• Journal of Microbiology and Biotechnology
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• 제20권1호
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• pp.63-70
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• 2010

Novel influenza A (H1N1) is a newly emerged flu virus that was first detected in April 2009. Unlike the avian influenza (H5N1), this virus has been known to be able to spread from human to human directly. Although it is uncertain how severe this novel H1N1 virus will be in terms of human illness, the illness may be more widespread because most people will not have immunity to it. In this study, we compared the codon usage bias between the novel H1N1 influenza A viruses and other viruses such as H1N1 and H5N1 subtypes to investigate the genomic patterns of novel influenza A (H1N1). Totally, 1,675 nucleotide sequences of the hemagglutinin (HA) and neuraminidase (NA) genes of influenza A virus, including H1N1 and H5N1 subtypes occurring from 2004 to 2009, were used. As a result, we found that the novel H1N1 influenza A viruses showed the most close correlations with the swine-origin H1N1 subtypes than other H1N1 viruses, in the result from not only the analysis of nucleotide compositions, but also the phylogenetic analysis. Although the genetic sequences of novel H1N1 subtypes were not exactly the same as the other H1N1 subtypes, the HA and NA genes of novel H1N1s showed very similar codon usage patterns with other H1N1 subtypes, especially with the swine-origin H1N1 influenza A viruses. Our findings strongly suggested that those novel H1N1 viruses seemed to be originated from the swine-host H1N1 viruses in terms of the codon usage patterns.

• Journal of Microbiology and Biotechnology
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• 제28권5호
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• pp.809-815
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• 2018

Influenza, which is a highly contagious disease caused by the influenza A virus, continues to be a major health concern worldwide. Although the accurate and early diagnosis of influenza virus infection is important for controlling the spread of this disease and rapidly initiating antiviral therapy, the current influenza diagnostic kits are limited by their low sensitivity. In this study, we developed several new influenza nucleoprotein (NP)-specific monoclonal antibodies (mAbs) and compared their sensitivity and specificity of those with commercially available anti-NP mAbs. Three mAbs, designated M24.11, M34.3, and M34.33, exhibited higher reactivities to recombinant NPs and A/Puerto Rico/8/1934 (H1N1) viral lysates compared with the commercial mAbs, as assessed using enzyme-linked immunosorbent assays. M34.3 and M34.33 showed higher reactivities with A/California/04/09 (pandemic H1N1) and A/Philippines/2/82 (H3N2) viral lysates than the commercial mAbs. In contrast, M24.11 had marked reactivity with H3N2 but not with pandemic H1N1. Immunofluorescent confocal microscopy showed that the three mAbs effectively detected the presence of influenza virus in lung tissues of mice infected with A/Puerto Rico/8/1934. These results indicate that the newly developed M34.3 and M34.33 mAbs could be useful for the development of influenza diagnostics.

• Clinical and Experimental Pediatrics
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• 제46권10호
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• pp.1024-1028
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• 2003

저자들은 인플루엔자 유행시기에, 생후 3년 1개월 환아에서 갑작스런 고열을 동반한 경련 발작과 의식소실을 주소로, 6일간 입원 치료에도 불구하고 급격한 급성 뇌증의 악화와 간기능수치 증가 및 신장기능 부전, 범발성 혈관내 응고증으로 사망한 남아에서 인플루엔자 바이러스 항체 검사상 A/H1N1에 대한 HI titer가 초 회 항체 역가의 4배 이상 증가됨을 관찰하여 국내에는 보고된 예가 없는 급성 인플루엔자 뇌증으로 진단한 1례를 경험하였기에 문헌 고찰과 함께 보고하는 바이다.

• Tuberculosis and Respiratory Diseases
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• 제79권2호
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• pp.70-73
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• 2016

In late March of 2009, an outbreak of influenza in Mexico, was eventually identified as H1N1 influenza A. In June 2009, the World Health Organization raised a pandemic alert to the highest level. More than 214 countries have reported confirmed cases of pandemic H1N1 influenza A. In Korea, the first case of pandemic influenza A/H1N1 infection was reported on May 2, 2009. Between May 2009 and August 2010, 750,000 cases of pandemic influenza A/H1N1 were confirmed by laboratory test. The H1N1-related death toll was estimated to reach 252 individuals. Almost one billion cases of influenza occurs globally every year, resulting in 300,000 to 500,000 deaths. Influenza vaccination induces virus-neutralizing antibodies, mainly against hemagglutinin, which provide protection from invading virus. New quadrivalent inactivated influenza vaccine generates similar immune responses against the three influenza strains contained in two types of trivalent vaccines and superior responses against the additional B strain.

• Journal of Microbiology
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• 제43권4호
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• pp.366-369
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• 2005

Avian influenza viruses playa crucial role i,n the creation of human pandemic viruses. In this study, we have demonstrated that both human and avian influenza receptors exist in cells in the respiratory and intestinal tracts of chickens. We have also determined that primarily cultured chicken lung cells can support the replication of both avian and human influenza viruses.

• Journal of Veterinary Science
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• 제19권6호
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• pp.750-758
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• 2018

Influenza virus infection is a zoonosis that has great socioeconomic effects worldwide. Influenza infection induces respiratory symptoms, while the influenza virus can infect brain and leave central nervous system sequelae. As children are more vulnerable to infection, they are at risk of long-term neurological effects once their brains are infected. We previously demonstrated that functional changes in hippocampal neurons were observed in mice recovered from neonatal influenza infection. In this study, we investigated changes in myelination properties that could affect neural dysfunction. Mice were infected with the influenza virus on postnatal day 5. Tissues were harvested from recovered mice 21-days post-infection. The expression levels for myelin basic protein (MBP) were determined, and immunohistochemical staining and transmission electron microscopy were performed. Real-time polymerase chain reaction and Western blot analyses showed that mRNA and protein expressions increased in the hippocampus and cerebellum of recovered mice. Increased MBP-staining signal was observed in the recovered mouse brain. By calculating the relative thickness of myelin sheath in relation to nerve fiber diameter (G-ratio) from electron photomicrographs, an increased G-ratio was observed in both the hippocampus and cerebellum of recovered mice. Influenza infection in oligodendrocyte-enriched primary brain cell cultures showed that proinflammatory cytokines may induce MBP upregulation. These results suggested that increased MBP expression could be a compensatory change related to hypomyelination, which may underlie neural dysfunction in recovered mice. In summary, the present results demonstrate that influenza infection during the neonatal period affects myelination and further induces functional changes in influenza-recovered mouse brain.

• IMMUNE NETWORK
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• 제20권4호
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• pp.31.1-31.14
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• 2020

The effectiveness of current influenza vaccines is considered suboptimal, and 1 way to improve the vaccines is using adjuvants. However, the current pool of adjuvants used in influenza vaccination is limited due to safety concerns. Aloe vera, or aloe, has been shown to have immunomodulatory functions and to be safe for oral intake. In this study, we explored the potential of orally administered processed Aloe vera gel (PAG) as an adjuvant for influenza vaccines in C57BL/6 mice. We first evaluated its adjuvanticity with a split-type pandemic H1N1 (pH1N1) Ag by subjecting the mice to lethal homologous influenza challenge. Oral PAG administration with the pH1N1 Ag increased survival rates in mice to levels similar to those of alum and MF59, which are currently used as adjuvants in influenza vaccine formulations. Similarly, oral PAG administration improved the survival of mice immunized with a commercial trivalent influenza vaccine against lethal homologous and heterologous virus challenge. PAG also increased hemagglutination inhibition and virus neutralization Ab titers against homologous and heterologous influenza strains following immunization with the split-type pH1N1 Ag or the commercial trivalent vaccine. Therefore, this study demonstrates that PAG may potentially be used as an adjuvant for influenza vaccines.

• 한국동물위생학회지
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• 제40권3호
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• pp.187-192
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• 2017

In this report, fifteen monoclonal antibodies (MAbs) against an avian influenza virus (H9N2 subtype) were newly produced and characterized. These MAbs proved to react to the epitopes of nucleocapsid protein (NP), hemagglutinin (HA), neuraminidase (NA) and non-structural protein 1 (NS1) of Korean H9N2 strain, respectively. Two HA-specific MAbs showed the ability to inhibit the hemagglutination activity of H9N2 subtype avian influenza virus when tested by hemagglutination inhibition (HI) assay. All MAbs did not cross-react with other avian-origin viruses (Newcastle disease virus, infectious bursal disease virus, infectious bronchitis virus and avian rotavirus) by immunofluorescence test or enzyme-linked immunosorbent assay. The MAbs produced in this study could be useful as the materials for diagnostics and therapeutics against Korean-lineage H9N2 virus infections.

• Journal of Microbiology and Biotechnology
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• 제22권5호
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• pp.699-707
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• 2012

Since the 2009 pandemic human H1N1 influenza A virus emerged in April 2009, novel reassortant strains have been identified throughout the world. This paper describes the detection and isolation of reassortant strains associated with human pandemic influenza H1N1 and swine influenza H1N2 (SIV) viruses in swine populations in South Korea. Two influenza H1N2 reassortants were detected, and subtyped by PCR. The strains were isolated using Madin-Darby canine kidney (MDCK) cells, and genetically characterized by phylogenetic analysis for genetic diversity. They consisted of human, avian, and swine virus genes that were originated from the 2009 pandemic H1N1 virus and a neuraminidase (NA) gene from H1N2 SIV previously isolated in North America. This identification of reassortment events in swine farms raises concern that reassortant strains may continuously circulate within swine populations, calling for the further study and surveillance of pandemic H1N1 among swine.

• Clinical and Experimental Pediatrics
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• 제56권4호
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• pp.165-175
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• 2013

Purpose: There was a global increase in the prevalence of oseltamivir-resistant influenza viruses during the 2007-2008 influenza season. This study was conducted to investigate the occurrence and characteristics of oseltamivir-resistant influenza viruses during the 2007-2008 and 2008-2009 influenza seasons among patients who were treated with oseltamivir (group A) and those that did not receive oseltamivir (group B). Methods: A prospective study was conducted on 321 pediatric patients who were hospitalized because of influenza during the 2007-2008 and 2008-2009 influenza seasons. Drug resistance tests were conducted on influenza viruses isolated from 91 patients. Results: There was no significant difference between the clinical characteristics of groups A and B during both seasons. Influenza A/H1N1, isolated from both groups A and B during the 2007-2008 and 2008-2009 periods, was not resistant to zanamivir. However, phenotypic analysis of the virus revealed a high oseltamivir $IC_{50}$ range and that H275Y substitution of the neuraminidase (NA) gene and partial variation of the hemagglutinin (HA) gene did not affect its antigenicity to the HA vaccine even though group A had a shorter hospitalization duration and fewer lower respiratory tract complications than group B. In addition, there was no significant difference in the clinical manifestations between oseltamivir-susceptible and oseltamivir-resistant strains of influenza A/H1N1. Conclusion: Establishment of guidelines to efficiently treat influenza with oseltamivir, a commonly used drug for treating influenza in Korean pediatric patients, and a treatment strategy with a new therapeutic agent is required.