Debasis Nayak

Viruses typically infiltrate host cells via specialized cellular receptors, a pivotal step that is challenging when suitable permissive cell lines or hosts are unavailable. Leveraging the unique internal replication machinery of negative-stranded (ns) RNA viruses, we demonstrate that purified nucleocapsid (NCs), their functional genomic templates, can directly initiate a complete viral life cycle upon intracellular delivery, bypassing conventional cell surface interaction. We successfully purified vesicular stomatitis virus (VSV) NCs, including those from a G-deleted pseudotyped variant (rVSV-ΔG-TFP). Exogenous delivery of these NCs into cells stimulated gene expression and generated infectious progeny virions (from full-length NCs). Critically, VSV-ΔG-TFP NCs, though self-amplifying, are inherently non-infectious, offering a safer, potentially more effective alternative for a vaccine development platform compared to live/attenuated viruses or mRNA-based systems. Furthermore, these NCs provide a secure method for transporting components of highly pathogenic nsRNA viruses (e.g., Nipah virus), acting as an inherent self-deactivating feature against accidental exposure. This study establishes NCs as a novel, intrinsically safer, and self-amplifying platform for antiviral screening, vaccine development, gene delivery, and biosafety in pathogen research.

Chandipura virus (CHPV), a Rhabdoviridae family member, is an emerging neurotropic pathogen responsible for acute encephalitis outbreaks in children, mainly in India. Despite its public health relevance, the mechanisms underlying CHPV entry into host cells remain poorly understood. In this study, we used pharmacological inhibitors in Vero cells to dissect the virus's entry pathways. Our results show that CHPV entry is clathrin-dependent and requires intact lipid rafts but is independent of caveolin-mediated endocytosis. The process is pH-dependent, underscoring the role of endosomal acidification in viral uncoating. These findings on CHPV entry mechanisms offer valuable insights for developing host-targeted antivirals.

Tissue adhesives that offer rapid wound sealing, reduce blood loss, enhance aesthetic outcomes, and lower biomedical issues can significantly augment the wound treatment regimen. Taking inspiration from proteinaceous adhesives secreted by marine organisms, herein we designed anionic and cationic polyamide polyelectrolytes (PEs) containing Horseradish Peroxidase (HRP)-responsive phenolic pendants. These PEs underwent facile polyelectrolyte complex (PEC) formation in aqueous medium. The PEC-rich phase was employed to formulate water-based biomedical adhesives that demonstrated robust adhesion to diverse surfaces - from biological tissues like bone to materials such as wood, glass, and metal. The PEC adhesive worked on both dry and wet substrates and its adhesive strength increased with environmental humidity. The strongest adhesion was found for wood with adhesive strength up to 10 MPa. The adhesive could be kept in a lyophilized powder form and reconstituted prior to use without significant impact on the adhesive performance. Furthermore, the PEC adhesive exhibited strong hemostatic and wound-healing capabilities in vivo in mice, significantly surpassing the commercial cyanoacrylate-based tissue adhesives in performance. These findings, coupled with the adhesive's biocompatibility and hemocompatibility, position these enzyme-cured PEC adhesives as promising contender in wound healing applications.

Context Flaviviruses cause severe encephalitic or hemorrhagic diseases in humans. Its members, Kyasanur forest disease virus (KFDV) and Alkhumra hemorrhagic fever virus (ALKV), cause hemorrhagic fever and are prevalent in India and Saudi Arabia, respectively, while the tick-borne encephalitis virus (TBEV) causes a dangerous encephalitic infection in Europe and Asia. However, little information is available about the targets of immune responses for these deadly viruses. Here, we predict potential antigenic peptide epitopes of viral envelope protein for inducing a cell-mediated and humoral immune response. Methods Using the Immune Epitope Database and Analysis Resource (IEDB-AR), we identified 13 MHC-I and two MHC-II dominant conserved epitopes in KFDV and ALKV and six MHC-I and three MHC-II epitopes in TBEV envelope proteins. Parallelly, we also predicted B-cell linear and discontinuous envelope protein epitopes for these viruses. Interestingly, the epitopes are conserved in all three viral envelope proteins. Further, the discontinuous epitopes are structurally compared with the available DENV, ZIKV, WNV, TBEV, and LIV envelope protein antibody structures. Overall structural comparison analyses highlight (i) lateral ridge epitope in the ED-III domain of E protein, and (ii) envelope dimer epitope (EDE) could be targeted for developing potent vaccine candidates as well as therapeutic antibody production. Moreover, existing structural and biochemical functions of the same epitopes in homologous viruses are predicted to have a reduced antibody-dependent enhancement (ADE) effect on flaviviral infection.

Capra hircus (Black Bengal goat) is a prized goat breed reared across the Southeast Asian region. Known for its excellent chevon quality and adaptability to hot and humid climates, it supports the livelihood of millions of farmers. The present study reveals the complete mitogenome of a Black Bengal goat of Indian origin utilizing a next-generation sequencing approach (GenBank acc. no.-MZ073671). This newly assembled whole mitochondrial genome (16,637 bp) is composed of a non-coding control region (D-loop region), two ribosomal RNA (rRNA genes), 13 protein-coding genes, and 22 transfer RNA (tRNA). Overall, the current mitogenome shares 99.77% sequence homology with previously reported mitogenomes of Capra hircus. The phylogenetic analysis inferred that the current mitogenome shares a close relationship with the Teressa goat breed of the Andaman and Nicobar Islands.

Avian pox disease is a highly contagious infection caused by pox virus and has serious consequences on avian species with regards to economic and conservation aspects. This viral genus named as Avipox virus (APV) that infects nearly 300 bird species and lack of enough complete genome information creates hindrance to infer this virus biology. Thus in this study, we have revealed the first complete genome of an Indian pigeon pox virus that belongs to the genus APV followed by comparative genomics analysis. The entire genome of present isolate (PPV/Pur-Od-4b/01/Ind) having 280058 bp nucleotide sequences with the GC content 29.51%. The unique feature of this complete genome revealed the presence of 270 open reading frames (ORFs) circumscribed by inverted terminal repeats (ITRs) of 4,689 bp at each end and lack of recombination events. The concatenated amino acid phylogenetic tree deciphered the present isolate closely related with Feral Pigeon pox virus derived from Africa. The molecular markers, such as microsatellites were ubiquitously distributed throughout the genome and more prevalent within the functional genes.

Nipah virus (NiV) causes severe encephalitis in humans. Three NiV strains NiV‐Malaysia (NiV_M), NiV Bangladesh (NiV_B), and NiV India (NiV_I reported in 2019) have been circulating in South‐Asian nations. Sporadic outbreak observed in South‐East Asian countries but human to human transmission raises the concern about its pandemic potential. The presence of the viral genome in reservoir bats has further confirmed that NiV has spread to the African and Australian continents. NiV research activities have gained momentum to achieve specific preparedness goals to meet any future emergency—as a result, several potential vaccine candidates have been developed and tested in a variety of animal models. Some of these candidate vaccines have entered further clinical trials. Research activities related to the discovery of therapeutic monoclonal antibodies (mAbs) have resulted in the identification of a handful of candidates capable of neutralizing the virion. However, progress in discovering potential antiviral drugs has been limited. Thus, considering NiV's pandemic potential, it is crucial to fast‐track ongoing projects related to vaccine clinical trials, anti‐NiV therapeutics. Here, we discuss the current progress in NiV‐vaccine research and therapeutic options, including mAbs and antiviral medications.