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Culture of infectious human norovirus isolated from live contaminated oysters.

Human noroviruses are a major cause of foodborne outbreaks worldwide. Filter-feeding shellfish, such as oysters, can bioaccumulate these viruses in their digestive tissue when grown in sewage-impacted coastal areas and are often implicated in norovirus foodborne outbreaks. Despite the high sensitivity of current molecular assays, these methods for norovirus detection in shellfish fail to distinguish between infectious and non-infectious particles. Assessing norovirus infectivity in shellfish remains a challenge due to the lack of suitable isolation methods that maintain capsid integrity. In this study, a protocol for isolating infectious norovirus from oyster tissues, based on chloroform-butanol elution and polyethylene glycol concentration (CB-PEG), was optimized for the recovery of human norovirus GI and GII. While CB-PEG method recovered various norovirus GI and GII genotypes, it was less efficient at the genomic level than a protocol based on proteinase K elution (adapted from ISO 15216) and showed genotype-dependent viral recovery rates. By optimizing the flocculation step, we improved the method's compatibility with human intestinal enteroid (HIE) cultures. Using this approach, we successfully quantified infectious norovirus GII.3 titers recovered from artificially-contaminated live oysters. Interestingly, infectious virus was better isolated following a freezing step of the digestive tissues, with titers ranging from 13 to 40 TCID50/mL for positive samples. In conclusion, this study established an optimized methodological approach for the relative quantification of infectious norovirus GII.3 in shellfish, paving the way for future research on viral persistence and inactivation strategies in this foodstuff.

Norovirus

Development and protective efficacy of a live attenuated vaccine candidate against goose astrovirus.

Goose astrovirus (GAstV) is a significant pathogen affecting goslings by inducing visceral gout, yet no commercial vaccine is currently available. This study involved the serial passaging of the GAstV-GXNN strain in LMH cells to investigate alterations in viral replication, genomic stability, and pathogenicity, as well as to assess the potential of a vaccine candidate. The findings indicated that the viral titer increased progressively with each passage, reaching 107.35 TCID50/mL by the 120th passage (GAstV-GXNNP120). Whole-genome sequencing revealed the presence of 6, 19, 26, and 28 nucleotide mutations at the 30th, 60th, 90th, and 120th passages, respectively. Pathogenicity assays demonstrated a reduction in virulence with successive passages, culminating in the complete attenuation of GAstV-GXNNP120, which did not induce clinical signs or lesions in one-day-old goslings. Following five successive passages in goslings, the attenuated strain exhibited stable genetic characteristics without any reversion to virulence. Goslings aged one day, inoculated with GAstV-GXNNP120 at dosages ranging from 102.0 to 105.0 TCID50, developed neutralizing antibodies by the third day post-vaccination. Antibody levels increased in a dose-dependent manner, peaking at day 21 and remaining elevated through day 42. Challenge experiments utilizing the virulent GAstV-GXNN strain revealed that groups vaccinated with doses of 103.0 TCID50 and above achieved complete protection. These groups exhibited no clinical symptoms or pathological damage post-challenge, and both tissue viral loads and virus shedding levels were significantly reduced compared to the control group. Consequently, the minimum effective vaccination dose was established at 103.0 TCID50. These results provide a crucial foundation for the development of a live attenuated GAstV vaccine.

Animals

Molecular characterization and biological characteristics of a highly pathogenic recombinant ALV-J strain (HUE2023) with cross-clade gp85 recombination.

Avian leukosis virus subgroup J (ALV-J) has undergone extensive diversification into phylogenetically distinct clades, yet whether recombination between these clades within the gp85 envelope glycoprotein generates variants with altered pathogenicity has received little direct investigation. A field strain (HUE2023) was recovered from breeding roosters displaying vascular tumors. The viral genome was sequenced and subjected to phylogenetic and recombination analyses. The three-dimensional structure of gp85 was predicted with AlphaFold3; electrostatic surface potentials and surface hydrophobicity were computed using the Adaptive Poisson-Boltzmann Solver and the Eisenberg hydrophobicity scale, respectively. Pathogenicity and immunosuppressive effects were assessed in Hy-Line Brown chickens. Recombination analysis revealed that HUE2023 is an inter-clade recombinant derived from Clade 1.1 (major parent: JS14NT01) and Clade 1.2 (minor parent: JS09GY3). A single-residue deletion at position 61 within receptor-binding domain 1 (RBD-1), unique to the recombinant, induced a localized conformational rearrangement that generated a concentrated electronegative surface patch and a contiguous hydrophobic pocket not observed in either parental gp85. Animal challenge showed that HUE2023 is highly pathogenic: female chickens in the high-dose group reached only 61% survival and displayed significant growth retardation (P&#x202f;<&#x202f;0.05) together with marked immunosuppression. The recombination in the RBD-1 led to local conformational rearrangement, resulting in a concentrated and negatively charged surface area as well as a continuous hydrophobic pocket, which were never present in any of the parental gp85 sequences. These results indicate that gp85 recombination across clades can yield variants with fundamentally altered receptor-binding surfaces and argue for integrating structural surveillance into ALV-J monitoring programmes.

Animals

Genome-wide identification and characterization of ABC transporters and their expression in response to saline-alkaline stress and WSSV infection in Fenneropenaeus chinensis.

ATP-binding cassette (ABC) transporters play crucial roles in stress responses across organisms, yet their functions in Fenneropenaeus chinensis remain largely unknown. In this study, we identified 42 FcABC genes (FcABCs) in the F. chinensis genome and analyzed their phylogenetic relationships, gene structures, and chromosomal distributions. Phylogenetic analysis grouped the FcABCs into eight subfamilies (ABCA-ABCH), with conserved motif and domain compositions within each subfamily. Expression analysis showed that several FcABC genes, including FcABCG5, FcABCA1, and FcABCC3, were significantly induced under saline-alkaline stress in gill and hepatopancreas tissues. In contrast, most FcABCs were downregulated after WSSV challenge, though a subset (e.g., FcABCB1, FcABCC1) exhibited early upregulation. Functional validation via RNA interference demonstrated that knockdown of FcABCG5 increased shrimp mortality under saline-alkaline stress. Cis-regulatory element analysis revealed an enrichment of stress- and immune-related elements in FcABC promoters. Protein-protein interaction network predictions indicated potential roles for FcABCs in cholesterol metabolism and organic anion transport. Our findings provide insights into the roles of FcABC genes in stress adaptation and immune defense, offering candidate genes for the breeding of stress-resistant shrimp varieties.

Animals

Pretreatment EBV-DNA/TLG-Based Risk Stratification Is Associated With Survival Outcomes in Nonmetastatic Nasopharyngeal Carcinoma: An Exploratory Study.

Whether combining pretreatment plasma Epstein-Barr virus DNA (EBV-DNA) with 18F-FDG PET/CT-derived total lesion glycolysis (TLG) improves prognostic stratification in nonmetastatic nasopharyngeal carcinoma (NPC) is unclear, particularly in nonendemic populations. We retrospectively analyzed 86 eligible nonmetastatic NPC patients treated with definitive radiotherapy (2010-2024) at a single nonendemic-region institution. EBV-DNA (prespecified cutoff 3500 copies/mL) and TLG (cutoff 200, ROC-derived within this cohort) were dichotomized. Both were available in 59/86 patients (68.6%), who differed from the rest in nodal and overall stage and in RT technique. Baseline PET/CT was in-house in 57 of 86 patients, and a robustness analysis in that subgroup is reported. Given limited events (13 PFS, 9 OS), Cox analyses are exploratory and were supplemented with penalized regression and bootstrap validation. At a median follow-up of 75.5&#x2009;months, 5-year PFS and OS for the whole cohort (n&#x2009;=&#x2009;86) were 81.1% and 85.9%. The EBV-DNAhigh/TLGhigh subgroup remained associated with inferior PFS after adjustment in an exploratory model (adjusted HR&#x2009;=&#x2009;3.97, 95% CI: 1.32-11.93) and, in a single-variable model, with inferior OS (HR&#x2009;=&#x2009;4.13, 95% CI: 1.10-15.52). Discrimination was comparable to the individual-biomarker model for PFS and lower for OS. Five-year PFS fell monotonically across the four risk groups in the complete-case cohort (n&#x2009;=&#x2009;59; 89.7%-58.3%). OS differed across groups (log-rank p&#x2009;=&#x2009;0.044) but was not strictly monotonic, with wide, overlapping confidence intervals. This two-biomarker model is hypothesis-generating and needs prospective, multicenter validation before any consideration of risk-adapted treatment.

Epstein&#x2013;Barr virus DNA

Influenza as a Less Commonly Recognized Cause of Hemophagocytic Lymphohistiocytosis: A Systematic Review of Case Reports and Case Series.

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hyper-inflammatory condition that can be triggered by viral infections. However, influenza is not commonly recognized as a cause of HLH, and there is no comprehensive synthesis of influenza-associated HLH in the literature to guide clinicians. We conducted a systematic search of Pubmed and Embase to identify case reports and case series on influenza-associated HLH, and included 29 articles involving 47 patients. Their age ranged from 2&#x2009;months to 72&#x2009;years. 67% were males. Influenza A accounted for 91.3% of the cases, predominantly H1N1 (90.2%). All patients had fever, 60% had anemia, 69.7% had thrombocytopenia, 46.6% had leukopenia, 61.3% had splenomegaly, 71.4% had hypertriglyceridemia, and 94.7% had elevated ferritin levels. 97.6% had hemophagocytosis on biopsy. Antiviral therapy was administered in 89.5% of patients. HLH-directed therapy included corticosteroids (77%), intravenous immunoglobulin (36%), and etoposide (23.1%). Intensive care was required in 95.2% of cases. Overall survival was 53.2%. Survival rate was 50% among patients who received either antiviral therapy alone or HLH-directed therapy alone, compared with 65.4% among those who received both. Further studies are necessary to establish standardized diagnostic and therapeutic protocols for influenza-associated HLH.

Humans

In Vivo Genome Editing Approach to Disrupt Hydroxyacid Oxidase 1 for the Treatment of Primary Hyperoxaluria Type 1.

Primary hyperoxaluria type 1 (PH1) is a rare autosomal recessive disorder that leads to kidney and liver failure. PH1 is caused by a mutation in the alanine glyoxylate aminotransferase (AGXT) gene, which encodes a key metabolic enzyme that converts glyoxylate to glycine in the liver. Inability to metabolize glyoxylate leads to oxalate overproduction, yielding insoluble calcium oxalate crystals; accumulation of these crystals leads to progressive organ failure. Here, we used a novel, minimally disruptive genome-editing approach to disrupt the mechanism of action of hydroxyacid oxidase 1 (HAO1), an upstream enzyme in the glyoxylate metabolic pathway. Successful gene editing and disruption of the HAO1 gene is expected to increase levels of glycolate, a harmless intermediate of the glycine metabolic pathway, thereby preventing the formation of calcium oxalate crystals. We intravenously administered an adeno-associated virus (AAV) vector expressing the M1HAO1 meganuclease to both wild-type and Agxt-/- mice, a mouse model of PH1. We observed >30% editing of HAO1 in Agxt-/- mice, correlating with a dose-dependent increase in serum glycolate levels. At the highest dose tested, urine glycolate levels increased by 79%, with a concomitant 75% decrease in urine oxalate levels. We also evaluated in&#xa0;vivo targeting in rhesus macaques injected with AAV expressing two different versions of the HAO1 meganuclease. Dose-dependent editing of hepatic DNA and RNA was achieved, and serum glycolate levels changed in a manner consistent with successful liver editing; additionally, the treatment was well tolerated. Our results indicate that AAV-delivered meganucleases can effectively target HAO1 in mice and nonhuman primates to achieve high levels of HAO1 gene editing. Moreover, increased glycolate levels in serum indicate that this intervention significantly impacts the HAO1-mediated glycolate-to-glyoxylate pathway. These data suggest that this approach may represent an effective treatment for PH1.

Hyperoxaluria, Primary

A multi-model genome-wide association study identifies genetic variants underlying resistance to Largemouth Bass Ranavirus (LMBV) in Micropterus salmoides.

Largemouth bass (Micropterus salmoides) is an economically important freshwater aquaculture species, yet recurrent outbreaks of Largemouth Bass Ranavirus (LMBV) continue to impair production and cause substantial losses. The genetic basis of host variation in LMBV resistance remains insufficiently characterized. Here, we applied a multi-model genome-wide association study (GWAS) to identify loci associated with resistance following a controlled challenge with the LMBV-23PY strain. Whole-genome resequencing was performed for 146 phenotyped fish, including 72 susceptible and 74 resistant individuals. After stringent quality control, 877,262 high-quality variants were retained and tested using six GWAS models. Across binary survival status and survival time phenotypes, 32 shared suggestive variants were consistently detected across models, representing suggestive loci for LMBV-23PY resistance. Genes within &#xb1;50&#xa0;kb of these loci were annotated, and functional enrichment highlighted immune- and redox-related biological processes. Three prioritized candidates-GSTT3L (glutathione S-transferase theta-3-like), CGRP2 (calcitonin gene-related peptide 2), and NPPC (natriuretic peptide C)-were associated with pathways involved in oxidative stress responses and immune regulation. Collectively, these results provide insight into the genetic architecture of LMBV-23PY resistance in largemouth bass and identify suggestive variants and associated candidate genes for downstream validation, functional interrogation, and the development of marker-assisted and genome-enabled breeding strategies.

Animals

A conserved distal-tail helical extension defines a tailspike attachment architecture in Gram-negative siphophages.

Rapid growth of bacteriophage genome collections has outpaced functional annotation of tail-tip proteins, limiting comparative analysis of host-recognition structures. Starting from a shared distal-tail gene organization in the Salmonella phages 9NA and Jersey, I developed a morphogenetic bioinformatic framework integrating gene synteny, sequence comparison, profile hidden Markov model (HMM) screening, structural evidence, structure-aware searching, and AlphaFold modeling. Comparison with the experimentally characterized lambda and Sf11 tail assemblies identified a predominantly alpha-helical C-terminal extension of the distal-tail (DT) protein associated with tailspike attachment, termed the distal-tail helical extension (DT-helix). Screening 541,986 proteins from 5167 complete NCBI RefSeq tailed-phage genomes, followed by evidence-based evaluation of sequence, genomic context, and structural architecture, identified 165 curated DT-helical-extension-associated phages. Their DT proteins segregated into six sequence groups. In the four principal multi-member groups, cognate tailspikes showed group-specific conservation in proximal N-terminal regions but substantially greater downstream diversity, consistent with sequence constraint at the DT-tailspike attachment boundary. A complementary ProstT5/Foldseek search supported the established groups but revealed no convincing additional highly divergent family. Together with the experimentally characterized Sf11 attachment interface, these findings define a recurrent morphogenetic architecture linking conserved distal-tail scaffolds to more variable receptor-binding proteins across siphophages infecting Gram-negative bacteria. Although universal exchangeability is not established, the identified scaffold-receptor-binding boundaries provide a framework for molecular characterization and rational phage engineering. Accession-level information for the 165 curated phages is available through PhageTailDB.

Viral Tail Proteins

A 4-year longitudinal wastewater surveillance of five gastroenteritis viruses and the correlation with clinical cases in Alberta, Canada.

Viruses are common causes of acute gastroenteritis worldwide. They are detected in large quantities in raw sewage making them amenable to wastewater-based surveillance (WBS). To monitor the prevalence of gastroenteritis viruses in wastewater and assess their correlation with clinical cases, wastewater samples collected between July 2020 and June 2024 from 12 wastewater treatment plants across Alberta, Canada were analyzed for norovirus (NoV) GI & GII, rotavirus (RoV), adenovirus (AdV), sapovirus (SaV) and astrovirus (AsV). Among the 5726 wastewater samples tested, AdV (80.5%) had the highest detection rate followed by NoV GII (75.6%), SaV (63.2%), NoV GI (59.4%), RoV (42.2%) and AsV (20.2%). Winter and spring seasonality was found for NoV and RoV in both wastewater and clinical disease. Public health interventions especially in the 1st year of the COVID-19 pandemic had a significant impact on their burden with marked reduction in wastewater detected viruses and clinical cases. NoV showed a strong correlation between its level in wastewater and the number of clinical cases, while moderate correlation was observed for the other four viruses. Cross-correlation analysis showed that changes of viral RNA concentration in wastewater lagged behind reported gastroenteritis cases by approximately 6&#xa0;days to 3&#xa0;weeks. To our knowledge, this is the longest multi-region WBS study monitoring multiple gastroenteritis viruses spanning both COVID-19 pandemic and post-pandemic periods. The data obtained from this study supported WBS as a complementary tool to track population-based circulation of gastroenteritis viruses, providing actionable public health data.

Clinical cases

Studies on functional differentiation of xpr1a and xpr1b genes in zebrafish.

Xenotropic and polytropic retrovirus receptor 1 (XPR1) is known to be involved in various biological processes, including phosphate homeostasis, cellular signaling, brain and vascular mineralization, whereas its specific contribution to bone development remains incompletely characterized. Due to genome duplication in teleosts, zebrafish Danio rerio possess two paralogous genes of XPR1 namely xpr1a and xpr1b, whose functional divergence remains unclear. The amino acid sequence similarity between zebrafish xpr1a and xpr1b was 83.26%. In situ hybridization demonstrated overlapping localization in the head and spinal cord at 24-48 hpf, while diverged by 72 hpf, with xpr1a becoming restricted to the head while xpr1b persisted in both regions. CRISPR/Cas9 was used to generate xpr1a and xpr1b mutants. The xpr1a mutants are comparatively healthy, viable but with mild growth reduction, whereas the xpr1b mutants display high mortality, reduced body length and severe vertebral deformities. Interestingly, all the double mutants died at the embryonic stage. Moreover, to further investigate the molecular and regulatory mechanisms, we conducted comparative transcriptome analysis on bone and brain tissues from xpr1b+/+ and xpr1b-/- zebrafish. In bone tissue, 6749 DEGs were identified, comprising 3846 upregulated and 2903 downregulated genes. These DEGs were mainly enriched in the MAPK signaling pathway, Wnt signaling pathway, cysteine and methionine metabolism, and ECM-receptor interaction. RT-qPCR validated results showed that seven osteogenesis-related genes (col1a1a, sp7, runx2b, col1a2, col1a1b, alp1 and entpd5), and two phosphate homeostasis related genes (slc20a2 and pdgfba), which are essential for skeletal mineralization and phosphate homeostasis, exhibited significantly downregulated expression in bone tissue of xpr1b mutant zebrafish. These results highlight the pivotal role of xpr1b in regulating skeletal mineralization and phosphate metabolism, thereby elucidating the functional specialization of XPR1 paralogs while providing a theoretical basis for understanding bone developmental mechanism in teleost vertebrates.

Animals

Pre-clinical immunogenicity and safety evaluation of H2 strain Hepatitis A Inactivated Vaccine in rhesus macaques.

BACKGROUND: Hepatitis A is a viral infection of the liver that can cause mild to severe illness. Currently, two types of HAV vaccines are used worldwide, inactivated hepatitis A vaccines, which are used in most countries, and live attenuated vaccines (H2 and L-A-1 strain), which are mainly used in China. The major disadvantage of live attenuated virus to cause secondary infections among contacts and mutation shifts of the live vaccine strain. The H2 strain was selected for the development of an inactivated hepatitis A vaccine to further reduce biosafety risks. Rhesus macaques high genomic homology with humans and the incubation period after hepatitis A vaccination and human natural infections are similar. We use rhesus macaques to assess immunogenicity and safety of the H2 strain Hepatitis A Inactivated Vaccine. METHODS: The vaccine was assessed in rhesus macaques, divided into four groups (n&#x202f;=&#x202f;10 per group): the control group (adjuvant buffer; aluminum content 0.35&#x202f;mg/mL; 2&#x202f;mL per dose), the low-dose group (320EU, 0.5&#x202f;mL of 640EU/mL with aluminum content 0.35&#x202f;mg/mL), the medium-dose group (640EU, 1&#x202f;mL of 640EU/mL with aluminum content 0.35&#x202f;mg/mL), and the high-dose group (1280EU, 2&#x202f;mL of 640EU/mL with aluminum content 0.35&#x202f;mg/mL). Animals were injected intramuscularly at multiple sites in the hind limbs and received four inoculations at 4-week intervals. Test items including Clinical indicators, immunogenicity indicators and Histopathological examination. RESULTS: No abnormalities were observed in any group in terms of general clinical condition throughout the study period except for slight decreases in body temperature after immunization. Hematological parameters, serum biochemistry indices, and histopathological findings showed fluctuated to different degrees of fluctuation after immunization across all groups. Immunogenicity assessments showed that the inactivated hepatitis A vaccine (H2) induced both humoral and cellular immune responses effectively, and the levels of antibodies increased with certain dose- and time-response trends. CONCLUSION: The inactivated hepatitis A vaccine (H2 strain, human diploid cell) was safe and immunogenic in non-human primates. The results provide strong preclinical support for the further clinical development of this vaccine candidate.

Animals

Efficacy of NAs in combination with Peg-IFN for functional cure in patients with CHB: a meta-analysis of RCTs.

BACKGROUND: The goal of treating chronic hepatitis B (CHB) is to achieve functional cure. We aimed to evaluate the efficacy of the combination of nucleoside (acid) analogues (NAs) and pegylated interferon (Peg-IFN) on the functional cure of CHB patients at the EOT and at the EOF. METHOD: PubMed, Embase, and Web of Science were searched systematically up to March 15, 2025. Sixteen RCTs on CHB patients receiving combination or monotherapy were included. RESULT: Compared with NAs treatment, the NAs combined with Peg-IFN treatment group significantly improved HBsAg clearance rate (RR: 14.05, 95% CI 6.13-32.20) and HBsAg seroconversion rate (RR: 12.82, 95% CI 5.08-32.33) at the EOT. Moreover, compared with NAs treatment, the NAs combined with Peg-IFN treatment group significantly improved HBsAg clearance rate (RR: 7.70, 95% CI 4.24-13.98), HBsAg seroconversion rate (RR: 11.93, 95% CI 5.14-27.67) at the EOF. However, compared with Peg-IFN monotherapy, the combination therapy group did not show any improvement in HBsAg clearance rate, HBsAg seroconversion rate, and the rate of qHBsAg decrease > 1 log10&#x2009;IU/mL at the EOT and the EOF. Moreover, in terms of safety, the Peg-IFN monotherapy group showed more ALT flares (ALT > 5&#x2009;&#xd7;&#x2009;ULN) during the treatment process. CONCLUSION: Compared with NAs therapy, Peg-IFN combined with NAs therapy significantly improves functional cure rate. However, combination therapy shows no additional advantage over Peg-IFN monotherapy in achieving functional cure. The Peg-IFN monotherapy group has a higher incidence of ALT flares than the combination therapy group.

Humans

Suppression of HIV-1 replication in CEM-A cell cultures by trans-splicing group I introns targeting PAS/PBS sequences and conditionally expressing &#x394;N-Bax.

Anti-HIV group I introns containing antisense guide sequences directed against the HIV-1 primer activation signal and primer-binding site (PAS/PBS) were designed and evaluated. Because PAS/PBS sequences are present in the viral RNA species examined, these RNAs can serve as trans-splicing substrates. The introns were active against both artificial target RNAs and viral RNA generated during infection. Cleavage and degradation of targeted viral RNA may have contributed to suppression, whereas inclusion of a 3' exon encoding the proapoptotic protein &#x394;N-Bax was associated with increased programmed cell death and may have augmented suppression of viral replication. In cultured CEM-A cells, transgene expression of these introns markedly suppressed HIV-1 replication, with p24 levels falling below the assay detection limit in selected clones. RESULTS: RT-PCR and sequence analysis detected splice products containing the expected PAS/PBS junctions. In the dual-luciferase assay, intron expression reduced normalized Gaussia luciferase signal by approximately 70% relative to the negative control. Qualitative Annexin V imaging and caspase-3 assays were consistent with infection-dependent apoptosis after &#x394;N-Bax splice-product formation. Transient expression of each intron in HEK293T cells followed by infection with VSV-G-pseudotyped HIV-1NL4-3&#x202f;at an MOI of 2 reduced p24 levels by approximately 50% at 4 days post-infection. Construct 128L produced the strongest RT-PCR band under the tested conditions and was selected for subsequent experiments. A canonical splice product and a low-abundance noncanonical splice product were detected; both involved the intended HIV-derived target RNA, although transcriptome-wide off-target splicing was not assessed. Heterogeneous transformed HEK293T populations showed an approximately 2-log10 reduction in p24. In selected clonal HEK293T and CEM-A lines, p24 was below the assay detection limit at the measured endpoints, including up to 90 days after infection in some CEM-A clones. CONCLUSIONS: PAS/PBS-targeting group I introns suppressed HIV-1-associated p24 production in the tested cell-culture models. Linking the introns to a &#x394;N-Bax 3' exon was associated with infection-dependent apoptosis and may further limit viral replication and spread. The use of highly conserved, functionally constrained target sequences may reduce the likelihood of escape, but viral evolution and transcriptome-wide off-target effects were not assessed. This conditional death-upon-infection strategy warrants further evaluation in primary-cell and in vivo models.

Humans

Characterisation of HIV-1 Gag Cytotoxic T-Lymphocyte Epitopes in the Southern African Region-A Systematic Review.

During early HIV-1 infection, robust Cytotoxic T-lymphocyte (CTL) responses are mostly targeted at immunodominant Gag p24 epitopes to reduce HIV-1 viraemia to a set-point. The aim of this study was to review the current body of knowledge on HIV-1 Gag CTL epitopes in the southern African region where subtype C is prevalent. Peer-reviewed records were obtained from three databases: PubMed Central, Web of Science Core Collection, and Scopus, using the following search terms: HIV subtype C Gag epitopes, and HIV clade C Gag epitopes. The search results were restricted to countries within the southern African region, and only data published in English and between the years 2000-2025 were considered for this review. The search from the three databases produced a total of 2103 peer-reviewed records, and 49 records were included in the review. The majority of studies (58.44%) were conducted in South Africa, followed by Botswana (15.58%), Zambia (10.39%), Malawi (7.79%), Zimbabwe (6.49%) and Angola (1.30%). There were no studies identified from other southern African countries. A total of 60 Gag CTL epitopes were identified, of which 17 (28.33%) were located within the matrix protein (p17), 33 (55.00%) within the capsid protein (p24), and 4 (6.67%) within the Gag polyprotein (p2p7p1p6). The commonly detected immunodominant epitopes were mostly located within the Gag p24 protein; and included TPQDLNTML (TL9, Gag p24 48-56) and TSTLQEQIGW (TW10, Gag p24 108-117) present at 16.00% and 13.3%, respectively. The proportion of HLA-A, B and C allotypes in this systematic review were 18%, 78%, and 4%, respectively. The more common HLA-B allotypes that restrict immunodominant Gag epitopes and facilitate better control of HIV-1 were HLA-B*57, -B*58:01, -B*42:01 and -B*81:01. This systematic review has provided important insights into the description of immunodominant Gag epitopes and HLA-I alleles that contribute to the control of HIV-1 viraemia in the southern African region. It has also exposed that some CTL epitopes identified in the southern African studies are not reported on the Los Alamos HIV database (LANL HIV database). This highlights a need to have this database updated with this information as it is used as a reference for epitopes. This review could provide insights into the design of an epitope-based HIV-1 vaccine that would also be effective in the southern African region.

Humans

Translating single-cell RNA sequencing into monocyte direct leukocyte subpopulation-transcript abundance assay ratio-based biomarkers (IFI27/PSAP or IFI27/CTSS) for clinical detection of viral infection.

A rapid method for triaging febrile patients by aetiology (e.g., viral or bacterial infection) using gene expression in peripheral blood (PB) is an intensively researched area. However, gene expression in blood represents a composite sum of gene expression of all the component cell types present in the sample. As a result, numerous genes are measured in most proposed signatures. Herein, we propose a simple ratio-based biomarker (RBB) called direct leukocyte subpopulation-transcript abundance assay (DIRECT LS-TA) that recapitulates gene expressions of a single cell type in PB (i.e., monocytes). Based on single-cell RNA sequencing (scRNAseq) data and bulk expression data, IFI27 and SIGLEC1 are found as interferon-stimulated genes (ISGs) predominantly expressed by monocytes. The DIRECT LS-TA method can use a simple ratio of two genes measured in PB as an RBB to represent the target gene expression in monocytes without the need for monocyte purification. Both scRNAseq and bulk RNA sequencing datasets were used to evaluate the correlation between ISG expression in monocytes and PB, with a particular focus on monocyte expression of IFI27. An iceberg plot of bulk transcriptome data was used to identify genes that were predominantly expressed by monocytes in PB. DIRECT LS-TA RBBs of the three genes (IFI27, IFI44L and SIGLEC1) were evaluated by group-wise comparison, receiver operating characteristic and meta-analysis. In addition, the conventional interferon (IFN) score was evaluated for comparison of diagnostic performance. In viral infection datasets, DIRECT LS-TA of IFI27 (IFI27/PSAP or IFI27/CTSS) was most intensely activated (p value by t test <1e-9) and had the best area under the curve (0.94) among the three potential monocyte ISGs analysed. DIRECT LS-TA SIGLEC1 was also another monocyte biomarker but showed a lower activation (p<9e-5). IFI27/PSAP showed better diagnostic performance than the conventional IFN score. On the other hand, IFI44L was not a predominant monocyte expression gene. DIRECT LS-TA of IFI27 (IFI27/PSAP or IFI27/CTSS) measured in PB was the best biomarker of viral infection and IFN activation among ISGs predominantly expressed by monocytes. It performed even better than the conventional IFN score which required quantification of eight genes. The results suggest that DIRECT LS-TA of IFI27 is a monocyte-informative biomarker which is easy to determine in PB without the need for cell sorting.

Humans

Chemical Complementarities of Neuroblastoma Tumor-Resident TCR CDR3s and CMV Antigens are Associated with a Better Outcome.

A likely immune response to a virus can be detected via the presence of TCR CDR3s that (a) exactly match CDR3s known to bind viral antigens or (b) represent chemical complementarity to viral antigens. Previous studies, based on genomics approaches to characterizing anti-CMV TCR CDR3s in patient blood samples, have indicated the possibility that a systemic CMV infection is associated with worse outcomes for NBL, as well as for breast cancer. Thus, the association of NBL tumor-resident anti-CMV TCR CDR3s and patient outcomes was evaluated here, with results indicating that high levels of chemical complementarity between tumor-resident TCR CDR3s and CMV antigens represented a better outcome. This is in apparent contrast to results obtained via the previous study of blood sourced, anti-CMV TCR CDR3s representing a worse outcome. This study identified gene expression values associated with the tumor-specific anti-CMV TCR CDR3s, representing exact matches to known anti-CMV TCR CDR3s, which may assist in identifying a potential underlying mechanism effecting the better outcomes associated with the tumor-resident, anti-CMV TCR CDR3s. Overall, results here raise the question of whether an anti-CMV response directly against the tumor, or within the tumor microenvironment, is involved in reductions in tumor progression or responsiveness to treatment?

Humans

A cooperative regulatory module between TAGL2 and JMJC1 activates specific defense genes against root-knot nematodes in tomato.

Plant-parasitic nematodes (PPNs) threaten global food security. Although epigenetic modifications are crucial for plant immunity, how histone modifiers contribute to root-knot nematodes (RKNs, Meloidogyne incognita) resistance remains unclear. Here, using genetic, molecular and biochemical approaches, we investigated the epigenetic and transcriptional mechanisms underlying RKN resistance mediated by the histone demethylase (HDM) JMJC1 and the MADS-box transcription factor TAGL2 in tomato (Solanum lycopersicum). We identified JMJC1 as an RKN-induced positive defense regulator targeting H3K9me3 and H3K27me3 histone marks. JMJC1 physically interacts with TAGL2, which also positively regulates RKN resistance. Transcriptomic analysis indicated that TAGL2 regulates multiple layers of the plant defense network, transcriptionally activating representative genes from distinct pathways (including PUB10, bHLH98, CCaMK, and SAUR3), which we validated as positive regulators of RKN resistance via virus-induced gene silencing (VIGS). At the chromatin level, TAGL2 and JMJC1 co-regulate these loci, associating with localized H3K9me3 and H3K27me3 reduction. Furthermore, TAGL2 directly activates JMJC1 transcription, establishing a positive feedback loop that amplifies immune signaling. Our findings reveal a cooperative model wherein a HDM and a transcription factor coordinate at specific loci to fine-tune multiple defense layers at both epigenetic and transcriptional levels, providing insights for breeding durable nematode-resistant plants.

Solanum lycopersicum