Extracellular ISG15 triggers ISGylation via a type-I interferon independent non-canonical mechanism to regulate host response during virus infection.

Type-I interferons (IFN) induce cellular proteins with antiviral activity. One such protein is Interferon Stimulated Gene 15 (ISG15). ISG15 is conjugated to proteins during ISGylation to confer antiviral activity and regulate cellular activities associated with inflammatory and neurodegenerative diseases and cancer. Apart from ISGylation, unconjugated free ISG15 is also released from cells during various conditions, including virus infection. The role of extracellular ISG15 during virus infection was unknown. We show that extracellular ISG15 triggers ISGylation and acts as a soluble antiviral factor to restrict virus infection via an IFN-independent mechanism. Specifically, extracellular ISG15 acts post-translationally to markedly enhance the stability of basal intracellular ISG15 protein levels to support ISGylation. Furthermore, extracellular ISG15 interacts with cell surface integrin (α5ß1 integrins) molecules via its RGD-like motif to activate the integrin-FAK (Focal Adhesion Kinase) pathway resulting in IFN-independent ISGylation. Thus, our studies have identified extracellular ISG15 protein as a new soluble antiviral factor that confers IFN-independent non-canonical ISGylation via the integrin-FAK pathway by post-translational stabilization of intracellular ISG15 protein.

Emerging porcine Enterovirus G infections, epidemiological, complete genome sequencing, evolutionary and risk factor analysis in India.

The current study reports the in-depth analysis of the epidemiology, risk factors, and molecular characterization of a complete genome of Enterovirus G (EV-G) isolated from Indian pigs. We analysed several genes of EV-G isolates collected from various provinces in India, using phylogenetic analysis, recombination detection, SimPlot, and selection pressure analyses. Our analysis of 534 porcine faecal samples revealed that 11.61% (62/534) of the samples were positive for EV-G. While the G6 genotype was the most predominant, our findings showed that Indian EV-G strains also clustered with EV-G types G1, G6, G8, and G9. Furthermore, Indian EV-G strains exhibited the highest nucleotide similarity with Vietnamese (81.3%) and Chinese EV-G isolates (80.3%). Moreover, we identified a recombinant Indian EV-G strain with a putative origin from a Japanese isolate and South Korean EV-G isolate. In summary, our findings provide significant insights into the epidemiology, genetic diversity, and evolution of EV-G in India.

Delivery of gene editing therapeutics.

For the past decades, gene editing demonstrated the potential to attenuate each of the root causes of genetic, infectious, immune, cancerous, and degenerative disorders. More recently, Clustered Regularly Interspaced Short Palindromic Repeats-CRISPR-associated protein 9 (CRISPR-Cas9) editing proved effective for editing genomic, cancerous, or microbial DNA to limit disease onset or spread. However, the strategies to deliver CRISPR-Cas9 cargos and elicit protective immune responses requires safe delivery to disease targeted cells and tissues. While viral vector-based systems and viral particles demonstrate high efficiency and stable transgene expression, each are limited in their packaging capacities and secondary untoward immune responses. In contrast, the nonviral vector lipid nanoparticles were successfully used for as vaccine and therapeutic deliverables. Herein, we highlight each available gene delivery systems for treating and preventing a broad range of infectious, inflammatory, genetic, and degenerative diseases. STATEMENT OF SIGNIFICANCE: CRISPR-Cas9 gene editing for disease treatment and prevention is an emerging field that can change the outcome of many chronic debilitating disorders.

CRISPR use in diagnosis and therapy for COVID-19.

Since the beginning of the COVID-19 pandemic, many diagnostic approaches (RT-qPCR, RAPID, LFA) have been adopted, with RT-qPCR being the most popular/gold standard. But, one of the major problems of COVID-19 diagnostics is the presentation of a wide range of symptoms which varies among different patients and needs early diagnosis for better management. Even though RT-qPCR is a precise molecular technique false negative results may be obtained. On the other hand, CRISPR-based SARS-CoV-2 detection approaches are cost and time efficient, highly sensitive and specific, and do not require sophisticated instruments. Moreover, they also show promise for increased scalability and diagnostic tests can be carried out at the point-of-care (POC). The CRISPR can be customized to the target of any genomic region of interest within the desired genome possessing a broad range of other applications and has been efficiently implemented for diagnosis of SARS-CoV-2. The CRISPR/Cas systems provide the specific gene targeting with immense potential to develop new generation diagnostics and therapeutics. Moreover, with the CRISPR/Cas based therapeutics, multiplexing is possible, where different sgRNAs or crRNAs can be guided to more than one target within the same gene thus decreasing the possibility of viral escape mutants. As an exceptionally efficient tool CRISPR/Cas13 and CARVER (Cas13-assisted restriction of viral expression and readout) systems can be implemented to target a broad range of ssRNA viruses that can be used for both, diagnosis and treatment for a variety of viral diseases including SARS-CoV-2. However, the efficacy and safety of the CRISPR-based therapeutics needs to be assessed in pre-clinical and clinical settings. Although the CRISPR biotechnologies are not very helpful to control the present pandemic of COVID-19 it is hopeful that the limitations of the CRISPR/Cas system can be overcome in the near future. The CRISPR based strategies may lead to a new era in the field of disease diagnosis and therapeutic development that would make us better prepared for future viral threats.

Identification and In Silico Characterization of a Genetically Distinct Avian Rotavirus D Capsid Gene, VP7.

Rotavirus D (RV-D) is gaining importance as a cause of gastroenteritis and runting and stunting syndrome (RSS) in poultry. To date, information is scarce on the molecular analysis of RV-D isolates worldwide. In this study, the VP7 gene, a major constituent of outer capsid structural protein, from a RV-D isolate (UKD48) obtained from Uttarakhand state was analyzed. Phylogenetically, the RV-D isolate was found to be closely related to a South Korean strain, and the nucleotide percent identity varied from 80.4–84.2% with other RV-D strains available globally. Furthermore, domain investigation within 21 aligned amino acid sequences of the VP7 gene affirmed that this gene has several domains: a conserved glycosylation site (N–I–T) having an important role in protein folding; a N-terminal signal peptide (“ITG”) for endoplasmic reticulum retention; and two hydrophobic sites for elucidating transmembrane portions, antigenic structures, and so forth. The findings suggest that the VP7 gene of the Indian RV-D isolate is genetically distinct from those of other avian RV-Ds. Although biological evidence is still needed to prove the functional characteristics of these domains in outer capsid structural proteins, the present study adds new knowledge and derives the need for further investigation.

Species C Rotaviruses in Children with Diarrhea in India, 2010-2013: A Potentially Neglected Cause of Acute Gastroenteritis.

All over the world, children and adults are severely affected by acute gastroenteritis, caused by one of the emerging enteric pathogens, rotavirus C (RVC). At present, no extensive surveillance program is running for RVC in India, and its prevalence is largely unknown except cases of local outbreaks. Here, we intended to detect the presence of RVC in diarrheic children visiting or admitted to hospitals in Haldwani (state of Uttarakhand, India), a city located in the foothills of the Himalayas. During 2010-2013, we screened 119 samples for RVC by an RVC VP6 gene-specific RT-PCR. Of these, 38 (31.93%) were found positive, which is higher than the incidence rates reported so far from India. The phylogenetic analysis of the derived nucleotide sequences from one of the human RVC (HuRVC) isolates, designated as HuRVC/H28/2013/India, showed that the study isolate belongs to genotype I2, P2 and E2 for RVC structural genes 6 and 4 (VP6, and VP4) and non-structural gene 4 (NSP4), respectively. Furthermore, the VP6 gene of HuRVC/H28/2013/India shows the highest similarity to a recently-reported human-like porcine RVC (PoRVC/ASM140/2013/India, KT932963) from India suggesting zoonotic transmission. We also report a full-length NSP4 gene sequence of human RVC from India. Under the One-health platforms there is a need to launch combined human and animal RVC surveillance programs for a better understanding of the epidemiology of RVC infections and for implementing control strategies.Reoviridae, possess 11 double-stranded segments of RNA that encode six structural viral proteins (VP1, VP2, VP3, VP4, VP6, VP7) and five/six non-structural proteins (NSP1-NSP5/6) [7]. Based on the antigenic properties of the major inner capsid protein (VP6), RVs are subdivided into eight well-characterized species (A-H) and two putative species viz. I and J [8-10]. Humans and other mammalian species are affected by species A, B, C and H rotaviruses and birds by species D, F and G, and species E has been reported exclusively in pigs [7,8,11-17]. The newly-proposed species I is reported in dogs [18] and cats [19], whereas species J is found in bats [10].

Avian Group D Rotaviruses: Structure, Epidemiology, Diagnosis, and Perspectives on Future Research Challenges.

In 1981, a new virus (virus 132) was described for the first time with morphological and biochemical similarities to rotaviruses (RVs), but without antigenic similarity to any of the previously known rotavirus groups. Subsequently, it was re-designated as D/132, and formed a new serogroup among rotaviruses, the group D rotavirus (RVD). Since their identification, RVs are the leading cause of enteritis and diarrhea in humans and various animal species, and are also associated with abridged growth, particularly in avian species. Recently, RVD has been suggested to play a role in the pathogenesis of runting and stunting syndrome (RSS), alongside other viruses such as reovirus, astrovirus, coronavirus, and others, all of which cause colossal economic losses to the poultry industry. RVD has been reported from several countries worldwide, and to date, only one complete genome sequence for RVD is available. Neither an immunodiagnostic nor a vaccine is available for the detection and prevention of RVD infection. Despite our growing understanding about this particular group, questions remain regarding its exact prevalence and pathogenecity, and the disease-associated annual losses for the poultry industry. Here, we describe the current knowledge about the identification, epidemiology, diagnosis, and prevention of RVD in poultry.