scholarly journals Highly pathogenic avian influenza A H5N1 and pandemic H1N1 virus infections have different phenotypes in Toll-like receptor 3 knockout mice

2014 ◽  
Vol 95 (9) ◽  
pp. 1870-1879 ◽  
Author(s):  
Y. H. Connie Leung ◽  
John M. Nicholls ◽  
Chuk Kwan Ho ◽  
Sin Fun Sia ◽  
Chris K. P. Mok ◽  
...  
Keyword(s):  
Body Weight ◽  
Influenza A ◽  
Immune Cell ◽  
Body Weight Loss ◽  
Lung Pathology ◽  
Pandemic H1n1 ◽  
Virus Infections ◽  
Viral Titre ◽  
Highly Pathogenic

Toll-like receptors (TLRs) play an important role in innate immunity to virus infections. We investigated the role of TLR3 in the pathogenesis of H5N1 and pandemic H1N1 (pH1N1) influenza virus infections in mice. Wild-type mice and those defective in TLR3 were infected with influenza A/HK/486/97 (H5N1) or A/HK/415742/09 (pH1N1) virus. For comparison, mice defective in the gene for myeloid differential factor 88 (MyD88) were also infected with the viruses, because MyD88 signals through a TLR pathway different from TLR3. Survival and body weight loss were monitored for 14 days, and lung pathology, the lung immune-cell profile, viral load and cytokine responses were studied. H5N1-infected TLR3−/− mice had better survival than H5N1-infected WT mice, evident by significantly faster regain of body weight, lower viral titre in the lung and fewer pathological changes in the lung. However, this improved survival was not seen upon pH1N1 infection of TLR3−/− mice. In contrast, MyD88−/− mice had an increased viral titre and decreased leukocyte infiltration in the lungs after infection with H5N1 virus and poorer survival after pH1N1 infection. In conclusion, TLR3 worsens the pathogenesis of H5N1 infection but not of pH1N1 infection, highlighting the differences in the pathogenesis of these two viruses and the different roles of TLR3 in their pathogenesis.

Perspectives on influenza evolution and the role of research

2010 ◽  
Vol 11 (1) ◽  
pp. 3-18 ◽  
Author(s):  
Heather L. Forrest ◽  
Robert G. Webster
Keyword(s):  
Influenza A ◽  
H1n1 Influenza ◽  
Influenza Viruses ◽  
Pandemic H1n1 ◽  
Knowledge Gaps ◽  
Highly Pathogenic ◽  
Pandemic H1n1 Influenza ◽  
Domestic Poultry ◽  
Molecular Determinants

AbstractInfluenza is a highly contagious respiratory pathogen that continues to evolve and threaten both veterinary and human public health. Influenza A viruses are continually undergoing molecular changes through mutations, reassortment, and, in rare instances, recombination. While they generally cause benign enteric infection in their natural reservoir of wild aquatic birds, they can cause catastrophic and potentially lethal disease outbreaks in humans, domestic poultry, and pigs when they cross the host species barrier. The continuing circulation of highly pathogenic (HP) H5N1 influenza viruses in domestic poultry in parts of Eurasia and the emergence and global spread of pandemic H1N1 2009 are current examples of influenza evolution. The spread of both HP H5N1 and pandemic H1N1 to multiple hosts emphasizes the potential for continued evolution. In this review, we discuss the current understanding of influenza A virus structure and strategies of variation, with a specific focus on the HP H5N1 and pandemic H1N1 influenza viruses. Additionally, we attempt to identify the gaps in our knowledge of H5N1 and pandemic H1N1 influenza viruses. These gaps include (i) an understanding of the molecular determinants of influenza virus and the host that permit efficient transmissibility and pandemic potential, (ii) the urgent need for prospective surveillance in apparently healthy swine, (iii) the molecular determinants of high pathogenicity in poultry, pigs, and people, (iv) the genetic basis of host susceptibility, (v) antigenic variability, (vi) the use of vaccine to control influenza, (vii) the role of wild birds as the reservoir of highly pathogenic avian influenza, (viii) the problems with vaccines, (ix) seasonality, (x) co-infections, and (xi) anti-influenza drug resistance. Our failure to eradicate HP H5N1 globally and to explain why H5N1 does not transmit efficiently in humans while an H1N1 pandemic virus of swine origin spread globally in months are key examples that emphasize the critical need to bridge these knowledge gaps. Future directions in influenza research that will help us resolve each of the above-mentioned knowledge gaps include complete genomic and proteomic analysis of both the virus and the host with the prospect of designing new control strategies and the development of genetically resistant hosts.

scholarly journals Impact of obesity and SARS-CoV-2 infection: implications for host defence - a living review

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Felix Clemens Richter ◽  
Aljawharah Alrubayyi ◽  
Alicia Teijeira Crespo ◽  
Sarah Hulin-Curtis ◽  
Keyword(s):  
Lipid Metabolism ◽  
Influenza A ◽  
Immune Cell ◽  
Cell Metabolism ◽  
Low Grade ◽  
Obese Patients ◽  
Healthy Weight ◽  
Virus Infections ◽  
Immune Alterations ◽  
And Function

Abstract The role of obesity in the pathophysiology of respiratory virus infections has become particularly apparent during the current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, where obese patients are twice as likely to suffer from severe coronavirus disease 2019 (COVID-19) than healthy weight individuals. Obesity results in disruption of systemic lipid metabolism promoting a state of chronic low-grade inflammation. However, it remains unclear how these underlying metabolic and cellular processes promote severe SARS-CoV-2 infection. Emerging data in SARS-CoV-2 and Influenza A virus (IAV) infections show that viruses can further subvert the host’s altered lipid metabolism and exploit obesity-induced alterations in immune cell metabolism and function to promote chronic inflammation and viral propagation. In this review, we outline the systemic metabolic and immune alterations underlying obesity and discuss how these baseline alterations impact the immune response and disease pathophysiology. A better understanding of the immunometabolic landscape of obese patients may aid better therapies and future vaccine design.

scholarly journals Exacerbation of Influenza Virus Infections in Mice by Intranasal Treatments and Implications for Evaluation of Antiviral Drugs

2012 ◽  
Vol 56 (12) ◽  
pp. 6328-6333 ◽  
Author(s):  
Donald F. Smee ◽  
Mark von Itzstein ◽  
Beenu Bhatt ◽  
E. Bart Tarbet
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
H1n1 Virus ◽  
Antiviral Agent ◽  
Virus Production ◽  
Lung Pathology ◽  
Virus Infections ◽  
Challenge Dose ◽  
Virus Challenge ◽  
Time To Death

ABSTRACTCompounds lacking oral activity may be delivered intranasally to treat influenza virus infections in mice. However, intranasal treatments greatly enhance the virulence of such virus infections. This can be partially compensated for by giving reduced virus challenge doses. These can be 100- to 1,000-fold lower than infections without such treatment and still cause equivalent mortality. We found that intranasal liquid treatments facilitate virus production (probably through enhanced virus spread) and that lung pneumonia was delayed by only 2 days relative to a 1,000-fold higher virus challenge dose not accompanied by intranasal treatments. In one study, zanamivir was 90 to 100% effective at 10 mg/kg/day by oral, intraperitoneal, and intramuscular routes against influenza A/California/04/2009 (H1N1) virus in mice. However, the same compound administered intranasally at 20 mg/kg/day for 5 days gave no protection from death although the time to death was significantly delayed. A related compound, Neu5Ac2en (N-acetyl-2,3-dehydro-2-deoxyneuraminic acid), was ineffective at 100 mg/kg/day. Intranasal zanamivir and Neu5Ac2en were 70 to 100% protective against influenza A/NWS/33 (H1N1) virus infections at 0.1 to 10 and 30 to 100 mg/kg/day, respectively. Somewhat more difficult to treat was A/Victoria/3/75 virus that required 10 mg/kg/day of zanamivir to achieve full protection. These results illustrate that treatment of influenza virus infections by the intranasal route requires consideration of both virus challenge dose and virus strain in order to avoid compromising the effectiveness of a potentially useful antiviral agent. In addition, the intranasal treatments were shown to facilitate virus replication and promote lung pathology.

The role of host cell Rab GTPases in influenza A virus infections

2021 ◽  
Author(s):  
Jing Wu ◽  
Jiaqi Gu ◽  
Li Shen ◽  
Xiaonan Jia ◽  
Yiqian Yin ◽  
...  
Keyword(s):  
Influenza A Virus ◽  
Influenza A ◽  
Respiratory Infections ◽  
Small Gtpase ◽  
Regulatory Mechanisms ◽  
Rab Proteins ◽  
Rab Gtpases ◽  
Virus Infections ◽  
Adaptation Mechanisms

Influenza A virus (IAV) is a crucial cause of respiratory infections in humans worldwide. Therefore, studies should clarify adaptation mechanisms of IAV and critical factors of the viral pathogenesis in human hosts. GTPases of the Rab family are the largest branch of the Ras-like small GTPase superfamily, and they regulate almost every step during vesicle-mediated trafficking. Evidence has shown that Rab proteins participate in the lifecycle of IAV. In this mini-review, we outline the regulatory mechanisms of different Rab proteins in the lifecycle of IAV. Understanding the role of Rab proteins in IAV infections is important to develop broad-spectrum host-targeted antiviral strategies.

scholarly journals 1343. Prophylactic Dosing of Baloxavir Acid Eliminates Mortality in Mice Lethal Influenza A Virus Infection Model

2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S410-S411
Author(s):  
Shinya Shano ◽  
Keita Fukao ◽  
Takeshi Noshi ◽  
Kenji Sato ◽  
Masashi Sakuramoto ◽  
...  
Keyword(s):  
Weight Loss ◽  
Body Weight ◽  
Virus Infection ◽  
Influenza A Virus ◽  
Influenza A ◽  
Lethal Dose ◽  
Body Weight Loss ◽  
Prophylactic Efficacy ◽  
Body Weights ◽  
Single Dosing

Abstract Background Baloxavir acid (BXA), an active form of orally available prodrug baloxavir marboxil (BXM, formerly S-033188), is a novel small molecule inhibitor of cap-dependent endonuclease (CEN) of influenza A and B virus, and was recently launched for the treatment of acute and uncomplicated influenza with single dosing of BXM (the trade name XOFLUZA™) in Japan in March 2018. Here, we evaluated the prophylactic efficacy of BXA in mice lethally infected with influenza A virus. Methods T1/2 of BXA in human is more than 10 times longer than that in mice. Therefore, suspension of BXA was subcutaneously administered at 0.8 or 1.6 mg/kg in mice to maintain the plasma concentration of BXA as seen in humans, and then mice were intranasally inoculated with a lethal dose of A/PR/8/34 strain at 48, 72, or 96 hours after the administration of BXA. Survival time and body weight change were then monitored through a 28-day period after virus infection. Mice were euthanized and regarded as dead if their body weights were lower than 70% of the initial body weights according to humane endpoints. Results Single dosing of BXA (1.6 mg/kg) completely eliminated mortality in mice, when the mice were administrated the drug at 48, 72, or 96 hours before virus infection (Figure 1). BXA treatment also significantly prevented body weight loss, consistent with the prolonged survival. Conclusion Prophylactic dosing of BXA exhibited significant protective efficacy against mortality and body weight loss in mice following a lethal infection with influenza A virus. The significant prophylactic efficacy observed in our mouse model suggests the potential utility of BXM for the prophylaxis of influenza in human. Disclosures S. Shano, Shionogi & Co., Ltd.: Employee, Salary. K. Fukao, Shionogi & Co., Ltd.: Employee, Salary. T. Noshi, Shionogi & Co., Ltd.: Employee, Salary. K. Sato, Shionogi & Co., Ltd.: Employee, Salary. M. Sakuramoto, Shionogi & Co., Ltd.: Employee, Salary. K. Baba, Shionogi TechnoAdvance Research & Co., Ltd.: Employee, Salary. T. Shishido, Shionogi & Co., Ltd.: Employee, Salary. A. Naito, Shionogi & Co., Ltd.: Employee, Salary.

The role of nutritional assessment for predicting Radiotherapy-induced adverse events in patients with gastric cancer

2021 ◽  
Author(s):  
Wenjie Sun ◽  
Guichao Li ◽  
Jing Zhang ◽  
Ji Zhu ◽  
Zhen Zhang
Keyword(s):  
Gastric Cancer ◽  
Body Weight ◽  
Adverse Events ◽  
Cancer Patients ◽  
Body Weight Loss ◽  
Nutritional Factors ◽  
Nrs 2002 ◽  
Grade 3 ◽  
Gastric Cancer Patients

Objectives: The aim of this study was to investigate the role of nutritional factors in predicting radiotherapy-associated toxicities for gastric cancer patients. Methods: A total of 285 gastric cancer patients who underwent radiotherapy in our hospital between 2010 and 2017 were included in this retrospective study. Nutritional status assessment included body weight loss (BWL), body mass index (BMI), serum albumin, nutrition risk screening 2002(NRS-2002), patient-generated subjective global assessment(PG-SGA) and nutritional risk index (NRI). Results: Of all patients, 19.6% were underweight (BMI <18.5 kg/m2), 25.6% were hypoalbuminemia (<35 g l−1) and 48.8% lost ≥10% of body weight in the 6 month interval before radiotherapy(BWL). Meanwhile, 73.3%, 78.6 and 47.2% of the patients were diagnosed as malnutrition based on NRS-2002, PG-SGA and NRI, respectively. Hematological adverse events were present in 91.2% (≥Grade 1) and 20.4% (≥Grade 3) of the patients. Non-hematological adverse events occurred in 89.8% (≥Grade1) and 14.4% (≥Grade 3) of the patients. Multivariate analyses indicated that only hypoalbuminemia(<35 g l−1) was independent predictor for Grade 3/4 hematological and non-hematological adverse events. Meanwhile, higher BWL(≥10%) was also independent predictor for Grade 3/4 non-hematological adverse events. NRS-2002, PG-SGA and NRI score were not associated with treatment-induced adverse events. Conclusions: Body weight loss and serum albumin are useful factors for predicting severe adverse events in gastric cancer patients who undergo radiotherapy. Advances in knowledge: The use of nutritional factors in predicting severe adverse events enables implementation of individualized treatment strategies for early and intensive nutritional interventions in high-risk patients.

scholarly journals The CCL20-CCR6 Axis in Cancer Progression

2020 ◽  
Vol 21 (15) ◽  
pp. 5186 ◽  
Author(s):  
Suguru Kadomoto ◽  
Kouji Izumi ◽  
Atsushi Mizokami
Keyword(s):  
Cancer Progression ◽  
Immune Cell ◽  
G Protein Coupled Receptors ◽  
Virus Infections ◽  
Cancer Breast ◽  
Inflammatory Protein ◽  
Immunodeficiency Virus ◽  
G Protein Coupled ◽  
Macrophage Inflammatory Protein

Chemokines, which are basic proteins that exert their effects via G protein-coupled receptors and a subset of the cytokine family, are mediators deeply involved in leukocyte migration during an inflammatory reaction. Chemokine (C-C motif) ligand 20 (CCL20), also known as macrophage inflammatory protein (MIP)-3α, liver activation regulated chemokine (LARC), and Exodus-1, is a small protein that is physiologically expressed in the liver, colon, and skin, is involved in tissue inflammation and homeostasis, and has a specific receptor C-C chemokine receptor 6 (CCR6). The CCL20-CCR6 axis has long been known to be involved in inflammatory and infectious diseases, such as rheumatoid arthritis and human immunodeficiency virus infections. Recently, however, reports have shown that the CCL20-CCR6 axis is associated with several cancers, including hepatocellular carcinoma, colorectal cancer, breast cancer, pancreatic cancer, cervical cancer, and kidney cancer. The CCL20-CCR6 axis promotes cancer progression directly by enhancing migration and proliferation of cancer cells and indirectly by remodeling the tumor microenvironment through immune cell control. The present article reviewed the role of the CCL20-CCR6 axis in cancer progression and its potential as a therapeutic target.

scholarly journals The neuraminidase and matrix genes of the 2009 pandemic influenza H1N1 virus cooperate functionally to facilitate efficient replication and transmissibility in pigs

2012 ◽  
Vol 93 (6) ◽  
pp. 1261-1268 ◽  
Author(s):  
Wenjun Ma ◽  
Qinfang Liu ◽  
Bhupinder Bawa ◽  
Chuanling Qiao ◽  
Wenbao Qi ◽  
...  
Keyword(s):  
Influenza A ◽  
H1n1 Virus ◽  
Swine Influenza ◽  
Influenza Viruses ◽  
Pandemic H1n1 ◽  
Efficient Replication ◽  
Pandemic Influenza H1n1 ◽  
The Right ◽  
Six Genes

The 2009 pandemic H1N1 virus (pH1N1) contains neuraminidase (NA) and matrix (M) genes from Eurasian avian-like swine influenza viruses (SIVs), with the remaining six genes from North American triple-reassortant SIVs. To characterize the role of the pH1N1 NA and M genes in pathogenesis and transmission, their impact was evaluated in the background of an H1N1 triple-reassortant (tr1930) SIV in which the HA (H3) and NA (N2) of influenza A/swine/Texas/4199-2/98 virus were replaced with those from the classical H1N1 A/swine/Iowa/15/30 (1930) virus. The laboratory-adapted 1930 virus did not shed nor transmit in pigs, but tr1930 was able to shed in infected pigs. The NA, M or both genes of the tr1930 virus were then substituted by those of pH1N1. The resulting virus with both NA and M from pH1N1 grew to significantly higher titre in cell cultures than the viruses with single NA or M from pH1N1. In a pig model, only the virus containing both NA and M from pH1N1 was transmitted to and infected sentinels, whereas the viruses with single NA or M from pH1N1 did not. These results demonstrate that the right combination of NA and M genes is critical for the replication and transmissibility of influenza viruses in pigs.

scholarly journals Efficacy of Repeated Intravenous Injection of Peramivir against Influenza A (H1N1) 2009 Virus Infection in Immunosuppressed Mice

2013 ◽  
Vol 57 (5) ◽  
pp. 2286-2294 ◽  
Author(s):  
Mitsutaka Kitano ◽  
Makoto Kodama ◽  
Yasushi Itoh ◽  
Takushi Kanazu ◽  
Masanori Kobayashi ◽  
...  
Keyword(s):  
Weight Loss ◽  
Body Weight ◽  
Virus Infection ◽  
Influenza A ◽  
Body Weight Loss ◽  
Repeated Administration ◽  
Vehicle Group ◽  
Influenza A H1n1 ◽  
Immunosuppressed Mice ◽  
Viral Titers

ABSTRACTThe efficacy of intravenous peramivir against influenza A (H1N1) 2009 virus infection was evaluated in mice in which the immune system was suppressed by cyclophosphamide (CP) treatment. The mortality rate of the vehicle control group was 100%, and the mice lost 20% of their body weight on average by day 13 postinfection (p.i.). Repeated administration of peramivir (40 mg/kg of body weight once a day, given intravenously for 20 days), starting at 1 h p.i., significantly reduced mortality, body weight loss, viral titers, and cytokine production in infected mice compared with results for administration of vehicle (P< 0.01). In addition, repeated administration of peramivir, starting at 24 h, 48 h, or 72 h p.i., also resulted in increases in survival rates and reduction of viral titers in the lungs (P< 0.01). The mean days to death (MDD) of the vehicle group was 14.5 days, while in the groups treated with peramivir starting at 24 h, 48 h, and 72 h p.i., the MDDs were >23.0, 20.9, and 21.8 days, respectively. In comparison, repeated administration of oseltamivir phosphate (5 mg/kg twice a day, given orally for 20 days), starting at 24 h, 48 h, and 72 h p.i., also significantly prevented body weight loss, whereas no significant differences in mortality rates and viral titers in the lungs were observed compared with results for the vehicle group. These data indicated that repeated administration of peramivir was effective in promoting the survival and reducing virus replication in immunosuppressed mice infected with influenza A (H1N1) 2009 virus.

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