Biology subjects

Raut, R.

Publications and source records attributed to Raut, R..

7 recordsLinked to original sources

bioRxiv2026

Dengue serotype-1 virus like particles induce antibody responses following HeLa cell expression

Dengue disease remains a significant global health threat, with current vaccines exhibiting variable efficacy and safety concerns. Virus-like particles (VLPs) offer a promising alternative by mimicking native virus structures without infectious genomes. We engineered a mammalian expression plasmid encoding Dengue-1 prM and E proteins, optimized for secretion using Japanese Encephalitis virus signal sequences, and transiently expressed it in HeLa cells. Purified VLPs exhibited spherical morphology ([~]39 nm diameter) consistent with native virions, as confirmed by transmission electron microscopy. Immunization of mice with these VLPs elicited robust Dengue-1 specific IgG antibody responses. Our study demonstrates production of immunogenic Dengue-1 VLPs in HeLa cells, highlighting their potential as a vaccine candidate and a tool for serodiagnosis. Further characterization of VLP epitopes and protective efficacy is warranted to advance vaccine development. ImportanceDengue remains a significant global health challenge, with serotype 1 being one of the dominant strains causing recurrent outbreaks in Nepal. Existing vaccines demonstrate limited efficacy and pose significant safety concerns, particularly in seronegative populations. To address these limitations, this study explores virus-like particles (VLPs) as a safer alternative vaccine platform. VLPs elicit robust immunogenicity by mimicking the structure of native virus while completely lacking genetic components. This study combines DENV1 structural proteins with optimized expression systems to enhance immunogenicity. This work is particularly significant as the first dengue vaccine research conducted in Nepal, directly addressing antigenic mismatches between existing commercial vaccines and locally circulating viral strains. Furthermore, the study provides scalable platform for developing region-specific dengue vaccines for other serotypes and flaviviruses.

immunology↗

bioRxiv2026

Rapid Isolation and Genomic Characterization of Sewage-Derived Bacteriophages Targeting Multidrug-Resistant Avian Pathogenic Escherichia coli in Poultry

Antimicrobial resistance (AMR) in Escherichia coli is a major threat to global poultry production, particularly for controlling colibacillosis caused by avian pathogenic E. coli (APEC). Intensive antibiotic use has accelerated the emergence of multidrug-resistant (MDR) strains, undermining treatment efficacy and facilitating zoonotic transmission of resistance genes. This study evaluated bacteriophage therapy as a targeted, antibiotic-independent strategy to control MDR E. coli in Nepalese poultry systems. Seventeen E. coli isolates were obtained from commercial broiler and local-breed chicken farms. Using the double-layer agar method, 18 lytic phages were isolated from three urban sewage samples, infecting eight isolates. Real Time PCR screening revealed extensive AMR profiles in six isolates; one broiler-derived strain (EcI8) harbored 30 resistance genes, including carbapenemases, ESBLs, aminoglycoside, quinolone, and last-resort antibiotic determinants associated with class 1 and 3 integrons. Purified phages were whole-genome sequenced and all of them belonged to the genera Tequatrovirus, Phapecoctavirus, Vequintavirus, and Gamaleyavirus--lineages previously used in veterinary and human phage therapy. Several exhibited broad host ranges (up to seven isolates) and lacked detectable virulence or resistance genes; they also encoded potent lytic enzymes, including endolysins, holins, spanins, and transglycosylases. Notably, one Phapecoctavirus (PG7) showed close similarity to established APEC-infecting phages. These findings demonstrate that sewage can be a readily accessible source of safe, therapeutically relevant phages targeting highly resistant poultry E. coli. Phage cocktails and derived enzybiotics delivered through drinking water or feed offer a scalable alternative for preventing and treating colibacillosis, reducing antibiotic dependence, and mitigating zoonotic AMR risks. This study establishes a rapid, reproducible pipeline for local phage isolation and genomic validation, supporting field deployment of tailored phage-based interventions in resource-limited poultry systems.

microbiology↗

bioRxiv2025

Stimulant medications affect arousal and reward, not attention

Prescription stimulants such as methylphenidate are being used by an increasing portion of the population, primarily children. These potent norepinephrine and dopamine reuptake inhibitors promote wakefulness, suppress appetite, enhance physical performance, and are purported to increase attentional abilities. Prior functional magnetic resonance imaging (fMRI) studies have yielded conflicting results about the effects of stimulants on the brains attention, action/motor, and salience regions that are difficult to reconcile with their proposed attentional effects. Here, we utilized resting-state fMRI (rs-fMRI) data from the large Adolescent Brain Cognitive Development (ABCD) Study to understand the effects of stimulants on brain functional connectivity (FC) in children (n = 11,875; 8-11 years old) using network level analysis (NLA). We validated these brain-wide association study (BWAS) findings in a controlled, precision imaging drug trial (PIDT) with highly-sampled (165-210 minutes) healthy adults receiving high-dose methylphenidate (Ritalin, 40 mg). In both studies, stimulants were associated with altered FC in action and motor regions, matching patterns of norepinephrine transporter expression. Connectivity was also changed in the salience (SAL) and parietal memory networks (PMN), which are important for reward-motivated learning and closely linked to dopamine, but not the brains attention systems (e.g. dorsal attention network, DAN). Stimulant-related differences in FC closely matched the rs-fMRI pattern of getting enough sleep, as well as EEG- and respiration-derived brain maps of arousal. Taking stimulants rescued the effects of sleep deprivation on brain connectivity and school grades. The combined noradrenergic and dopaminergic effects of stimulants may drive brain organization towards a more wakeful and rewarded configuration, explaining improved task effort and persistence without direct effects on attention networks.

neuroscience↗

bioRxiv2025

LSD1 inhibition corrects dysregulated MHC-I and dendritic cells activation through IFNγ-CXCL9-CXCR3 axis to promote antitumor immunity in HNSCC

Poor infiltration of CD8+ T cells and dysregulated MHC-I confer resistance to anticancer clinical therapies. This study aimed to elucidate the mechanisms of lysine-specific demethylase 1 (LSD1, encoded by KDM1A gene) in antitumor immunity in Head and Neck Squamous cell carcinoma (HNSCC). LSD1 inhibition in syngeneic and chronic tobacco carcinogen-induced HNSCC mice recruited activated dendritic cells (DCs), CD4+ and CD8+ T cells, enriched interferon-gamma (IFN{gamma}) in T cells, CXCL9 in DCs, and CXCR3 in T cells, as evaluated using flow cytometry and single-cell RNA-seq analysis. Humanized HNSCC mice and TCGA data validated the inverse correlation of KDM1A with DC markers, CD8+ T cells, and their activating chemokines. Kdm1a knockout in mouse HNSCC and LSD1 inhibitor treatment to co-culture of human HNSCC cells with human peripheral blood mononuclear cells (PBMCs) resulted in MHC-I upregulation in cancer cells for efficient antigen presentation in tumors. Overall, LSD1 inhibition in tumor cells upregulates MHC class I and induces DCs to produce CXCL9, which in turn activates CD8+ T cells through the CXCL9-CXCR3 axis to produce IFN{gamma}. Finally, we identified a novel mechanism by which LSD1 inhibition promotes the activation of H3K4me2 and its direct interaction with MHC-I to induce antitumor immunity. This may have implications in poorly immunogenic and immunotherapy-resistant cancers. Statement of SignificanceLSD1-mediated unique mechanisms have impact on epigenetic therapy, MHC-I resistant HNSCC therapies, and poor CD8+ and dendritic cell infilterated tumors.

cancer biology↗

bioRxiv2024

Insulin-like Growth Factor 2 mRNA-binding protein 2 (IGF2BP2) Promotes Castration-Resistant Prostate Cancer Progression by Regulating AR-V7 mRNA Stability

The emergence of constitutively active androgen receptor (AR) splice variant AR-V7 poses a formidable challenge in treating prostate cancer, as it lacks the ligand binding region targeted by androgen deprivation therapies such as enzalutamide and abiraterone. AR-V7 is critical for castration-resistant prostate cancer (CRPC) development and progression, however the molecular mechanisms regulating its expression and biological function remain poorly understood. Here, we investigate the role of IGF2BP2 in regulating AR-V7 expression and CRPC progression. We demonstrate that IGF2BP2 silencing leads to downregulation of AR-V7 and its downstream target genes without affecting AR levels. Additionally, IGF2BP2 knockdown also enhances the sensitivity of CRPC cells to enzalutamide while overexpression increases AR-V7 expression and confers increased resistance to enzalutamide. Mechanistically, our experiments demonstrate that IGF2BP2 binds to the intronic splicing enhancer (ISE) region of AR-V7, thereby enhancing its mRNA stability Furthermore, our domain-deletion analysis pinpoints the role of KH3 and KH4 domains of IGF2BP2 in regulating AR-V7 stability and enzalutamide resistance. Taken together, our findings suggest that IGF2BP2 plays a critical role in regulating AR-V7 expression and stability, offering a novel target for developing therapeutic interventions for CRPC.

cancer biology↗

bioRxiv2023

Teaching transposon classification as a means to crowd source the curation of repeat annotation - a tardigrade perspective

The advancement of sequencing technologies results in the rapid release of hundreds of new genome assemblies a year providing unprecedented resources for the study of genome evolution. Within this context, the significance of in-depth analyses of repetitive elements, transposable elements (TEs) in particular, is increasingly recognized in understanding genome evolution. Despite the plethora of available bioinformatic tools for identifying and annotating TEs, the phylogenetic distance of the target species from a curated and classified database of repetitive element sequences constrains any automated annotation effort. Manual curation of raw repeat libraries is deemed essential due to the frequent incompleteness of automatically generated consensus sequences. However, manual curation and classification are time-consuming processes that offer limited short-term academic rewards and are typically confined to a few research groups where methods are taught through hands-on experience. Crowd sourcing efforts could offer a significant opportunity to bridge the gap between learning the methods of curation effectively and empowering the scientific community with high-quality, reusable repeat libraries. Here, we present an example of such crowd sourcing effort developed through both in-person and online courses built around a collaborative peer-reviewed teaching process that can be used as teaching reference guide for similar projects. The collaborative manual curation of TEs from two tardigrade species, for which there were no TE libraries available, resulted in the successful characterization of hundreds of new and diverse TEs: A hidden treasure awaits discovery within non-model organisms.

evolutionary biology↗

bioRxiv2022

Identification and Characterization of Probiotics Isolates from Indigenous Chicken (Gallus domesticus) of Nepal

BackgroundExcessive and irrational use of antibiotics as growth promoters in poultry has been one of key factors contributing to increased emergence of antibiotics resistant bacteria. Drug resistant infections are becoming major concerns in poultry production impacting both human and poultry health. Several alternatives for antibiotic growth promoters are being sought, and the search for effective probiotics to be used as feed additives is amongst the promising ones. Our study aimed to isolate and test potential probiotics bacteria from cloacal swabs of various indigenous chicken (Gallus domesticus) breeds from rural outskirts of the Kathmandu valley (Nepal). MethodsSelective isolation of probiotics was conducted by micro-aerophilic enrichment of sample in MRS Broth at 37{degrees}C, followed by culturing on MRS agar supplemented with 5 g/L of CaCO3. Isolated bacterial colonies producing transparent halo were selected as potential lactic acid bacteria (LAB), and tested for their antibacterial activity, phenotypic and biochemical characteristics, acidic yield, and tolerance to acid and bile. ResultsA total of 90 potential LAB were isolated from cloacal samples collected from 41 free-ranging chickens of indigenous breeds. Of these, 52 LAB isolates (57%) showed variable antibacterial activity to at least one bacterial pathogen. Of 52 LAB, 46 isolates fulfilled phenotypic and biochemical criteria of Lactobacillus spp. Of these, 37 isolates produced varying percentage yields of lactic acid, 27 isolates showed survival at pH 3.0, and 17 isolates showed survival tolerances in the presence of 0.3% and 0.5% bile salts for 24 hours. Phylogenetic analysis of 16SrDNA sequencing of LAB isolates fulfilling in vitro probiotics properties showed that 3 isolates had genetic identity of 99.38% with Lactobacillus plantarum, while one isolate was genetically similar (99.85%) with the clade of L. reuteri, L. antri and L. panis. ConclusionsOur study identified four Lactobacillus spp. strains having potential probiotics properties. Further investigations are needed to evaluate these isolates to be used as poultry probiotics feed supplement.

microbiology↗