RESUMO
We isolated highly pathogenic avian influenza (HPAI) H5N5 and H5N1 viruses from crows in Hokkaido, Japan, during winter 2023-24. They shared genetic similarity with HPAI H5N5 viruses from northern Europe but differed from those in Asia. Continuous monitoring and rapid information sharing between countries are needed to prevent HPAI virus transmission.
RESUMO
Ocular herpes, caused by herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) infections, remains an important corneal disease, which may result in loss of vision. Because the frequency of acyclovir resistance in HSV has increased, novel antiviral agents are needed for therapeutic approaches to ocular herpes. Several studies have demonstrated that fusion proteins containing entire ectodomain of HSV glycoprotein D receptors, including herpesvirus entry mediator A (HVEM), nectin-1 and nectin-2, and the Fc portion of human IgG (HVEMIg, nectin-1Ig, and nectin-2Ig, respectively), can exert antiviral effects in vitro and in vivo. Here, to evaluate the antiviral potential of HVEMIg, nectin-1Ig, and nectin-2Ig against ocular infections with HSV, transgenic mice expressing these fusion proteins were ocularly inoculated with HSV-1 and HSV-2. Transgenic mouse lines expressing HVEMIg and nectin-1Ig showed marked resistance to ocular herpes; on the other hand, mouse lines expressing nectin-2Ig did not. Furthermore, to investigate the therapeutic effects of nectin-1Ig, which can neutralize HSVs in vitro against ocular disease, transgenic mouse serum containing nectin-1Ig was dropped into the eyes of wild-type mice after HSV infection. Reduction of severe symptoms could be observed in mice treated with nectin-1Ig serum. These results warrant further study of soluble HVEM and nectin-1 products as preventive and therapeutic agents against ocular herpes caused by HSV-1 and HSV-2 infections, especially nectin-1Ig as a new eye drop.
Assuntos
Antivirais/farmacologia , Ceratite Herpética/prevenção & controle , Receptores Virais/metabolismo , Animais , Modelos Animais de Doenças , Resistência à Doença , Herpesvirus Humano 1/efeitos dos fármacos , Herpesvirus Humano 2/efeitos dos fármacos , Humanos , Ceratite Herpética/patologia , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteínas Recombinantes de Fusão/farmacologiaRESUMO
Herpesvirus entry mediator A (HVEM), nectin-1 and nectin-2 are cellular receptors of glycoprotein D (gD) of herpes simplex virus type-2 (HSV-2). It has been shown that soluble forms of HSV gD receptors have the antiviral potential in cultured cells and transgenic mice. Here, to compare antiviral potential of soluble forms of HVEM, nectin-1 and nectin-2 against HSV-2 infections in vivo, transgenic mice expressing fusion proteins consisting of the entire ectodomain of HVEM, nectin-1 or nectin-2 and the Fc portion of human IgG (HVEMIg, nectin-1Ig and nectin-2Ig, respectively) were intraperitoneally infected with HSV-2. In the infection with 3 MLD50 (50â% mouse lethal dose), effective resistance was not observed in transgenic mice expressing nectin-2Ig. In a transgenic mouse line with high expression of nectin-1Ig, significant protection from the infection with 30 and 300 MLD50 was observed (survival rate of 100 and 71â%, respectively). On the other hand, transgenic mice expressing HVEMIg showed a complete resistance to the lethal infection even with 300 MLD50 (survival rate of 100â%). These results demonstrated that HVEMIg could exert effective antiviral activities against HSV-2 infections in vivo as compared with other soluble forms of HSV gD receptors.
Assuntos
Moléculas de Adesão Celular/imunologia , Herpes Simples/imunologia , Herpesvirus Humano 2/metabolismo , Membro 14 de Receptores do Fator de Necrose Tumoral/imunologia , Receptores Virais/imunologia , Proteínas do Envelope Viral/metabolismo , Animais , Moléculas de Adesão Celular/genética , Moléculas de Adesão Celular/metabolismo , Herpes Simples/genética , Herpes Simples/metabolismo , Herpes Simples/virologia , Herpesvirus Humano 2/genética , Herpesvirus Humano 2/imunologia , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Nectinas , Membro 14 de Receptores do Fator de Necrose Tumoral/genética , Membro 14 de Receptores do Fator de Necrose Tumoral/metabolismo , Receptores Virais/genética , Receptores Virais/metabolismo , Proteínas do Envelope Viral/genéticaRESUMO
Highly pathogenic avian influenza viruses (HPAIVs) A(H5N6) were concurrently introduced into several distant regions of Japan in November 2016. These viruses were classified into the genetic clade 2.3.4.4c and were genetically closely related to H5N6 HPAIVs recently isolated in South Korea and China. In addition, these HPAIVs showed further antigenic drift.
Assuntos
Vírus da Influenza A/genética , Vírus da Influenza A/patogenicidade , Influenza Aviária/virologia , Animais , Aves , Influenza Aviária/epidemiologia , Influenza Aviária/mortalidade , Japão , FilogeniaRESUMO
Since 2014, clade 2.3.4.4 H5 subtype highly pathogenic avian influenza viruses (HPAIVs) have been distributed worldwide. These viruses, which were reported to be highly virulent in chickens by intravenous inoculation, have a consensus HPAI motif PLRERRRKR at the HA cleavage site. However, two-clade 2.3.4.4 H5N8 viruses which we isolated from wild migratory birds in late 2014 in Japan possessed atypical HA cleavage sequences. A swan isolate, Tottori/C6, had a novel polybasic cleavage sequence, PLGERRRKR, and another isolate from a dead mandarin duck, Gifu/01, had a heterogeneous mixture of consensus PLRERRRKR and variant PLRERRRRKR sequences. The polybasic HA cleavage site is the prime virulence determinant of AIVs. Therefore, in the present study, we examined the pathogenicity of these H5N8 isolates in chickens by intravenous inoculation. When 106 EID50 of these viruses were intravenously inoculated into chickens, the mean death time associated with Tottori/C6 was substantially longer (>6.1 days) than that associated with Gifu/01 (2.5 days). These viruses had comparable abilities to replicate in tissue culture cells in the presence and absence of exogenous trypsin, but the growth of Tottori/C6 was hampered. These results indicate that the novel cleavage motif of Tottori/C6 did not directly affect the infectivity of the virus, but Tottori/C6 caused attenuated pathogenicity in chickens because of hampered replication efficiency. It is important to test for the emergence of diversified HPAIVs, because introduction of HPAIVs with a lower virulence like Tottori/C6 might hinder early detection of affected birds in poultry farms.
Assuntos
Motivos de Aminoácidos , Glicoproteínas de Hemaglutininação de Vírus da Influenza/química , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Vírus da Influenza A Subtipo H5N8/genética , Influenza Aviária/virologia , Sequência de Aminoácidos , Animais , Animais Selvagens/virologia , Linhagem Celular , Galinhas , Glicoproteínas de Hemaglutininação de Vírus da Influenza/metabolismo , Vírus da Influenza A Subtipo H5N8/metabolismo , Vírus da Influenza A Subtipo H5N8/patogenicidade , Influenza Aviária/mortalidade , Filogenia , Doenças das Aves Domésticas/virologia , Análise de Sequência de DNA , Carga Viral , Virulência , Replicação ViralRESUMO
The nucleoprotein (NP) possesses regions that are highly conserved among influenza A viruses, and has therefore been one of the target viral proteins for development of a universal influenza vaccine. It has been expected that human or humanized antibodies will be made available for the prophylaxis, pre-emptive and acute treatment of viral infection. However, it is still unclear whether anti-NP human antibody can confer protection against influenza virus infection. In this study, we generated transgenic mice expressing anti-NP human mAbs derived from lymphocytes of a patient infected with H5N1 highly pathogenic avian influenza (HPAI) virus, and experimental infections were conducted to examine antiviral effects of the anti-NP antibodies against H5N1 HPAI viral infections with a high fatality rate in mammals. Transgenic mouse lines expressing the anti-NP human mAbs at more than 1 mg ml-1 showed marked resistance to H5N1 virus infections. In addition, resistance to infection with an H1N1 subtype that shows strong pathogenicity to mice was also confirmed. Although the anti-NP mAbs expressed in the transgenic mice did not neutralize the virus, the mAbs could bind to NP located on the surface of infected cells. These results suggested a possibility that the non-neutralizing anti-NP human mAbs could induce indirect antiviral effects, such as antibody-dependent cellular cytotoxicity or complement-dependent cytotoxicity. Taken together, these results demonstrated that anti-NP human mAbs play an important role in heterosubtypic protection against lethal influenza virus infections in vivo.
Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Antivirais/imunologia , Fatores Imunológicos/imunologia , Virus da Influenza A Subtipo H5N1/imunologia , Infecções por Orthomyxoviridae/imunologia , Proteínas de Ligação a RNA/imunologia , Proteínas do Core Viral/imunologia , Animais , Anticorpos Monoclonais/genética , Anticorpos Antivirais/genética , Modelos Animais de Doenças , Resistência à Doença , Humanos , Fatores Imunológicos/genética , Vírus da Influenza A Subtipo H1N1/imunologia , Camundongos , Camundongos Transgênicos , Proteínas do Nucleocapsídeo , Proteínas de Ligação a RNA/genética , Análise de Sobrevida , Proteínas do Core Viral/genéticaRESUMO
L-Kynurenine (L-KYN) is a central metabolite of tryptophan degradation through the kynurenine pathway (KP). The systemic administration of L-KYN sulfate (L-KYNs) leads to a rapid elevation of the neuroactive KP metabolite kynurenic acid (KYNA). An elevated level of KYNA may have multiple effects on the synaptic transmission, resulting in complex behavioral changes, such as hypoactivity or spatial working memory deficits. These results emerged from studies that focused on rats, after low-dose L-KYNs treatment. However, in several studies neuroprotection was achieved through the administration of high-dose L-KYNs. In the present study, our aim was to investigate whether the systemic administration of a high dose of L-KYNs (300 mg/bwkg; i.p.) would produce alterations in behavioral tasks (open field or object recognition) in C57Bl/6j mice. To evaluate the changes in neuronal activity after L-KYNs treatment, in a separate group of animals we estimated c-Fos expression levels in the corresponding subcortical brain areas. The L-KYNs treatment did not affect the general ambulatory activity of C57Bl/6j mice, whereas it altered their moving patterns, elevating the movement velocity and resting time. Additionally, it seemed to increase anxiety-like behavior, as peripheral zone preference of the open field arena emerged and the rearing activity was attenuated. The treatment also completely abolished the formation of object recognition memory and resulted in decreases in the number of c-Fos-immunopositive-cells in the dorsal part of the striatum and in the CA1 pyramidal cell layer of the hippocampus. We conclude that a single exposure to L-KYNs leads to behavioral disturbances, which might be related to the altered basal c-Fos protein expression in C57Bl/6j mice.
RESUMO
The polymerase basic 2 (PB2) protein is one of four proteins that make up the influenza A virus replication complex, which is responsible for viral gene transcription and replication. To assess the antiviral potential of an anti-PB2 monoclonal antibody that inhibits RNA transcription of influenza A viruses, Mardin-Darby canine kidney (MDCK) cells were transformed with two transgenes that encode the light and heavy chains of the monoclonal antibody. The transformed cell lines expressing this monoclonal antibody displayed resistance to several subtypes of influenza A virus infection. In the transformed cell lines infected with influenza A virus, the level of viral RNA transcription was decreased and the effective nuclear transportation of the PB2 protein was also inhibited. These results demonstrate that the anti-PB2 intrabody is potentially able to interfere with the effective nuclear transportation of PB2 protein, resulting in the observed resistance to influenza A virus infection in vitro.
Assuntos
Anticorpos Antivirais/genética , Vírus da Influenza A/genética , RNA Polimerase Dependente de RNA/genética , Proteínas Virais/genética , Animais , Anticorpos Antivirais/metabolismo , Antivirais/metabolismo , Linhagem Celular Transformada , Embrião de Galinha , Galinhas , Cães , Ensaio de Imunoadsorção Enzimática/veterinária , Técnica Direta de Fluorescência para Anticorpo/veterinária , Vírus da Influenza A/metabolismo , Células Madin Darby de Rim Canino , RNA Viral/genética , RNA Viral/metabolismo , RNA Polimerase Dependente de RNA/metabolismo , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Proteínas Virais/metabolismoRESUMO
Due to concerns that wild birds could possibly spread H5N1 viruses, surveillance was conducted to monitor the types of avian influenza viruses circulating among the wild birds migrating to or inhabiting in northern Vietnam from 2006 to 2009. An H5N2 virus isolated from a Eurasian woodcock had a close phylogenetic relationship to H5 viruses recently isolated in South Korea and Japan, suggesting that H5N2 has been shared between Vietnam, South Korea, and Japan. An H9N2 virus isolated from a Chinese Hwamei was closely related to two H9N2 viruses that were isolated from humans in Hong Kong in 2009, suggesting that an H9N2 strain relevant to the human isolates had been transmitted to and maintained among the wild bird population in Vietnam and South China. The results support the idea that wild bird species play a significant role in the spread and maintenance of avian influenza and that this also occurs in Vietnam.
Assuntos
Vírus da Influenza A/classificação , Influenza Aviária/epidemiologia , Influenza Aviária/virologia , Animais , Aves/virologia , Geografia , Glicoproteínas de Hemaglutininação de Vírus da Influenza/química , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , História do Século XXI , Humanos , Vírus da Influenza A Subtipo H5N2/genética , Vírus da Influenza A Subtipo H5N2/isolamento & purificação , Vírus da Influenza A Subtipo H9N2/genética , Vírus da Influenza A Subtipo H9N2/isolamento & purificação , Vírus da Influenza A/genética , Vírus da Influenza A/isolamento & purificação , Influenza Aviária/história , Neuraminidase/química , Neuraminidase/genética , Filogenia , VietnãRESUMO
In Vietnam, numerous surveillance programs are conducted to monitor the prevalence of avian influenza (AI) viruses. Three serological methods-the agar-gel immunodiffusion test, hemagglutination inhibition (HI) test, and enzyme-linked immunosorbent assay-are well established for detection of AI virus antibodies in poultry sera. Several recent reports have validated egg yolk as an alternative source for detection of AI virus antibodies. In this study, we investigated AI virus antibodies in ducks by HI testing using egg yolk. Ten duck eggs were collected every month from 10 randomly selected markets in Hanoi from April 2010 to March 2012. The HI test was performed using low pathogenic avian influenza (LPAI) viruses (H3, H4, H6, H7, H9, and H11 subtypes) and highly pathogenic avian influenza (HPAI) viruses (H5N1 clade 2.3.4 and 2.3.2.1) as antigens. HI testing for H3, H6, and H9 was 29% positive in November 2010, 50% positive in October and November 2010, and 12% positive in June 2011. These results indicated that several epidemics of LPAI viruses had occurred during the study period. In addition, antibodies against H7 were negative. The results of HI testing for H5N1 showed that the reactivity of the dominant HI antibody shifted from H5N1 clade 2.3.4 to clade 2.3.2.1. In conclusion, egg yolk is useful for long term monitoring of AI virus antibodies and the use of egg-based antibody detection may contribute to improvements in animal welfare.
Assuntos
Anticorpos Antivirais/imunologia , Patos/imunologia , Gema de Ovo/imunologia , Vírus da Influenza A/imunologia , Influenza Aviária/imunologia , Doenças das Aves Domésticas/imunologia , Animais , Patos/virologia , Gema de Ovo/virologia , Testes de Inibição da Hemaglutinação , Vírus da Influenza A/classificação , Vírus da Influenza A/genética , Influenza Aviária/epidemiologia , Influenza Aviária/virologia , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/virologia , Vigilância de Evento Sentinela/veterinária , Vietnã/epidemiologiaRESUMO
Repeated epizootics of highly pathogenic avian influenza (HPAI) virus subtype H5N1 were reported from 2003 to 2005 among poultry in Vietnam. More than 200 million birds were killed to control the spread of the disease. Human cases of H5N1 infection have been sporadically reported in an area where repeated H5N1 outbreaks among birds had occurred. Subtype H5N1 strains are established as endemic among poultry in Vietnam, however, insights into how avian influenza viruses including the H5N1 subtype are maintained in endemic areas is not clear. In order to determine the prevalence of different avian influenza viruses (AIVs), including H5N1 circulating among poultry in northern Vietnam, surveillance was conducted during the years 2006-2009. A subtype H5N1 strain was isolated from an apparently healthy duck reared on a farm in northern Vietnam in 2008 and was identified as an HPAI. Although only one H5N1 virus was isolated, it supports the view that healthy domestic ducks play a pivotal role in maintaining and transmitting H5N1 viruses which cause disease outbreaks in northern Vietnam. In addition, a total of 26 AIVs with low pathogenicity were isolated from poultry and phylogenetic analysis of all the eight gene segments revealed their diverse genetical backgrounds, implying that reassortments have occurred frequently among strains in northern Vietnam. It is, therefore, important to monitor the prevalence of influenza viruses among healthy poultry between epidemics in an area where AIVs are endemic.
Assuntos
Galinhas , Patos , Virus da Influenza A Subtipo H5N1/classificação , Influenza Aviária/epidemiologia , Doenças das Aves Domésticas/epidemiologia , Animais , Cloaca/virologia , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Virus da Influenza A Subtipo H5N1/química , Virus da Influenza A Subtipo H5N1/isolamento & purificação , Influenza Aviária/virologia , Camundongos , Epidemiologia Molecular , Dados de Sequência Molecular , Neuraminidase/genética , Filogenia , Reação em Cadeia da Polimerase/veterinária , Doenças das Aves Domésticas/virologia , Análise de Sequência de DNA/veterinária , Análise de Sequência de Proteína , Traqueia/virologia , Vietnã/epidemiologiaRESUMO
We report the genetic characterization of low pathogenic avian influenza (LPAI) viruses isolated from domestic ducks in northern Vietnam in 2009. In total, 22 influenza A viruses consisting of 21 H6N1 subtypes and one H9N2 subtype were isolated from 1488 ducks collected in February, March, and April 2009, accounting the overall virus isolation rate for 1.5%. No H5N1 strain was isolated in this study. Phylogenetic analysis indicated that all the eight genes of the H6N1 and H9N2 subtypes analyzed in this study were similar to those isolated in Korea, southeast China and northern Japan, and wild birds which migrate along the coastal East Asian Flyway are estimated to transmit these viruses. There was no evidence that the H6N1 and H9N2 subtypes share the gene segments with H5N1 subtypes. However, it is important to monitor the prevalence and genetical backgrounds of LPAI viruses among poultry in an area where several different influenza A subtypes are in circulation.
Assuntos
Patos/virologia , Vírus da Influenza A/classificação , Vírus da Influenza A/isolamento & purificação , Influenza Aviária/virologia , Animais , Análise por Conglomerados , Genótipo , Epidemiologia Molecular , Filogenia , RNA Viral/genética , Análise de Sequência de DNA , VietnãRESUMO
H5N1 highly pathogenic avian influenza (HPAI) viruses were isolated from dead wild waterfowl at Khunt, Erkhel, Doityn Tsagaan, Doroo, and Ganga Lakes in Mongolia in July 2005, May 2006, May 2009, July 2009, and May 2010, respectively. The isolates in 2005 and 2006 were classified into genetic clade 2.2, and those in 2009 and 2010 into clade 2.3.2. A/whooper swan/Mongolia/6/2009 (H5N1) experimentally infected ducks and replicated systemically with higher mortality than that of the isolates in 2005 and 2006. Intensive surveillance of avian influenza in migratory waterfowl flying from their nesting lakes in Siberia to Mongolia in every autumn indicate that HPAI viruses have not perpetuated at their nesting lakes until 2009. The present results demonstrate that wild waterfowl were sporadically infected with H5N1 HPAI viruses prevailing in domestic poultry in the southern Asia and died in Mongolia on the way back to their northern territory in spring.
Assuntos
Anseriformes/virologia , Virus da Influenza A Subtipo H5N1/isolamento & purificação , Influenza Aviária/virologia , Sequência de Aminoácidos , Migração Animal , Animais , Ásia , Galinhas , Patos , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Virus da Influenza A Subtipo H5N1/classificação , Virus da Influenza A Subtipo H5N1/genética , Virus da Influenza A Subtipo H5N1/patogenicidade , Influenza Aviária/transmissão , Dados de Sequência Molecular , Mongólia , Filogenia , Aves Domésticas/virologia , Especificidade da Espécie , Sus scrofa , Suínos , VirulênciaRESUMO
The recent epidemic caused by H5N1 highly pathogenic avian influenza (HPAI) viruses has spread over many parts of Asia, Europe and Africa. Wild birds, particularly waterfowl, are considered to play a role in viral dissemination. However, detailed information on whether wild terrestrial birds act as carriers is currently unavailable. To investigate the susceptibility of terrestrial birds to HPAI viruses, two species of wild bird (great reed warbler and pale thrush) that are common in East Asia were infected with H5N1 HPAI virus. The results showed that both species were highly susceptible to the virus. The great reed warbler showed fatal infection with 100% mortality, but the pale thrush survived for longer periods (>8 days) with viral shedding. These findings suggest that there is variation in clinical outcome after infection of wild terrestrial birds, and that some bird species could become subclinical excretors of the H5N1 virus.
Assuntos
Virus da Influenza A Subtipo H5N1/fisiologia , Influenza Aviária/virologia , Passeriformes/virologia , Animais , Suscetibilidade a Doenças/patologia , Suscetibilidade a Doenças/virologia , Vetores de Doenças , Ásia Oriental , Influenza Aviária/patologia , Eliminação de Partículas ViraisRESUMO
To estimate the prevalence of influenza A subtype H5N1 viruses among domestic ducks in the period between October and November 2006 when H5N1 outbreaks had been absent, 1106 healthy ducks raised in northern Vietnam were collected. Inoculation of all throat and cloacae samples into embryonated eggs resulted in the isolation of subtype H3N8 in 13 ducks, but not H5N1 viruses. Serological analyses demonstrated that five ducks (0.45%) solely developed H5N1 subtype-specific hemagglutinin-inhibiting and neuraminidase-inhibiting antibodies together with anti-non-structural protein 1 antibodies. The results suggested that the ducks were naturally infected with H5N1 viruses when obvious H5N1 outbreaks were absent.
Assuntos
Virus da Influenza A Subtipo H5N1/fisiologia , Influenza Aviária/transmissão , Influenza Aviária/virologia , Animais , Patos , Virus da Influenza A Subtipo H5N1/metabolismo , Vietnã , Proteínas Virais/metabolismoRESUMO
OBJECTIVES: We evaluated the effectiveness and safety of a disinfectant newly developed by our laboratories for use against influenza viruses. METHODS: The effectiveness of our new disinfectant against avian, swine and human influenza viruses was tested in ovo. The acute toxicity of this disinfectant to two different cultured cell lines was investigated. RESULTS: This new disinfectant showed very strong anti-influenza viral activity in the in ovo tests. All of the influenza viruses tested were inactivated very quickly. Following exposure to the disinfectant, the infectivity of all viral strains tested had been eliminated within ≤10 min. The infectant showed a weak acute toxicity in vitro. CONCLUSION: This new disinfectant is expected to be useful for preventing viral infection during a new influenza pandemic.
RESUMO
Reverse transcription loop-mediated isothermal amplification (RT-LAMP) is an established gene amplification method for rapid diagnosis of various infectious diseases. In order to detect avian influenza viruses, particularly in field specimens, specific primers targeting the matrix gene were designed. Thirty-four virus samples, including isolates from wild and domestic avian hosts belonging to various geographical areas, were used to confirm the validity of the primers. All samples were confirmed to be positive in less than 1 hr. The RT-LAMP assay was also able to detect avian influenza virus in the various field samples, such as swabs, tissues, and feces. These results indicate that the developed RT-LAMP assay with uniquely designed primers is potentially useful in comprehensive avian influenza surveillance.
Assuntos
Aves/virologia , Vírus da Influenza A/genética , Vírus da Influenza A/isolamento & purificação , Influenza Aviária/diagnóstico , Alantoide/virologia , Animais , Sequência de Bases , Encéfalo/virologia , Primers do DNA , DNA Viral/genética , Fezes/virologia , Amplificação de Genes , Músculo Esquelético/virologia , RNA Viral/genética , RNA Viral/isolamento & purificação , Transcrição Reversa , Traqueia/virologiaRESUMO
During 2001-2004, 41 H7 influenza viruses (2 H7N1 and 39 H7N7 strains) were isolated from fecal samples of migratory ducks that flew from Siberia in the autumn of each year to Japan and Mongolia. A phylogenetic analysis of the hemagglutinin (HA) genes of the nine representative isolates revealed that they belonged to the Eurasian lineage and the deduced amino acid sequence at the cleavage site of the HAs represented apathogenic profiles. One of the H7 isolates A/duck/Mongolia/736/02 (H7N7) was chosen from these H7 isolates for the preparation of the test vaccine. To improve the growth potential of A/duck/Mongolia/736/02 (H7N7) in chicken embryos, A/duck/Hokkaido/Vac-2/04 (H7N7) was generated by genetic reassortment between A/duck/Mongolia/736/02 (H7N7) as the donor of the PB2, PB1, PA, HA, NA, and NS genes and A/duck/Hokkaido/49/98 (H9N2) as that of NP and M genes. The test vaccine was prepared as follows; A/duck/Hokkaido/Vac-2/04 (H7N7) was propagated in chicken embryos and the virus in the allantoic fluid was inactivated and adjuvanted to form an oil-in-water emulsion. The test vaccine conferred immunity to chickens, completely protecting the manifestation of clinical signs against the challenge with lethal dose of H7 highly pathogenic avian influenza virus. These results indicate that influenza viruses isolated from natural reservoirs are useful for vaccine strains.
Assuntos
Patos/virologia , Vírus da Influenza A Subtipo H7N7/fisiologia , Vacinas contra Influenza/administração & dosagem , Influenza Aviária/prevenção & controle , Vírus Reordenados/imunologia , Animais , Anticorpos Antivirais/análise , Anticorpos Antivirais/biossíntese , Especificidade de Anticorpos , Galinhas , Reações Cruzadas , DNA Viral/genética , Surtos de Doenças/prevenção & controle , Patos/imunologia , Vírus da Influenza A Subtipo H7N7/imunologia , Vacinas contra Influenza/genética , Vacinas contra Influenza/imunologia , Influenza Aviária/genética , Influenza Aviária/imunologia , Vírus Reordenados/crescimento & desenvolvimentoRESUMO
Introducing double-stranded DNA (dsDNA) into the cytoplasm of macrophages and dendritic cells triggers the activation of these professional antigen-presenting cells (APCs). This process is characterized by the up-regulation of costimulatory molecules and the production of various cytokines, chemokines, and antibacterial/viral factors. Current findings indicate that interferon-beta (IFN-beta) plays a key role in the stimulatory cascade triggered by dsDNA. Both immune and non-immune cells respond to intracytoplasmic dsDNA by up-regulating IFN-beta) expression, a process that reduces host susceptibility to infection. The immune activation induced by dsDNA is independent of MyD88, TRIF and DNA-PKcs, indicating that a Toll-like receptor-independent mechanism underlies the cellular activation mediated by intracytoplasmic dsDNA.
Assuntos
DNA/imunologia , Interferon beta/imunologia , Proteínas Adaptadoras de Transdução de Sinal/imunologia , Proteínas Adaptadoras de Transporte Vesicular/imunologia , Animais , Citocinas/biossíntese , Citocinas/genética , Proteína Quinase Ativada por DNA/imunologia , Proteínas de Ligação a DNA/imunologia , Relação Dose-Resposta Imunológica , Feminino , Fibroblastos/virologia , Herpes Simples/prevenção & controle , Herpesvirus Humano 2 , Interferon beta/biossíntese , Macrófagos Peritoneais/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos SCID , Fator 88 de Diferenciação Mieloide , Proteínas Nucleares/imunologia , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Transfecção , Regulação para Cima/imunologiaRESUMO
OBJECTIVE: Attenuated, replication-competent herpes simplex viruses (HSVs) have shown promise as antitumor agents for cancer therapy. In this study, we sought to develop a novel type of oncolytic HSV with more potent antitumor activity for use in localized malignant tumors. STUDY DESIGN: A new, attenuated multimutated HSV (termed HL) was developed, and then a highly metastatic murine fibrosarcoma cell line, NfSa Y83, was injected into the necks or flanks of immunocompetent C3H mice. The mice were treated with attenuated HSV mutants by intratumoral injection, and antitumor efficacy was assessed by measuring tumor dimensions and overall survival rates. RESULTS: Treatment with intratumoral injection of HL resulted in marked regression of tumors. In fact, roughly 75% of flank tumors and 50% of neck tumors were completely eradicated. CONCLUSION: A novel type of attenuated HSV recombinant HL demonstrated a remarkable antitumor efficacy in a localized tumor model in mice.