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The Preventive Effect of the Traditional Japanese Herbal Medicine, Hochuekkito, against Influenza A Virus via Autophagy in vitro
Abstract
Background:
Hochuekkito (HKT), a traditional Japanese herbal medicine, enhances the immunity of elderly or weak individuals. It is also known to have preventive effects against influenza clinically. However, the detailed mechanisms of the preventive effects have not been clarified. We examined the relationship between the preventive effects of HKT and autophagy, a known stress response and quality control mechanism, using Madin-Darby canine kidney cells and influenza A/PR/8/34 (H1N1) virus.
Methods:
The effect of HKT on autophagy in influenza A virus (IAV)-infected cells was assessed by Western blotting and fluorescence microscopy using an RFP-GFP-LC3B sensor kit.
Results:
In Western blotting, treatment with HKT before IAV infection (pre-HKT) tended to induce autophagy in IAV-infected cells at an early stage of infection, eventually suppressing IAV-induced autophagy. Moreover, several autolysosomes, indicative of normal autophagosome-lysosome fusion, were observed in Pre-HKT cells transduced with RFP-GFP-LC3B but not in untreated IAV-infected cells.
Conclusions:
These findings indicated that IAV-mediated inhibition of the fusion of autophagosomes with lysosomes was prevented by HKT treatment before infection. According to these results, we propose that this phenomenon is one of the preventive effects of HKT against IAV.
... Autophagy induction and regulation of energy homeostasis by hochuekkito (HET) treatment Next, we investigated the effects of HET on energy homeostasis in aged FR mice, because recent studies have demonstrated the potential of HET to induce autophagy 16,17 and restore metabolic c The proportions of mice divided by the degree of locomotor activity between 60 and120 min after alanine injection. *P < 0.05 by chi-square test; young FR saline (n = 14), young FR alanine (n = 14), aged FR saline (n = 9), and aged FR alanine (n = 10). ...
... Clinical studies have reported that HET improves fatigue, lack of energy, and low body temperature in adult patients with appetite loss 37 , QOL and immunological status of elderly patients with weakness 38 , and nutritional status in elderly patients with chronic obstructive pulmonary disease 39 . Several studies carried out in vitro have demonstrated the potential of HET to restore metabolic homeostasis 18 and promote autophagy 16,17 . We confirmed that HET and 9 of its chemical ingredients derived from astragalus root, jujube, ginger, and ginseng induced autophagy in studies featuring reporter cells; these studies suggest that these compounds may contribute to the inductive effects of HET. ...
Chronic undernutrition contributes to the increase in frailty observed among elderly adults, which is a pressing issue in the sector of health care for older people worldwide. Autophagy, an intracellular recycling system, is closely associated with age-related pathologies. Therefore, decreased autophagy in aging could be involved in the disruption of energy homeostasis that occurs during undernutrition; however, the physiological mechanisms underlying this process remain unknown. Here, we showed that 70% daily food restriction (FR) induced fatal hypoglycemia in 23–26-month-old (aged) mice, which exhibited significantly lower hepatic autophagy than 9-week-old (young) mice. The liver expressions of Bcl-2, an autophagy-negative regulator, and Beclin1–Bcl-2 binding, were increased in aged mice compared with young mice. The autophagy inducer Tat-Beclin1 D11, not the mTOR inhibitor rapamycin, decreased the plasma levels of the glucogenic amino acid and restored the blood glucose levels in aged FR mice. Decreased liver gluconeogenesis, body temperature, physical activity, amino acid metabolism, and hepatic mitochondrial dynamics were observed in the aged FR mice. These changes were restored by treatment with hochuekkito that is a herbal formula containing several autophagy-activating ingredients. Our results indicate that Bcl-2 upregulation in the liver during the aging process disturbs autophagy activation, which increases the vulnerability to undernutrition. The promotion of liver autophagy may offer clinical therapeutic benefits to frail elderly patients.
... In addition to the above flavonoids, natural products such as Tanreqing injection , Moringa A from Moringa oleifera seeds (Xiong et al., 2021), gallic acid (Chang et al., 2024b), Isatis indigotica (Chang et al., 2024a), eugenol (Dai et al., 2013b) and Hochuekkito (Takanashi et al., 2017) have been recognized for their ability to anti-IAV virus infections by modulating autophagy. The reduced production of H1N1 virus proteins (M1, M2, and NP proteins), the significant decrease in LC3B II conversion, and the decrease in the accumulation of autophagosomes with the increase in gallic acid concentration in gallic acid-treated H1N1 IAV suggest that gallic acid maybe suppresses H1N1 viral infectivity by inhibiting the autophagy pathway and suppressing the production of virulent M1, M2, and NP proteins (Chang et al., 2024b). ...
Influenza A virus (IAV) can cause seasonal epidemics and global pandemics, posing serious threats to public health, making a deeper understanding of its biological characteristics and effective countermeasure strategies essential. Autophagy not only maintains cellular homeostasis but also plays an important role in host defense against IAV infection. However, the relationship between IAV and autophagy is complex, and effective antiviral drugs are not yet available. Natural products have shown excellent potential in disease control due to their diversity and multi-targeting. This review focuses on the relationship between IAV and autophagy and discusses the potential of targeting autophagic pathways for the development of new antiviral therapies. Particularly, the use of plant extracts as autophagy modulators has garnered attention due to their non-toxic nature and cost-effectiveness, which provides strong support for the development of future antiviral drugs that can help to inhibit viral infections and slow down disease progression.
... Hochuekkito (TJ-41), a traditional Japanese herbal medicine, consists of 10 natural herbs and exerts beneficial effects on malnutrition and frailty [4]. Previous studies have reported that TJ-41 improved the healthrelated quality of life of patients with COPD [5], inhibited the entry of influenza virus into cells and influenza virusinduced autophagy [6,7], and restored metabolic homeostasis between mitochondrial and glycolytic pathways impaired by influenza virus infection [8]. Based on these facts, we hypothesized that TJ-41 might have a favorable effect on AECOPD associated with viral respiratory infection. ...
b> Introduction: The traditional Japanese herbal medicine hochuekkito (TJ-41) has been reported to ameliorate systemic inflammation and malnutrition in patients with chronic obstructive pulmonary disease (COPD). TJ-41 has also been known to have preventive effects against influenza virus infection. However, its role in the acute exacerbation of COPD (AECOPD) remains to be elucidated. Our previous study established a murine model of viral infection-associated AECOPD that was induced by intratracheal administration of porcine pancreatic elastase (PPE) and polyinosinic-polycytidylic acid [poly(I:C)]. Here, we used this model and investigated the effects of TJ-41 in AECOPD. Methods: Specific pathogen-free C57BL/6J mice were used. A COPD model was induced by treating mice intratracheally with PPE on day 0. To generate the murine model of AECOPD, poly(I:C) was administered intratracheally following PPE treatment on days 22–24. Mice were sacrificed and analyzed on day 25. Mice were fed a diet containing 2% TJ-41 or a control diet. Results: Daily oral intake of TJ-41 significantly decreased the numbers of neutrophils and lymphocytes in the bronchoalveolar lavage fluid (BALF), which was accompanied by decreased transcripts of CXC chemokines involved in neutrophil migration, viz., Cxcl1 and Cxcl2, in whole lung homogenates and reduced Cxcl2 concentration in BALF. Conclusion: This study demonstrates the anti-inflammatory effects of TJ-41 in a mouse model of AECOPD, suggesting the effectiveness of TJ-41 for the management of COPD. Clinical investigations evaluating the therapeutic efficacy of TJ-41 in AECOPD would be meaningful.
... The compound cocktail (Arctiin, Daidzein, Glycyrrhizic acid and Liquiritin) induced autophagic flux in natural killer cells [130]. A traditional Chinese medicine, Edible bird's nest reduced LC3-II expression and induced the degradation of autophagy protein in lysosome in presence of IAV, suggesting that Edible bird's nest utilized autophagy mechanisms to show its antiviral activity [131]. In addition, traditional Japanese herbal medicine, Hochuekkito promoted autolysosomes formation in IAV-infected cells at the early post-infection stage [132]. ...
Influenza A virus (IAV) is an infectious pathogen, threatening the population and public safety with its epidemics. Therefore, it is essential to better understand influenza virus biology to develop efficient strategies against its pathogenicity. Autophagy is an important cellular process to maintain cellular homeostasis by cleaning up the hazardous substrates in lysosome. Accumulating research has also suggested that autophagy is a critical mechanism in host defense responses against IAV infection by degrading viral particles and activating innate or acquired immunity to induce viral clearance. However, IAV has conversely hijacked autophagy to strengthen virus infection by blocking autophagy maturation and further interfering host antiviral signalling to promote viral replication. Therefore, how the battle for autophagy between host and IAV is carried out need to be known. In this review, we describe the role of autophagy in host defence and IAV survival, and summarize the role of influenza proteins in subverting the autophagic process as well as then concentrate on how host utilize antiviral function of autophagy to prevent IAV infection.
... Recent scientific research, on the contrary, has indicated that the combinatorial effect of mixed EAHM preparation can be particularly effective for complicated disorders, such as PN, autoimmune disease, degenerative disease, and cancer, which do not react well with single compound-based modern pharmaceutics [121][122][123][124]. As an example, recent research has demonstrated that EAHM can be used in large-scale public health emergencies, such as COVID-19 or preventive medicine using modern analytical tools, such as synthetic biology, data mining, and genomics [123,[125][126][127][128]. Future studies need to be conducted to identify the properties of EAHM to be utilized in actual drug discovery. ...
This review aimed to comprehensively assess the efficacy and safety of oral East Asian herbal medicine (EAHM) for overall peripheral neuropathy (PN). In addition, an Apriori algorithm-based association rule analysis was performed to identify the core herb combination, thereby further generating useful hypotheses for subsequent drug discovery. A total of 10 databases were searched electronically from inception to July 2021. Randomized clinical trials (RCTs) comparing EAHM with conventional analgesic medication or usual care for managing PN were included. The RCT quality was appraised using RoB 2.0, and the random effects model was used to calculate the effect sizes of the included RCTs. The overall quality of evidence was evaluated according to the Grading of Recommendations Assessment, Development, and Evaluation. By analyzing the constituent herb data, the potential association rules of core herb combinations were explored. A total of 67 RCTs involving 5753 patients were included in this systematic review. In a meta-analysis, EAHM monotherapy and combined EAHM and western medicine therapy demonstrated substantially improved sensory nerve conduction velocity, motor nerve conduction velocity, and response rate. Moreover, EAHM significantly improved the incidence rate, pain intensity, Toronto clinical scoring system, and Michigan diabetic neuropathy score. The evidence grade was moderate to low due to the substantial heterogeneity among the studies. Nine association rules were identified by performing the association rule analysis on the extraction data of 156 EAHM herbs. Therefore, the constituents of the herb combinations with consistent association rules were Astragali Radix, Cinnamomi Ramulus, and Spatholobi Calulis. This meta-analysis supports the hypothesis that EAHM monotherapy and combined therapy may be beneficial for PN patients, and follow-up research should be conducted to confirm the precise action target of the core herb.
... In addition to the aforementioned expectation of future clinical application, knowledge of the detailed mechanisms by which Kampo interferes with autophagy will provide insight into the regulation of autophagy. To date, very few studies have focused on the relationship between Kampo and autophagy [11], [12]. We took advantages of our original tf-LC3 screening system, which could quantitatively estimate the effect of each drug on autophagy [13]. ...
Kampo, a system of traditional Japanese therapy utilizing mixtures of herbal medicine, is widely accepted in the Japanese medical system. Kampo originated from traditional Chinese medicine, and was gradually adopted into a Japanese style. Although its effects on a variety of diseases are appreciated, the underlying mechanisms remain mostly unclear. Using a quantitative tf-LC3 system, we conducted a high-throughput screen of 128 kinds of Kampo to evaluate the effects on autophagy. The results revealed a suppressive effect of Shigyakusan/TJ-35 on autophagic activity. TJ-35 specifically suppressed dephosphorylation of ULK1 and TFEB, among several TORC1 substrates, in response to nutrient deprivation. TFEB was dephosphorylated by calcineurin in a Ca²⁺ dependent manner. Cytosolic Ca²⁺ concentration was increased in response to nutrient starvation, and TJ-35 suppressed this increase. Thus, TJ-35 prevents the starvation-induced Ca²⁺ increase, thereby suppressing induction of autophagy.
Oncolytic adenoviruses (Ads) have potential applications in cancer therapy due to their ability to replicate and induce tumor cell death. However, their clinical application has been limited by the lack of efficient cell-based delivery systems that can provide protection from immune attack and prevent virus clearance by neutralizing antibodies. We previously demonstrated that menstrual blood-derived mesenchymal stem cells (MenSCs) can specifically target tumor cells and serve as a novel drug delivery platform. We engineered CRAd5/F11 chimeric oncolytic Ads that can infect MenSCs and preserve their tumor targeting ability in vitro. MenSCs loaded with these Ads were transplanted in a mouse tumor model. We found that a large number of the CRAd5/F11 viruses were accumulated in tumor site and mediated marked inhibitory effects against colorectal cancer (CRC). Thus, we concluded that MenSC-cloaked oncolytic Ads hold great potential as a novel virus-delivery platform for the therapy of various cancers, including CRC.
Bu-Zhong-Yi-Qi-Tang (BZYQT), a famous traditional Chinese medicine prescription (TCMP), has been extensively used for conditioning sub-health status and diseases caused by spleen-qi deficiency in China for over 700 years. BZYQT is prevalent not only in China, but also in Japan and South Korea for the clinical treatment of chronic diseases, such as fatigue, tuberculosis and loss of appetite after surgery. However, due to a lack of research on the holistic metabolism of BZYQT, the in vivo bioactive components of BZYQT remain unclear, hindering further study of its in vivo mechanism of action and quality control. In the present study, a four-step integrated strategy based on ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UHPLC-Q-TOF/MS) was established to systematically screen the in vivo xenobiotics of BZYQT. Ultimately, a total of 162 xenobiotics (59 prototypes and 103 metabolites) were identified or tentatively characterized, including 48 in plasma, 147 in urine and 58 in feces, while the in vivo metabolic profile of atractylenolide III (a major component of BZYQT) was elucidated for the first time. The xenobiotics of BZYQT mainly included flavonoids from Astragali Radix, Glycyrrhizae Radix et Rhizoma and Citrus reticulatae Pericarpium; lactones from Angelicae Sinensis Radix and Atractylodis Macrocephalae Rhizoma; and triterpenoid saponins from Cimicifugae Rhizoma. After oral administration, BZYQT-related components underwent diverse metabolic pathways. Among them, flavonoids mainly underwent glucuronidation, sulfation and demethylation, while lactones mainly underwent hydroxylation and acetylcysteine conjugation, and deglycosylation was the major metabolic reaction of saponins. Our investigation gives a comprehensive analysis of the metabolic characteristics of BZYQT and will provide an important basis for further studying the pharmacokinetics of BZYQT to explore its in vivo disposal features and discover its in vivo bioactive components.
Current influenza vaccines afford substantial protection in humans by inducing strain-specific neutralizing antibodies (Abs). Most of these Abs target highly variable immunodominant epitopes in the globular domain of the viral hemagglutinin (HA). Therefore, current vaccines may not be able to induce heterosubtypic immunity against the divergent influenza subtypes. The identification of broadly neutralizing Abs (BnAbs) against influenza HA using recent technological advancements in antibody libraries, hybridoma, and isolation of single Ab-secreting plasma cells has increased the interest in developing a universal influenza vaccine as it could provide life-long protection. While these BnAbs can serve as a source for passive immunotherapy, their identification represents an important step towards the design of such a universal vaccine. This review describes the recent advances and approaches used in the development of universal influenza vaccine based on highly conserved HA regions identified by BnAbs.
Influenza A virus is a dreadful pathogen of animals and humans, causing widespread infection and severe morbidity and mortality. It is essential to characterize the influenza A virus-host interaction and develop efficient counter measures against the viral infection. Autophagy is known as a catabolic process for the recycling of the cytoplasmic macromolecules. Recently, it has been shown that autophagy is a critical mechanism underlying the interaction between influenza A virus and its host. Autophagy can be induced by the infection with influenza A virus, which is considered as a necessary process for the viral proliferation, including the accumulation of viral elements during the replication of influenza A virus. On the other hand, influenza A virus can inhibit the autophagic formation via interaction with the autophagy-related genes (Atg) and signaling pathways. In addition, autophagy is involved in the influenza virus-regulated cell deaths, leading to significant changes in host apoptosis. Interestingly, the high pathogenic strains of influenza A virus, such as H5N1, stimulate autophagic cell death and appear to interplay with the autophagy in distinct ways as compared with low pathogenic strains. This review discusses the regulation of autophagy, an influenza A virus driven process.
Six influenza A(H1N1)pdm09 viruses were detected in Sapporo, Japan, between November and December 2013. All six viruses possessed an H275Y substitution in the neuraminidase protein, which confers cross-resistance to oseltamivir and peramivir. No epidemiological link among the six cases could be identified; none of them had received neuraminidase inhibitors before specimen collection. The haemagglutinin and neuraminidase genes of the six viruses were closely related to one another, suggesting clonal spread of a single resistant virus.
We have performed a broad-ranging analysis of the adjuvant effect of a Kampo medicine, juzentaihoto (JTT), on influenza vaccination in a multicenter randomized controlled trial. In this study, the enhancing effect of JTT on antibody titer after influenza vaccination was studied for 28 weeks in elderly people who were in the high-risk group for influenza infection. In total, 91 subjects over 65 years old were recruited from four long-term-care facilities located in Chiba, Gunma, and Toyama prefectures in Japan. Participants were randomly assigned to the JTT and the control groups. Blood samples were taken at 4 weeks before vaccination, at the time of vaccination, and then at 4, 8, 12, and 24 weeks after vaccination. The hemagglutination inhibition (HI) titers against A/California/7/2009 (H1N1), A/Victoria/210/2009 (H3N2), and B/Brisbane/60/2008 were then manually measured. A significant increase in HI titer against H3N2 was observed at week 8 after vaccination in the JTT group compared with the control group (P = 0.0229), and the HI titer of the JTT group significantly increased from 4 to 24 weeks (P = 0.0468), compared with the control group. In conclusion, our results indicated that JTT increased and prolonged antibody production against A/Victoria/210/2009 (H3N2), in particular, after influenza vaccination.
In this research, we have established a drug screening method based on the autophagy signal pathway using the bimolecular fluorescence complementation-fluorescence resonance energy transfer (BiFC-FRET) technique to develop novel anti-influenza A virus (IAV) drugs. We selected Evodia rutaecarpa Benth out of 83 examples of traditional Chinese medicine and explored the mechanisms of evodiamine, the major active component of Evodia rutaecarpa Benth, on anti-IAV activity. Our results showed that evodiamine could significantly inhibit IAV replication, as determined by a plaque inhibition assay, an IAV vRNA promoter luciferase reporter assay and the Sulforhodamine B method using cytopathic effect (CPE) reduction. Additionally, evodiamine could significantly inhibit the accumulation of LC3-II and p62, and the dot-like aggregation of EGFP-LC3. This compound also inhibited the formation of the Atg5-Atg12/Atg16 heterotrimer, the expressions of Atg5, Atg7 and Atg12, and the cytokine release of TNF-α, IL-1β, IL-6 and IL-8 after IAV infection. Evodiamine inhibited IAV-induced autophagy was also dependent on its action on the AMPK/TSC2/mTOR signal pathway. In conclusion, we have established a new drug screening method, and selected evodiamine as a promising anti-IAV compound.
Pathogen recognition is the first and crucial step in innate immunity. Molecular families involved in the recognition of pathogens
and activation of the innate immune responses in immunoreactive cells include the Toll-like receptor family in mammals and
the peptidoglycan recognition protein (PGRP) family in Drosophila, which sense microorganisms in an extracellular or luminal compartment. Other emerging families are the intracellular recognition
molecules for bacteria, such as nucleotide binding and oligomerization domain-like receptors in mammals and PGRP–LE in Drosophila, several of which have been shown to detect structures of bacterial peptidoglycan in the host cell cytosol. Exciting advances
in recent studies on autophagy indicate that macroautophagy (referred to here as autophagy) is selectively induced by intracellular
recognition molecules and has a crucial role in the elimination of intracellular pathogens, including bacteria, viruses and
parasites. This review discusses recent studies related to intracellular recognition molecules and innate immune responses
to intracellular pathogens, and highlights the role of autophagy in innate immunity.
Autophagy is a tightly regulated pathway involving the lysosomal degradation of cytoplasmic organelles or cytosolic components. This pathway can be stimulated by multiple forms of cellular stress, including nutrient or growth factor deprivation, hypoxia, reactive oxygen species, DNA damage, protein aggregates, damaged organelles, or intracellular pathogens. Both specific, stimulus-dependent and more general, stimulus-independent signaling pathways are activated to coordinate different phases of autophagy. Autophagy can be integrated with other cellular stress responses through parallel stimulation of autophagy and other stress responses by specific stress stimuli, through dual regulation of autophagy and other stress responses by multifunctional stress signaling molecules, and/or through mutual control of autophagy and other stress responses. Thus, autophagy is a cell biological process that is a central component of the integrated stress response.
The His274→Tyr274 (H274Y) mutation confers oseltamivir resistance on N1 influenza neuraminidase but had long been thought to compromise viral
fitness. However, beginning in 2007–2008, viruses containing H274Y rapidly became predominant among human seasonal H1N1 isolates.
We show that H274Y decreases the amount of neuraminidase that reaches the cell surface and that this defect can be counteracted
by secondary mutations that also restore viral fitness. Two such mutations occurred in seasonal H1N1 shortly before the widespread
appearance of H274Y. The evolution of oseltamivir resistance was therefore enabled by “permissive” mutations that allowed
the virus to tolerate subsequent occurrences of H274Y. An understanding of this process may provide a basis for predicting
the evolution of oseltamivir resistance in other influenza strains.
Autophagy is involved in the replication of viruses, especially those that perform RNA assembly on the surface of cytoplasmic membrane in host cells. However, little is known about the regulatory role of autophagy in influenza A virus replication. Using fluorescence and electron microscopy, we observed that autophagosomes can be induced and identified upon influenza A virus infection. The virus increased the amount of the autophagosome marker protein microtubule-associated protein light chain 3-II (LC3-II) and enhanced autophagic flux. When autophagy was pharmacologically inhibited by either 3-methylademine or wortmannin, the titers of influenza A virus were remarkably decreased. Viral reduction via autophagy inhibition was further confirmed by RNA interference, through which two different proteins required for autophagy were depleted. Noticeably, the compounds utilized had no marked effect on virus entry or cell viability, either of which might limit viral replication. Furthermore, alteration of cellular autophagy via pharmacological reagents or RNA interference impaired viral protein accumulation. Taken together, these findings indicate that autophagy is actively involved in influenza A virus replication.
We found that the autophagic machinery could effectively eliminate pathogenic group A Streptococcus (GAS) within nonphagocytic cells. After escaping from endosomes into the cytoplasm, GAS became enveloped by autophagosome-like compartments and were killed upon fusion of these compartments with lysosomes. In autophagy-deficient Atg5(-/-) cells, GAS survived, multiplied, and were released from the cells. Thus, the autophagic machinery can act as an innate defense system against invading pathogens.
Japanese herbal (Kampo) medicine, Hochuekkito (Bu-Zhong-Yi-Qi-Tang in Chinese, TJ-41) and Juzentaihoto (Shi-Quan-Da-Bu-Tang in Chinese, TJ-48) are well-known Kampo formulas used as tonic. Although these medicines have separately been applied to the patients clinically depending on their symptoms, the differences of the pharmacological activities for these medicines have not been fully understood. TJ-48 and TJ-41 were compared for their effects on antibody response in upper respiratory mucosal immune system in vivo. Oral administration of TJ-41 (100 mg kg(-1) per day) to early aged BALB/c mice, which were nasally sensitized with influenza hemagglutinin vaccine, significantly enhanced influenza virus-specific IgA and IgG antibody titers in nasal cavity and sera, respectively. However, oral administration of TJ-48 (100 mg kg(-1) per day) failed to show the enhancing activity. TJ-41 increased not only influenza virus-specific IgA antibody titer but also total IgA antibody titer in nasal cavity. The stimulating activity of TJ-41 disappeared after treatment with methotrexate. The present study strongly suggests that TJ-41 can stimulate the mucosal immune system of upper respiratory tract, and results in enhancement of antigen-specific antibody response in upper respiratory mucosal and systemic immune systems.
No reliable cell culture assay is currently available for monitoring human influenza virus sensitivity to neuraminidase inhibitors (NAI). This can be explained by the observation that because of a low concentration of sialyl-alpha2,6-galactose (Sia[alpha2,6]Gal)-containing virus receptors in conventional cell lines, replication of human virus isolates shows little dependency on viral neuraminidase. To test whether overexpression of Sia(alpha2,6)Gal moieties in cultured cells could make them suitable for testing human influenza virus sensitivity to NAI, we stably transfected MDCK cells with cDNA of human 2,6-sialyltransferase (SIAT1). Transfected cells expressed twofold-higher amounts of 6-linked sialic acids and twofold-lower amounts of 3-linked sialic acids than parent MDCK cells as judged by staining with Sambucus nigra agglutinin and Maackia amurensis agglutinin, respectively. After transfection, binding of a clinical human influenza virus isolate was increased, whereas binding of its egg-adapted variant which preferentially bound 3-linked receptors was decreased. The sensitivity of human influenza A and B viruses to the neuraminidase inhibitor oseltamivir carboxylate was substantially improved in the SIAT1-transfected cell line and was consistent with their sensitivity in neuraminidase enzyme assay and with the hemagglutinin (HA) receptor-binding phenotype. MDCK cells stably transfected with SIAT1 may therefore be a suitable system for testing influenza virus sensitivity to NAI.
During the process of autophagy, autophagosomes undergo a maturation process consisting of multiple fusions with endosomes and lysosomes, which provide an acidic environment and digestive function to the interior of the autophagosome. Here we found that a fusion protein of monomeric red-fluorescence protein and LC3, the most widely used marker for autophagosomes, exhibits a quite different localization pattern from that of GFP-LC3. GFP-LC3 loses fluorescence due to lysosomal acidic and degradative conditions but mRFP-LC3 does not, indicating that the latter can label the autophagic compartments both before and after fusion with lysosomes. Taking advantage of this property, we devised a novel method for dissecting the maturation process of autophagosomes. mRFP-GFP tandem fluorescent-tagged LC3 (tfLC3) showed a GFP and mRFP signal before the fusion with lysosomes, and exhibited only the mRFP signal subsequently. Using this method, we provided evidence that overexpression of a dominant negative form of Rab7 prevented the fusion of autophagosomes with lysosomes, suggesting that Rab7 is involved in this step. This method will be of general utility for analysis of the autophagosome maturation process.
To enhance the effect of anti-influenza-virus agent treatment, the effect of combined administration of oseltamivir phosphate and hochu-ekki-to (Japanese traditional herbal medicine, HET) on early viral clearance was examined. Senescence-accelerated mice were given HET in drinking water for 2 weeks, followed by intranasal infection with influenza A virus strain PR8. After 4 hours of infection, oseltamivir was administered orally for 5 days. The viral loads in the lungs of the group receiving combined treatment were dramatically lower when compared with the viral loads in the lungs of the group receiving oseltamivir alone. HET significantly increased the induction of IL-1β and TNF-α in the lungs of PR8-infected mice and stimulated alveolar macrophage phagocytosis. From these results, we conclude that these functions may be responsible the increased effect on viral load reduction. Here, we show that the combined administration of oseltamivir and HET is very useful for influenza treatment in senescence-accelerated mice.
A Kampo medicine, Hochuekkito (TJ-41), with an influenza virus-preventing effect had life-extending effectiveness, and immunological responses other than interferon (IFN)-α release were examined. TJ-41 (1 g/kg) was given to C57BL/6 male mice orally once a day for 2 weeks. Mice were then intranasally infected with influenza virus. After infection, virus titers and various parameters, mRNA levels and protein expression, for immunoresponses in the bronchoalveolar lavage fluid or removed lung homogenate, were measured by plaque assay, quantitative RT-PCR and ELISA. IFN-α and -β levels of TJ-41-treated mice were higher than those of the control. Toll-like receptor TLR7 and TLR9 mRNAs were elevated after infection, but retinoic acid-inducible gene (RIG-1) family mRNA levels, RIG-1, melanoma differentiation-associated gene 5 and Leishmania G protein 2 showed no response in either TJ-41 or control groups. Interferon regulatory transcription factor (IRF)-3 mRNA levels to stimulate type I (α/β) IFN were increased, but IRF-7 did not change. Only granulocyte-macrophage colony-stimulating factor (GM-CSF) after Hochuekkito treatment was significantly elevated 2 and 3 days after infection. The mRNA levels of 7 defensins after infection increased compared to preinfection values. The key roles of TJ-41 were not only stimulation of type I IFN release but also GM-CSF-derived anti-inflammation activity. Furthermore, defensin (antimicrobial peptide) mRNA levels increased by infection and were further enhanced by TJ-41 treatment. Defensin might prevent influenza virus replication.
Background/objectives:
Japan has the highest frequency of neuraminidase (NA) inhibitor use against influenza in the world. Therefore, Japan could be at high risk of the emergence and spread of NA inhibitor-resistant viruses. The aim of this study was to monitor the emergence of NA inhibitor-resistant viruses and the possibility of human-to-human transmission during four influenza seasons in Japan.
Methods:
To monitor antiviral-resistant A(H1N1)pdm09 viruses, we examined viruses isolated in four seasons from the 2008-2009 season through the 2011-2012 season in Japan by allelic discrimination, NA gene sequencing, and NA inhibitor susceptibility.
Results:
We found that 157 (1·3%) of 12 026 A(H1N1)pdm09 isolates possessed an H275Y substitution in the NA protein that confers about 400- and 140-fold decreased susceptibility to oseltamivir and peramivir, respectively, compared with 275H wild-type viruses. The detection rate of resistant viruses increased from 1·0% during the pandemic period to 2·0% during the post-pandemic period. The highest detection rate of the resistant viruses was found in patients who were 0-9 years old. Furthermore, among the cases with resistant viruses, the percentage of no known exposure to antiviral drugs increased from 16% during the pandemic period to 44% during the post-pandemic period, implying that suspected human-to-human transmission of the resistant viruses gradually increased in the post-pandemic period.
Conclusions:
A(H1N1)pdm09 viruses resistant to oseltamivir and peramivir were sporadically detected in Japan, but they did not spread throughout the community. No viruses resistant to zanamivir and laninamivir were detected.
Autophagy, a vital catabolic process that degrades cytoplasmic components within the lysosome, is an essential cytoprotective response to pathologic stresses that occur during diseases such as cancer, ischemia, and infection. In addition to its role as a stress-response pathway, autophagy plays an essential quality-control function in the cell by promoting basal turnover of long-lived proteins and organelles, as well as by selectively degrading damaged cellular components. This homeostatic function protects against a wide variety of diseases, including neurodegeneration, myopathy, liver disease, and diabetes. This review discusses our current understanding of these two principal functions of autophagy and describes in detail how alterations in autophagy promote human disease. Expected final online publication date for the Annual Review of Pathology: Mechanisms of Disease Volume 8 is January 24, 2013. Please see http://www.annualreviews.org/catalog/pubdates.aspx for revised estimates.
Influenza virus is a respiratory pathogen that causes a high degree of morbidity and mortality every year in multiple parts of the world. Therefore, precise diagnosis of the infecting strain and rapid high-throughput screening of vast numbers of clinical samples is paramount to control the spread of pandemic infections. Current clinical diagnoses of influenza infections are based on serologic testing, polymerase chain reaction, direct specimen immunofluorescence and cell culture (1,2). Here, we report the development of a novel diagnostic technique used to detect live influenza viruses. We used the mouse-adapted human A/PR/8/34 (PR8, H1N1) virus (3) to test the efficacy of this technique using MDCK cells (4). MDCK cells (10(4) or 5 x 10(3) per well) were cultured in 96- or 384-well plates, infected with PR8 and viral proteins were detected using anti-M2 followed by an IR dye-conjugated secondary antibody. M2 (5) and hemagglutinin (1) are two major marker proteins used in many different diagnostic assays. Employing IR-dye-conjugated secondary antibodies minimized the autofluorescence associated with other fluorescent dyes. The use of anti-M2 antibody allowed us to use the antigen-specific fluorescence intensity as a direct metric of viral quantity. To enumerate the fluorescence intensity, we used the LI-COR Odyssey-based IR scanner. This system uses two channel laser-based IR detections to identify fluorophores and differentiate them from background noise. The first channel excites at 680 nm and emits at 700 nm to help quantify the background. The second channel detects fluorophores that excite at 780 nm and emit at 800 nm. Scanning of PR8-infected MDCK cells in the IR scanner indicated a viral titer-dependent bright fluorescence. A positive correlation of fluorescence intensity to virus titer starting from 10(2)-10(5) PFU could be consistently observed. Minimal but detectable positivity consistently seen with 10(2)-10(3) PFU PR8 viral titers demonstrated the high sensitivity of the near-IR dyes. The signal-to-noise ratio was determined by comparing the mock-infected or isotype antibody-treated MDCK cells. Using the fluorescence intensities from 96- or 384-well plate formats, we constructed standard titration curves. In these calculations, the first variable is the viral titer while the second variable is the fluorescence intensity. Therefore, we used the exponential distribution to generate a curve-fit to determine the polynomial relationship between the viral titers and fluorescence intensities. Collectively, we conclude that IR dye-based protein detection system can help diagnose infecting viral strains and precisely enumerate the titer of the infecting pathogens.
The past decade has witnessed an explosion of research on a fundamental cell biology pathway called autophagy (Greek for “self-eating”). The discovery of evolutionarily conserved genes (initially identified in yeast) that are required for autophagy has enabled scientists to uncover a vast array of homeostatic, developmental, and other physiological functions of autophagy. Moreover, increasing evidence suggests that the deregulation of autophagy may contribute to a broad spectrum of mammalian diseases (Levine and Kroemer, 2008 and Mizushima et al., 2008). Consequently, there is a rapidly growing need among scientists to be able to accurately detect autophagy and to study its function in diverse biological processes, especially in mammalian systems.
Influenza A virus is an important human pathogen causing significant morbidity and mortality every year and threatening the human population with epidemics and pandemics. Therefore, it is important to understand the biology of this virus to develop strategies to control its pathogenicity. Here, we demonstrate that influenza A virus inhibits macroautophagy, a cellular process known to be manipulated by diverse pathogens. Influenza A virus infection causes accumulation of autophagosomes by blocking their fusion with lysosomes, and one viral protein, matrix protein 2, is necessary and sufficient for this inhibition of autophagosome degradation. Macroautophagy inhibition by matrix protein 2 compromises survival of influenza virus-infected cells but does not influence viral replication. We propose that influenza A virus, which also encodes proapoptotic proteins, is able to determine the death of its host cell by inducing apoptosis and also by blocking macroautophagy.
An increasing number of infections of highly pathogenic avian influenza virus (H5N1) in humans has been reported in South-East Asia and other areas of the world. High mortality (>60%) of this viral infection and its pathosis of systemic infection are features of this new human disease. Moreover, there is great concern that this avian H5N1 virus could cause a pandemic of new influenza in humans, once it acquires the ability for human to human transmission. To prevent such highly contagious infectious diseases as influenza, it is essential to prepare effective vaccines. Especially in the case of new influenza virus, we cannot predict the strain which will cause the pandemic. In such a situation, a vaccine that induces cross-protective immunity against variant viruses is extremely important. However currently used parenteral seasonal influenza vaccine is strain-specific, and is less effective against variant viruses. In order to overcome the weakness of current vaccines we need to learn from the immune responses induced by natural infection with influenza viruses. In the case of mucosally acquired acute respiratory infection such as influenza, mucosal immunity induced by natural infection plays important role in protection against the infection, as mucosal secretory IgA antibody plays an important role in cross-protection. In this review we describe the advantages and development of mucosal vaccine against highly pathogenic H5N1 influenza viruses.
The carbocyclic transition state sialic acid analog GS4071 ([3R,4R,5S]-4-acetamido-5-amino-3-[1-ethylpropoxy]-1-cyclohexane-1 -carboxylic acid), a potent influenza virus neuraminidase inhibitor, was highly inhibitory to influenza A/NWS/33 (H1N1), A/Victoria/3/75 (H3N2), A/Shangdong/09/93 (H3N2) and B/Hong Kong/5/72 viruses in Madin Darby canine kidney (MDCK) cells. The 50% effective concentrations in these experiments ranged from 1.8 to 59.5 microM, with no cytotoxicity evident at 1000 microM, using inhibition of viral cytopathic effect determined visually and by neutral red dye uptake. The ethyl ester prodrug of GS4071, GS4104, administered by oral gavage (p.o.), had significant inhibitory effects on infections in mice induced by these viruses. Antiviral effects were seen as prevention of death, increase in mean day to death, inhibition of decline of arterial oxygen saturation, lessened lung consolidation and inhibition of infectious virus recovered from the lungs. No toxicity was seen in dosages up to 100 mg/kg/day (highest evaluated). Comparison experiments run versus the influenza A (H1N1) virus-induced infection using GS4104, GS4071 and the neuraminidase inhibitor zanamivir (GG167, 4-guanidino-Neu5Ac2en), all administered p.o., indicated a 10-fold or greater potency for inhibiting the infection by GS4104. The minimum effective dosage for GS4104 was 0.1 mg/kg/day, with the compound administered twice daily for 5 days beginning 4 h pre-virus exposure. Oral therapy with GS4104 could be delayed from 48 to at least 60 h after exposure of mice to influenza A (H1N1) virus and still render a significant antiviral effect, the time of delay being dependent on the viral challenge dose. Intranasal instillation of GS4071 and GG167 to mice infected with influenza virus was highly inhibitory to the infection, the minimum effective dosages to significantly prevent death being 0.01 mg/kg/day for GS4071 and 0.1 mg/kg/day for GG167. Caging of infected mice treated with 10 mg/kg/day of GS4104 with infected saline-treated animals did not transfer any influenza-inhibitory effect to the latter animals. These data provide strong evidence of the potential of orally administered GS4104 for treatment of influenza A and B virus infections in humans.
A series of influenza neuraminidase inhibitors with the cyclohexene scaffold containing lipophilic side chains have been synthesized and evaluated for influenza A and B neuraminidase inhibitory activity. The size and geometry of side chains have been modified systematically in order to investigate structure-activity relationships of this class of compounds. The X-ray crystal structures of several analogues complexed with neuraminidase revealed that the lipophilic side chains bound to the hydrophobic pocket consisted of Glu276, Ala246, Arg224, and Ile222 of the enzyme active site. The structure-activity relationship studies of this series have also demonstrated remarkably different inhibitory potency between influenza A and B neuraminidase. This indicated that the lipophilic side chains had quite different hydrophobic interactions with influenza A and B neuraminidase despite their complete homology in the active site. Influenza B neuraminidase appeared to be much more sensitive toward the increased steric bulkiness of inhibitors compared to influenza A neuraminidase. From the extensive structure-activity relationship investigation reported in this article, GS 4071 emerged as one of the most potent influenza neuraminidase inhibitors against both influenza A and B strains.
The innate immunity against murine cytomegalovirus (MCMV) at the early phase of infection is mediated by NK cells and macrophages. We studied the effects of hochu-ekki-to (HET), a traditional Chinese herbal medicine, on the regulation of innate immunity mediated by NK cells and macrophages. We found the oral administration of HET to increase both the number of leukocytes in the spleen and liver and the splenic NK cell cytotoxicity associated with the increased induction of serum IFN-alpha/beta after an MCMV infection but it had no effect on liver NK cells. However, no differences were found in the serum IL-12, IFN-gamma, TNF-alpha and nitric oxide (NO) production in the culture of macrophages between the HET- and PBS-treated mice on day 2 after MCMV infection. In addition, HET-treated splenic and peritoneal macrophages were found to show a higher intrinsic resistance against in vitro MCMV infection than that of PBS-treated mice. Therefore, the HET-induced effects on NK cells and macrophages selectively reduced the viral load in the spleen but not in the liver at an early phase of MCMV infection. HET may thus be useful in the treatment of human cytomegalovirus infection which commonly occurs in HIV-infected AIDS patients.
The antiviral effect of Hochu-ekki-to (TJ-41), a Japanese herbal medicine, was investigated using mice infected with influenza virus. TJ-41 was found to increase the survival rate, prolong the mean survival days, suppress viral growth in bronchoalveolar labage fluid (BALF) and inhibit the lung index (lung consolidation) on day 4 after infection in mice infected with influenza, after the agent had been administered orally once daily from day 7 to 2 before infection and from day 0 to 4 after infection. Administration of TJ-41 decreased the BALF concentrations of IL-1alpha, IL-6 and GM-CSF, but not TNF-alpha or interferon-gamma (IFN-gamma), on day 4 after infection. In addition, TJ-41 elevated the level of IFN-alpha in BALF on day 2 after infection. Yet, TJ-41 did not show any inhibitory effect on the growth of influenza virus in vitro. These results suggest that TJ-41 exerts its inhibitory effect on influenza virus infection via enhancement of the host immune responses in this experimental murine system.
In general, the elderly show a significant age-related decline in their immune response, thus leading to an increased vulnerability to infections or to an increase in the occurrence of malignant tumors. In this study, we examined the effect of Hochu-ekki-to (HOT or TJ-41) on the immunological capacity of the elderly. A group of elderly patients complaining of general fatigue or weakness were orally administered 7.5 g of HOT everyday for at least 120 days (4 months), whereas another group of aged patients mainly complaining of a loss of appetite were daily given 7.5 g of Anchu-san (TJ-5) during the same period and served as a control group. From the immunological point of view, the total number of circulating leukocytes remained unchanged, during the observation period both in the HOT and Anchu-san groups, as well as the ratios between CD3(+) T and CD20(+) B cells and between CD4(+) T and CD8(+) T cells. In addition, no differences were observed in the expression of CD25 antigen, which represents an activated state of T cells. However, as verified on day 30 as well as on day 120 after the administration of HOT, the natural killer (NK) activity against K562 target cells was significantly enhanced, in comparison to the results on day 0 in the HOT group, as well as to that activity on days 0, 30 and 120 in the Anchu-san group. In addition, on days 30 and 120 in the HOT group, there was a significant increase in the serum IFN-gamma level, which is thought to be associated with the NK activity, whereas no significant changes in that level were observed in the Anchu-san group, during the study period. From these results, it may be concluded that the administration of HOT to elderly people may help them improve, at least to some degree, their immunological capacity.
Autophagy is an intracellular bulk degradation process, through which a portion of cytoplasm is delivered to lysosomes to be degraded. In many organisms, the primary role of autophagy is adaptation to starvation. However, we have found that autophagy is also important for intracellular protein quality control. Atg5(-/-) mice die shortly after birth due, at least in part, to nutrient deficiency. These mice also exhibit an intracellular accumulation of protein aggregates in neurons and hepatocytes. We now report the generation of neural cell-specific Atg5-deficient mice. Atg5( flox/flox);Nestin-Cre mice show progressive deficits in motor function and degeneration of some neural cells. In autophagy-deficient cells, diffuse accumulation of abnormal proteins occurs, followed by the generation of aggregates and inclusions. This study emphasizes the point that basal autophagy is important even in individuals who do not express neurodegenerative disease-associated mutant proteins. Furthermore, the primary targets of autophagy are diffuse cytosolic proteins, not protein aggregates themselves.
The Preventive Effect of HKT against IAV via
The Preventive Effect of HKT against IAV
via Autophagy
Pharmacology 2017;99:99-105
DOI: 10.1159/000452474
Prevention of 2009 pandemic influenza A/H1N1 virus infection by administration of Hochuekkito, a Japanese herbal medicine
- M Niimi
Niimi M: Prevention of 2009 pandemic influenza A/H1N1 virus infection by administration of Hochuekkito, a Japanese herbal medicine. BMJ 2009; 339:b5213.