Biology subjects

Riyesh, T.

Publications and source records attributed to Riyesh, T..

5 recordsLinked to original sources

bioRxiv2022

Evaluation of the safety, immunogenicity and efficacy of a new live-attenuated lumpy skin disease vaccine in India

Lumpy skin disease (LSD) was reported for the first time in India in 2019 and since then, it has become endemic. Since a homologous (LSD-virus based) vaccine was not available in the country, goatpox virus (GPV)-based heterologous vaccine was authorized for mass immunization against LSD in cattle. This study describes the evaluation of safety, immunogenicity and efficacy of a new live-attenuated LSD vaccine developed using an Indian field strain (LSDV/India/2019/Ranchi). The virus was attenuated by continuous passage (P=50) in Vero cells. The vaccine (50th LSDV passage in Vero cells, named as Lumpi-ProVacInd) did not induce any local or systemic reaction upon its experimental inoculation in calves (n=10). At day 30 post-vaccination (pv), the vaccinated animals were shown to develop antibody- and cell-mediated immune response and exhibited complete protection upon virulent LSDV challenge. We observed a minimum Neethling response (0.018% animals; 5 out of 26940 animals) of the vaccine in field trials among 26940 animals. There was no significant reduction in the milk yield in lactating animals (n=10108), besides there was no abortion or any other reproductive disorder in the pregnant animals (n=2889). Sero-conversion was observed in 85.18% animals in the field by day 30 pv.

microbiology↗

bioRxiv2020

Emetine as an antiviral agent suppresses SARS-CoV-2 replication by inhibiting interaction of viral mRNA with eIF4E: An in vitro study

Emetine is a FDA-approved drug for the treatment of amebiasis. In the recent times we had also demonstrated the antiviral efficacy of emetine against some RNA and DNA viruses. Following emergence of the COVID-19, we further evaluated thein vitro antiviral activity of emetine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The therapeutic index of emetine was determined to be 10910.4, at a cytotoxic concentration 50 (CC50) of 1603.8 nM and effective concentration 50 (EC50) of 0.147 nM.Besides, we also demonstrated the protective efficacy of emetine against lethal challenge with infectious bronchitis virus (IBV; a chicken coronavirus) in the embryonated chicken egg infection model. Emetine treatment was shown to decrease viral RNA and protein synthesis without affecting other steps of viral life cycle such as attachment, entry and budding.In a chromatin immunoprecipitation (CHIP) assay, emetine was shown to disrupt the binding of SARS-CoV-2 RNA with eIF4E (eukaryotic translation initiation factor 4E, a cellular cap-binding protein required for initiation ofprotein translation). Further, SARS-CoV-2 was shown to exploit ERK/MNK1/eIF4E signalling pathwayfor its effective replication in the target cells. To conclude, emetine targets SARS-CoV-2 protein synthesis which is mediated via inhibiting the interaction of SARS-CoV-2 RNA with eIF4E. This is a novel mechanistic insight on the antiviral efficacy of emetine. In vitro antiviral efficacy against SARS-CoV-2 and its ability to protect chicken embryos against IBV suggests that emetine could be repurposed to treat COVID-19.

microbiology↗

bioRxiv2020

Isolation and characterization of lumpy skin disease virus from cattle in India

Lumpy skin disease (LSD) has devastating economic impact. During the last decade, LSD had spread to climatically new and previously disease-free countries, which also includes its recent emergence in the Indian subcontinent (2019). This study deals with the LSD outbreak(s) from cattle in Ranchi (India). Virus was isolated from the scabs (skin lesions) in the primary goat kidney cells. Phylogenetic analysis based on nucleotide sequencing of LSD virus (LSDV) ORF011, ORF012 and ORF036 suggested that the isolated virus (LSDV/Bos taurus-tc/India/2019/Ranchi) is closely related to Kenyan LSDV strains. Further, we adapted the isolated virus in Vero cells, an alternative cell line that was found suitable for LSDV propagation. In addition, kinetics of viral DNA synthesis and one-step growth curve analysis suggested that LSDV initiates synthesizing its genome at [~]24 hours post-infection (hpi) with a peak level at [~]96 hpi whereas evidence of progeny virus particles was observed at 36-48 hours (h) with a peak titre at [~]120 h. This study reports the first successful isolation of LSDV in India, besides describing alternative cells for virus isolation (primary goat kidney cells) and in vitro propagation (Vero cells) as well as providing some insights on LSDV life cycle. Author SummaryThis study describes the first successful isolation of LSDV in India. Nucleotide sequencing of LSDV ORF011, ORF012 and ORF036 suggested that the isolated virus is closely related to Kenyan LSDV strains. This is in accordance with the previous (only) study, thereby suggesting that a single LSDV strain is circulating in India. For the first time, we employed primary goat kidney (PGK) cells for the isolation of LSDV, where PGK cells were found more sensitive for LSDV isolation as compared to the primary lamb testicle (PLT) and primary goat testicle (PGT) cells. We also adapted the isolated virus in Vero cells and demonstrated that Vero cells are also suitable for in vitro propagation of LSDV. Besides, we also provide some insights on the LSDV life cycle.

microbiology↗

bioRxiv2020

Isolation and characterization of bovine herpes virus 5 (BHV5) from cattle in India

Bovine herpesvirus 1 (BHV1) and 5 (BHV5) are genetically and antigenically related alphaherpesviruses. Infection with one virus induces protective immunity against the other. However, disease associated with BHV1 and BHV5 varies significantly; whereas BHV1 infection is usually associated with rhinotracheitis and abortion, BHV5 causes encephalitis in cattle. BHV5 outbreaks are sporadic and mainly restricted to the South American countries. We report BHV5 infection for the first time from aborted cattle in India. Based on the characteristic cytopathic effects in MDBK cells, amplification of the viral genome in PCR, differential PCR for BHV1/BHV5, nucleotide sequencing and restriction endonuclease patterns, identity of the virus was confirmed as BHV5 subtype A. Serum samples from the aborted cattle strongly neutralized both BHV1 and BHV5 suggesting an active viral infection in the herd. Upon UL27, UL44 and UL54 gene-based sequence and phylogenetic analysis, the isolated virus clustered with BHV5 strains and showed highest similarity with the Brazilian BHV5 strains. Author SummaryBHV5 causes fatal meningoencephalitis that may result in a mortality rate of up to 100% in cattle. BHV5 is rarely associated with abortion and its distribution is restricted to South American countries. Only a few cases of this disease have been reported from other countries. For the first time, we provide a strong evidence of BHV5 infection from aborted cattle in India. The finding may necessitate inclusion of BHV5 test protocol in testing of semen for sexually transmitted diseases. Also, the isolated virus would be useful for developing diagnostic, prophylactic and therapeutic agents to combat BHV5 disease in the country.

microbiology↗

bioRxiv2018

Inhibitor of sarco/endoplasmic reticulum calcium-ATPase impairs paramyxovirus replication

Sarco/endoplasmic reticulum calcium-ATPase (SERCA) is a membrane bound cytosolic enzyme that is known to regulate the uptake of calcium into the sarco/endoplasmic reticulum. Herein, we demonstrate for the first time that SERCA can also regulate paramyxovirus [Peste des petits ruminants virus (PPRV) and Newcastle disease virus (NDV)] replication. Treatment of Vero cells with SERCA specific inhibitor (Thapsigargin) at a concentration that is nontoxic to the cells significantly reduced virus replication. Conversely, overexpression of SERCA rescued the inhibitory effect of Thapsigargin on virus replication. PPRV/NDV infection induced SERCA expression in Vero cells which could be blocked by Thapsigargin. With the help of time-of-addition and virus step-specific assays, it was observed that Thapsigargin specifically inhibits viral entry and subcellular localization of the viral proteins. Furthermore, NDV, but not PPRV acquired a significant resistance to Thapsigargin on long-term passage (P=70) in Vero cells. To the best of our knowledge, this is the first report describing virus supportive role of SERCA and a rare report suggesting that viruses may acquire resistance even in the presence of an inhibitor that targets a cellular factor. This study will contribute in understanding paramyxovirus replication and development of antiviral therapeutics using SERCA (host factor) as a candidate drug target.

microbiology↗