@article {126683, title = {Evolutionary dynamics of dengue virus in India.}, journal = {PLoS Pathog}, volume = {19}, year = {2023}, month = {2023 Apr 03}, pages = {e1010862}, abstract = {

More than a hundred thousand dengue cases are diagnosed in India annually, and about half of the country{\textquoteright}s population carries dengue virus-specific antibodies. Dengue propagates and adapts to the selection pressures imposed by a multitude of factors that can lead to the emergence of new variants. Yet, there has been no systematic analysis of the evolution of the dengue virus in the country. Here, we present a comprehensive analysis of all DENV gene sequences collected between 1956 and 2018 from India. We examine the spatio-temporal dynamics of India-specific genotypes, their evolutionary relationship with global and local dengue virus strains, interserotype dynamics and their divergence from the vaccine strains. Our analysis highlights the co-circulation of all DENV serotypes in India with cyclical outbreaks every 3-4 years. Since 2000, genotype III of DENV-1, cosmopolitan genotype of DENV-2, genotype III of DENV-3 and genotype I of DENV-4 have been dominating across the country. Substitution rates are comparable across the serotypes, suggesting a lack of serotype-specific evolutionary divergence. Yet, the envelope (E) protein displays strong signatures of evolution under immune selection. Apart from drifting away from its ancestors and other contemporary serotypes in general, we find evidence for recurring interserotype drift towards each other, suggesting selection via cross-reactive antibody-dependent enhancement. We identify the emergence of the highly divergent DENV-4-Id lineage in South India, which has acquired half of all E gene mutations in the antigenic sites. Moreover, the DENV-4-Id is drifting towards DENV-1 and DENV-3 clades, suggesting the role of cross-reactive antibodies in its evolution. Due to the regional restriction of the Indian genotypes and immunity-driven virus evolution in the country, ~50\% of all E gene differences with the current vaccines are focused on the antigenic sites. Our study shows how the dengue virus evolution in India is being shaped in complex ways.

}, issn = {1553-7374}, doi = {10.1371/journal.ppat.1010862}, author = {Jagtap, Suraj and Pattabiraman, Chitra and Sankaradoss, Arun and Krishna, Sudhir and Roy, Rahul} } @article {105164, title = {Immune profile and responses of a novel Dengue DNA vaccine encoding EDIII-NS1 consensus design based on Indo-African sequences.}, journal = {Mol Ther}, year = {2022}, month = {2022 Jan 06}, abstract = {

The ongoing COVID-19 pandemic highlights the need to tackle viral variants, expand the number of antigens and assess diverse delivery systems for vaccines against emerging viruses. In the present study, a DNA vaccine candidate was generated by combining in tandem envelope protein domain III (EDIII) of dengue virus serotypes 1-4 and a DENV-2 NS1 protein coding region. Each domain was designed as a serotype-specific consensus coding sequence derived from different genotypes based on whole genome sequencing of clinical isolates in India and complemented with data from Africa. This sequence was further optimized for protein expression. In silico structural analysis of the EDIII consensus sequence revealed that epitopes are structurally conserved and immunogenic. Vaccination of mice with this construct induced pan-serotype neutralizing antibodies and antigen-specific T cell responses. Assaying of intracellular IFN-γ staining, immunoglobulin IgG2(a/c)/IgG1 ratios and immune gene profiling suggest a strong Th1-dominant immune response. Finally, passive transfer of immune sera protected AG129 mice challenged with a virulent, non-mouse adapted DENV-2 strain. Our findings collectively suggest an alternative strategy for dengue vaccine design; offering a novel vaccine candidate with a possible broad spectrum protection and successful clinical translation either as a stand-alone or in a mix and match strategy.

}, issn = {1525-0024}, doi = {10.1016/j.ymthe.2022.01.013}, author = {Sankaradoss, Arun and Jagtap, Suraj and Nazir, Junaid and Moula, Shefta-E and Modak, Ayan and Fialho, Joshuah and Iyer, Meenakshi and Shastri, Jayanthi S and Dias, Mary and Gadepalli, Ravisekhar and Aggarwal, Alisha and Vedpathak, Manoj and Agrawal, Sachee and Pandit, Awadhesh and Nisheetha, Amul and Kumar, Anuj and Bordoloi, Mahasweta and Shafi, Mohamed and Shelar, Bhagyashree and Balachandra, Swathi S and Damodar, Tina and Masika, Moses Muia and Mwaura, Patrick and Anzala, Omu and Muthumani, Kar and Sowdhamini, Ramanathan and Medigeshi, Guruprasad R and Roy, Rahul and Pattabiraman, Chitra and Krishna, Sudhir and Sreekumar, Easwaran} } @article {43846, title = {Complete assembly of a dengue virus type 3 genome from a recent genotype III clade by metagenomic sequencing of serum.}, journal = {Wellcome Open Res}, volume = {3}, year = {2019}, month = {01/2019}, pages = {44}, abstract = {

Mosquito-borne flaviviruses, such as dengue and Japanese encephalitis virus (JEV), cause life-threatening diseases, particularly in the tropics. Here we performed unbiased metagenomic sequencing of RNA extracted from the serum of four patients and the plasma of one patient, all hospitalized at a tertiary care centre in South India with severe or prolonged febrile illness, together with the serum from one healthy control, in 2014. We identified and assembled a complete dengue virus type 3 sequence from a case of severe dengue fever. We also identified a small number of JEV sequences in the serum of two adults with febrile illness, including one with severe dengue. Phylogenetic analysis revealed that the dengue sequence belonged to genotype III. It has an estimated divergence time of 13.86 years from the most highly related Indian strains. In total, 11 amino acid substitutions were predicted for this strain in the antigenic envelope protein, when compared to the parent strain used for development of the first commercial dengue vaccine.\  We demonstrate that both genome assembly and detection of a low number of viral sequences are possible through the unbiased sequencing of clinical material. These methods may help ascertain causal agents for febrile illnesses with no known cause.

}, issn = {2398-502X}, doi = {10.12688/wellcomeopenres.14438.1}, author = {Dias, Mary and Pattabiraman, Chitra and Siddappa, Shilpa and Gowda, Malali and Shet, Anita and Smith, Derek and Muehlemann, Barbara and Tamma, Krishnapriya and Solomon, Tom and Jones, Terry and Krishna, Sudhir} } @article {48889, title = {Isolation and molecular characterization of Dengue virus clinical isolates from pediatric patients in New Delhi.}, journal = {Int J Infect Dis}, volume = {84}, year = {2019}, month = {07/2019}, pages = {S25-S33}, abstract = {

OBJECTIVES: To characterize the in vitro replication fitness, viral diversity and phylogeny of dengue viruses (DENV) isolated from Indian patients.

METHODS: DENV was isolated from whole blood collected from patients by passaging in cell culture. Passage 3 viruses were used for growth kinetics in C6/36 mosquito cells. Parallel efforts also focused on isolation of DENV RNA from plasma samples of the same patients and processed for next generation sequencing.

RESULTS: We were able to isolate 64 clinical isolates, mostly DENV-2, of which 25 were further used for growth curve analysis in vitro which showed a wide range of replication kinetics. Highest viral titers were of isolates from dengue with warning signs and severe dengue cases. We obtained full genome sequences of 21 DENV isolates. Genome analysis mapped the circulating DENV-2 strains to the Cosmopolitan genotype.

CONCLUSIONS: The replication kinetics of isolates from patients with mild or severe infection was not significantly different but the viral titers between the isolates varied by two orders of magnitude suggesting differences in replication fitness among the circulating DENV-2 isolates.

}, issn = {1878-3511}, doi = {10.1016/j.ijid.2018.12.003}, author = {Kar, Meenakshi and Nisheetha, Amul and Kumar, Anuj and Jagtap, Suraj and Shinde, Jitendra and Singla, Mohit and M, Saranya and Pandit, Awadhesh and Chandele, Anmol and Kabra, Sushil K and Krishna, Sudhir and Roy, Rahul and Lodha, Rakesh and Pattabiraman, Chitra and Medigeshi, Guruprasad R} } @article {53190, title = {A SUV39H1-low chromatin state characterises and promotes migratory properties of cervical cancer cells.}, journal = {Exp Cell Res}, year = {2019}, month = {2019 Feb 14}, abstract = {

Metastatic progression is a major cause of mortality in cervical cancers, but factors regulating migratory and pre-metastatic cell populations remain poorly understood. Here, we sought to assess whether a SUV39H1-low chromatin state promotes migratory cell populations in cervical cancers, using meta-analysis of data from The Cancer Genome Atlas (TCGA), immunohistochemistry, genomics and functional assays. Cervical cancer cells sorted based on migratory ability in vitro have low levels of SUV39H1 protein, and SUV39H1 knockdown in vitro enhanced cervical cancer cell migration. Further, TCGA SUV39H1-low tumours correlated with poor clinical outcomes and showed gene expression signatures of cell migration. SUV39H1 expression was examined within biopsies, and SUV39H1 cells within tumours also demonstrated migratory features. Next, to understand genome scale transcriptional and chromatin changes in migratory populations, cell populations sorted based on migration in vitro were examined using RNA-Seq, along with ChIP-Seq for H3K9me3, the histone mark associated with SUV39H1. Migrated populations showed SUV39H1-linked migratory gene expression signatures, along with broad depletion of H3K9me3 across gene promoters. We show for the first time that a SUV39H1-low chromatin state associates with, and promotes, migratory populations in cervical cancers. Our results posit SUV39H1-low cells as key populations for prognosis estimation and as targets for novel therapies.

}, issn = {1090-2422}, doi = {10.1016/j.yexcr.2019.02.010}, author = {Rodrigues, Calvin and Pattabiraman, Chitra and Vijaykumar, Anjali and Arora, Reety and Narayana, Suma Mysore and Kumar, Rekha V and Notani, Dimple and Varga-Weisz, Patrick and Krishna, Sudhir} } @article {36950, title = {Recovery of Five Complete Influenza A(H1N1)pdm09 Genome Sequences from the 2015 Influenza Outbreak in India by Metagenomic Sequencing.}, journal = {Genome Announc}, volume = {6}, year = {2018}, month = {2018 Jun 28}, abstract = {

Five complete (H1N1)pdm09 viral sequences were recovered from hospitalized individuals during the 2015 influenza outbreak by metagenomic sequencing. Four of the genomes are from oropharyngeal swabs, and one is from an isolate. All five sequences belong to an emerging 6B clade. Studying them further is critical for outbreak preparedness.

}, issn = {2169-8287}, doi = {10.1128/genomeA.00511-18}, author = {Dash, Paban Kumar and Pattabiraman, Chitra and Tandel, Kundan and Sharma, Shashi and Kumar, Jyoti S and Siddappa, Shilpa and Gowda, Malali and Krishna, Sudhir and Parida, Manmohan} }