Amaryllidaceae alkaloids inhibit nuclear‐to‐cytoplasmic export of ribonucleoprotein (RNP) complex of highly pathogenic avian influenza virus H5N1

Please cite this paper as: He et al. (2013) Amaryllidaceae alkaloids inhibit nuclear‐to‐cytoplasmic export of ribonucleoprotein (RNP) complex of highly pathogenic avian influenza virus H5N1. Influenza and Other Respiratory Viruses 7(6), 922–931. Background  Few drugs are currently licensed to treat influenza A infection, and new therapies are needed, especially for highly pathogenic strains. Traditional medicinal plants, such as Lycoris radiata, are a potential source of new antiviral agents. Objective  To test 15 Amaryllidaceae alkaloids isolated from the bulbs of L. radiata in vitro for antiviral activities against influenza virus type A, A/Chicken/GuangDong/178/2004 (H5N1, 178). Methods  Antiviral activities of the compounds were tested in time‐of‐addition assays, hemagglutination inhibition (HI) assays, neuraminidase (NA) activity assays, and viral entry inhibition assays using H5N1‐HIV pseudoviruses. Effects of the compounds on localization and activity of the viral ribonucleoprotein (RNP) were determined by immunofluorescence and an RNP minigenome assay, respectively. Results  Among the alkaloids, lycorine (AA1), hippeastrine (AA2), hemanthamine (AA3) and 11‐hydroxy vittatine (AA4) exhibited antiviral activities, with EC₉₀ values of 0·52, 82·07, 4·15, and 13·45 μm, respectively. These compounds did not affect the function of the outer membrane proteins or the viral entry process and viral RNP activity. As AA1 and AA3 exhibited stronger antiviral activities, they were further analyzed. Intracellular nucleoprotein (NP) localization showed that AA1 and AA3 inhibited the RNP complex in the nucleus at an early stage of a single‐round and multi‐round of replication. Conclusion  Four Amaryllidaceae alkaloids were first determined that could exert anti‐influenza activities after virus entry into cells. Furthermore, AA1 and AA3 could inhibit nuclear‐to‐cytoplasmic export of the RNP complex of virus replication. Thus, these compounds may be developed further as anti‐influenza drug candidates.     

Prior infection of pigs with a recent human H3N2 influenza virus confers minimal cross‐protection against a European swine H3N2 virus

Background

H3N2 influenza viruses circulating in humans and European pigs originate from the pandemic A/Hong Kong/68 virus. Because of slower antigenic drift in swine, the antigenic divergence between swine and human viruses has been increasing. It remains unknown to what extent this results in a reduced cross‐protection between recent human and swine H3N2 influenza viruses.

Objectives

We examined whether prior infection of pigs with an old [A/Victoria/3/75 (A/Vic/75)] or a more recent [A/Wisconsin/67/05 (A/Wis/05)] human H3N2 virus protected against a European swine H3N2 virus [sw/Gent/172/08 (sw/Gent/08)]. Genetic and antigenic relationships between sw/Gent/08 and a selection of human H3N2 viruses were also assessed.

Results

After challenge with sw/Gent/08, all challenge controls had high virus titers in the entire respiratory tract at 3 days post‐challenge and nasal virus excretion for 5–6 days. Prior infection with sw/Gent/08 or A/Vic/75 offered complete virological protection against challenge. Pigs previously inoculated with A/Wis/05 showed similar virus titers in the respiratory tract as challenge controls, but the mean duration of nasal shedding was 1·3 days shorter. Unlike sw/Gent/08‐ and A/Vic/75‐inoculated pigs, A/Wis/05‐inoculated pigs lacked cross‐reactive neutralizing antibodies against sw/Gent/08 before challenge, but they showed a more rapid antibody response to sw/Gent/08 than challenge controls after challenge. Cross‐protection and serological responses correlated with genetic and antigenic differences.

Conclusions

Infection immunity to a recent human H3N2 virus confers minimal cross‐protection against a European swine H3N2 virus. We discuss our findings with regard to the recent zoonotic infections of humans in the United States with a swine‐origin H3N2 variant virus.     

A study of Chitosan and c‐di‐GMP as mucosal adjuvants for intranasal influenza H5N1 vaccine

Please cite this paper as: Svindland et al. (2012) A study of Chitosan and c‐di‐GMP as mucosal adjuvants for intranasal influenza H5N1 vaccine. Influenza and Other Respiratory Viruses 10.1111/irv.12056000(000), 000–000. Background  Highly pathogenic avian influenza A/H5N1 virus remains a potential pandemic threat, and it is essential to continue vaccine development against this subtype. A local mucosal immune response in the upper respiratory tract may stop influenza transmission. It is therefore important to develop effective intranasal pandemic influenza vaccines that induce mucosal immunity at the site of viral entry. Objectives  We evaluated the humoral and cellular immune responses of two promising mucosal adjuvants (Chitosan and c‐di‐GMP) for intranasal influenza H5N1 vaccine in a murine model. Furthermore, we evaluated the concept of co‐adjuvanting an experimental adjuvant (c‐di‐GMP) with chitosan. Methods  BALB/c mice were intranasally immunised with two doses of subunit NIBRG‐14 (H5N1) vaccine (7·5, 1·5 or 0·3 μg haemagglutinin (HA) adjuvanted with chitosan (CSN), c‐di‐GMP or both adjuvants. Results  All adjuvant formulations improved the serum and local antibody responses, with the highest responses observed in the 7·5 μg HA CSN and c‐di‐GMP‐adjuvanted groups. The c‐di‐GMP provided dose sparing with protective single radial haemolysis (SRH), and haemagglutination inhibition (HI) antibody responses found in the 0·3 μg HA group. CSN elicited a Th2 response, whereas c‐di‐GMP induced higher frequencies of virus‐specific CD4⁺ T cells producing one or more Th1 cytokines (IFN‐γ⁺, IL‐2⁺, TNF‐α⁺). A combination of the two adjuvants demonstrated effectiveness at 7·5 μg HA and triggered a more balanced Th cytokine profile. Conclusion  These data show that combining adjuvants can modulate the Th response and in combination with ongoing studies of adjuvanted intranasal vaccines will dictate the way forward for optimal mucosal influenza vaccines.     

The immunogenicity of seasonal and pandemic influenza vaccination in autoimmune inflammatory rheumatic patients—a 6-month follow-up prospective study

Clinical Rheumatology - Influenza may cause severe complications in patients with autoimmune inflammatory rheumatic disease (AIRD), to whom vaccinations are especially recommended. However, AIRD...     

Emergence of H3N2pM‐like and novel reassortant H3N1 swine viruses possessing segments derived from the A (H1N1)pdm09 influenza virus,Korea

Background

Human‐to‐swine transmission of the pandemic H1N1 2009 [A(H1N1)pdm09] virus in pig populations resulted in reassortment events with endemic swine influenza viruses worldwide.

Objective

We investigated whether A(H1N1)pdm09‐derived reassortant viruses are present in South Korea and sought to determine the pathogenic potential of the novel swine viruses.

Methods

Pig lung tissues were collected from commercially slaughtered pigs. Isolated swine influenza viruses were genetically analyzed and characterized in vitro and in vivo.

Results

We identified reassortant H3N2 (H3N2pM‐like) and H3N1 swine viruses containing A(H1N1)pdm09‐like segments in Korean pigs that are genetically closely related to strains recently detected in pigs and humans in North America. Although the H3N2pM‐like and novel H3N1 reassortants demonstrated efficient replication in mice and ferrets, all the H3N1 strains exhibited growth advantage over the representative H3N2pM‐like virus in human airway cells. Interestingly, A/swine/Korea/CY02‐07/2012(H3N1) and A/swine/Korea/CY03‐13/2012(H3N1) reassortants were more readily transmitted to respiratory‐droplet‐contact ferrets compared with the H3N2pM‐like (A/swine/Korea/CY02‐10/2012) isolate. Furthermore, serologic evaluation showed poor antigenicity to contemporary reference human seasonal H3N2 vaccine strains.

Conclusions

We report here for the first time the isolation of H3N2pM‐like viruses outside North America and of novel reassortant swine H3N1 viruses with A(H1N1)pdm09‐derived genes. Apart from further complicating the genetic diversity of influenza A viruses circulating in domestic pigs, our data also indicate that these strains could potentially pose threat to public health asserting the need for continuous virus monitoring in these ecologically important hosts.     

Evaluation of a commercial enzyme‐linked immunosorbent assay for detection of antibodies against the H5 subtype of Influenza A virus in waterfowl

The ID Screen Influenza H5 Antibody Competition enzyme‐linked immunosorbent assay was tested for the detection of antibodies to the H5 subtype of influenza A (IA) virus in waterfowl. Assays were conducted with sera obtained from Mallards (Anas platyrhynchos) and Pekin Ducks (Anas platyrhynchos domestica), experimentally infected with eight low pathogenic (LP) and nine highly pathogenic (HP) H5N1 IA viral strains. Three incubation periods (1, 4 and 18 hours) and two dilutions (1:2 and 1:5) were tested. All serum samples from LP H5‐infected birds tested positive; however, improved detection rates were observed for viruses belonging to the HP H5N1 clade 2.2.1 as compared with those belonging to clade 2.1.3.     

Robust immunogenicity to the H3N2 component of influenza A vaccine in primary Sjögren syndrome

Clinical Rheumatology - Influenza A (H3N2) virus is the major cause of morbidity/mortality due to seasonal influenza over 50 years. Data about the safety/immunogenicity of influenza...     

Experimental transmission of avian-like swine H1N1 influenza virus between immunologically naïve and vaccinated pigs

Please cite this paper as: Lloyd et al. (2011) Experimental transmission of avian‐like swine H1N1 influenza virus between immunologically naïve and vaccinated pigs. Influenza and Other Respiratory Viruses 5(5), 357–364. Background Infection of pigs with swine influenza has been studied experimentally and in the field; however, little information is available on the natural transmission of this virus in pigs. Two studies in an experimental transmission model are presented here, one in immunologically naïve and one in a combination of vaccinated and naïve pigs. Objectives To investigate the transmission of a recent ‘avian‐like’ swine H1N1 influenza virus in naive piglets, to assess the antibody response to a commercially available vaccine and to determine the efficiency of transmission in pigs after vaccination. Methods Transmission chains were initiated by intranasal challenge of two immunologically naïve pigs. Animals were monitored daily for clinical signs and virus shedding. Pairs of pigs were sequentially co‐housed, and once virus was detected in recipients, prior donors were removed. In the vaccination study, piglets were vaccinated and circulating antibody levels were monitored by haemagglutination inhibition assay. To study transmission in vaccinates, a pair of infected immunologically naïve animals was co‐housed with vaccinated recipient pigs and further pairs of vaccinates were added sequentially as above. The chain was completed by the addition of naive pigs. Results and conclusions Transmission of the H1N1 virus was achieved through a chain of six pairs of naïve piglets and through four pairs of vaccinated animals. Transmission occurred with minimal clinical signs and, in vaccinates, at antibody levels higher than previously reported to protect against infection.     

Risk factors for infection with influenza A(H3N2) virus on a US university campus,October–November 2021

Background

Knowledge of the specific dynamics of influenza introduction and spread in university settings is limited.

Methods

Persons with acute respiratory illness symptoms received influenza testing by molecular assay during October 6–November 23, 2022. Viral sequencing and phylogenetic analysis were conducted on nasal swab samples from case-patients. Case–control analysis of a voluntary survey of persons tested was used to identify factors associated with influenza; logistic regression was conducted to calculate odds ratios and 95% CIs. A subset of case-patients tested during the first month of the outbreak was interviewed to identify sources of introduction and early spread.

Results

Among 3268 persons tested, 788 (24.1%) tested positive for influenza; 744 (22.8%) were included in the survey analysis. All 380 sequenced specimens were influenza A (H3N2) virus clade 3C.2a1b.2a.2, suggesting rapid transmission. Influenza (OR [95% CI]) was associated with indoor congregate dining (1.43 [1.002–2.03]), attending large gatherings indoors (1.83 [1.26–2.66]) or outdoors (2.33 [1.64–3.31]), and varied by residence type (apartment with ≥1 roommate: 2.93 [1.21–7.11], residence hall room alone: 4.18 [1.31–13.31], or with roommate: 6.09 [2.46–15.06], or fraternity/sorority house: 15.13 [4.30–53.21], all compared with single-dwelling apartment). Odds of influenza were lower among persons who left campus for ≥1 day during the week before their influenza test (0.49 [0.32–0.75]). Almost all early cases reported attending large events.

Conclusions

Congregate living and activity settings on university campuses can lead to rapid spread of influenza following introduction. Isolating following a positive influenza test or administering antiviral medications to exposed persons may help mitigate outbreaks.     

Phenotypic characteristics of novel swine‐origin influenza A/California/07/2009 (H1N1) virus

Background  The 2009 novel A(H1N1) virus appears to be of swine origin. This strain causing the current outbreaks is a new virus that has not been seen previously either in humans or animals. We have previously reported that viruses causing pandemics or large outbreaks were able to grow at a temperature above the normal physiological range (temperature resistance, non‐ts phenotype), were found to be inhibitor resistant and restricted in replication at suboptimal temperature (sensitivity to grow at low temperature, non‐ca phenotype). In this study, we performed phenotypic analysis of novel A(H1N1) virus to evaluate its pandemic potential and its suitability for use in developing a live attenuated influenza vaccine. Objectives  The goal of this study is to identify phenotypic properties of novel A(H1N1) influenza virus. Methods  A/California/07/2009 (H1N1) swine‐origin influenza virus was studied in comparison with some influenza A viruses isolated in different years with respect to their ability to grow at non‐permissive temperatures. We also analyzed its sensitivity to gamma‐inhibitors of animal sera and its ability to agglutinate chicken, human and guinea pig erythrocytes. Results  Swine‐origin A/California/07/2009 (H1N1) virus was found to be non‐ts and inhibitor resistant and was not able to grow at 25°C (non‐ca). We did not find any difference in the ability of the hemagglutinin of A/California/07/2009 (H1N1) virus to bind to erythrocytes of different origin. Conclusion  The novel swine‐origin A(H1N1) virus displays a phenotype typical of the past pandemic and epidemic viruses. This finding suggests that this virus might be a good wild type parental prototype for live vaccine for potential use for controlling pandemic influenza.     

High coverage and safety of influenza A (H1N1) 2009 monovalent vaccination among health care personnel in Thailand

We aimed to report the coverage and safety of the influenza A (H1N1) 2009 monovalent vaccination (Panenza; Sanofi Pasteur, Val de Reuil Cedex, France) among health care personnel (HCP) in a university hospital setting in Thailand. The hospital set up a system to vaccinate HCP and did surveillance of the adverse effects (AEs). During a 4-week period, 6,210 (78.7%) HCP were vaccinated. There were 82 reported nonserious AEs among 32 HCP. The most common AE was fatigue/uncomfortable feeling (24%).     

Intranasal influenza vaccination using a new synthetic mucosal adjuvant SF‐10: induction of potent local and systemic immunity with balanced Th1 and Th2 responses

Background

We found previously that bovine pulmonary Surfacten^® used in newborns with acute respiratory distress syndrome is a safe and efficacious antigen vehicle for intranasal vaccination.

Objectives

The objective of this study was to industrially produce a synthetic adjuvant mimicking Surfacten^® for clinical use without risk of bovine spongiform encephalopathy.

Methods

We selected three Surfacten lipids and surfactant protein (SP)‐C as essential constituents for adjuvanticity. For replacement of the hydrophobic SP‐C, we synthesized SP‐related peptides and analyzed their adjuvanticity. We evaluated lyophilization to replace sonication for the binding of influenza virus hemagglutinin (HA) to the synthetic adjuvant. We also added a carboxy vinyl polymer (CVP) to the synthetic adjuvant and named the mixture as SF‐10 adjuvant. HA combined with SF‐10 was administered intranasally to mice, and induction of nasal‐wash HA‐specific secretory IgA (s‐IgA) and serum IgG with Th1‐/Th2‐type cytokine responses in nasal cavity and virus challenge test were assessed.

Results and Conclusions

Intranasal immunization with HA–SF–10 induced significantly higher levels of anti‐HA‐specific nasal‐wash s‐IgA and serum IgG than those induced by HA‐poly(I:C), a reported potent mucosal vaccine, and provided highly efficient protection against lethal doses of virus challenge in mice. Anti‐HA‐specific serum IgG levels induced by HA–SF–10 were almost equivalent to those induced by subcutaneous immunization of HA twice. Intranasal administration of HA–SF–10 induced balanced anti‐HA‐specific IgG1 and IgG2a in sera and IFN‐γ‐ and IL‐4‐producing lymphocytes in nasal cavity without any induction of anti‐HA IgE. The results suggest that HA–SF–10 is a promising nasal influenza vaccine and that SF‐10 can be supplied in large quantities commercially.     

Effect of hepatitis C virus nonstructural protein 5A and its domains Ⅱ on hepatocyte gluconeogenesis in mice

正Objective To investigate the role of hepatitis C virus nonstructural protein 5A(NS5A)and its domainsⅠ,Ⅱ,andⅢin regulating gluconeogenesis in mice and the underlying mechanism.Methods A total of 60 male C57BL/6J mice were randomly divided into six groups.Recombinant lentiviral particles with specific expression