultures [isolated CD4+ T cells or CD8+ depleted peripheral blood mononuclear cells (PBMCs)], HIV strains (laboratory strains, isolates, reporter viruses) and read-outs of virus inhibition (p24 ELISA, intracellular measurement of p24, luciferase reporter expression, and viral gag RNA) have been reported. Here, we describe multiple modifications to a 7-day VIA protocol, the most impactful being the introduction of independent replicate cultures for both HIV infected-CD4 (HIV-CD4) and HIV-CD4:CD8 T cell cultures. Virus inhibition was quantified using a ratio of weighted averages of p24+ cells in replicate cultures and the corresponding 95% confidence intervals. We identify methodological and analysis changes that could be incorporated into other protocols to improve assay reproducibility. We found that in people living with HIV (PLWH) on antiretroviral therapy (ART), CD8 T cell virus inhibition was largely stable over time, supporting the use of this assay and/or analysis methods to examine therapeutic interventions. Graphic abstract.

Human stem cell models of neurodegeneration: From basic science of amyotrophic lateral sclerosis to clinical translation.

Neurodegenerative diseases are characterized by progressive cell loss leading to disruption of the structure and function of the central nervous system. Amyotrophic lateral sclerosis (ALS) was among the first of these disorders modeled in patient-specific iPSCs, and recent findings have translated into some of the earliest iPSC-inspired clinical trials. Focusing on ALS as an example, we evaluate the status of modeling neurodegenerative diseases using iPSCs, including methods for deriving and using disease-relevant neuronal and glial lineages. We further highlight the remaining challenges in exploiting the full potential of iPSC technology for understanding and potentially treating neurodegenerative diseases such as ALS.

Corrigendum: Reliable estimation of CD8 T cell inhibition of in vitro HIV-1 replication.

[This corrects the article DOI: 10.3389/fimmu.2021.666991.].

Isolated Enhancement Effect is the Only MRI Finding for Wernicke's encephalopathy.

Wernicke's encephalopathy (WE) is an acute neuropsychiatric disorder that results from thiamine (vitamin B1) deficiency. The typical clinical manifestations, which occur as triads in 20% of patients with the disorder, are acute mental status changes, ophthalmoplegia, and ataxia. Brain magnetic resonance imaging (MRI) has important value in diagnosis as it can reveal abnormalities in the thalamus, mammillary body, third and fourth ventricles, and periaqueductal area. Here we describe a 44-year-old female patient with WE, in the context of fasting following bowel surgery. The unique neuroimaging findings were symmetrical mammillary body and dorsal midbrain abnormalities, only evident on contrast-enhanced brain MRI.

Immune escape mechanisms and immunotherapy of urothelial bladder cancer.

BACKGROUND AND AIM: Urothelial bladder cancer (UBC) is a common malignant tumor of the urogenital system with a high rate of recurrence. Due to the sophisticated and largely unexplored mechanisms of tumorigenesis of UBC, the classical therapeutic approaches including transurethral resection and radical cystectomy combined with chemotherapy have remained unchanged for decades. However, with increasingly in-depth understanding of the microenvironment and the composition of tumor-infiltrating lymphocytes of UBC, novel immunotherapeutic strategies have been developed. Bacillus Calmette-Guerin (BCG) therapy, immune checkpoint blockades, adoptive T cell immunotherapy, dendritic cell (DC) vaccines, etc., have all been intensively investigated as immunotherapies for UBC. This review will discuss the recent progress in immune escape mechanisms and immunotherapy of UBC. METHODS: Based on a comprehensive search of the PubMed and ClinicalTrials.gov database, this review included the literature reporting the immune escape mechanisms of UBC and clinical trials assessing the effect of immunotherapeutic strategies on tumor or immune cells in UBC patients published in English between 1999 and 2020. RESULTS: Immune surveillance, immune balance, and immune escape are the three major processes that occur during UBC tumorigenesis. First, the role of immunosuppressive cells, immunosuppressive molecules, immunosuppressive signaling molecules, and DCs in tumor microenvironment is introduced elaborately in the immune escape mechanisms of UBC section. In addition, recent progress of immunotherapies including BCG, checkpoint inhibitors, cytokines, adoptive T cell immunotherapy, DCs, and macrophages on UBC patients are summarized in detail. Finally, the need to explore the mechanisms, molecular characteristics and immune landscape during UBC tumorigenesis and development of novel and robust immunotherapies for UBC are also proposed and discussed. CONCLUSION: At present, BCG and immune checkpoint blockades have been approved by the US Food and Drug Administration for the treatment of UBC patients and have achieved encouraging therapeutic results, expanding the traditional chemotherapy and surgery-based treatment for UBC. RELEVANCE FOR PATIENTS: Immunotherapy has achieved desirable results in the treatment of UBC, which not only improve the overall survival but also reduce the recurrence rate and the occurrence of treatment-related adverse events of UBC patients. In addition, the indicators to predict the effectiveness and novel therapy strategies, such as combination regimen of checkpoint inhibitor with checkpoint inhibitor or chemotherapy, should be further studied.

Reliable Estimation of CD8 T Cell Inhibition of In Vitro HIV-1 Replication.

The HIV-1 viral inhibition assay (VIA) measures CD8 T cell-mediated inhibition of HIV replication in CD4 T cells and is increasingly used for clinical testing of HIV vaccines and immunotherapies. The VIA has multiple sources of variability arising from in vitro HIV infection and co-culture of two T cell populations. Here, we describe multiple modifications to a 7-day VIA protocol, the most impactful being the introduction of independent replicate cultures for both HIV infected-CD4 (HIV-CD4) and HIV-CD4:CD8 T cell cultures. Virus inhibition was quantified using a ratio of weighted averages of p24+ cells in replicate cultures and the corresponding 95% confidence interval. An Excel template is provided to facilitate calculations. Virus inhibition was higher in people living with HIV suppressed on antiretroviral therapy (n=14, mean: 40.0%, median: 43.8%, range: 8.2 to 73.3%; p < 0.0001, two-tailed, exact Mann-Whitney test) compared to HIV-seronegative donors (n = 21, mean: -13.7%, median: -14.4%, range: -49.9 to 20.9%) and was stable over time (n = 6, mean %COV 9.4%, range 0.9 to 17.3%). Cross-sectional data were used to define 8% inhibition as the threshold to confidently detect specific CD8 T cell activity and determine the minimum number of culture replicates and p24+ cells needed to have 90% statistical power to detect this threshold. Last, we note that, in HIV seronegative donors, the addition of CD8 T cells to HIV infected CD4 T cells consistently increased HIV replication, though the level of increase varied markedly between donors. This co-culture effect may contribute to the weak correlations observed between CD8 T cell VIA and other measures of HIV-specific CD8 T cell function.

Mulberroside A from Cortex Mori Enhanced Gut Integrity in Diabetes.

BACKGROUND: Diabetic endotoxemia has been recognized as one of the hallmarks of type 2 diabetes mellitus (T2DM). Recent findings suggest that gut leak plays a pivotal role in diabetic endotoxemia. Cortex Mori (CM) has been widely applied in China to ameliorate development of T2DM, but its effect on endotoxemia is unknown. METHODS: The study was constructed with two parts: (1) in vivo study of CM on diabetic endotoxemia in db/db mice. Eight C57BL/6 mice were set as normal control; (2) in vitro study of mulberroside A (MBA) from CM on diabetic endotoxemia. Potential mechanism of MBA on ameliorating diabetic endotoxemia was also explored. RESULTS: The present study found that CM water extract decreased levels of blood glucose, ameliorated liver and renal damage in db/db mice, and ameliorated diabetic endotoxemia (p < 0.01). We also found that the water extract enhanced gut integrity and decreased gut inflammatory protein ICAM-1 expression in db/db mice as detected by H&E staining and immunohistochemistry methods. In the in vitro study, MBA decreased levels of MDA and ROS induced by LPS (p < 0.01) and enhanced the integrity of gut epithelial barrier (p < 0.01). CONCLUSIONS: We found that Cortex Mori and its active component mulberroside A could ameliorate diabetic endotoxemia by preserving gut integrity.

Regulating the Film Growth and Reducing the Defects for Efficient CsPbIBr2 Solar Cells.

Inorganic lead halide perovskite CsPbIBr2 possesses good stability with a suitable band gap for tandem solar cells. Decreasing the defect concentration and improving the film quality is crucial to further increase the power conversion efficiency of CsPbIBr2 solar cells. Here, the crystallization dynamics of CsPbIBr2 films is regulated by introducing the volatile organic salt, formamidinium acetate (FAAc) into the precursor solution. It is found that FAAc slows the crystallization process of CsPbIBr2 films and pinhole-free films with large grains and smooth surfaces are obtained. The defect concentration of the films is decreased and the nonradiative recombination is significantly inhibited. By improving the film quality, the FAAc remarkably enhances the efficiency of CsPbIBr2 solar cells. The champion device delivers a power conversion efficiency of 9.44% and exhibits higher stability than the reference device. This finding provides an effective strategy for reducing defects, suppressing the recombination, and improving the performance of CsPbIBr2 solar cells.

The HIV-1 latent reservoir is largely sensitive to circulating T cells.

HIV-1-specific CD8+ T cells are an important component of HIV-1 curative strategies. Viral variants in the HIV-1 reservoir may limit the capacity of T cells to detect and clear virus-infected cells. We investigated the patterns of T cell escape variants in the replication-competent reservoir of 25 persons living with HIV-1 (PLWH) durably suppressed on antiretroviral therapy (ART). We identified all reactive T cell epitopes in the HIV-1 proteome for each participant and sequenced HIV-1 outgrowth viruses from resting CD4+ T cells. All non-synonymous mutations in reactive T cell epitopes were tested for their effect on the size of the T cell response, with a≥50% loss defined as an escape mutation. The majority (68%) of T cell epitopes harbored no detectable escape mutations. These findings suggest that circulating T cells in PLWH on ART could contribute to control of rebound and could be targeted for boosting in curative strategies.

CsPbBr3 nanowire polarized light-emitting diodes through mechanical rubbing.

Anisotropic films composed of aligned CsPbBr3 nanowires (NWs) have been successfully fabricated using a mechanical rubbing method. The films with a dense and uniform morphology show polarization photoluminescence (PL) behavior. Combined with an optimal device structure, a polarized light-emitting diode (LED) with a turn-on voltage as low as 6.5 V was obtained.

EM2D9, A monoclonal antibody against integrin α5ß1, has potent antitumor activity on endometrial cancer in vitro and in vivo.

Endometrial cancer, a type of primary epithelial malignant tumor in the endometrium, is one of the three most common malignant tumors of the female reproductive system. While the incidence of endometrial cancer has been recently rising, its etiology remains unclear. In this study we found that EM2D9, an independently developed monoclonal antibody, specifically recognized endometrial cancer cells; we further determined that EM2D9 target protein was α5ß1. In vitro and in vivo experiments showed that EM2D9 inhibited the migration of endometrial cancer cells. Real-time quantitative PCR results showed that the expression of CD151 mRNA in endometrial carcinoma cells significantly decreased after EM2D9 treatment. We also found that EM2D9 affected the FAK signaling pathway. Collectively, these results shed light on a new mechanism for the development of endometrial carcinoma.