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Search Results: 1 - 10 of 221918 matches for " Akhilesh C. Mishra "
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Non structural protein of avian influenza A (H11N1) virus is a weaker suppressor of immune responses but capable of inducing apoptosis in host cells
Mukherjee Sanjay,Majumdar Shamik,Vipat Veena C,Mishra Akhilesh C
Virology Journal , 2012, DOI: 10.1186/1743-422x-9-149
Abstract: Background The Non-Structural (NS1) protein of Influenza A viruses is an extensively studied multifunctional protein which is commonly considered as key viral component to fight against host immune responses. Even though there has been a lot of studies on the involvement of NS1 protein in host immune responses there are still ambiguities regarding its role in apoptosis in infected cells. Interactions of NS1 protein with host factors, role of NS1 protein in regulating cellular responses and apoptosis are quite complicated and further studies are still needed to understand it completely. Results NS1 genes of influenza A/Chicken/India/WBNIV2653/2008 (H5N1) and A/Aquatic bird/India/NIV-17095/2007(H11N1) were cloned and expressed in human embryonic kidney (293T) cells. Microarray based approach to study the host cellular responses to NS1 protein of the two influenza A viruses of different pathogenicity showed significant differences in the host gene expression profile. NS1 protein of H5N1 resulted in suppression of IFN-β mediated innate immune responses, leading to down-regulation of the components of JAK-STAT pathway like STAT1 which further suppressed the expression of pro-inflammatory cytokines like CXCL10 and CCL5. The degree of suppression of host immune genes was found considerable with NS1 protein of H11N1 but was not as prominent as with H5N1-NS1. TUNEL assay analyses were found to be positive in both the NS1 transfected cells indicating both H5N1 as well as H11N1 NS1 proteins were able to induce apoptosis in transfected cells. Conclusions We propose that NS1 protein of both H5N1 and H11N1 subtypes of influenza viruses are capable of influencing host immune responses and possess necessary functionality to support apoptosis in host cells. H11N1, a low pathogenic virus without any proven evidence to infect mammals, contains a highly potential NS1 gene which might contribute to greater virus virulence in different gene combinations.
Molecular characterization of Umbre virus (Bunyaviridae)
Pragya D Yadav, Akhilesh C Mishra, Devendra T Mourya
Virology Journal , 2008, DOI: 10.1186/1743-422x-5-115
Abstract: The viruses of Bunyaviridae family are spherical particles, range 80 to 120 nm in diameter and share a common genetic organization of three predominantly negative stranded RNA segments (S, M and L). Based on antigenic, genetic and ecological relatedness, the Bunyaviruses are divided into five genera. The genus Orthobunyavirus includes approximately 60 viruses, which are known to cause disease in humans (Elliot, 1996). Virological surveillance of these viruses depends primarily on detecting the viruses in arthropod vector populations in nature. Although, serological test like immunoassays are available for antigen detection for a few viruses, cross-reaction in closely related viruses cannot be ignored (Artsob et. al., 1984; Hildreth et. al., 1982).Umbre virus (UMB) [strain G-1424] was first isolated from Culex bitaeniorhynchus mosquitoes, collected in 1955 at Umbre, Kolaba district, Maharashtra State, India. The virus has been registered in the International Arbovirus Catalogue No. 43 (Dandwate et. al., 1969). During further field investigations, seven more strains of virus were isolated from Cx. vishnui mosquitoes. Recent reports on Bunyaviruses via. Ganjam virus isolation from Maharashtra (Joshi et. al., 2004) and antibody detection of Hantan virus in India (Chandi et. al., 2005), has provided evidences that Bunyaviruses are circulating in this country but their involvement in causing human and animal disease are not known yet. In the Gene Bank, only one sequence of Turlock serogroup i.e. N gene of M'poke virus is available.UMB viruses used in this study are listed in (Table 1) along with their geographical origin, host source and year of isolation. The available eight strains of this virus was procured from the virus registry of National Institute of Virology, Pune and propagated in VeroE-6 cells. Cytopathic effect (CPE) was observed during 4th – 6th post infection day. Infected cells were harvested, centrifuged and supernatant was used for molecular characterizat
Pandemic (H1N1) 2009 influenza virus induces weaker host immune responses in vitro: a possible mechanism of high transmissibility
Sanjay Mukherjee, Veena C Vipat, Akhilesh C Mishra, Shailesh D Pawar, Alok K Chakrabarti
Virology Journal , 2011, DOI: 10.1186/1743-422x-8-140
Abstract: To achieve a better understanding of the risk posed by the pH1N1 and to understand its pathogenicity, we studied the host gene expression response to Indian isolate of pH1N1 infection and compared it with seasonal H1N1 infection. The response was studied at four different time points (4, 8, 16 and 24 h) post infection (hpi) in A549 cells using microarray platform. We found that pH1N1 induces immune response earlier than seasonal H1N1 viruses, but at the later stages of infection there is a suppression of host immune responses. The infection with pH1N1 resulted in considerable decrease in the expression of cytokine and other immune genes namely IL8, STAT1, B2 M and IL4 compared to seasonal H1N1.We propose that the inability to induce strong innate immune response could be a reason for the high transmissibility, pathogenicity and mortality caused by pH1N1 virus.The pandemic (H1N1) 2009 influenza A virus (pH1N1) has already killed more than 19,000 people worldwide since it appeared in April 2009 [1]. Although on 10th of August 2010, the Director General of the World Health Organization (WHO) has announced that the world is no longer in phase 6 of influenza pandemic alert and we are now moving into the post-pandemic period, the virus transmission is still highly active in many parts of South Asia, West Africa, and Central America [2]. In Asia, the most active areas of pandemic influenza virus transmission currently are in parts of India, Bangladesh, Bhutan, Myanmar Nepal, and Thailand. The virus (pH1N1) is still a serious threat to children as well as susceptible young and old population in developing countries like India.Till date, there are reports of 2720 deaths from pandemic H1N1 influenza virus infection in India which is approximately 14% of the total world mortality http://mohfw-h1n1.nic.in/august.html; webcitehttp:/ / netindian.in/ news/ 2010/ 11/ 15/ 0008699/ 6-h1n1-deaths-india-during-past-wee k-govt webcite. The pandemic H1N1 virus is antigenically distinct f
Host gene expression profiling in influenza A virus-infected lung epithelial (A549) cells: a comparative analysis between highly pathogenic and modified H5N1 viruses
Alok K Chakrabarti, Veena C Vipat, Sanjay Mukherjee, Rashmi Singh, Shailesh D Pawar, Akhilesh C Mishra
Virology Journal , 2010, DOI: 10.1186/1743-422x-7-219
Abstract: The response was studied at time points 4, 8, 16 and 24 hours post infection (hpi). Gene ontology analysis revealed that the genes affected by both the viruses were qualitatively similar but quantitatively different. Significant differences were observed in the expression of genes involved in apoptosis and immune responses, specifically at 16 hpi.We conclude that subtle differences in the ability to induce specific host responses like apoptotic mechanism and immune responses make the highly pathogenic viruses more virulent.Outbreaks of avian influenza A (H5N1) virus, a highly pathogenic avian influenza (HPAI), are considered as a public health risk with pandemic potential [1]. Understanding the pathology, transmission, clinical features and treatments has become necessary for the prevention and management of such outbreaks [2,3]. The mechanisms responsible for the virulence of HPAI viruses in humans are not completely understood. Viral factors are necessary for productive infection but are not sufficient to explain the pathogenesis of HPAI infection in humans [4,5].It is well recognized that host immunological and genetic factors also play an important role in the pathogenesis of H5N1 viruses in humans [5,6]. Recent studies have shown that the high fatality rate of avian influenza virus infections is a consequence of the complex interaction of virus and host immune responses which include overactive inflammatory response in the form of hypercytokinemia (cytokine storm), that is initiated inside the infected cells or tissue in response to virus replication resulting in excessive cellular apoptosis and tissue damage [7-9]. In vitro, in vivo and clinical studies have suggested that H5N1 viruses are very strong inducers of various cytokines and chemokines [Tumor Necrosis Factor (TNF)-alpha, Interferon (IFN)-gamma, IFN-alpha/beta, Interleukin (IL)-6, IL-1, MIP-1 (Macrophage Inflammatory Protein), MIG (Monokine Induced by IFN-gamma), IP-10 (Interferon-gamma-Inducible Prot
Pandemic Influenza (H1N1) 2009 Is Associated with Severe Disease in India
Akhilesh C. Mishra,Mandeep S. Chadha,Manohar L. Choudhary,Varsha A. Potdar
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0010540
Abstract: Pandemic influenza A (H1N1) 2009 has posed a serious public health challenge world-wide. In absence of reliable information on severity of the disease, the nations are unable to decide on the appropriate response against this disease.
Receptor specificity and erythrocyte binding preferences of avian influenza viruses isolated from India
Pawar Shailesh D,Parkhi Saurabh S,Koratkar Santosh S,Mishra Akhilesh C
Virology Journal , 2012, DOI: 10.1186/1743-422x-9-251
Abstract: Introduction Hemagglutination (HA) and hemagglutination inhibition (HI) assays are conventionally used for detection and identification of influenza viruses. HI assay is also used for detection of antibodies against influenza viruses. Primarily turkey or chicken erythrocytes [red blood cells (RBCs)] are used in these assays, as they are large, nucleated, and sediment fast, which makes it easy to determine the titer. Human influenza viruses agglutinate RBCs from chicken, human, and guinea pig, but not from horse. Human influenza viruses bind preferentially to sialic acid (SA) linked to galactose (Gal) by α 2, 6 linkage (SA α 2, 6-Gal), whereas avian influenza (AI) viruses bind preferentially to SA α 2, 3-Gal linkages. With this background, the present study was undertaken to study erythrocyte binding preferences and receptor specificities of AI viruses isolated from India. Materials and methods A total of nine AI virus isolates (four subtypes) from India and three reference AI strains (three subtypes) were tested in HA and HI assays against mammalian and avian erythrocytes. The erythrocytes from turkey, chicken, goose, guinea pig and horse were used in the study. The receptor specificity determination assays were performed using goose and turkey RBCs. The amino acids present at 190 helix, 130 and 220 loops of the receptor-binding domain of the hemagglutinin protein were analyzed to correlate amino acid changes with the receptor specificity. Results All tested highly pathogenic avian influenza (HPAI) H5N1 viruses reacted with all five types of RBCs in the HA assay; AI H9N2 and H5N2 viruses did not react with horse RBCs. For H5N1 viruses guinea pig and goose RBCs were best for both HA and HI assays. For H9N2 viruses, guinea pig, fowl and turkey RBCs were suitable. For other tested AI subtypes, avian and guinea pig RBCs were better. Eight isolates of H5N1, one H4N6 and one H7N1 virus showed preference to avian sialic acid receptors. Importantly, two isolates of HPAI H5N1, H9N2 and H11N1 viruses showed receptor specificity preference to both avian and mammalian sialic acid (α-2, 3 and α-2, 6) receptors. Conclusions Use of different types of RBCs resulted in titer variations in HA and HI assays. This showed that RBCs giving optimum HA and HI titers would increase sensitivity of detection and would be more appropriate for identification and antigenic analysis of AI viruses. Analysis of 16 amino acids in the receptor-binding domain of the hemagglutinin of HPAI H5N1 viruses revealed that the only variation observed was in S221P amino acid position. Two
Genetic Characterization of the Influenza A Pandemic (H1N1) 2009 Virus Isolates from India
Varsha A. Potdar,Mandeep S. Chadha,Santosh M. Jadhav,Jayati Mullick,Sarah S. Cherian,Akhilesh C. Mishra
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0009693
Abstract: The Influenza A pandemic H1N1 2009 (H1N1pdm) virus appeared in India in May 2009 and thereafter outbreaks with considerable morbidity and mortality have been reported from many parts of the country. Continuous monitoring of the genetic makeup of the virus is essential to understand its evolution within the country in relation to global diversification and to track the mutations that may affect the behavior of the virus.
Surveillance in eastern India (2007-2009) revealed reassortment event involving ns and PB1-F2 gene segments among co-circulating influenza a subtypes
Mehuli Sarkar, Shampa Chanda, Sekhar Chakrabarti, Jaydeep Mazumdar, Anirban Ganguly, Mandeep S Chadha, Akhilesh C Mishra, Mamta Chawla-Sarkar
Virology Journal , 2012, DOI: 10.1186/1743-422x-9-3
Abstract: 55 out of 166 circulating influenza A strains (31 H1N1 and 24 H3N2) were randomly picked during 2007-2009 and NS and PB1-F2 genes were sequenced. Phylogenetic analysis was carried out with reference to the prototype strains, concurrent vaccine strains and other reference strains isolated world wide.Comparative analysis of both nucleotide and deduced amino acid sequences, revealed presence of NS gene with A/PR/8/34(H1N1)-like mutations (H4N, Q21R, A22V, K44R, N53D, C59R, V60A, F103S and M106I) in both RNA-binding and effector domain of NS1 protein, and G63E, the HPAI-H5N1-like mutation in NEP/NS2 of five A/H1N1 strains of 2007 and 2009. NS1 of other A/H1N1 strains clustered with concurrent A/H1N1 vaccine strains. Of 31 A/H1N1 strains, five had PB1-F2 similar to the H3N2 strains; six had non-functional PB1-F2 protein (11 amino acids) similar to the 2009 pandemic H1N1 strains and rest 20 strains had 57 amino acids PB1-F2 protein, similar to concurrent A/H1N1 vaccine strain. Interestingly, three A/H1N1 strains with H3N2-like PB1-F2 protein carried primitive PR8-like NS gene. Full gene sequencing of PB1 gene confirmed presence of H3N2-like PB1 gene in these A/H1N1 strains.Overall the study highlights reassortment event involving gene segments other than HA and NA in the co-circulating A/H1N1 and A/H3N2 strains and their importance in complexity of influenza virus genetics. In contrast, NS and PB1-F2 genes of all A/H3N2 eastern India strains were highly conserved and homologous to the concurrent A/H3N2 vaccine strains suggesting that these gene segments of H3N2 viruses are evolutionarily more stable compared to H1N1 viruses.Influenza A virus (IAV) is a cytolytic virus that is responsible for significant morbidity and mortality worldwide per year. The genome of IAV consists of eight single-stranded, negative- sense viral RNA segments encoding the subunits of the transcriptase complex (PB1, PB2, PA), nucleoprotein (NP), the matrix protein (M1), two non-structural proteins (
Detection, Isolation and Confirmation of Crimean-Congo Hemorrhagic Fever Virus in Human, Ticks and Animals in Ahmadabad, India, 2010–2011
Devendra T. Mourya ,Pragya D. Yadav,Anita M. Shete,Yogesh K. Gurav,Chandrashekhar G. Raut,Ramesh S. Jadi,Shailesh D. Pawar,Stuart T. Nichol,Akhilesh C. Mishra
PLOS Neglected Tropical Diseases , 2012, DOI: 10.1371/journal.pntd.0001653
Abstract: Background In January 2011, human cases with hemorrhagic manifestations in the hospital staff were reported from a tertiary care hospital in Ahmadabad, India. This paper reports a detailed epidemiological investigation of nosocomial outbreak from the affected area of Ahmadabad, Gujarat, India. Principal Findings Samples from 3 suspected cases, 83 contacts, Hyalomma ticks and livestock were screened for Crimean-Congo hemorrhagic fever (CCHF) virus by qRT-PCR of which samples of two medical professionals (case C and E) and the husband of the index case (case D) were positive for CCHFV. The sensitivity and specificity of indigenous developed IgM ELISA to screen CCHFV specific antibodies in human serum was 75.0% and 97.5% respectively as compared to commercial kit. About 17.0% domestic animals from Kolat, Ahmadabad were positive for IgG antibodies while only two cattle and a goat showed positivity by qRT-PCR. Surprisingly, 43.0% domestic animals (Buffalo, cattle, sheep and goat) showed IgG antibodies in the adjoining village Jivanpara but only one of the buffalo was positive for CCHFV. The Hyalomma anatolicum anatolicum ticks were positive in PCR and virus isolation. CCHFV was isolated from the blood sample of case C, E in Vero E-6 cells and Swiss albino mice. In partial nucleocapsid gene phylogeny from CCHFV positive human samples of the years 2010 and 2011, livestock and ticks showed this virus was similar to Tajikistan (strain TAJ/H08966), which belongs in the Asian/middle east genetic lineage IV. Conclusions The likely source of CCHFV was identified as virus infected Hyalomma ticks and livestock at the rural village residence of the primary case (case A). In addition, retrospective sample analysis revealed the existence of CCHFV in Gujarat and Rajasthan states before this outbreak. An indigenous developed IgM ELISA kit will be of great use for screening this virus in India.
Avian Influenza H9N2 Seroprevalence among Poultry Workers in Pune, India, 2010
Shailesh D. Pawar, Babasaheb V. Tandale, Chandrashekhar G. Raut, Saurabh S. Parkhi, Tanaji D. Barde, Yogesh K. Gurav, Sadhana S. Kode, Akhilesh C. Mishra
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0036374
Abstract: Avian influenza (AI) H9N2 has been reported from poultry in India. A seroepidemiological study was undertaken among poultry workers to understand the prevalence of antibodies against AI H9N2 in Pune, Maharashtra, India. A total of 338 poultry workers were sampled. Serum samples were tested for presence of antibodies against AI H9N2 virus by hemagglutination inhibition (HI) and microneutralization (MN) assays. A total of 249 baseline sera from general population from Pune were tested for antibodies against AI H9N2 and were negative by HI assay using ≥40 cut-off antibody titre. Overall 21 subjects (21/338 = 6.2%) were positive for antibodies against AI H9N2 by either HI or MN assays using ≥40 cut-off antibody titre. A total of 4.7% and 3.8% poultry workers were positive for antibodies against AI H9N2 by HI and MN assay respectively using 40 as cut-off antibody titre. This is the first report of seroprevalence of antibodies against AI H9N2 among poultry workers in India.
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