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Biology subjects

Siddappa, S.

Publications and source records attributed to Siddappa, S..

3 recordsLinked to original sources

Therapeutic role of Filarial HSP70 in murine models of polymicrobial sepsis and H1N1 Influenza

Nematodes characteristically modulate effector immune responses by synthesizing and releasing both anti-inflammatory as well as proinflammatory molecules in infected hosts. Pre-clinical studies suggest that immuno-modulatory molecules and synthetic small molecules that mimic parasite products could have therapeutic value to ameliorate tissue damage found in inflammatory diseases. We report here identification of a glycoprotein from filarial parasite, a homologue of mammalian Heat Shock Protein 70 with immunostimulatory attributes. The purified native glycoprotein designated as FHSP70 and its recombinant protein moiety, WFL were found to be TLR2 and TLR4 agonists in vitro in human myeloid cells and induce systemic inflammatory cytokines in vivo. Cecal ligation and puncture (CLP) performed in mice which leads to onset of poly microbial sepsis and mortality could be treated by therapeutic administration of a single dose of FHSP70, along with antibiotics, suggesting its potential as a immunotherapeutic adjuvant for clinical management of Sepsis. Intra-nasal administration of WFL to mice followed by challenge with virulent human Influenza-A virus resulted in decreased viral growth as well as improved survival. The protective effect was demonstrable by both prophylactic as well as therapeutic intranasal administration of WFL. Further, therapeutic administration of WFL by intraperitoneal route 5 days post viral challenge also resulted in significant decrease in viral load in the respiratory tract. One sentence SummarySystemic administration of a Filarial HSP70 acts as an adjuvant therapy, through immuno-modulation, for improved survival against murine Polymicrobial Sepsis and Viral Infection while its intra nasal administration protects mice prophylactically as well as therapeutically against H1N1 Influenza viral challenge.

immunology↗

Next-Gen sequencing of novel pandemic swine flu virus in India revealed novel mutations across the genome

The Influenza A H1N1 virus of 2009 was the first pandemic flu virus of the 21st century. Identifying the emergence of mutations in rapidly mutating Influenza viruses that allow increased transmission or confer resistance are invaluable to global outbreak response. Here we recovered 5 complete Influenza A genomes from 4 oropharygeal swabs and one cell culture isolate from a severe Indian outbreak of flu in early 2015. Multiple amino acids substitutions including those known to confer resistance to Oseltamivir and increased pathogenecity in mice were found in the Neuraminidase gene. Additional mutations both reported and novel were found throughout the genome compared to the vaccine strain (California/04/2009). All eight segments of the complete genomes were found to be genetically related to the 2009 pandemic strain, A(H1N1)pdm09 and belonging to the emerging genogroup 6B. This group was found to be of south East Asian origin by time scale phylogentic analysis. A phylogeographic analysis revealed 39 significant migration events among globally circulating viruses. This study is the first extensive complete genome and phylogeographic analysis of 2015 Indian A(H1N1) pdm09 viruses. We report several novel mutations in the 2015 Indian strains which need to be evaluated for effect on viral replication, transmission and resistance to therapy. The identification of mutant A(H1N1)pdm09 from India warrants continuous monitoring of viral evolution for implementation of suitable medical countermeasures.

genomics↗

Complete assembly of a dengue virus type 3 genome from a recent genotype III clade by metagenomic sequencing of serum

BackgroundMosquito-borne flaviviruses causing diseases such as dengue and Japanese encephalitis are devastating, particularly in the tropics. Although, multiple flaviviruses are known to co-circulate in India, when a patient presents with febrile illness, testing is usually limited to specific pathogens. Unbiased metagenomic sequencing of febrile cases can reveal the presence of multiple pathogens and provide complete genome information. Sequence information, a cornerstone for tracing virus evolution, is relevant for the design of vaccines and therapeutics. In order to assess the usefulness of unbiased metagenomic sequencing for the identification of viruses associated with febrile illness, we sequenced serum from four individuals and plasma from one individual, all hospitalized at a tertiary care centre in South India with severe or prolonged febrile illnesses, together with one healthy control in 2014.\n\nResultsWe identified and assembled a complete dengue virus type 3 (DENV3) sequence from the serum of a case classified as severe dengue. We also found a small number of Japanese encephalitis virus (JEV) sequences in the serum of two adults with febrile illness, including the one who had dengue. Phylogenetic analysis of the dengue sequence indicates that it belongs to a predominantly Asian, DENV3, genotype III clade. It had an estimated divergence time of 13.86 years (95% Highest Posterior Densities 12.94 - 14.83 years) with the closest Indian strain. Amino acid substitutions were present throughout the sequenced genome, including 11 substitutions in the antigenic envelope protein compared to the strain used for the development of the first commercial dengue vaccine. Of these one substitution (E361D) was unique and six were in critical antigenic sites.\n\nConclusionsWe demonstrate that both genome assembly and detection of a low number of viral sequences are possible by unbiased sequencing of clinical material. Complete dengue virus sequence analysis places the sequenced genome in a recent, predominantly Asian clade within genotype III of DENV3. The detection of JEV, an agent not routinely tested in febrile illness in India, warrants further analysis and highlights the need to study co-circulating flaviviruses in parallel.

microbiology↗