Sperm, but not oocyte, DNA methylome is inherited by zebrafish early embryos.

5-methylcytosine is a major epigenetic modification that is sometimes called "the fifth nucleotide." However, our knowledge of how offspring inherit the DNA methylome from parents is limited. We generated nine single-base resolution DNA methylomes, including zebrafish gametes and early embryos. The oocyte methylome is significantly hypomethylated compared to sperm. Strikingly, the paternal DNA methylation pattern is maintained throughout early embryogenesis. The maternal DNA methylation pattern is maintained until the 16-cell stage. Then, the oocyte methylome is gradually discarded through cell division and is progressively reprogrammed to a pattern similar to that of the sperm methylome. The passive demethylation rate and the de novo methylation rate are similar in the maternal DNA. By the midblastula stage, the embryo's methylome is virtually identical to the sperm methylome. Moreover, inheritance of the sperm methylome facilitates the epigenetic regulation of embryogenesis. Therefore, besides DNA sequences, sperm DNA methylome is also inherited in zebrafish early embryos.

USP25 Promotes the Antimycobacterial Response of Macrophages Through Stabilizing B-Raf and C-Raf.

Ubiquitin-specific peptidase 25 (USP25) is one of the best-characterized deubiquitinating enzymes and plays a vital regulatory role in various biological processes, especially in cancer development and immune regulation. However, the exact role of USP25 and its underlying mechanisms in macrophage activation and immunogenicity during Mycobacterium tuberculosis infection remain unclear. In this study, we found that M tuberculosis infection induced USP25 expression in human and mouse macrophages. In particular, USP25 expression is elevated in multiple cell types, especially monocytes, in patients with tuberculosis. Additionally, USP25 deficiency in macrophages and mice resulted in compromised immunity against M tuberculosis infection, accompanied by reduced expressions of various proinflammatory cytokines and chemokines. Mechanistically, USP25 in macrophages promoted the activation of the ERK signaling pathway through deubiquitination and stabilization of B-Raf and C-Raf. These findings collectively suggest the critical roles of USP25 in M tuberculosis infection and its potential as a therapeutic target.

Apolipoprotein E is a prognostic factor for pancreatic cancer and associates with immune infiltration.

BACKGROUND: The expression level of apolipoprotein E (APOE) in pancreatic ductal adenocarcinoma (PDAC) and its effect on the prognosis of PDAC patients are not clear. The effect of APOE on the immune status of patients with PDAC has not been elucidated. METHODS: We obtained pancreatic cancer data from the TCGA and GETx databases. Patients with PDAC who underwent pancreatic surgery at the Second Affiliated Hospital of Jiaxing University between 2012 and 2021 were included. Clinical pathological data were recorded, plasma APOE levels were measured, and tissue samples were collected. A tissue microarray was generated using the collected tissue samples. APOE and CD4 staining was performed to determine immunoreactive scores (IRSs). The expression of APOE in the plasma and tumour tissues of pancreatic cancer patients was analysed and compared. The correlations between plasma APOE levels, tissue APOE levels and clinicopathological characteristics were analysed. Survival prognosis was analysed using Kaplan-Meier survival analysis and Cox multivariate regression analysis. The correlations between APOE expression levels and immune biomarkers and immune cells were further analysed. Single-cell analysis of APOE distribution in various cells was performed on the TISCH website. RESULTS: APOE was highly expressed in the tumour tissue of pancreatic cancer patients, and high plasma APOE levels were associated with poor prognosis. Females, patients with high-grade disease and patients with pancreatic head carcinoma had high plasma APOE levels. High APOE expression in tumour tissues was associated with good prognosis. Mononuclear macrophages in the pancreatic cancer microenvironment primarily expressed APOE. APOE levels positively correlated with immune biomarkers, such as CD8A, PDCD1, GZMA, CXCL10, and CXCL9, in the tumour microenvironment. APOE promoted CD4 + T cell or dendritic cell infiltration in the tumour microenvironment. CONCLUSIONS: APOE may affect the occurrence and development of pancreatic cancer by regulating the infiltration of immune cells in the tumour microenvironment.

Role of IL-6-IL-27 Complex in Host Antiviral Immune Response.

The IL family of cytokines participates in immune response and regulation. We previously found that soluble IL-6 receptor plays an important role in the host antiviral response. In this study, we detected the IL-6-IL-27 complex in serum and throat swab samples from patients infected with influenza A virus. A plasmid expressing the IL-6-IL-27 complex was constructed to explore its biological function. The results indicated that the IL-6-IL-27 complex has a stronger antiviral effect than the individual subunits of IL-6, IL-27A, and EBV-induced gene 3. Furthermore, the activity of the IL-6-IL-27 complex is mainly mediated by the IL-27A subunit and the IL-27 receptor α. The IL-6-IL-27 complex can positively regulate virus-triggered expression of IFN and IFN-stimulated genes by interacting with adaptor protein mitochondrial antiviral signaling protein, potentiating the ubiquitination of TNF receptor-associated factors 3 and 6 and NF-κB nuclear translocation. The secreted IL-6-IL-27 complex can induce the phosphorylation of STAT1 and STAT3 and shows antiviral activity. Our results demonstrate a previously unrecognized mechanism by which IL-6, IL-27A, and EBV-induced gene 3 form a large complex both intracellularly and extracellularly, and this complex acts in the host antiviral response.

The effects of intravenous remifentanil on umbilical artery serum-derived exosomes in parturients undergoing epidural anesthesia: a randomized trail.

BACKGROUND: Umbilical artery serum-derived exosomes (UEs) serve as messengers for maternal-fetal information exchange and cellular regulation. Intravenous remifentanil could be considered as an effective adjunct to epidural anesthesia in providing a favorable analgesia effect for cesarean section (C-section), but its effects on UEs are currently unknown. METHODS: From 01/12/2021 to 30/06/2022, eligible parturients scheduled for repeated C-section at the First Affiliated Hospital of Wenzhou Medical University were randomized to receive either an intravenous bolus (0.15 µg/kg) followed by a continuous infusion (0.075 µg/kg/min) of remifentanil or normal saline throughout the procedure. The primary outcome was the number of UEs. Secondary outcomes included the size and protein amount of UEs, the vital signs, visceral pain score, sedation score, maternal satisfaction score, Apgar score, the incidence of neonatal asphyxia, umbilical arterial pH, and the presence of complications. RESULTS: Nanoparticle tracking analysis indicated similar size of UEs between the two groups, but the number and protein amount of UEs were increased in the remifentanil group  compared to the control group (P < 0.05). In parturients receiving remifentanil, visceral pain scores were decreased, which was accompanied by the increased scores of maternal satisfaction with the anesthetic method (P < 0.05). Other maternal and neonatal outcomes were comparable between the two groups (P > 0.05). CONCLUSION: The intravenous administration of remifentanil increased the number of UEs in parturients undergoing repeated C-section under epidural anesthesia, with improved birth experience and minimal neonatal complications.

A compound formulation of EGF-modified paclitaxel micelles and EGF-modified emodin micelles enhance the therapeutic effect of ovarian cancer.

Ovarian cancer is a serious threat to female health, although the incidence of it is relatively low, its mortality rate remains high due to its intense invasion and metastasis. Therefore, it is urgent to explore new treatment strategies for ovarian cancer. In this study, paclitaxel and emodin were encapsulated in different micelles, and loaded on the surface of the micelles with epidermal growth factor (EGF) as the targeting molecule, made compound formulations in proportion. In this study, EGF-modified paclitaxel micelles and EGF-modified emodin micelles were characterized, their inhibitory effects on SKOV3 cell proliferation and invasion were studied in vivo and in vitro, and its targeting ability was confirmed. The results showed that the shape, particle size, zeta potential, release rate, encapsulation rate, polydispersity index, and other physical and chemical properties of EGF-modified paclitaxel micelles plus EGF-modified emodin micelles meet the requirements, and the modification of EGF on the micelle surface could obviously improve the uptake of SKOV3 cells and inhibit the proliferation of SKOV3 cells. The compound formulation can inhibit the invasion and metastasis of ovarian cancer by inhibiting the expression of hypoxia inducible factor-α, MMP-2, MMP-9, and VE-cadherin. The in vivo studies have also showed significant pharmacodynamics results. These results indicated that EGF-modified paclitaxel micelles plus EGF-modified emodin micelles provide a new strategy for the treatment of ovarian cancer.

Comparison and Correlation of Corynespora cassiicola Populations from Kiwifruit and Other Hosts Based on Morphology, Phylogeny, and Pathogenicity.

Corynespora leaf spot, which is caused by Corynespora cassiicola (Berk. & M. A. Curtis) C.T. Wei (C. cassiicola), has been globally reported in many plant species. 'Hongyang' was reported as highly sensitive kiwifruit cultivar to C. cassiicola. This cultivar is an important germplasm resource in the Actinidiaceae family and is widely cultivated throughout China. Even though C. cassiicola has been identified as the pathogen associated with kiwifruits in China, the C. cassiicola population from kiwifruit has not been characterized based on morphology, phylogeny, and pathogenicity. In this study, 133 and 48 representative C. cassiicola isolates from kiwifruit and 11 other hosts, respectively, recovered from symptomatic leaves were classified into eight morphological subgroups based on host origins. Using three loci (rDNA ITS, caa5, and act1), a phylogenetic tree showed that C. cassiicola isolates in Sichuan Province were grouped into three clades. All kiwifruit isolates were genetically identical to the rubber isolates from different countries. However, most isolates from other hosts in this study were genetically identical to the cucumber, soybean, and cowpea isolates in China, Brazil, and the United States, and two strawberry isolates clustered with isolates from tomato and other hosts in China, Brazil, and the United States. Furthermore, we confirmed host shift of C. cassiicola among different plant species in this study. Although 51 isolates from kiwifruit and different hosts were pathogenic to kiwifruit, blueberry, cucumber, and soybean, virulence levels of the pathogen were diverse for four hosts. Kiwifruit isolates exhibited host specificity with regards to the original host in degree. In addition, those isolates revealed a correlation between morphology and pathogenicity. The results suggest that C. cassiicola in Sichuan Province were derived from three different phylogenetic lineages. Promotion of the susceptible 'Hongyang' cultivar led to the emergence of a regnant C. cassiicola population from kiwifruit. In conclusion, rapid development of the C. cassiicola-sensitive crop in agricultural systems led to the emergence of a regnant C. cassiicola population. In some dominant populations (e.g., the C. cassiicola population from kiwifruit in this study), host origin was found to be a key factor influencing the morphologic, genetic, and pathogenic characterization of C. cassiicola.

Study on collateral circulation level and prognosis of acute ischemic stroke by 4D CTA-CTP integrated technology and serum S100B.

OBJECTIVE: To evaluate the cerebral collateral circulation in patients with acute ischemic stroke (AIS) by Four-dimensional CT angiography-CT perfusion (4D CTA-CTP)-integrated technology, and to explore the feasibility of predicting the prognosis of patients with AIS by using cerebral collateral circulation and serum S100B protein concentration. METHODS: Thirty-two patients with anterior circulation AIS who underwent 4D CTA-CTP were retrospectively analysed. The level of cerebral collateral circulation was assessed by multi-phase CT angiography (mCTA) scores and regional leptomeningeal collateral (rLMC) scores. Combined with serum S100B protein concentration, multivariate binary logistic regression was used to explore the indicators that can independently predict the prognosis of AIS neurological function. RESULTS: Univariate analysis showed that the baseline National Institutes of Health stroke scale score, rLMC score, and mCTA score were correlated with the neurological prognosis of patients with AIS; multivariate analysis showed that mCTA cerebral collateral circulation score was the only indicator that could independently predict the neurological prognosis of AIS patients (OR = 0.065, P = 0.030). The baseline serum S100B protein concentration could not independently predict the neurological prognosis of AIS patients. CONCLUSION: mCTA cerebral collateral circulation scores can independently predict the neurological prognosis of patients with AIS. For the assessment of neurological prognosis of AIS patients, the cerebral collateral circulation phase score is better than the regional score.

Lactobacillus acidophilus ameliorates obesity in mice through modulation of gut microbiota dysbiosis and intestinal permeability.

Obesity associated with low-grade chronic inflammation and intestinal dysbiosis is considered as a worldwide public health crisis. In the meanwhile, different probiotics have demonstrated beneficial effects on this condition, thus increasing the interest in the development of probiotic treatments. In this context, the aim of this study is to investigate the anti-obesity effects of potential probiotic Lactobacillus acidophilus isolated from the porcine gut. Then, it is found that L. acidophilus reduces body weight, fat mass, inflammation and insulin resistance in mice fed with a high-fat diet (HFD), accompanied by activation in brown adipose tissue (BAT) as well as improvements of energy, glucose and lipid metabolism. Besides, our data indicate that L. acidophilus not only reverses HFD-induced gut dysbiosis, as indicated by the decreased Firmicutes-to-Bacteroidetes ratios and endotoxin bearing Gram-negative bacteria levels, but also maintains intestinal barrier integrity, reduces metabolic endotoxemia, and inhibits the TLR4 / NF- κB signaling pathway. In addition, the results of microbiome phenotype prediction by BugBase and bacterial functional potential prediction using PICRUSt show that L. acidophilus treatment improves the gut microbiota functions involving metabolism, immune response, and pathopoiesia. Furthermore, the anti-obesity effect is transmissible via horizontal faeces transfer from L. acidophilus-treated mice to HFD-fed mice. According to our data, it is seen that L. acidophilus could be a good candidate for probiotic of ameliorating obesity and associated diseases such as hyperlipidemia, nonalcoholic fatty liver diseases, and insulin resistance through its anti-inflammatory properties and alleviation of endothelial dysfunction and gut dysbiosis.

Genetic and treatment profiles of patients with concurrent Epidermal Growth Factor Receptor (EGFR) and Anaplastic Lymphoma Kinase (ALK) mutations.

BACKGROUND: EGFR and ALK alternations often contribute to human malignancies, including lung cancer. EGFR and ALK mutations are usually sensitive to EGFR-tyrosine kinase inhibitors (TKIs) and ALK-TKIs. Although generally mutually exclusive, these mutations do co-exist in rare cases. This study investigated the frequencies, clinical characteristics, therapeutic efficacies, and genetic profiles of lung cancer patients with EGFR and ALK co-mutations. METHODS: Patients with concurrent EGFR and ALK mutations were included in this study, which analyzed mutation profiles and treatment histories. SPSS20.0 were used for survival analysis. RESULTS: Among 271 ALK-positive (ALK-pos) and 2975 EGFR-positive (EGFR-pos) patients in our database, nine (2.6% of ALK-pos and 0.2% of EGFR-pos) patients had concurrent EGFR and ALK mutations (including three exon19 Indel + EML4-ALK, two exon19 Indel + STRN-ALK, two L858R + L1152R, one L858R + EML4-ALK, and one G719C + S768I + STRN-ALK). Eight patients had at least one type of EGFR-TKIs treatment. The median progression free survival (PFS) of these patients on first-generation EGFR-TKIs was 14.5 months (95% CI: 11 - NR). Of these eight patients, one who progressed on Gefitinib and subsequently on Osimertinib had a T790M + C797G. The other seven EGFR-TKIs resistance patients had no known resistance mutations. No patients had ALK mutations before treatment, so ALK mutations may have developed as resistance mechanisms during EGFR-TKIs therapies. EGFR-TKIs-treated patients with EGFR/ALK L1152R mutations generally had a shorter PFS than patients with other mutation combinations. CONCLUSIONS: ALK and EGFR mutations coincide at a relatively low frequency in lung cancer patients. ALK mutations developed either synchronously or heterochronously with EGFR mutations. Two ALK mutations (L1152R and STRN-ALK) may co-exist with EGFR mutations at a higher frequency than others. Most EGFR/ALK co-alteration patients (other than the EGFR/ALK L1152R type) can benefit from first line EGFR-TKIs.

Preoperative CT feature of incomplete overlying enhancing mucosa as a high-risk predictor in gastrointestinal stromal tumors of the stomach.

OBJECTIVES: To determine whether the CT finding of overlying enhancing gastric mucosa (OEGM) can be used to predict risk stratifications by observing CT features of gastrointestinal stromal tumors (GISTs) of the stomach. METHODS: Clinical characteristics and CT features within pathologically demonstrated GISTs were retrospectively reviewed. Risk stratifications were classified into non-high group and high-risk group according to the modified National Institutes of Health criteria. Univariate analysis and multivariate logistic regression analysis were performed in order to determine significant predictors for high-risk stratification. Receiver operating characteristic (ROC) curve analysis, subgroup analysis, and pathologic-radiologic correlation analysis were all executed. RESULTS: A total of 147 patients were finally enrolled as test subjects. Within the univariate analysis, high-risk tumors tended to have a larger diameter, irregular shape, exophytic growth pattern, present necrosis, incomplete OEGM, tumor vessels, heterogeneous enhancement, and present rupture. According to ROC curve analysis, incomplete OEGM showed the largest area under curve values for diagnosing lesions (0.835; 95% CI, 0.766-0.904; p < 0.001). Multivariate analysis showed that the incomplete OEGM was the strongest independent predictor for high-risk stratification of gastric GISTs (OR = 21.944; 95% CI, 4.344-110.863; p < 0.001). Within the subgroup analysis, incomplete OEGM was more frequently associated with tumors size > 10 cm, irregular shape, exophytic growth pattern, high mitotic count, and disrupted mucosa on pathology. CONCLUSIONS: The CT feature of incomplete OEGM is an independent predictive factor for high-risk stratification of gastric GISTs and strongly correlated with pathological mucosal changes. KEY POINTS: • Preoperative CT features can be helpful in assessment of risk stratifications of gastric GISTs. • OEGM is an independent predictor for high-risk stratification of gastric GISTs. • Incomplete OEGM likely indicates high-risk stratification of gastric GISTs.

Quantitative CT for detecting COVID­19 pneumonia in suspected cases.

BACKGROUND: Corona Virus Disease 2019 (COVID-19) is currently a worldwide pandemic and has a huge impact on public health and socio-economic development. The purpose of this study is to explore the diagnostic value of the quantitative computed tomography (CT) method by using different threshold segmentation techniques to distinguish between patients with or without COVID-19 pneumonia. METHODS: A total of 47 patients with suspected COVID-19 were retrospectively analyzed, including nine patients with positive real-time fluorescence reverse transcription polymerase chain reaction (RT-PCR) test (confirmed case group) and 38 patients with negative RT-PCR test (excluded case group). An improved 3D convolutional neural network (VB-Net) was used to automatically extract lung lesions. Eight different threshold segmentation methods were used to define the ground glass opacity (GGO) and consolidation. The receiver operating characteristic (ROC) curves were used to compare the performance of various parameters with different thresholds for diagnosing COVID-19 pneumonia. RESULTS: The volume of GGO (VOGGO) and GGO percentage in the whole lung (GGOPITWL) were the most effective values for diagnosing COVID-19 at a threshold of - 300 HU, with areas under the curve (AUCs) of 0.769 and 0.769, sensitivity of 66.67 and 66.67%, specificity of 94.74 and 86.84%. Compared with VOGGO or GGOPITWL at a threshold of - 300 Hounsfield units (HU), the consolidation percentage in the whole lung (CPITWL) with thresholds at - 400 HU, - 350 HU, and - 250 HU were statistically different. There were statistical differences in the infection volume and percentage of the whole lung, right lung, and lobes between the two groups. VOGGO, GGOPITWL, and volume of consolidation (VOC) were also statistically different at the threshold of - 300 HU. CONCLUSIONS: Quantitative CT provides an image quantification method for the auxiliary diagnosis of COVID-19 and is expected to assist in confirming patients with COVID-19 pneumonia in suspected cases.

Inclusion bodies of human parainfluenza virus type 3 inhibit antiviral stress granule formation by shielding viral RNAs.

Viral invasion triggers the activation of the host antiviral response. Besides the innate immune response, stress granules (SGs) also act as an additional defense response to combat viral replication. However, many viruses have evolved various strategies to suppress SG formation to facilitate their own replication. Here, we show that viral mRNAs derived from human parainfluenza virus type 3 (HPIV3) infection induce SG formation in an eIF2α phosphorylation- and PKR-dependent manner in which viral mRNAs are sequestered and viral replication is inhibited independent of the interferon signaling pathway. Furthermore, we found that inclusion body (IB) formation by the interaction of the nucleoprotein (N) and phosphoprotein (P) of HPIV3 correlated with SG suppression. In addition, co-expression of P with NL478A (a point mutant of N, which is unable to form IBs with P) or with NΔN10 (lacking N-terminal 10 amino acids of N, which could form IBs with P but was unable to synthesize or shield viral RNAs) failed to inhibit SG formation, suggesting that inhibition of SG formation also correlates with the capacity of IBs to synthesize and shield viral RNAs. Therefore, we provide a model whereby viral IBs escape the antiviral effect of SGs by concealing their own newly synthesized viral RNAs and offer new insights into the emerging role of IBs in viral replication.

Picornavirus 2A protease regulates stress granule formation to facilitate viral translation.

Stress granules (SGs) contain stalled messenger ribonucleoprotein complexes and are related to the regulation of mRNA translation. Picornavirus infection can interfere with the formation of SGs. However, the detailed molecular mechanisms and functions of picornavirus-mediated regulation of SG formation are not clear. Here, we found that the 2A protease of a picornavirus, EV71, induced atypical stress granule (aSG), but not typical stress granule (tSG), formation via cleavage of eIF4GI. Furthermore, 2A was required and sufficient to inhibit tSGs induced by EV71 infection, sodium arsenite, or heat shock. Infection of 2A protease activity-inactivated recombinant EV71 (EV71-2AC110S) failed to induce aSG formation and only induced tSG formation, which is PKR and eIF2α phosphorylation-dependent. By using a Renilla luciferase mRNA reporter system and RNA fluorescence in situ hybridization assay, we found that EV71-induced aSGs were beneficial to viral translation through sequestering only cellular mRNAs, but not viral mRNAs. In addition, we found that the 2A protease of other picornaviruses such as poliovirus and coxsackievirus also induced aSG formation and blocked tSG formation. Taken together, our results demonstrate that, on one hand, EV71 infection induces tSG formation via the PKR-eIF2α pathway, and on the other hand, 2A, but not 3C, blocks tSG formation. Instead, 2A induces aSG formation by cleaving eIF4GI to sequester cellular mRNA but release viral mRNA, thereby facilitating viral translation.

Inducible microRNA-590-5p inhibits host antiviral response by targeting the soluble interleukin-6 (IL6) receptor.

MicroRNA (miR)-590-5p has been identified as an important regulator of some signaling pathways such as cell proliferation and tumorigenesis. However, little is known about its role during viral infection. Here, we report that miR-590-5p was significantly induced by various viruses and effectively potentiated virus replication in different viral infection systems. Furthermore, miR-590-5p substantially attenuated the virus-induced expression of type I and type III interferons (IFNs) and inflammatory cytokines, resulting in impaired downstream antiviral signaling. Interleukin-6 receptor (IL6R) was identified as a target of miR-590-5p. Interestingly, the role of miR-590-5p in virus-triggered signaling was abolished in IL6R knockout cells, and this could be rescued by restoring the expression of the soluble IL6R (sIL6R) but not the membrane-bound IL6R (mIL6R), suggesting that sIL6R is indispensable for miR-590-5p in modulating the host antiviral response. Furthermore, miR-590-5p down-regulated endogenous sIL6R and mIL6R expression through a translational repression mechanism. These findings thus uncover a previously uncharacterized role and the underlying mechanism of miR-590-5p in the innate immune response to viral infection.

Trans-cinnamaldehyde shows anti-depression effect in the forced swimming test and possible involvement of the endocannabinoid system.

Depression is a mental disease that significantly reduces the quality of patients' life. Around 322 million people of all ages carry the heavy burden of depression on a worldwide scale, with a life-time prevalence of 20% according to the WHO. Trans-cinnamaldehyde (TCA) is an excellent COX-2 inhibitor in central nervous system which is a main constituent of GUIZHI as a member of traditional Chinese herb. Furthermore, previous studies demonstrated that TCA suppressed depression-like behavior in chronic unexpected mild stress, plus maze test and open field test. However, the molecular mechanism of TCA anti-depression effect is not clear. We examined the immobility of TCA pretreated male BALB/c mice in the forced swimming test (FST). Results show that TCA (50 mg/kg, po) revealed a significant effect on reduced immobility in the FST, compared with SAL group which indicated that TCA suppressed depression-like behavior. Moreover, TCA elevated the level of 5-HT and decreased the ratio of Glu/GABA in mice hippocampus. Compared with SAL + FST group, TCA + FST group significantly decreased COX-2, TRPV1 and CB1 protein level in mice hippocampus (p < 0.05, p < 0.05, p < 0.01). These findings suggest that TCA treatment exerted anti-depressive effect and was able to regulate neurotransmitters in the FST. This effect may have positive influence on the endocannabinoid (eCB) system.

Inducible TAP1 Negatively Regulates the Antiviral Innate Immune Response by Targeting the TAK1 Complex.

The innate immune response is critical for host defense and must be tightly controlled, but the molecular mechanisms responsible for its negative regulation are not yet completely understood. In this study, we report that transporter 1, ATP-binding cassette, subfamily B (TAP1), a virus-inducible endoplasmic reticulum-associated protein, negatively regulated the virus-triggered immune response. In this study, we observed upregulated expression of TAP1 following virus infection in human lung epithelial cells (A549), THP-1 monocytes, HeLa cells, and Vero cells. The overexpression of TAP1 enhanced virus replication by inhibiting the virus-triggered activation of NF-κB signaling and the production of IFNs, IFN-stimulated genes, and proinflammatory cytokines. TAP1 depletion had the opposite effect. In response to virus infection, TAP1 interacted with the TGF-ß-activated kinase (TAK)1 complex and impaired the phosphorylation of TAK1, subsequently suppressing the phosphorylation of the IκB kinase complex and NF-κB inhibitor α (IκBα) as well as NF-κB nuclear translocation. Our findings collectively suggest that TAP1 plays a novel role in the negative regulation of virus-triggered NF-κB signaling and the innate immune response by targeting the TAK1 complex.

Soluble IL-6 Receptor and IL-27 Subunit p28 Protein Complex Mediate the Antiviral Response through the Type III IFN Pathway.

Previously, we demonstrated that the soluble IL-6R (sIL-6R) plays an important role in the host antiviral response through induction of type I IFN and sIL-6R-mediated antiviral action via the IL-27 subunit p28; however, the mechanism that underlies sIL-6R and p28 antiviral action and whether type III IFN is involved remain unknown. In this study, we constructed a sIL-6R and p28 fusion protein (sIL-6R/p28 FP) and demonstrated that the fusion protein has stronger antiviral activity than sIL-6R alone. Consequently, knockout of sIL-6R inhibited virus-triggered IFN-λ1 expression. In addition, sIL-6R/p28 FP associated with mitochondrial antiviral signaling protein and TNFR-associated factor 6, the retinoic acid-inducible gene I adapter complex, and the antiviral activity mediated by sIL-6R/p28 FP was dependent on mitochondrial antiviral signaling protein. Furthermore, significantly reduced binding of p50/p65 and IFN regulatory factor 3 to the IFN-λ1 promoter was observed in sIL-6R knockout cells compared with the control cells. Interestingly, a novel heterodimer of c-Fos and activating transcription factor 1 was identified as a crucial transcriptional activator of IFN-λ1 The sIL-6R/p28 FP upregulated IFN-λ1 expression by increasing the binding abilities of c-Fos and activating transcription factor 1 to the IFN-λ1 promoter via the p38 MAPK signaling pathway. In conclusion, these results demonstrate the important role of sIL-6R/p28 FP in mediating virus-induced type III IFN production.

Immune regulator ABIN1 suppresses HIV-1 transcription by negatively regulating the ubiquitination of Tat.

BACKGROUND: A20-binding inhibitor of NF-κB activation (ABIN1), an important immune regulator, was previously shown to be involved in HIV-1 replication. However, the reported studies done with overexpressed ABIN1 provided controversial results. RESULTS: Here we identified ABIN1 as a suppressor of HIV-1 transcription since transient knockdown of ABIN1 led to increased HIV-1 replication both in transformed Jurkat T cell line and in primary human CD4+ T lymphocytes. Depletion of ABIN1 specifically enhanced the HIV-1 transcription from the integrated genome during viral life cycle, but not the earlier steps such as reverse transcription or integration. Immunoprecipitation assays revealed that ABIN1 specifically inhibits the proto-oncogene HDM2 catalyzed K63-linked polyubiquitination of Tat at Lys71, which is critical for the transactivation activity of Tat. The ubiquitin chain binding activity of ABIN1 carried by UBAN domain turned out to be essential for the inhibitory role of ABIN1. The results of immunofluorescence localization experiments suggested that ABIN1 may obstruct Tat ubiquitination by redistributing some of HDM2 from the nucleus to the cytoplasm. CONCLUSIONS: Our findings have revealed ABIN1 as intrinsic suppressor of HIV-1 mRNA transcription by regulating the ubiquitination of Tat.