Objective To investigate the role and mechanism of the zinc finger protein Kruppel-like transcription factor 9 (KLF9) in the stimulation of type I interferon expression induced by herpes simplex virus type 1 (HSV-1) in macrophages. Methods Agarose Gel electrophoresis, quantitative real-time PCR (qRT-PCR) and western blot analyses were employed to detect the KLF9 relative expression in bone marrow-derived macrophages (BMDMs) from Klf9^-/- (gKO) mice and wild-type (WT) mice. RNA-seq analysis was utilized to identify the potential targeted genes upon HSV-1 stimulation in BMDMs. ELISA was used to measure the potent of IFN-β in the supernatant of BMDMs derived from gKO and WT mice after HSV-1 stimulation. qRT-PCR analysis was employed to further confirm the changes of Ifnb1 and interferon-stimulated gene (ISG) such as interferon-induced protein with tetratricopeptide repeats 1 (Ifit1), interferon-stimulated exonuclease gene 20 (Isg20), cholesterol 25-hydroxylase (Ch25h) and 2'-5' oligoadenylate synthetase-like 1 (Oasl1). Western blot was used to detect the expression of phosphorylated interferon regulatory factor-3 (p-IRF3), IRF3, phosphorylated interferon regulatory factor-7 (p-IRF7), IRF7, phosphorylated nuclear factor-kappa B p65 (p-NF-κB p65) and NF-κB p65. CUT-Tag and ChIP-qPCR assay were utilized to confirm the binding region of KLF9 in Ifnb1. Results The KLF9 expression was significantly decreased in BMDMs from gKO mice compared with that from WT mice. The RNA-seq analysis showed that Klf9 deletion in BMDMs resulted in an impaired type I interferon signaling pathway. The qRT-PCR analysis revealed that Klf9 deletion in BMDMs led to a significant decrease of Ifnb1 and ISG such as Ifit1, Ch25h and Oasl1 except Isg20. Moreover, ELISA revealed that Klf9 knockout in BMDMs resulted in a significant decrease of IFN-β secreted from BMDMs. Mechanistically, KLF9 directly binds to the promoter of Ifnb1. Conclusion KLF9 is essential for macrophages to resist HSV-1 infection.
Animals ; Kruppel-Like Transcription Factors/physiology* ; Interferon-beta/metabolism* ; Macrophages/virology* ; Mice ; Herpesvirus 1, Human/physiology* ; Mice, Knockout ; Signal Transduction ; Mice, Inbred C57BL ; Interferon Regulatory Factor-3/genetics* ; Interferon Regulatory Factor-7/genetics* ; Gene Expression Regulation

OBJECTIVE: To investigate the inhibitory effect of Tanreqing Injection (TRQ) on the activation of nucleotide-binding oligomerization domain-like receptor pyrin domain containing 3 (NLRP3) inflammasome in macrophages infected with influenza A virus and the underlying mechanism based on mitophagy pathway. METHODS: The inflammatory model of murine macrophage J774A.1 induced by influenza A virus [strain A/Puerto Rico/8/1934 (H1N1), PR8] was constructed and treated by TRQ, while the mitochondria-targeted antioxidant Mito-TEMPO and autophagy specific inhibitor 3-methyladenine (3-MA) were used as controls to intensively study the anti-inflammatory mechanism of TRQ based on mitophagy-mitochondrial reactive oxygen species (mtROS)-NLRP3 inflammasome pathway. The levels of NLRP3, Caspase-1 p20, microtubule-associated protein 1 light chain 3 II (LC3II) and P62 proteins were measured by Western blot. The release of interleukin-1β (IL-1β) was tested by enzyme linked immunosorbent assay, the mtROS level was detected by flow cytometry, and the immunofluorescence and co-localization of LC3 and mitochondria were observed under confocal laser scanning microscopy. RESULTS: Similar to the effect of Mito-TEMPO and contrary to the results of 3-MA treatment, TRQ could significantly reduce the expressions of NLRP3, Caspase-1 p20, and autophagy adaptor P62, promote the expression of autophagy marker LC3II, enhance the mitochondrial fluorescence intensity, and inhibit the release of mtROS and IL-1β (all P<0.01). Moreover, LC3 was co-localized with mitochondria, confirming the type of mitophagy. CONCLUSION TRQ could reduce the level of mtROS by promoting mitophagy in macrophages infected with influenza A virus, thus inhibiting the activation of NLRP3 inflammasome and the release of IL-1β, and attenuating the inflammatory response.
Mitophagy/drug effects* ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Animals ; Macrophages/virology* ; Inflammasomes/drug effects* ; Drugs, Chinese Herbal/pharmacology* ; Mice ; Mitochondria/metabolism* ; Reactive Oxygen Species/metabolism* ; Influenza A virus/physiology* ; Interleukin-1beta/metabolism* ; Cell Line ; Injections

This work aims to explore the effect of glycolysis on the replication of porcine reproductive and respiratory syndrome virus (PRRSV) in porcine alveolar macrophages (PAMs). The changes of glucose metabolism, PRRSV protein levels, PRRSV titers, and the relative expression levels of genes and proteins in PAMs were analyzed by ELISA, qPCR, virus titration, and Western blotting after PRRSV infection. The effect of hypoxia-inducible factor-1α (HIF-1α) on PRRSV replication was subsequently assessed by specific siRNAs targeting to HIF-1α. The results showed that PRRSV infection enhanced glycolysis, elevated the levels of glucose uptake and lactate in the supernatant (P<0.05 and 0.01, respectively), reduced ATP production (P<0.05), and up-regulated the expression of hexokinase 2 (HK2), 6-phosphofructo-2-kinase/fructose-2, 6-biphosphatase 3 (PFKFB3), and pyruvate kinase isozyme type M2 (PKM2) in PAMs (P<0.05 and 0.01, respectively). Glycolysis inhibitors down-regulated the expression of PRRSV proteins and reduced virus titers (P<0.01). The knockdown of HIF-1α by siRNAs inhibited glycolysis and lowered PRRSV titers (P<0.05). In addition, the interferon pathways inhibited by PRRSV infection were reversed by the inhibition of glycolysis. These findings may facilitate further investigation of the role of glycolysis in PRRSV replication.
Porcine respiratory and reproductive syndrome virus/physiology* ; Glycolysis ; Swine ; Animals ; Virus Replication ; Hypoxia-Inducible Factor 1, alpha Subunit/genetics* ; Macrophages, Alveolar/metabolism* ; Porcine Reproductive and Respiratory Syndrome/virology* ; Cells, Cultured ; RNA, Small Interfering/genetics*

In order to study the signal pathway secreting type Ⅰ interferon in porcine alveolar macrophages (PAMs) infected with porcine circovirus type 2 (PCV2), the protein and the mRNA expression levels of cGAS/STING pathways were analyzed by ELISA, Western blotting and quantitative reverse transcriptase PCR in PAMs infected with PCV2. In addition, the roles of cGAS, STING, TBK1 and NF-κB/P65 in the generation of type I interferon (IFN-I) from PAMs were analyzed by using the cGAS and STING specific siRNA, inhibitors BX795 and BAY 11-7082. The results showed that the expression levels of IFN-I increased significantly at 48 h after infection with PCV2 (P<0.05), the mRNA expression levels of cGAS increased significantly at 48 h and 72 h after infection (P<0.01), the mRNA expression levels of STING increased significantly at 72 h after infection (P<0.01), and the mRNA expression levels of TBK1 and IRF3 increased at 48 h after infection (P<0.01). The protein expression levels of STING, TBK1 and IRF3 in PAMs infected with PCV2 were increased, the content of NF-κB/p65 was decreased, and the nuclear entry of NF-κB/p65 and IRF3 was promoted. After knocking down cGAS or STING expression by siRNA, the expression level of IFN-I was significantly decreased after PCV2 infection for 48 h (P<0.01). BX795 and BAY 11-7082 inhibitors were used to inhibit the expression of IRF3 and NF-κB, the concentration of IFN-I in BX795-treated group was significantly reduced than that of the PCV2 group (P<0.01), while no significant difference was observed between the BAY 11-7028 group and the PCV2 group. The results showed that PAMs infected with PCV2 induced IFN-I secretion through the cGAS/STING/TBK1/IRF3 signaling pathway.
Animals ; Cells, Cultured ; Circovirus ; Interferon Type I/genetics* ; Macrophages, Alveolar/virology* ; Membrane Proteins/metabolism* ; Nucleotidyltransferases/metabolism* ; Signal Transduction ; Swine

The severe fever with thrombocytopenia syndrome virus (SFTSV) is a new member in the genus Phlebovirus of the family Bunyaviridae identified in China. The SFTSV is also the causative pathogen of an emerging infectious disease: severe fever with thrombocytopenia syndrome. Using immunofluorescent staining and confocal microscopy, the intracellular distribution of nucleocapsid protein (NP) in SFTSV-infected THP-1 cells was investigated with serial doses of SFTSV at different times after infection. Transmission electron microscopy was used to observe the ultrafine intracellular structure of SFTSV-infected THP-1 cells at different times after infection. SFTSV NP could form intracellular inclusion bodies in infected THP-1 cells. The association between NP-formed inclusion bodies and virus production was analyzed: the size of the inclusion body formed 3 days after infection was correlated with the viral load in supernatants collected 7 days after infection. These findings suggest that the inclusion bodies formed in SFTSV-infected THP-1 cells could be where the SFTSV uses host-cell proteins and intracellular organelles to produce new viral particles.
Cell Line ; China ; Humans ; Inclusion Bodies, Viral ; ultrastructure ; virology ; Macrophages ; ultrastructure ; virology ; Phlebotomus Fever ; virology ; Phlebovirus ; genetics ; physiology ; ultrastructure ; Thrombocytopenia ; virology

OBJECTIVETo observe the anti-virus effects of andrographolide (AD) on the retinoic acid-inducible gene-I (RIG-I)-like receptors (RLRs) signaling pathway when immunological cells were infected with H1N1.

METHODSLeukomonocyte was obtained from umbilical cord blood by Ficoll density gradient centrifugation, and immunological cells were harvested after cytokines stimulation. Virus infected cell model was established by H1N1 co-cultured with normal human bronchial epithelial cell line (16HBE). The optimal concentration of AD was defined by methyl-thiazolyl-tetrazolium (MTT) assay. After the virus infected cell model was established, AD was added into the medium as a treatment intervention. After 24-h co-culture, cell supernatant was collected for interferon gamma (IFN-γ) and interleukin-4 (IL-4) enzyme-linked immunosorbent assay (ELISA) detection while immunological cells for real-time polymerase chain reaction (RT-PCR).

RESULTSThe optimal concentration of AD for anti-virus effect was 250 μg/mL. IL-4 and IFN-γ in the supernatant and mRNA levels in RLRs pathway increased when cells was infected by virus, RIG-I, IFN-β promoter stimulator-1 (IPS-1), interferon regulatory factor (IRF)-7, IRF-3 and nuclear transcription factor κB (NF-κB) mRNA levels increased significantly (P<0.05). When AD was added into co-culture medium, the levels of IL-4 and IFN-γ were lower than those in the non-interference groups and the mRNA expression levels decreased, RIG-I, IPS-1, IRF-7, IRF-3 and NF-κB decreased significantly in each group with significant statistic differences (P<0.05).

CONCLUSIONSThe RLRs mediated viral recognition provided a potential molecular target for acute viral infections and andrographolide could ameliorate H1N1 virus-induced cell mortality. And the antiviral effects might be related to its inhibition of viral-induced activation of the RLRs signaling pathway.

Adaptor Proteins, Signal Transducing ; genetics ; metabolism ; Antiviral Agents ; pharmacology ; Cells, Cultured ; Coculture Techniques ; DEAD Box Protein 58 ; DEAD-box RNA Helicases ; genetics ; metabolism ; Dendritic Cells ; drug effects ; immunology ; virology ; Diterpenes ; pharmacology ; Fetal Blood ; cytology ; Humans ; Influenza A Virus, H1N1 Subtype ; drug effects ; immunology ; Influenza, Human ; drug therapy ; immunology ; virology ; Interferon-beta ; genetics ; metabolism ; Interferon-gamma ; metabolism ; Interleukin-4 ; metabolism ; Leukocytes, Mononuclear ; drug effects ; immunology ; virology ; Macrophages ; drug effects ; virology ; NF-kappa B ; genetics ; metabolism ; Promoter Regions, Genetic ; drug effects ; immunology ; RNA, Messenger ; metabolism ; Signal Transduction ; drug effects ; genetics ; immunology

In this study, apoptosis was induced by new type gosling viral enteritis virus (NGVEV) in experimentally infected goslings is reported in detail for the first time. After 3-day-old goslings were orally inoculated with a NGVEV-CN strain suspension, the time course of NGVEV effects on apoptotic morphological changes of the internal tissues was evaluated. These changes were observed by histological analysis with light microscopy and ultrastructural analysis with transmission electron microscopy. DNA fragmentation was assessed with a terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay and DNA ladder analysis. A series of characteristic apoptotic morphological changes including chromatin condensation and margination, cytoplasmic shrinkage, plasma membrane blebbing, and formation of apoptotic bodies were noted. Apoptosis was readily observed in the lymphoid and gastrointestinal organs, and sporadically occurred in other organs after 3 days post-infection (PI). The presence and quantity of TUNEL-positive cells increased with infection time until 9 days PI. DNA extracted from the NGVEV-infected gosling cells displayed characteristic 180~200 bp ladders. Apoptotic cells were ubiquitously distributed, especially among lymphocytes, macrophages, monocytes, and epithelial and intestinal cells. Necrosis was subsequently detected during the late NGVEV-infection phase, which was characterized by cell swelling, plasma membrane collapse, and rapidly lysis. Our results suggested that apoptosis may play an important role in the pathogenesis of NGVE disease.
*Adenoviridae/classification/pathogenicity ; Adenoviridae Infections/pathology/*veterinary/virology ; Animals ; *Anseriformes ; *Apoptosis ; Bird Diseases/*virology ; DNA Fragmentation ; Enteritis/*veterinary/virology ; Epithelial Cells/cytology/virology ; In Situ Nick-End Labeling ; Intestines/cytology/virology ; Leukocytes/cytology/virology ; Lymphoid Tissue/cytology/virology ; Macrophages ; Microscopy, Electron, Transmission

Animals ; Female ; Macrophages ; microbiology ; Mice ; Mice, Inbred BALB C ; Microscopy, Electron ; Mycobacteriophages ; physiology ; Mycobacterium tuberculosis ; virology ; Virus Replication