Peste des petits ruminants virus non-structural V and C proteins interact with the NF-κB p65 subunit and modulate pro-inflammatory cytokine gene induction.

Peste des petits ruminants virus (PPRV) is known to induce transient immunosuppression in infected small ruminants by modulating several cellular pathways involved in the antiviral immune response. Our study shows that the PPRV-coded non-structural proteins C and V can interact with the cellular NF-κB p65 subunit. The PPRV-C protein interacts with the transactivation domain (TAD) while PPRV-V interacts with the Rel homology domain (RHD) of the NF-κB p65 subunit. Both viral proteins can suppress the NF-κB transcriptional activity and NF-κB-mediated transcription of cellular genes. PPRV-V protein expression can significantly inhibit the nuclear translocation of NF-κB p65 upon TNF-α stimulation, whereas PPRV-C does not affect it. The NF-κB-mediated pro-inflammatory cytokine gene expression is significantly downregulated in cells expressing PPRV-C or PPRV-V protein. Our study provides evidence suggesting a role of PPRV non-structural proteins V and C in the modulation of NF-κB signalling through interaction with the NF-κB p65 subunit.

Nucleocapsid Protein (N) of Peste des petits ruminants Virus (PPRV) Interacts with Cellular Phosphatidylinositol-3-Kinase (PI3K) Complex-I and Induces Autophagy.

Autophagy is an essential and highly conserved catabolic process in cells, which is important in the battle against intracellular pathogens. Viruses have evolved several ways to alter the host defense mechanisms. PPRV infection is known to modulate the components of a host cell's defense system, resulting in enhanced autophagy. In this study, we demonstrate that the N protein of PPRV interacts with the core components of the class III phosphatidylinositol-3-kinase (PI3K) complex-I and results in the induction of autophagy in the host cell over, thereby expressing this viral protein. Our data shows the interaction between PPRV-N protein and different core components of the autophagy pathway, i.e., VPS34, VPS15, BECN1 and ATG14L. The PPRV-N protein can specifically interact with VPS34 of the PI3K complex-I and colocalize with the proteins of PI3K complex-I in the same sub-cellular compartment, that is, in the cytoplasm. These interactions do not affect the intracellular localization of the different host proteins. The autophagy-related genes were transcriptionally modulated in PPRV-N-expressing cells. The expression of LC3B and SQSTM1/p62 was also modulated in PPRV-N-expressing cells, indicating the induction of autophagic activity. The formation of typical autophagosomes with double membranes was visualized by transmission electron microscopy in PPRV-N-expressing cells. Taken together, our findings provide evidence for the critical role of the N protein of the PPR virus in the induction of autophagy, which is likely to be mediated by PI3K complex-I of the host.

Susceptibility to foot and mouth disease virus infection in vaccinated cattle, and host BoLA A and BoLA DRB3 genes polymorphism.

The vaccination of the susceptible animal population against FMDV remains the most important measure to control the virus and prevent economic loss. Occurrence of infection in vaccinated animals is well-known in some diseases and is termed as breakthrough infection. The reasons include host genetic factors which can play an important role resulting in differences in susceptibility of animals to virus infection even with vaccine induced protective immune response. The Major Histocompatibility Complex (MHC) of bovines i.e. Bovine Leukocyte Antigen (BoLA) is important for antigen presentation. The BoLA DRB3 allele, which codes for the beta chain in Class II antigen, has been extensively studied and numerous reports have previously shown association of polymorphism in the gene with resistance/ susceptibility to several bacterial and viral diseases. In addition, previous studies have shown relationship between BoLA Class I and resistance or susceptibility to different diseases in cattle. The present study investigated the polymorphism in BoLA DRB3 and BoLA gene sequences of host and their relation with breakthrough FMDV infection in vaccinated animals. The study has identified three polymorphic sites each in both the genes which correlate with evidence of recent infection indicating their role in determining susceptibility of vaccinated animals to FMDV infection. Our limited study was performed on a relatively small samples size collected from one region of country. Further validation would require more detailed investigations on larger sample size. Supplementary Information: The online version contains supplementary material available at 10.1007/s13337-021-00754-8.

Identifying ranges of combined lime and heat treatments to achieve biosolids stabilization fecal coliform targets.

To ensure safe reuse, biosolids are stabilized to reduce pathogens, odor, and volatile solids. Stabilization by lime addition have high material costs, high transportation costs, and loss of ammonia. Decreasing required lime additions would improve the sustainability of biosolids reuse. This study examined combining lime and heat treatment to reduce lime additions needed for required fecal coliform destruction. In contrast to the current best management practice requiring a pH of 12, fecal coliform reduction for final concentrations <1000 MPN/g (where MPN is most probable number) was achieved with pH as low as 10 when combined with a short (1-h) incubation at 60 °C. Analysis of D-values (the time required to destroy 1-log fecal coliform) supported a synergistic treatment response at moderate pH and heat treatments. Samples receiving higher temperature treatments had lower specific oxygen uptake rates, suggesting that readily-available carbon was lost during heat treatment. Samples with lower lime additions had higher final ammonia concentrations, which is a desired characteristic for biosolids reclaimed as a fertilizer. The study demonstrated that optimizing combined lime and heat stabilization can improve beneficial reuse as a means toward enhancing environmental sustainability and improving the circular economy.

The molecular biology of intracellular events during Coronavirus infection cycle.

CoV-2 which is the causative agent of COVID-19 belongs to genus betacoronaviruses. The sequence analysis of S protein of CoV-2 has shown that it has acquired a 'polybasic cleavage site' consisting of 12 aminoacids that has been predicted to enable its cleavage by other cellular proteases possibly increasing its transmissibility. The aminoacids present in receptor binding domain of S protein of SARS CoV which are critical for its binding to cellular receptor are different in CoV-2. The presence of heptanucleotide slippery sequence in ORF1 resulting in ribosomal frameshifting, and presence of transcription regulatory sequences between ORFs resulting in discontinuous transcription, are peculiar features of Coronavirus infection cycle. The exonuclease activity of nsp14 provides possible proofreading ability to RNA polymerase makes coronaviruses different from other RNA viruses allowing coronaviruses to maintain their relatively large genome size. This mini-review summarizes the peculiar features of Coronaviruses genome and the critical events during the infection cycle with focus on CoV-2.