Avian influenza A/H7N9 virus infection causes pneumonia in humans with a high case fatality rate. However, virus-induced modulation of immune responses is being recognized increasingly as a factor in the pathogenesis of this disease. In this study, we compared the pathogenicity of A/H7N9 infection in BALB/c and C57BL/6 mouse models, and investigated the putative involvement of proinflammatory cytokines in lung injury and viral clearance. In both mouse strains, A/Anhui/1/2013(H7N9) infection with 10(6) TCID50 resulted in viral replication in lung, severe body weight loss and acute lung injury. During the early infection stage, infected C57BL/6 mice exhibited more severe lung injury, slower recovery from lung damage, less effective viral clearance, higher levels of interlukine (IL)-6, monocyte chemotactic protein (MCP)-1, and IL-1β, and lower levels of tumor necrosis factor (TNF)-α and interferon (IFN)-γ than infected BALB/c mice. These results suggest that TNF-α and IFN-γ may help suppress viral gene expression and increase viral clearance, and that IL-6 and MCP-1 may contribute to lung injury in A/H7N9-infected individuals. In addition, lung damage and the distribution of virus antigen in tissues were similar in young and middle-aged mice. These results suggest that the more serious lung injury in middle-aged or older H7N9 cases is not mainly caused by differences in viral replication in the lung but probably by a dysregulated immune response induced by underlying comorbidities. These results indicate that the extent of dysregulation of the host immune response after H7N9 virus infection most probably determines the outcome of H7N9 virus infection.

HIV-1 Rev plays an important role in the late phase of HIV-1 replication, which facilitates export of unspliced viral mRNAs from the nucleus to cytoplasm in infected cells. Recent studies have shown that DDX1 and DDX3 are co-factors of Rev for the export of HIV-1 transcripts. In this report, we have demonstrated that DDX5 (p68), which is a multifunctional DEAD-box RNA helicase, functions as a new cellular co-factor of HIV-1 Rev. We found that DDX5 affects Rev function through the Rev-RRE axis and subsequently enhances HIV-1 replication. Confocal microscopy and co-immunoprecipitation analysis indicated that DDX5 binds to Rev and this interaction is largely dependent on RNA. If the DEAD-box motif of DDX5 is mutated, DDX5 loses almost all of its ability to bind to Rev, indicating that the DEAD-box motif of DDX5 is required for the interaction between DDX5 and Rev. Our data indicate that interference of DDX5-Rev interaction could reduce HIV-1 replication and potentially provide a new molecular target for anti-HIV-1 therapeutics.

PIWI interacting RNAs (piRNAs) are highly expressed in germline cells and are involved in maintaining genome integrity by silencing transposons. These are also involved in DNA/histone methylation and gene expression regulation in somatic cells of invertebrates. The functions of piRNAs in somatic cells of vertebrates, however, remain elusive. We found that snoRNA-derived and C (C')/D' (D)-box conserved piRNAs are abundant in human CD4 primary T-lymphocytes. piRNA (piR30840) significantly downregulated interleukin-4 (IL-4) via sequence complementarity binding to pre-mRNA intron, which subsequently inhibited the development of Th2 T-lymphocytes. Piwil4 and Ago4 are associated with this piRNA, and this complex further interacts with Trf4-Air2-Mtr4 Polyadenylation (TRAMP) complex, which leads to the decay of targeted pre-mRNA through nuclear exosomes. Taken together, we demonstrate a novel piRNA mechanism in regulating gene expression in highly differentiated somatic cells and a possible novel target for allergy therapeutics.

Flowering in the appropriate season is critical for successful reproduction in angiosperms. The orchid species, Dendrobium nobile, requires vernalization to achieve flowering in the spring, but the underlying regulatory network has not been identified to date. The MADS-box transcription factor DnAGL19 was previously identified in a study of low-temperature treated D. nobile buds and was suggested to regulate vernalization-induced flowering. In this study, phylogenetic analysis of DnAGL9 and the MADS-box containing proteins showed that DnAGL19 is phylogenetically closely related to the SOC1-like protein from orchid Dendrobium Chao Parya Smile, DOSOC1. The orchid clade closed to but is not included into the SOC1-1/TM3 clades associated with either eudicots or monocots, suggesting that DnAGL19 is an SOC1-1/TM3-like ortholog. DnAGL19 was found to be highly expressed in pseudobulbs, leaves, roots, and axillary buds but rarely in flowers, and to be substantially upregulated in axillary buds by prolonged low-temperature treatments. Overexpression of DnAGL19 in Arabidopsis thaliana resulted in a small but significantly reduced time to bolting, suggesting that flowering time was slightly accelerated under normal growth conditions. Consistent with this, the A. thaliana APETELA1 (AP1) gene was expressed at an earlier stage in transgenic lines than in wild type plants, while the FLOWERING LOCUS T (FT) gene was suppressed, suggesting that altered regulations on these transcription factors caused the weak promotion of flowering. HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENE 1 (HOS1) was slightly activated under the same conditions, suggesting that the HOS1-FT module may be involved in the DnAGL19-related network. Under vernalization conditions, FT expression was significantly upregulated, whereas HOS1 expression in the transgenic A. thaliana has a level similar to that in wild type. Taken together, these results suggest that DnAGL19 controls the action of the HOS1-FT module depending on temperature cues, which could contribute to regulation of D. nobile flowering time. These data provide insights into how flowering is fine-tuned in D. nobile to acclimate the plant to seasonal changes in temperature.

Although combined antiretroviral therapy (cART) successfully decreases plasma viremia to undetectable levels, the complete eradication of human immunodeficiency virus type 1 (HIV-1) remains impractical because of the existence of a viral reservoir, mainly in resting memory CD4(+) T cells. Various cytokines, protein kinase C activators, and histone deacetylase inhibitors (HDACi) have been used as latency-reversing agents (LRAs), but their unacceptable side effects or low efficiencies limit their clinical use. Here, by a mutation accumulation strategy, we generated an attenuated HIV-1 Tat protein named Tat-R5M4, which has significantly reduced cytotoxicity and immunogenicity, yet retaining potent transactivation and membrane-penetration activity. Combined with HDACi, Tat-R5M4 activates highly genetically diverse and replication-competent viruses from resting CD4(+) T lymphocytes isolated from HIV-1-infected individuals receiving suppressive cART. Thus, Tat-R5M4 has promising potential as a safe, efficient, and specific LRA in HIV-1 treatment.

To investigate whether unilateral pedicle screw fixation is superior than bilateral pedicle screw fixation for lumbar degenerative diseases.

The antiviral activity of host factor apolipoprotein B mRNA editing enzyme catalytic polypeptide-like 3G (APOBEC3G, A3G) and its degradation mediated by human immunodeficiency virus type 1 (HIV-1) Vif protein are important topics. Although accumulating evidence indicates the importance of deubiquitination enzymes (DUBs) in innate immunity, it is unknown if they participate in A3G stability. Here, we found that USP49 directly interacts with A3G and efficiently removes ubiquitin, consequently increasing A3G protein expression and significantly enhancing its anti-HIV-1 activity. Unexpectedly, A3G degradation was also mediated by a Vif- and cullin-ring-independent pathway, which was effectively counteracted by USP49. Furthermore, clinical data suggested that USP49 is correlated with A3G protein expression and hypermutations in Vif-positive proviruses, and inversely with the intact provirus ratio in the HIV-1 latent reservoir. Our studies demonstrated a mechanism to effectively stabilize A3G expression, which could comprise a target to control HIV-1 infection and eradicate the latent reservoir.

Bioelectrochemical systems (BESs) are capable of simultaneous wastewater treatment and resource recovery at low temperatures. However, the direct enrichment of psychrophilic and electroactive biofilms in BESs at 4°C is difficult due to the lack of understanding in the physioecology of psychrophilic exoelectrogens. Here, we report the start-up and operation of microbial fuel cells (MFCs) at 4°C with pre-acclimated inocula at different temperatures (4°C, 10°C, 25°C, and -20°C) for 7 days and 14 days. MFCs with 7-day-pretreated inocula reached higher peak voltages than did those with 14-day-pretreated inocula. The highest power densities were obtained by MFCs with 25°C - 7-day-, 25°C - 14-day-, and 4°C - 7-day-pretreated inocula (650-700 mW/m2). In contrast, the control MFCs with untreated inocula were stable at 450 mW/m2. The power densities of MFCs with 7-day-pretreated inocula were higher than those obtained by MFCs with 14-day-pretreated inocula. The MFCs with 10°C - 7-day-pretreated inocula and the control MFCs showed higher chemical oxygen demand (COD) removal (90-91%) than other MFCs. Illumina HiSeq sequencing based on 16S rRNA gene amplicons indicated that bacterial communities of the anode biofilms were shaped by pretreated inocula at different temperatures. Compared with the control MFCs with untreated inocula, MFCs with temperature-pretreated inocula demonstrated higher microbial diversity, but did not do so with -20°C-pretreated inocula. Principal components analysis (PCA) revealed an obvious separation between the inocula pretreated at 4°C and those pretreated at 10°C, implying that bacterial community structures could be shaped by pretreated inocula at low temperatures. The pretreatment period also had a diverse impact on the abundance of exoelectrogens and non-exoelectrogens in MFCs with inocula pretreated at different temperatures. The majority of the predominant population was affiliated with Geobacter with a relative abundance of 17-70% at different pre-acclimated temperatures, suggesting that the exoelectrogenic Geobacter could be effectively enriched at 4°C even with inocula pretreated at different temperatures. This study provides a strategy that was previously neglected for fast enrichment of psychrophilic exoelectrogens in BESs at low temperatures.

Excessive immune responses played an important role in pathophysiology of mycoplasma pneumonia (MP) infection. Tumor necrosis factor-α-induced protein 8-like 2 (TIPE2) is a negative regulator of immune response. This study investigated the expression change of TIPE2 and its role in immune defense against MP infection, as well as the underlying mechanisms. Expressions of TIPE2 both in patients and in macrophages in vitro after MP infection were measured. We further studied cytokine production and mitogen-activated protein kinase (MAPK) signaling function in macrophages with interfered expression of TIPE2 upon MP infection. A significant decrease of TIPE2 mRNA expression was observed in peripheral blood mononuclear cells (PBMCs) from MP patients, which was correlated with the severity of infection. Accordingly we found down-regulation of TIPE2 expression in macrophages after MP infection. In vitro study further suggested that TIPE2 jeopardized inflammatory cytokine production trigged by MP infection via inhibiting MAPK signaling pathway. These findings provided evidences of the novel function of TIPE2 in anti-MP immunity and its possible clinical utility related clinical significance.

Microbial extracellular electron transfer (EET) is essential in driving the microbial interspecies interaction and redox reactions in bioelectrochemical systems (BESs). Magnetite (Fe3O4) and magnetic fields (MFs) were recently reported to promote microbial EET, but the mechanisms of MFs stimulation of EET and current generation in BESs are not known. This study investigates the behavior of current generation and EET in a state-of-the-art pulse electromagnetic field (PEMF)-assisted magnetic BES (PEMF-MBES), which was equipped with magnetic carbon particle (Fe3O4@N-mC)-coated electrodes. Illumina Miseq sequencing of 16S rRNA gene amplicons was also conducted to reveal the changes of microbial communities and interactions on the anode in response to magnetic field.

CD39, expressed by tumor-infiltrating lymphocytes (TILs), is a marker to identify tumor-reactive T cells, which is frequently associated with stronger antitumor activity than bystander T cells in a variety of malignancies. Therefore, CD39 could be a promising marker for identifying the active antitumor immune cells used for cellular immunotherapy. To test this possibility, we constructed the hepatitis B virus (HBV) surface protein-specific chimeric antigen receptor T cells (HBVs-CAR-T cells) and generated the personalized tumor-reactive CD8+ T cells. We subsequently assessed their antitumor efficiency mainly with a co-culture system for autologous HBVs+ HCC organoid and T cells. We found that both CD39+ HBVs-CAR-T and CD39+ personalized tumor-reactive CD8+ T cells induced much more apoptosis in HCC organoids. Although the exhaustion status of CAR-T cells increased in CD39+ CAR-T cells, triple knockdown of PD-1, Tim-3, and Lag-3 with shRNAs further enhanced antitumor activity in CD39+ CAR-T cells. Furthermore, these CD39+ CAR-T cells exerted an increased secretion of interferon-γ and stronger antitumor effect in a patient-derived xenograft mouse model. Our findings demonstrated that CD39 could be a promising biomarker to enrich active immune cells and become an indicator marker for evaluating the prognosis of immunotherapy for HCC patients.

Idiopathic pulmonary fibrosis (IPF) is a chronic and diffuse form of interstitial lung disease of unknown etiology with a fatal outcome. Although various strategies for IPF have been developed over the last few decades, no significant positive impact on the prognosis of IPF has been observed. According to the current paradigm, macrophages have been recognized to play a significant role in IPF pathogenesis. Here, we report a potential nanomedicine-based gene therapy for IPF based on regulate macrophage polarization. Method: C57BL/6 mice were obtained and used to establish a bleomycin (BLM)-induced pulmonary fibrosis animal model, and Sart1 siRNA-loaded liposomes were designed for in vivo experiment. The experimental animals were administered BLM intratracheally on day 0 and treated with Sart1 siRNA on days 14 and 17. In the in vitro experiment, we further examined the function of Sart1 in macrophages. Results: Our data indicated that the liposomes could passively target the fibrotic area in the lung and efficiently accumulate in macrophages. The suppression of Sart1 by siRNA-loaded liposomes significantly protected mice against BLM-induced lung injury and fibrosis, which was attributed to attenuated M2 macrophage infiltration in the lung. Conclusion: Our study provides a valuable reference for modulating macrophage polarization and a promising strategy for the treatment of pulmonary fibrosis in clinical settings.

The etiologic agent of COVID-19 is highly contagious and has caused a severe global pandemic. Until now, there has been no simple and reliable system available in a lower-biosafety-grade laboratory for SARS-CoV-2 virologic research and inhibitor screening. In this study, we reported a replicon system which consists of four plasmids expressing the required segments of SARS-CoV-2. Our study revealed that the features for viral RNA synthesis and responses to antivirus drugs of the replicon are similar to those of wild-type viruses. Further analysis indicated that ORF6 provided potent in trans stimulation of the viral replication. Some viral variations, such as 5'UTR-C241T and ORF8-(T28144C) L84S mutation, also exhibit their different impact upon viral replication. Besides, the screening of clinically used drugs identified that several tyrosine kinase inhibitors and DNA-Top II inhibitors potently inhibit the replicon, as well as authentic SARS-CoV-2 viruses. Collectively, this replicon system provides a biosafety-worry-free platform for studying SARS-CoV-2 virology, monitoring the functional impact of viral mutations, and developing viral inhibitors.IMPORTANCE COVID-19 has caused a severe global pandemic. Until now, there has been no simple and reliable system available in a lower-biosafety-grade laboratory for SARS-CoV-2 virologic research and inhibitor screening. We reported a replicon system which consists of four ordinary plasmids expressing the required segments of SARS-CoV-2. Using the replicon system, we developed three application scenarios: (i) to identify the effects of viral proteins on virus replication, (ii) to identify the effects of mutations on viral replication during viral epidemics, and (iii) to perform high-throughput screening of antiviral drugs. Collectively, this replicon system would be useful for virologists to study SARS-CoV-2 virology, for epidemiologists to monitor virus mutations, and for industry to develop antiviral drugs.

Colorectal cancer is a malignant tumor of the digestive system with high morbidity and mortality. 5-fluorouracil remains a widely used chemotherapeutic drug in the treatment of advanced colorectal cancer, but chemotherapy drugs are prone to develop drug resistance, p53 deletion or mutation is an important reason for the resistance of colorectal cancer cells to 5-fluorouracil. β-elemene has been proved to have the potential of reverse chemotherapy drug resistance, but the mechanism is unknown. This study aimed to investigate the effect of β-elemene to 5-fluorouracil in drug-resistant p53-deficient colorectal cancer cells HCT116p53-/-, and determine the possible molecular mechanism of β-elemene to reverse 5-fluorouracil resistance.

With the development and progression of genetic technology, preimplantation genetic testing (PGT) has made it possible to block the inheritance of autosomal dominant polycystic kidney disease (ADPKD) as early as possible. However, we need to know the patients' fertility intentions and their acceptance of PGT.

The wall teichoic acid (WTA) is a major cell wall component of Gram-positive bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA), a common cause of fatal clinical infections in humans. Thus, the indispensable ABC transporter TarGH, which flips WTA from cytoplasm to extracellular space, becomes a promising target of anti-MRSA drugs. Here, we report the 3.9-Å cryo-electron microscopy (cryo-EM) structure of a 50% sequence-identical homolog of TarGH from Alicyclobacillus herbarius at an ATP-free and inward-facing conformation. Structural analysis combined with activity assays enables us to clearly decode the binding site and inhibitory mechanism of the anti-MRSA inhibitor Targocil, which targets TarGH. Moreover, we propose a "crankshaft conrod" mechanism utilized by TarGH, which can be applied to similar ABC transporters that translocate a rather big substrate through relatively subtle conformational changes. These findings provide a structural basis for the rational design and optimization of antibiotics against MRSA.IMPORTANCE The wall teichoic acid (WTA) is a major component of cell wall and a pathogenic factor in methicillin-resistant Staphylococcus aureus (MRSA). The ABC transporter TarGH is indispensable for flipping WTA precursor from cytoplasm to the extracellular space, thus making it a promising drug target for anti-MRSA agents. The 3.9-Å cryo-EM structure of a TarGH homolog helps us to decode the binding site and inhibitory mechanism of a recently reported inhibitor, Targocil, and provides a structural platform for rational design and optimization of potential antibiotics. Moreover, we propose a "crankshaft conrod" mechanism to explain how a big substrate is translocated through subtle conformational changes of type II exporters. These findings advance our understanding of anti-MRSA drug design and ABC transporters.

Current treatment of T-cell acute lymphoblastic leukemia (T-ALL) is primarily based on high-intensity combination chemotherapy, which has serious side effects. Therefore, developments of novel targeted therapeutics are urgently needed for treatment of T-ALL. In this study, we found that mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1) is a novel promising therapeutic target for treatment of T-ALL. MALT1 inhibitor MI-2 significantly suppressed the cell growth, proliferation, and colony formation of T-ALL cells. Furthermore, MI-2 induced cell apoptosis of T-ALL via a mitochondrial-dependent pathway. In a T-ALL mouse model, MI-2 significantly reduced leukemic burden and prolonged the survival of leukemia-bearing mice. Mechanistically, MALT1 inhibition effectively blocked both baseline and Notch1-induced activation of nuclear factor κB pathway, which mediates T-ALL cell survival. In conclusion, our results highlight the potential role of MALT1 as an attractive target for treatment of T-ALL and support the potential of MI-2 or other MALT1 inhibitors to clinical trials in T-ALL.

The purpose of the current study was to explore the role and underlying mechanism of FGF-2 in dexamethasone (DEX)-induced apoptosis in MC3T3-E1 cells.

CD8+ T cells are major components of adaptive immunity and confer robust protective cellular immunity, which requires adequate T-cell numbers, targeted migration, and efficient T-cell proliferation. Altered CD8+ T-cell homeostasis and impaired proliferation result in dysfunctional immune response to infection or tumorigenesis. However, intrinsic factors controlling CD8+ T-cell homeostasis and immunity remain largely elusive. Here, we demonstrate the prominent role of Brd4 on CD8+ T cell homeostasis and immune response. By upregulating Myc and GLUT1 expression, Brd4 facilitates glucose uptake and energy production in mitochondria, subsequently supporting naïve CD8+ T-cell survival. Besides, Brd4 promotes the trafficking of naïve CD8+ T cells partially through maintaining the expression of homing receptors (CD62L and LFA-1). Furthermore, Brd4 is required for CD8+ T cell response to antigen stimulation, as Brd4 deficiency leads to a severe defect in clonal expansion and terminal differentiation by decreasing glycolysis. Importantly, as JQ1, a pan-BRD inhibitor, severely dampens CD8+ T-cell immune response, its usage as an anti-tumor agent or latency-reversing agent for human immunodeficiency virus type I (HIV-1) should be more cautious. Collectively, our study identifies a previously-unexpected role of Brd4 in the metabolic regulation of CD8+ T cell-mediated immune surveillance and also provides a potential immunomodulation target.

Therapeutic blockade of the immune checkpoint proteins programmed cell death protein 1 (PD-1) and cytotoxic T lymphocyte antigen 4 (CTLA4) has transformed cancer treatment. However, the overall response rate to these treatments is low, suggesting that immune checkpoint activation is not the only mechanism leading to dysfunctional anti-tumour immunity. Here we show that butyrophilin-like protein 2 (BTNL2) is a potent suppressor of the anti-tumour immune response. Antibody-mediated blockade of BTNL2 attenuates tumour progression in multiple in vivo murine tumour models, resulting in prolonged survival of tumour-bearing mice. Mechanistically, BTNL2 interacts with local γδ T cell populations to promote IL-17A production in the tumour microenvironment. Inhibition of BTNL2 reduces the number of tumour-infiltrating IL-17A-producing γδ T cells and myeloid-derived suppressor cells, while facilitating cytotoxic CD8+ T cell accumulation. Furthermore, we find high BTNL2 expression in several human tumour samples from highly prevalent cancer types, which negatively correlates with overall patient survival. Thus, our results suggest that BTNL2 is a negative regulator of anti-tumour immunity and a potential target for cancer immunotherapy.