M. S. Gambo, Manjunath S. Hurakadli, Man Mohan Baghel, S. A. Suleiman, Nitin Jangra, Aditya Dagar
The rapid spread of begomoviruses (family Geminiviridae) threatens global cucurbit production, yet the drivers of their emergence and the readiness of management strategies remain poorly integrated. This review synthesizes current understanding of cucurbit-infecting begomoviruses, contrasting the intercontinental spread of key Old World viruses, particularly Tomato leaf curl New Delhi virus (ToLCNDV), with persistent New World complexes such as Squash leaf curl virus (SLCV) and Cucurbit leaf crumple virus (CuLCrV). It examines how recombination, pseudorecombination and betasatellites drive host-range expansion and intensify disease severity; provides a comparative framework for diagnostic methods — including PCR, isothermal amplification (LAMP, RPA) and portable sequencing — highlighting differences in sensitivity, speed and field-deployability; and evaluates integrated management strategies from host resistance and vector control to RNA interference and CRISPR-based approaches. Finally, it identifies priority research needs in genomic surveillance, field-deployable diagnostics and durable region-specific resistance to sustain cucurbit production under intensifying climate change and whitefly pressure.
The ubiquity of Micro- and nanoplastics (MP/NPs) pollution has reached a critical point, with these synthetic particles now detected across all environmental compartments and within human systemic circulation. As the global landscape faces an escalating frequency of viral outbreaks, there is an urgent need to understand how persistent xenobiotics modulate host-pathogen dynamics. This review posits that MP/NPs represent the “missing link” between environmental degradation and the rising severity of infectious diseases. By synthesizing recent toxicological and immunological data, here we delineate how MP/NPs function as biological “Trojan horses.” By forming a complex “chemical corona,” MP/NPs stabilize viral particles, enhancing their persistence and facilitating their translocation across compromised mucosal barriers. At the cellular level, internalized MP/NPs trigger chronic immune dysfunction by overactivating the NLRP3 inflammasome and inducing mitochondrial oxidative stress, while paradoxically suppressing essential antiviral signaling pathways, such as the type I interferon response. Furthermore, we highlight novel mechanisms of MP/NPs-mediated viral dissemination via migrasomes and hypothesize their potential to exacerbate chronic viral infections like HIV. Our findings redefine MP/NPs not merely as inert contaminants but as potent immunological modifiers that heighten host susceptibility and alter viral pathogenicity. This paradigm shift is vital for advancing One Health strategies and refining risk assessments in an increasingly plastic-polluted world.
Movement proteins (MPs) are essential for plant virus spread, mediating cell-to-cell transport through plasmodesmal connections. A plethora of studies have been reported for molecular characterization of Tobamovirus fructirugosum (tomato brown rugose fruit virus, ToBRFV) and its interactions with the host plants, however subcellular localization of the ToBRFV-movement protein (ToBRFV-MP) has not been reported in any host to date. Here, we investigated the subcellular localization of 266 amino acid long ToBRFV-MP in Nicotiana glutinosa using a transient expression system. The expression construct comprising N-terminal cMyc-tagged MP fused to cyan fluorescent protein (ToBRFV-MP-CFP) at its C-terminus via a five-amino acid linker sequence (GGGGS), and driven by CaMV 35S promotor was cloned into pCAMBIA2300 binary vector for the expression of recombinant fusion protein, and designated as pCAM-ToBRFV-MP-CFP. This construct was introduced into Agrobacterium tumefaciens LBA4404 for in planta expression through standard agroinfiltration assay. The expression and integrity of about 59 kDa fusion protein was confirmed in Western blot analysis using anti-cMyc tag antibody. The localization of MP-CFP fusion protein to inner cell periphery was suggested by the cyan fluorescence, in a distinct punctate pattern, under confocal laser scanning microscopy. Subsequent aniline blue staining demonstrated the co-localization of MP-CFP fluorescence alongside the plasmodesmata-associated callose deposits, supporting plasmodesmal localization of movement protein. These findings demonstrated the first experimental evidence for the plasmodesmata-associated localization of the ToBRFV-MP, and was in support of its proposed role in inter- and intracellular movement. By establishing this transient expression system, we have created conditions for analyzing the behavior of viral movement proteins in diverse plant species and gained insight into their role in the trafficking of viruses through plasmodesmata.
Reham M. Alahmadi, Maaweya Awadalla, Halah Z. Al-Rawi, Ayman Mubarak, Wafa Ali Eltayb, Mohnad Abdalla, Han Yu, Bandar Alosaimi
Human metapneumovirus (HMPV) is a leading cause of acute respiratory tract infections in infants, older adults, and immunocompromised individuals; however, no licensed vaccine is currently available. This study employed an immunoinformatics-guided reverse vaccinology approach to design novel BAFF- and APRIL-adjuvanted multi-epitope vaccine candidates against HMPV. Major structural and non-structural HMPV proteins, including fusion (F), attachment glycoprotein (G), (matrix) M2-1, M2-2, phosphoprotein (P), nucleoprotein (N), small hydrophobic (SH), and RNA-dependent RNA polymerase (L) proteins, were screened for antigenicity. Cytotoxic T lymphocyte (CTL), helper T lymphocyte (HTL), B-cell, and interferon-γ (IFN-γ)-inducing epitopes were predicted and evaluated for antigenicity, allergenicity, toxicity, and immunogenicity before being assembled into multi-epitope constructs using appropriate peptide linkers. BAFF and APRIL were incorporated as candidate immunomodulatory components based on their established roles in B-cell biology and humoral immune responses. The final vaccine constructs contained 24 selected epitopes (8 CTL, 8 HTL, and 8 B-cell epitopes) and demonstrated favorable predicted antigenicity, stability, hydrophilicity, thermostability, and non-allergenic and non-toxic properties. Secondary structure analysis revealed balanced proportions of α-helices, β-strands, and random coils, supporting structural stability and epitope accessibility. Molecular docking predicted putative interactions between the vaccine constructs and Toll-like receptors TLR1 and TLR4, with the predicted complexes exhibiting multiple intermolecular contacts at the receptor-ligand interfaces. These findings suggest structural compatibility between the vaccine constructs and the selected TLRs; however, functional receptor binding and activation require experimental validation. The in silico analyses identified BAFF- and APRIL-containing multi-epitope constructs with favorable predicted antigenic, physicochemical, structural, and immunological characteristics that warrant further experimental investigation. These computational findings provide a basis for prioritizing candidate constructs. Nevertheless, molecular dynamics simulations and in vitro and in vivo studies are required to validate the structural stability, immunogenicity, safety, and protective efficacy of the proposed vaccine candidates.
Jerrell Tisnado, Ana Luisa Duran Meza, David Silverio Moreno Gutierrez, Nina M. Harpell, Alyssa Cruz, Charles M. Knobler, William M. Gelbart
Virus-like particles (VLPs) derived from Tobacco mosaic virus (TMV) have emerged as attractive platforms for nanotechnology and molecular delivery applications owing to their robust self-assembly, stoichiometric precision, and highly accessible surface architecture. Here we report the development of a yeast-based platform for the production of TMV VLPs – nanorods – that can be site-specific functionalized and that contain RNA of interest. TMV coat proteins engineered with a C-terminal LPETG Sortase A (SrtA) recognition motif were expressed in Komagataella phaffii along with a self-amplifying RNA construct containing the TMV origin of assembly sequence (OAS) – the “packaging signal” – enabling the intracellular formation of nanorods. Transmission electron microscopy (TEM) confirmed the assembly of particles with wildtype TMV virion morphology, while RT-PCR analysis of these purified VLPs preparations demonstrated their packaging of target RNA. The accessibility of the engineered LPETG motif following assembly enabled SrtA mediated conjugation of N-terminal polyglycine-modified ligands, including fluorescent polyG-Alexa probes and a targeting affibody. Successful conjugation was verified by SDS-PAGE and fluorescence analyses, demonstrating efficient post-assembly functionalization while preserving particle integrity. Further, affibody-functionalized TMV nanorods were coupled to gold nanoparticles, and TEM confirmed the surface presentation and accessibility of the conjugated ligands on intact particles. Together, these results establish K. phaffii as a scalable platform for the production of engineered TMV nanorods and demonstrate that genetically encoded SrtA recognition motifs enable versatile post-assembly surface modification. This approach provides a modular framework for the development of customizable TMV-based nanomaterials for in vivo targeting, imaging, and nanobiotechnology applications.
