ISG12a promotes immunotherapy of HBV-associated hepatocellular carcinoma through blocking TRIM21/AKT/ß-catenin/PD-L1 axis.

Hepatitis B virus (HBV) infection generally elicits weak type-I interferon (IFN) immune response in hepatocytes, covering the regulatory effect of IFN-stimulated genes. In this study, low level of IFN-stimulated gene 12a (ISG12a) predicted malignant transformation and poor prognosis of HBV-associated hepatocellular carcinoma (HCC), whereas high level of ISG12a indicated active NK cell phenotypes. ISG12a interacts with TRIM21 to inhibit the phosphorylation activation of protein kinase B (PKB, also known as AKT) and ß-catenin, suppressing PD-L1 expression to block PD-1/PD-L1 signaling, thereby enhancing the anticancer effect of NK cells. The suppression of PD-1-deficient NK-92 cells on HBV-associated tumors was independent of ISG12a expression, whereas the anticancer effect of PD-1-expressed NK-92 cells on HBV-associated tumors was enhanced by ISG12a and treatments of atezolizumab and nivolumab. Thus, tumor intrinsic ISG12a promotes the anticancer effect of NK cells by regulating PD-1/PD-L1 signaling, presenting the significant role of innate immunity in defending against HBV-associated HCC.

Single-cell transcriptome reveals a novel mechanism of C-Kit+-liver sinusoidal endothelial cells in NASH.

AIM: To understand how liver sinusoidal endothelial cells (LSECs) respond to nonalcoholic steatohepatitis (NASH). METHODS: We profiled single-LSEC from livers of control and MCD-fed mice. The functions of C-Kit+-LSECs were determined using coculture and bone marrow transplantation (BMT) methods. RESULTS: Three special clusters of single-LSEC were differentiated. C-Kit+-LSECs of cluster 0, Msr1+-LSECs of cluster 1 and Bmp4+Selp+-VECs of cluster 2 were revealed, and these cells with diverse ectopic expressions of genes participated in regulation of endothelial, fibrosis and lipid metabolism in NASH. The number of C-Kit+-primary LSECs isolated from MCD mice was lower than control mice. Immunofluorescence co-staining of CD31 and C-KIT showed C-Kit+-LSECs located in hepatic sinusoid were also reduced in NASH patients and MCD mice, compared to AIH patients and control mice respectively. Interestingly, lipotoxic hepatocytes/HSCs cocultured with C-Kit+-LSECs or the livers of MCD mice receipting of C-Kit+-BMCs (bone marrow cells) showed less steatosis, inflammation and fibrosis, higher expression of prolipolytic FXR and PPAR-α, lower expression of TNF-α and α-SMA. Furthermore, coculturing or BMT of C-Kit+-endothelial derived cells could increase the levels of hepatic mitochondrial LC3B, decrease the degree of mitochondrial damage and ROS production through activating Pink1-mediated mitophagy pathway in NASH. CONCLUSIONS: Hence, a novel transcriptomic view of LSECs was revealed to have heterogeneity and complexity in NASH. Importantly, a cluster of C-Kit+-LSECs was confirmed to recovery Pink1-related mitophagy and NASH progression.

PZR suppresses innate immune response to RNA viral infection by inhibiting MAVS activation in interferon signaling mediated by RIG-I and MDA5.

RNA viral infections seriously endanger human health. Src homology 2 (SH2) domain-containing protein tyrosine phosphatase 2 (SHP2) suppresses innate immunity against influenza A virus, and pharmacological inhibition of SHP2 provokes hepatic innate immunity. SHP2 binds and catalyzes tyrosyl dephosphorylation of protein zero-related (PZR), but the regulatory effect of PZR on innate immune response to viral infection is unclear. In this study, the transcription and protein level of PZR in host cells were found to be decreased with RNA viral infection, and high level of PZR was uncovered to inhibit interferon (IFN) signaling mediated by RIG-I and MDA5. Through localizing in mitochondria, PZR targeted and interacted with MAVS (also known as IPS-1/VISA/Cardif), suppressing the aggregation and activation of MAVS. Specifically, Y263 residue in ITIM is critical for PZR to exert immunosuppression under RNA viral infection. Moreover, the recruited SHP2 by PZR that modified with tyrosine phosphorylation under RNA viral infection might inhibit phosphorylation activation of MAVS. In conclusion, PZR and SHP2 suppress innate immune response to RNA viral infection through inhibiting MAVS activation. This study reveals the regulatory mechanism of PZR-SHP2-MAVS signal axis on IFN signaling mediated by RIG-I and MDA5, which may provide new sight for developing antiviral drugs.

Establishment of cell culture model and humanized mouse model of chronic hepatitis B virus infection.

IMPORTANCE: Approximately 257 million people worldwide have been infected with hepatitis B virus (HBV), and HBV infection can cause chronic hepatitis, cirrhosis, and even liver cancer. The lack of suitable and effective infection models has greatly limited research in HBV-related fields for a long time, and it is still not possible to discover a method to completely and effectively remove the HBV genome. We have constructed a hepatocellular carcinoma cell line, HLCZ01, that can support the complete life cycle of HBV. This model can mimic the long-term stable infection of HBV in the natural state and can replace primary human hepatocytes for the development of human liver chimeric mice. This model will be a powerful tool for research in the field of HBV.

Carboxypeptidase A4 negatively regulates HGS-ETR1/2-induced pyroptosis by forming a positive feedback loop with the AKT signalling pathway.

Pyroptosis, a mode of inflammatory cell death, has recently gained significant attention. However, the underlying mechanism remains poorly understood. HGS-ETR1/2 is a humanized monoclonal antibody that can bind to DR4/5 on the cell membrane and induce cell apoptosis by activating the death receptor signalling pathway. In this study, by using morphological observation, fluorescence double staining, LDH release and immunoblot detection, we confirmed for the first time that HGS-ETR1/2 can induce GSDME-mediated pyroptosis in hepatocellular carcinoma cells. Our study found that both inhibition of the AKT signalling pathway and silencing of CPA4 promote pyroptosis, while the overexpression of CPA4 inhibits it. Furthermore, we identified a positive regulatory feedback loop is formed between CPA4 and AKT phosphorylation. Specifically, CPA4 modulates AKT phosphorylation by regulating the expression of the AKT phosphatase PP2A, while inhibition of the AKT signalling pathway leads to a decreased transcription and translation levels of CPA4. Our study reveals a novel mechanism of pyroptosis induced by HGS-ETR1/2, which may provide a crucial foundation for future investigations into cancer immunotherapy.

Effect of cinnamon essential oil dietary supplementation on the growth, fatty acid composition, and meat quality of tilapia.

This study was conducted to investigate the effects of dietary supplementation of 0%, 0.2%, 0.35%, and 0.5% cinnamon essential oil on growth performance, fatty acid, and fillet quality of tilapia (Oreochromis niloticus). The results of growth experiments showed that the weight gain rate linearly and quadratically increased with increasing cinnamon essential oil doses (p < 0.05). The results of fatty acids experiments showed that the addition of essential oil significantly decreased the saturated fatty acids levels from 36.67% to 30.82% and increased the polyunsaturated fatty acids (PUFA) levels from 24.55% to 46.89%; especially, the n - 3 PUFA of 0.5% essential oil treatment showed the highest levels. Moreover, the n - 6 PUFA of 0.2% essential oil treatment were increased from 22.17% to 32.99%. The results of fillet quality experiments showed that the hardness and cohesiveness were linearly and quadratically increased with the increasing essential oil doses on days 4 and 7, respectively. The b* values linearly and quadratically decreased as the doses increased on day 7 (p < 0.05). The total volatile basic nitrogen levels were quadratically decreased with increasing cinnamon essential oil doses on day 7 (p < 0.05). In general, it can be concluded that cinnamon essential oil presented positive effects on the growth, nutritive values, and meat quality in tilapia.

Activation of AIM2 by hepatitis B virus results in antiviral immunity that suppresses hepatitis C virus during coinfection.

IMPORTANCE: Clinical data suggest that Hepatitis C virus (HCV) levels are generally lower in Hepatitis B virus (HBV) co-infected patients, but the mechanism is unknown. Here, we show that HBV, but not HCV, activated absent in melanoma-2. This in turn results in inflammasome-mediated cleavage of pro-IL-18, leading to an innate immune activation cascade that results in increased interferon-γ, suppressing both viruses.

Primary malignant melanoma of the cervix: A comprehensive analysis of case reports in the Chinese population.

PURPOSE: Malignant melanoma is a tumor generated from the basal melanocytes of human epidermis. Primary malignant melanoma of the cervix (PMMC) is derived from cervical melanocytes. It is an uncommon disease, mostly occurring in perimenopausal women. PMMC has a bad prognosis and lacks a defined protocol or treatment standards. The aim of this study was to analyze the impact of different surgical procedures and different adjuvant treatment modalities on their prognosis and to find risk factors for their prognosis by integrating published case report data based on the Chinese population. METHODS AND RESULTS: This study included 165 patients with PMMC in the Chinese population. We used the Kaplan-Meier method to build the survival curve, and the log-rank test to examine the variations among the subgroups. Prognostic factors were examined utilizing the Cox proportional hazards regression model. We found that patients who underwent radical hysterectomy-based surgery, those who underwent lymphadenectomy, and those who underwent other treatments in addition to surgery had significantly better survival rates. The overall analysis, showed that age, and FIGO Stage II, III, and IV, increased the risk of death. Moreover, radical hysterectomy (RH), total hysterectomy (TAH), lymphadenectomy, and adjuvant therapy were correlated with a decreased mortality risk. CONCLUSION: After summarizing the current data, we recommend radical hysterectomy, and lymphadenectomy treatment for patients with PMMC. For patients who had already undergone surgery, other treatment options had a positive effect on prognosis. For patients who had already undergone surgery, other treatment options had a positive effect on prognosis; therefore patient-specific treatment options need to be further discussed.

The redox cycling of STAT2 maintains innate immune homeostasis.

Interferons (IFNs) are essential in antiviral defense, antitumor effects, and immunoregulatory activities. Although methionine oxidation is associated with various physiological and pathophysiological processes in plants, animals, and humans, its role in immunity remains unclear. We find that the redox cycling of signal transducer and activator of transcription 2 (STAT2) is an intrinsic cellular biological process, and that impairment of the redox status contributes to STAT2 methionine oxidation, inhibiting its activation. IFN protects STAT2 from methionine oxidation through the recruitment of methionine sulfoxide reductase MSRB2, whose enzymatic activity is enhanced by N-acetyltransferase 9 (NAT9), a chaperone of STAT2 defined in this study, upon IFN treatment. Consequently, loss of Nat9 renders mice more susceptible to viral infection. Our study highlights the key function of methionine oxidation in immunity, which provides evidence for the decline of immune function by aging and may provide insights into the clinical applications of IFN in immune-related diseases.

The oncogenic miR-27a/BTG2 axis promotes obesity-associated hepatocellular carcinoma by mediating mitochondrial dysfunction.

Obesity is closely related to the initiation and development of hepatocellular carcinoma (HCC). The regulatory mechanism of obesity-associated HCC remains unclear. HepG2 cells treated with palmitic acid (PA) and diethylnitrosamine (DEN)-induced HCC mice fed a high-fat diet (HFD) were established. The expression of miR-27a and B-cell translocation gene 2 (BTG2) mRNA and protein were detected via qPCR and western blotting. Prediction software and luciferase assays were employed to verify the miR-27a/BTG2 axis. The biological effects of HepG2 cells were evaluated with ORO staining, MTT assays, Transwell assays, Mito-Timer, and Mito-SOX staining. Significantly upregulated miR-27a and downregulated BTG2 mRNA and protein were observed in HepG2 cells and liver tissues of HCC mice. Overexpressing miR-27a (mi-miR-27a) markedly promoted cellular lipid accumulation, proliferation, and invasion, accompanied by aggravated mitochondrial dysfunction (increased fading and ROS products of mitochondria) in HepG2 cells. Additionally, these effects were further reinforced in HepG2 cells treated with mi-miR-27a and PA. BTG2 was identified as a direct target and was negatively regulated by miR-27a. Similarly, BTG2 knockdown (sh-BTG2) had effects identical to those of mi-miR-27a on HepG2 cells. Additionally, PA evidently enhanced these effects of sh-BTG2 in HepG2 cells. Moreover, BTG2 overexpression effectively reversed the effects of miR-27a, including lipotropic and oncogenic effects, and simultaneously promoted mitochondrial imbalance in HepG2 cells. Thus, obesity-associated miR-27a acts as an oncogene to promote lipid accumulation, proliferation, and invasion by negatively regulating BTG2-mediated mitochondrial dysfunction in HCC.

Heat Shock-Binding Protein 21 Regulates the Innate Immune Response to Viral Infection.

The induction of interferons (IFNs) plays an important role in the elimination of invading pathogens. Heat shock binding protein 21 (HBP21), first known as a molecular chaperone of HSP70, is involved in tumor development. Heat shock binding proteins have been shown to regulate diverse biological processes, such as cell cycle, kinetochore localization, transcription, and cilium formation. Their role in antimicrobial immunity remains unknown. Here, we found that HBP21 drives a positive feedback loop to promote IRF3-mediated IFN production triggered by viral infection. HBP21 deficiency significantly impaired the virus-induced production of IFN and resulted in greater susceptibility to viral infection both in vitro and in vivo. Mechanistically, HBP21 interacted with IRF3 and promoted the formation of a TBK1-IRF3 complex. Moreover, HBP21 abolished the interaction between PP2A and IRF3 to repress the dephosphorylation of IRF3. Analysis of HBP21 protein structure further confirmed that HBP21 promotes the activation of IRF3 by depressing the dephosphorylation of IRF3 by PP2A. Further study demonstrated that virus-induced phosphorylation of Ser85 and Ser153 of HBP21 itself is important for the phosphorylation and dimerization of IRF3. Our study identifies HBP21 as a new positive regulator of innate antiviral response, which adds novel insight into activation of IRF3 controlled by multiple networks that specify behavior of tumors and immunity. IMPORTANCE The innate immune system is the first-line host defense against microbial pathogen invasion. The physiological functions of molecular chaperones, involving cell differentiation, migration, proliferation and inflammation, have been intensively studied. HBP21 as a molecular chaperone is critical for tumor development. Tumor is related to immunity. Whether HBP21 regulates immunity remains unknown. Here, we found that HBP21 promotes innate immunity response by dual regulation of IRF3. HBP21 interacts with IRF3 and promotes the formation of a TBK1-IRF3 complex. Moreover, HBP21 disturbs the interaction between PP2A and IRF3 to depress the dephosphorylation of IRF3. Analysis of HBP21 protein structure confirms that HBP21 promotes the activation of IRF3 by blocking the dephosphorylation of IRF3 by PP2A. Interestingly, virus-induced Ser85 and Ser153 phosphorylation of HBP21 is important for IRF3 activation. Our findings add to the known novel immunological functions of molecular chaperones and provide new insights into the regulation of innate immunity.

The Role of REC8 in the Innate Immune Response to Viral Infection.

REC8 meiotic recombination protein (REC8) is a member of structural maintenance of chromosome (SMC) protein partners, which play an important role in meiosis, antitumor activity, and sperm formation. As the adaptor proteins of RIG-I-like receptor (RLR) signaling and cyclic GMP-AMP synthase (cGAS)-DNA signaling, the activity and stability of MAVS (mitochondrial antiviral signaling protein; also known as VISA, Cardif, and IPS-1) and STING (stimulator of interferon genes; also known as MITA) are critical for innate immunity. Here, we report that REC8 interacts with MAVS and STING and inhibits their ubiquitination and subsequent degradation, thereby promoting innate antiviral signaling. REC8 is upregulated through the JAK-STAT signaling pathway during viral infection. Knockdown of REC8 impairs the innate immune responses against vesicular stomatitis virus (VSV), Newcastle disease virus (NDV), and herpes simplex virus (HSV). Mechanistically, during infection with viruses, the SUMOylated REC8 is transferred from the nucleus to the cytoplasm and then interacts with MAVS and STING to inhibit their K48-linked ubiquitination triggered by RNF5. Moreover, REC8 promotes the recruitment of TBK1 to MAVS and STING. Thus, REC8 functions as a positive modulator of innate immunity. Our work highlights a previously undocumented role of meiosis-associated protein REC8 in regulating innate immunity. IMPORTANCE The innate immune response is crucial for the host to resist the invasion of viruses and other pathogens. STING and MAVS play a critical role in the innate immune response to DNA and RNA viral infection, respectively. In this study, REC8 promoted the innate immune response by targeting STING and MAVS. Notably, REC8 interacts with MAVS and STING in the cytoplasm and inhibits K48-linked ubiquitination of MAVS and STING triggered by RNF5, stabilizing MAVS and STING protein to promote innate immunity and gradually inhibiting viral infection. Our study provides a new insight for the study of antiviral innate immunity.

Age is the only predictor for upper gastrointestinal malignancy in Chinese patients with uncomplicated dyspepsia: a prospective investigation of endoscopic findings.

BACKGROUND: Dyspepsia is a common cause of physician visits. If and when endoscopy should be performed depend on the regions and the populations. This study aimed to identify the current risk factors predictive of upper gastrointestinal malignancy or peptic ulcer in China with high prevalence of gastric cancer. METHODS: A questionnaire was conducted among consecutive outpatients undergoing their first esophagogastroduodenoscopy for dyspepsia. Symptoms other than alarm symptoms in this study were defined as uncomplicated dyspepsia. RESULTS: 4310 outpatients (mean age 44, median 42, range 14-86) were included in the final analyses. Significant pathology was found in 13.8% (595/4310) patients including peptic ulcer (12.3%) and upper gastrointestinal malignancy (1.5%). Age, male sex and alarm symptoms were significantly associated with malignancy. The age cut-off identified for upper gastrointestinal malignancy was 56 years among patients with uncomplicated dyspepsia, which was similar to the combined cutoff of age and gender. CONCLUSIONS: Age should be considered as the primary predictor for upper gastrointestinal malignancy in Chinese patients with uncomplicated dyspepsia. 56 could probably be the optimal age to identify those lesions in this population. TRIAL REGISTRATION: Chictr.org (ChiCTR2000040775).

Development of Near-Infrared Nucleic Acid Mimics of Fluorescent Proteins for In Vivo Imaging of Viral RNA with Turn-On Fluorescence.

GFP-like fluorescent proteins and their molecular mimics have revolutionized bioimaging research, but their emissions are largely limited in the visible to far-red region, hampering the in vivo applications in intact animals. Herein, we structurally modulate GFP-like chromophores using a donor-acceptor-acceptor (D-A-A') molecular configuration to discover a set of novel fluorogenic derivatives with infrared-shifted spectra. These chromophores can be fluorescently elicited by their specific interaction with G-quadruplex (G4), a unique noncanonical nucleic acid secondary structure, via inhibition of the chromophores' twisted-intramolecular charge transfer. This feature allows us to create, for the first time, FP mimics with tunable emission in the near-infrared (NIR) region (Emmax = 664-705 nm), namely, infrared G-quadruplex mimics of FPs (igMFP). Compared with their FP counterparts, igMFPs exhibit remarkably higher quantum yields, larger Stokes shift, and better photostability. In a proof-of-concept application using pathogen-related G4s as the target, we exploited igMFPs to directly visualize native hepatitis C virus (HCV) RNA genome in living cells via their in situ formation by the chromophore-bound viral G4 structure in the HCV core gene. Furthermore, igMFPs are capable of high contrast HCV RNA imaging in living mice bearing a HCV RNA-presenting mini-organ, providing the first application of FP mimics in whole-animal imaging.

States Transitions Inference of Postpartum Depression Based on Multi-State Markov Model.

Background: Postpartum depression (PPD) has been recognized as a severe public health problem worldwide due to its high incidence and the detrimental consequences not only for the mother but for the infant and the family. However, the pattern of natural transition trajectories of PPD has rarely been explored. Methods: In this research, a quantitative longitudinal study was conducted to explore the PPD progression process, providing information on the transition probability, hazard ratio, and the mean sojourn time in the three postnatal mental states, namely normal state, mild PPD, and severe PPD. The multi-state Markov model was built based on 912 depression status assessments in 304 Chinese primiparous women over multiple time points of six weeks postpartum, three months postpartum, and six months postpartum. Results: Among the 608 PPD status transitions from one visit to the next visit, 6.2% (38/608) showed deterioration of mental status from the level at the previous visit; while 40.0% (243/608) showed improvement at the next visit. A subject in normal state who does transition then has a probability of 49.8% of worsening to mild PPD, and 50.2% to severe PPD. A subject with mild PPD who does transition has a 20.0% chance of worsening to severe PPD. A subject with severe PPD is more likely to improve to mild PPD than developing to the normal state. On average, the sojourn time in the normal state, mild PPD, and severe PPD was 64.12, 6.29, and 9.37 weeks, respectively. Women in normal state had 6.0%, 8.5%, 8.7%, and 8.8% chances of progress to severe PPD within three months, nine months, one year, and three years, respectively. Increased all kinds of supports were associated with decreased risk of deterioration from normal state to severe PPD (hazard ratio, HR: 0.42-0.65); and increased informational supports, evaluation of support, and maternal age were associated with alleviation from severe PPD to normal state (HR: 1.46-2.27). Conclusions: The PPD state transition probabilities caused more attention and awareness about the regular PPD screening for postnatal women and the timely intervention for women with mild or severe PPD. The preventive actions on PPD should be conducted at the early stages, and three yearly; at least one yearly screening is strongly recommended. Emotional support, material support, informational support, and evaluation of support had significant positive associations with the prevention of PPD progression transitions. The derived transition probabilities and sojourn time can serve as an importance reference for health professionals to make proactive plans and target interventions for PPD.

Lessons learned from upper gastrointestinal endoscopy in asymptomatic Chinese.

BACKGROUND: The Helicobacter pylori (H. pylori) infection-related diseases, peptic ulcer, and gastric cancer are frequently asymptomatic until the onset of complications. This study aimed to investigate the prevalence of H. pylori, erosive esophagitis, peptic ulcer, and precancerous lesions such as atrophic gastritis, intestinal metaplasia, gastric dysplasia, and upper gastrointestinal (GI) malignancy in asymptomatic Chinese. METHODS: From January to December 2017, a questionnaire was administered to consecutive asymptomatic patients undergoing routine physical examination, which included their first screening esophagogastroduodenoscopy. H. pylori infection was determined by one of positive 13 C urea breath tests or rapid urease test and histology. The presence of H. pylori infection, erosive esophagitis, peptic ulcer, precancerous gastric histology, and upper GI malignancy was analyzed in relation to demographic factors. RESULTS: A total of 1108 subjects (mean age: 48, range 21 to 79, 39.5% men) were included. The findings were: erosive esophagitis 7.8%, active H. pylori infection 44%, peptic ulcer 9.1% (duodenal 5.8%, gastric 2.5% or both 0.8%); 0.5% had gastric cancer. Male, smoking history, and current H. pylori infection were all significantly related to the presence of peptic ulcer. Totally, 1095 patients had gastric histopathology and premalignant gastric lesions were present in 67.4%; atrophic gastritis (67.4%), intestinal metaplasia (27.4%), and gastric dysplasia (0.5%). Age, current and previous H. pylori infection were risk factors significantly associated with precancerous lesions. CONCLUSIONS: Upper GI pathology as a sequelae of H. pylori infection is common in asymptomatic Chinese. These findings support institution of a nationwide test and treat program to eradicate H. pylori in China.

The innate immune effector ISG12a promotes cancer immunity by suppressing the canonical Wnt/ß-catenin signaling pathway.

The ability to harness innate immunity is a promising solution for improving cancer immunotherapy. Interferon (IFN) induces expression of IFN-stimulated genes (ISGs) by activating the JAK-STAT signaling pathway to promote innate immunity and inhibit malignant tumor growth, but the functions and mechanisms of most ISGs in cancer regulation are unknown. As an innate immune effector, ISG12a promotes the innate immune response to viral infection. In this study, ISG12a was found to be expressed at low levels in gastrointestinal cancer, represented by hepatocellular cancer (HCC) and gastric cancer (GC), and it identified as a tumor suppressor that affects clinical prognosis. ISG12a silencing accelerated the malignant transformation and epithelial-mesenchymal transition of cancer cells. Mechanistically, ISG12a promoted ß-catenin proteasomal degradation by inhibiting the degradation of ubiquitinated Axin, thereby suppressing the canonical Wnt/ß-catenin signaling pathway. Notably, ß-catenin was identified as a transcription factor for PD-L1. Inhibition of Wnt/ß-catenin signaling by ISG12a suppressed expression of the immune checkpoint PD-L1, rendering cancer cells sensitive to NK cell-mediated killing. This study reveals a mechanism underlying the anticancer effects of IFN. Some ISGs, as represented by ISG12a, may be useful in cancer therapy and prevention. The identified interrelations among innate immunity, Wnt/ß-catenin signaling, and cancer immunity may provide new insight into strategies that will improve the efficiency of immunotherapy.

Lighting up the Native Viral RNA Genome with a Fluorogenic Probe for the Live-Cell Visualization of Virus Infection.

RNA viruses represent a major global health threat, and the visualization of their RNA genome in infected cells is essential for virological research and clinical diagnosis. Due to the lack of chemical toolkits for the live-cell imaging of viral RNA genomes, especially native viral genomes without labeling and genetic modification, studies on native virus infection at the single-live-cell level are challenging. Herein, taking hepatitis C virus (HCV) as a representative RNA virus, we propose that the innate noncanonical G-quadruplex (G4) structure of viral RNA can serve as a specific imaging target and report a new benzothiazole-based G4-targeted fluorescence light-up probe, ThT-NE, for the direct visualization of the native RNA genome of HCV in living host cells. We demonstrate the use of the ThT-NE probe for several previously intractable applications, including the sensitive detection of individual virus-infected cells by small-molecule staining, real-time monitoring of the subcellular distribution of the viral RNA genome in live cells, and continuous live-cell tracking of the infection and propagation of clinically isolated native HCV. The fluorogenic-probe-based viral RNA light-up system opens up a promising chemical strategy for cutting-edge live-cell viral analysis, providing a potentially powerful tool for viral biology, medical diagnosis, and drug development.

Morphological control of gold nanorods via thermally driven bi-surfactant growth and application for detection of heavy metal ions.

We report a modified synthesis route of colloidal gold nanorods (AuNRs) by combining the thermal re-shaping treatment and bi-surfactant modification using hexadecyltrimethylammonium bromide (CTAB) and sodium oleate (NaOL). Aspect ratios down to 1.3 ± 0.1 can be achieved in addition to good monodispersity, uniformity, and chemical stability of the materials. Furthermore, without needing post-treatment, metal ions directly interact with the AuNRs efficiently, allowing rapid and sensitive colorimetric detection of heavy metal ions such as Pb2+ and Cu2+ with a low concentration down to 2.5 µM. The detection performance in terms of selectivity, sensitivity and stability is systematically evaluated. The AuNRs with tunable aspect ratios as well as chemical stability have potential in surface-plasmon-based applications such as biochemical sensing, biochemical imaging, medical diagnostics, and cancer therapy.

TRIM21 Promotes Innate Immune Response to RNA Viral Infection through Lys27-Linked Polyubiquitination of MAVS.

Human innate immunity responds to viral infection by activating the production of interferons (IFNs) and proinflammatory cytokines. The mitochondrial adaptor molecule MAVS plays a critical role in innate immune response to viral infection. In this study, we show that TRIM21 (tripartite motif-containing protein 21) interacts with MAVS to positively regulate innate immunity. Under viral infection, TRIM21 is upregulated through the IFN/JAK/STAT signaling pathway. Knockdown of TRIM21 dramatically impairs innate immune response to viral infection. Moreover, TRIM21 interacts with MAVS and catalyzes its K27-linked polyubiquitination, thereby promoting the recruitment of TBK1 to MAVS. Specifically, the PRY-SPRY domain of TRIM21 is the key domain for its interaction with MAVS, while the RING domain of TRIM21 facilitates the polyubiquitination chains of MAVS. In addition, the MAVS-mediated innate immune response is enhanced by both the PRY-SPRY and RING domains of TRIM21. Mutation analyses of all the lysine residues of MAVS further revealed that Lys325 of MAVS is catalyzed by TRIM21 for the K27-linked polyubiquitination. Overall, this study reveals a novel mechanism by which TRIM21 promotes the K27-linked polyubiquitination of MAVS to positively regulate innate immune response, thereby inhibiting viral infection.IMPORTANCE Activation of innate immunity is essential for host cells to restrict the spread of invading viruses and other pathogens. MAVS plays a critical role in innate immune response to RNA viral infection. In this study, we demonstrated that TRIM21 targets MAVS to positively regulate innate immunity. Notably, TRIM21 targets and catalyzes K27-linked polyubiquitination of MAVS and then promotes the recruitment of TBK1 to MAVS, leading to upregulation of innate immunity. Our study outlines a novel mechanism by which the IFN signaling pathway blocks RNA virus to escape immune elimination.