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Strain-level differences in Gardnerella urinary tract persistence and pathogenesis are consistent with comparative phylogenomic analyses.

BACKGROUND: Gardnerella is a genus of gram variable anaerobic bacteria that is commonly present in the female urogenital tract, especially during bacterial vaginosis (BV). BV is linked with increased risk of urinary tract infections (UTI) and Gardnerella has been frequently detected in urine collected directly from the bladder. Understanding the contribution of Gardnerella to urogenital pathogenesis has been complicated by its genetic heterogeneity and a shortage of data from in vivo models. Recently, a clinical isolate of Gardnerella displayed covert pathogenesis in a mouse urinary tract inoculation model, triggering urothelial exfoliation and promoting UTI by uropathogenic E. coli. Data from clinical studies suggests differential association of Gardnerella phylogenetic clades with BV or urogenital infections. In vitro data has demonstrated heterogeneity in the presence and expression of putative virulence determinants between Gardnerella strains. This study was designed to compare diverse Gardnerella strains in vivo to identify genomic variation associated with urinary tract persistence and pathogenesis. METHODS: Eighteen Gardnerella clinical isolates from each of the four main phylogenetic clades were individually inoculated transurethrally into female C57BL/6 mice. Bacteriuria was monitored by quantitative culturing of Gardnerella in urine. Pathologic features were assessed by immunofluorescent and histological staining of bladder tissues. Pan-genome phylogenetic analyses were performed on the 18 Gardnerella isolates used for mouse infections to identify accessory genes that were associated with observable in vivo phenotypes, including long and short-term persistence, urothelial exfoliation and bladder edema. Genes that were significantly associated to phenotype were then matched against a pangenome analysis of 291 publicly available Gardnerella genomes to determine the conservation of these putative colonization and virulence factors across the genus. RESULTS: Gardnerella strains displayed clear differences in persistence and pathogenesis in the mouse bladder that were congruent with phylogeny. Clade 2 strains were more persistent in the urinary tract whereas strains from the other three clades either caused transient bacteriuria or were undetectable. Strains from clade 2 and 4 induced urothelial exfoliation while edema was triggered by strains from clades 2, 3 and 4. Pangenome analyses revealed 45 genes that were associated with in vivo persistence and pathogenicity. Among the wider 291 publicly available genomes, clade 2 strains encoded more of the genes associated with bacteriuria phenotypes compared to strains in the other three clades. Exfoliation-associated genes were present in most clade 4 strains. Clade 3 strains lack most of the in vivo-associated genes, whereas clade 1 strains were more heterogenous. CONCLUSIONS: This study provides in vivo evidence for differential urinary tract colonization and pathogenesis by strains from different clades/species within the genus Gardnerella and identifies new putative persistence and virulence factors. Utilizing the in vivo data from tested strains, pangenome analyses predicts that clade 2 Gardnerella are the most likely to persist in the urinary tract and that clades 2 and 4 have the highest uropathogenic potential. These findings inform future targeted screening and treatment approaches aimed at limiting harmful Gardnerella urinary tract exposures.

Journal Article

Acute MeCP2 loss in adult mice reveals transcriptional and chromatin changes that precede neurological dysfunction and inform pathogenesis.

Mutations in the X-linked methyl-CpG-binding protein 2 (MECP2) gene cause Rett syndrome, a severe childhood neurological disorder. MeCP2 is a well-established transcriptional repressor, yet upon its loss, hundreds of genes are dysregulated in both directions. To understand what drives such dysregulation, we deleted Mecp2 in adult mice, circumventing developmental contributions and secondary pathogenesis. We performed time series transcriptional, chromatin, and phenotypic analyses of the hippocampus to determine the immediate consequences of MeCP2 loss and the cascade of pathogenesis. We find that loss of MeCP2 causes immediate and bidirectional progressive dysregulation of the transcriptome. To understand what drives gene downregulation, we profiled genome-wide histone modifications and found that a decrease in histone H3 acetylation (ac) at downregulated genes is among the earliest molecular changes occurring well before any measurable deficiencies in electrophysiology and neurological function. These data reveal a molecular cascade that drives disease independent of any developmental contributions or secondary pathogenesis.

Animals

Lineage-associated differences in adenine methylation patterns of mammalian-associated Campylobacter fetus isolates: a possible role for epigenetic factors in host tropism and pathogenesis.

Mammalian Campylobacter fetus (CF) is divided into two subspecies, C. fetus fetus (CFF) and C. fetus venerealis (CFV), the latter being bovine-adapted and responsible for the notifiable disease bovine genital campylobacteriosis (BGC). Differentiation between CF subspecies has traditionally been undertaken by a few biochemical tests, but these are complicated by the existence of a biotype, C. fetus venerealis intermedius (CFVi), which shares attributes of both CFF and CFV. Molecular methods targeting specific genes have gained acceptance for more accurate subtype identification and align well with whole-genome analysis. However, limited genomic diversity between subtypes has confounded efforts to understand the genetic basis for differential host tropism and pathogenesis of these organisms. A previous study of a small cohort of C. fetus isolates suggested that dam gene coding variations might correlate with CF subtype. Accordingly, this study examines a cohort of 331 C. fetus genomes, representative of all seven phylogenetic groups for their complement of adenine methylases and the genomic motifs they target in representative isolates. All CF isolates retained a cfeM1 gene, the presence of which correlates with RAATTY methylation, while seven other adenine methylase genes exhibited distinct cladal distributions. Notably, a cjeM1 gene appears to target the CCAN7TAG/CTAN7TGG motif in CFV and CFVi isolates only. Given the increasing recognition of the impact of adenine methylation on bacterial-host interactions, further exploration of the role of adenine methylation in C. fetus pathogenesis could reveal mechanisms contributing to BGC and thus aid in its eradication.IMPORTANCECampylobacter fetus remains an important zoonotic pathogen, for which a better understanding of its host tropism and pathogenesis is sought. However, the limited genomic variation observed between subtypes has to date confounded efforts in this regard. This study suggests that an alternative approach that examines epigenetic differences between subtypes, specifically adenine methylation patterns, may reveal mechanisms critical to the pathologies of these organisms.

Animals

A Multitrait Locus Regulates Sarbecovirus Pathogenesis.

Infectious diseases have shaped the human population genetic structure, and genetic variation influences the susceptibility to many viral diseases. However, a variety of challenges have made the implementation of traditional human Genome-wide Association Studies (GWAS) approaches to study these infectious outcomes challenging. In contrast, mouse models of infectious diseases provide an experimental control and precision, which facilitates analyses and mechanistic studies of the role of genetic variation on infection. Here we use a genetic mapping cross between two distinct Collaborative Cross mouse strains with respect to severe acute respiratory syndrome coronavirus (SARS-CoV) disease outcomes. We find several loci control differential disease outcome for a variety of traits in the context of SARS-CoV infection. Importantly, we identify a locus on mouse chromosome 9 that shows conserved synteny with a human GWAS locus for SARS-CoV-2 severe disease. We follow-up and confirm a role for this locus, and identify two candidate genes, CCR9 and CXCR6, that both play a key role in regulating the severity of SARS-CoV, SARS-CoV-2, and a distantly related bat sarbecovirus disease outcomes. As such we provide a template for using experimental mouse crosses to identify and characterize multitrait loci that regulate pathogenic infectious outcomes across species. IMPORTANCE Host genetic variation is an important determinant that predicts disease outcomes following infection. In the setting of highly pathogenic coronavirus infections genetic determinants underlying host susceptibility and mortality remain unclear. To elucidate the role of host genetic variation on sarbecovirus pathogenesis and disease outcomes, we utilized the Collaborative Cross (CC) mouse genetic reference population as a model to identify susceptibility alleles to SARS-CoV and SARS-CoV-2 infections. Our findings reveal that a multitrait loci found in chromosome 9 is an important regulator of sarbecovirus pathogenesis in mice. Within this locus, we identified and validated CCR9 and CXCR6 as important regulators of host disease outcomes. Specifically, both CCR9 and CXCR6 are protective against severe SARS-CoV, SARS-CoV-2, and SARS-related HKU3 virus disease in mice. This chromosome 9 multitrait locus may be important to help identify genes that regulate coronavirus disease outcomes in humans.

Animals

Optic disc edema in raised intracranial pressure. V. Pathogenesis.

The pathogenesis of optic disc edema (ODE) in raised intracranial pressure is discussed in the light of recent observations on the subject. The findings indicate that ODE is a mechanical phenomenon. The raised cerebrospinal fluid pressure (CSFP) in the sheath of the optic nerve produces axoplasmic flow stasis in the optic nerve head. This results in swelling of the axons, which manifests as early ODE and secondarily produces the well-known optic disc and retinal vascular changes associated with ODE. The pathogenesis of ODE seen in different conditions without raised CSFP cannot be explained by any single mechanism in spite of the occurrence of axoplasmic flow stasis in most cases, because the stasis in different situations has different mechanisms.

Adolescent

Development and Characterization of an Inducible Bacterial Artificial Chromosome System for Studying Lytic Replication and Pathogenesis of Kaposi's Sarcoma-Associated Herpesvirus.

Bacterial artificial chromosome (BAC) is widely used to manipulate herpesvirus genome and generate recombinant virus. Here, we developed a new KSHV BACmid, namely as iBAC, by replacing the EGFP with TET3G transactivator under EF1α promoter and inserted Tet response elements in the promoter of RTA in the original KSHV BAC16 clone and characterized KSHV lytic replication in SLK-iBAC cells. SLK-iBAC cells developed more efficient lytic replication and generated more progeny virus than iSLK-BAC16 cells upon the same conditions of doxycycline treatment. Since SLK-iBAC cells only occupied hygromycin selection marker, it is convenient to generate cellular gene knockout via lentivirus-mediated CRISPR-Cas9 or stably express viral or cellular gene via lentivirus followed by antibiotic selection, making iBAC system a better tool to identify cellular targets of viral proteins in the context of virus infection or study the role of viral or cellular genes for KSHV lytic replication and pathogenesis. In addition, iBAC is color-free and can be utilized to track subcellular localization of viral proteins or colocalization between different viral proteins by introducing fusing fluorescent proteins into the BAC backbone. Therefore, the new KSHV iBAC is a powerful inducible tool to study KSHV lytic replication and pathogenesis in cell model.

Chromosomes, Artificial, Bacterial

Pathogenesis of duodenal ulceration produced by cysteamine or propionitrile: influence of vagotomy, sympathectomy, histamine depletion, H-2 receptor antagonists and hormones.

Insight into the pathogenesis and etiology of experimental duodenal ulceration was sought by studying the modulation of this disease in rats by selective vagotomy, chemical sympathectomy, histamine depletion, histamine H-2 receptor antagonists (eg, metiamide, cimetidine), or endocrine ablations. Gastric secretion was examined in intact and pylorus-ligated animals. The formation of duodenal ulcers induced by the administration of propionitrile or cysteamine was abolished by vagotomy, decreased by sympathectomy, histamine depletion, histamine H-2 receptor antagonists, hypophysectomy, thyroidectomy, or adrenalectomy. Cimetidine and metiamide exerted a dose-dependent antiulcer effect, but metiamide enhanced the mortality of rats given propionitrile or cysteamine. The non-ulcerogen derivative of cysteamine, ethanolamine, did not increase mortality when given in combination with metiamide. The gastric hyperacidity elicited by cysteamine was reduced by metiamide or vagotomy, the latter being more effective in this respect. Thus, the chemically induced duodenal ulcer in rats resembles the human peptic ulcer disease in sensitivity to therapeutic modalities and may serve as an appropriate model to study the role of neural, hormonal, and other factors in the etiology and pathogenesis of this disorder.

Adrenalectomy

Novel HLA class I and II insights into the pathogenesis of systemic sclerosis-associated interstitial lung disease.

OBJECTIVES: Systemic sclerosis-associated interstitial lung disease (SSc-ILD) is the leading cause of mortality in systemic sclerosis (SSc), yet its genetic architecture remains incompletely understood. Therefore, given the key role of the major histocompatibility complex (MHC) in SSc, we aimed to perform a comprehensive MHC-wide association study in the largest SSc-ILD cohort to date. METHODS: We analysed 2412 patients with SSc-ILD⁺, 3550 patients with SSc-ILD⁻, and 15,076 controls of European ancestry from 10 international cohorts. After quality control, the MHC region was imputed, and inverse variance weighted meta-analysis was performed. Subsequently, conditional stepwise analyses, adjustment for antitopoisomerase autoantibody (ATA) status, and functional annotation of significant single-nucleotide polymorphisms were performed. Finally, we constructed a composite score combining genetic, clinical, and demographic variables to predict SSc-ILD. RESULTS: After conditional analysis, we detected 12 significant associations within class I and class II human leukocyte antigen (HLA) genes. ATA adjustment reduced the significance of class II HLA variants, whereas class I HLA variants remained unaffected. Finally, the built composite score had an area under the curve of 0.754, significantly outperforming the models including any of the variables alone. CONCLUSIONS: In this study, we identify genetic mechanisms underlying SSc-ILD that support the potential implication of CD8+ T cells and ATAs in its pathogenesis. Moreover, we also demonstrate the enhanced efficacy of integrating genetic information into predictive models to detect patients at high risk of SSc-ILD. These findings provide new insights into disease pathogenesis and suggest potential biomarkers and therapeutic targets for improved patient management.

Humans

Intrathymic pathogenesis and dual genetic control of myasthenia gravis.

We propose a two-step model for the pathogenesis of myasthenia gravis. In the first step, primitive intrathymic stem-cells are induced by abnormal stimuli to differentiate to (abnormal?) myogenic cells. In the second step, immunocompetent T lymphocytes start an autoimmune reaction against these newly differentiated myogenic cells. The clinical stage is reached when autosensitised effector T lymphocytes leave the thymus and either infiltrate the synaptic spaces of peripheral muscles or participate in the formation of autoantibodies, causing the neuromuscular symptoms. At two points the pathogenesis is under genetic control--the first at the differentiation of the stem-cells to myogenic cells and the second at the immune responsiveness of the lymphocytes to these atypical intrathymic muscle cells.

Animals

Possible role for impaired renal prostaglandin production in pathogenesis of hyporeninaemic hypoaldosteronism.

A 57-year-old woman with hypertension and moderate renal insufficiency had chronic unexplained hyperkalaemia. Metabolic balance studies confirmed a diagnosis of hyporeninaemic hypoaldosteronism. Two observations suggested that impaired renal prostaglandin production contributed to the pathogenesis of the patient's disorder. Baseline renal-prostaglandin synthesis (as determined by urinary excretion of P.G.E and P.G.F) was was substantially depressed when compared with that in nine normal females. Infusion of low doses of P.G.A1 produced a significant increase in serum-aldosterone and urinary potassium excretion; it also led to a dramatic fall in blood-pressure and serum-potassium. It appears from these studies that a defect in renal prostaglandin synthesis has an important role in the pathogenesis of hyporeninaemic hypoaldosteronism.

Adrenal Insufficiency

EIF4H and YBX1 are essential host factors for hepatitis E virus replication and pathogenesis.

Hepatitis E virus (HEV) is a leading cause of acute viral hepatitis worldwide, responsible for approximately 20 million infections annually. Despite the availability of a vaccine in China, no direct-acting antivirals are approved, and host factors required for HEV replication remain poorly defined. Here, using a genome-wide CRISPR/Cas9 knockout screen in a replicon system, we identified Eukaryotic Translation Initiation Factor 4H (EIF4H) and Y-Box Binding Protein 1 (YBX1) as essential host factors for HEV replication and pathogenesis. Knockout of either factor markedly impaired replication of HEV genotypes 1, 3, and 4, as well as HEV infection and production in hepatocellular carcinoma cells and human induced pluripotent stem cell-derived hepatocyte-like cells, while leaving SARS-CoV-2, hepatitis B virus, hepatitis C virus, and Zika virus unaffected, underscoring their HEV-specific roles. Mechanistically, EIF4H interacts with ORF1 via its methyltransferase-Y-papain-like protease region, and EIF4H deficiency alters the composition of the ORF1-associated replication complex. By contrast, YBX1 is dispensable for ORF1 translation and RNA binding but is specifically required for ORF1 proteolytic processing, a prerequisite for assembling a functional replication machinery. EIF4H knockout rats and liver-specific YBX1 knockout rats were largely resistant to rat HEV-C1 infection, showing profound reductions in viral shedding, suppressed hepatic and intestinal viral loads, and protection from liver pathology. Together, our findings establish EIF4H and YBX1 as essential host factors for HEV infection and pathogenesis and reveal potential targets for antiviral intervention.

Virus Replication

Impact of pH and Mycoplasma hominis endosymbiosis on Trichomonas vaginalis pathogenesis.

The parasite Trichomonas vaginalis colonizes the human vaginal tract and adheres to and lyses epithelial cells causing an inflammatory infection. The vaginal tract is typically acidic, ranging from pH 3.8 to 5.1; however, pathogenesis studies have previously been conducted on parasites grown at pH 5.9 to 6.2. Here we compared the adherence and cytotoxicity of T. vaginalis grown at pH 5.1 and pH 5.9, identifying changes in the surface proteome that contribute to increased pathogenesis of the parasite at pH 5.1. We show that growth of the parasite at pH 5.1 significantly enhances adherence to and lysis of host cells and that this is strongly amplified by the presence of a common bacterial endosymbiont, Mycoplasma hominis. Quantitative proteomics revealed the upregulation of putative surface proteins, three of which were found to be involved in increased parasite adherence and host cell killing. Mechanistic assays demonstrated that a Ricin B-like protein mediates parasite adherence dependent on host glycosaminoglycans via its carbohydrate-recognition domain, while an EF-hand-like protein is shown to promote Ca2+dependent adherence. Ricin B overexpression was found to reprogram host metabolism, activating ERK1/2 and HIF-1α and driving a Warburg-like glycolytic shift with greatly increased lactate release, which may create a nutrient-rich niche that supports parasite persistence and host cell cytotoxicity. These studies demonstrate a coordinated upregulation of multiple adhesins rather than a single factor at pH 5.1 in the presence of M. hominis and explore the mechanisms underlying the interaction of parasite surface proteins with the host cell.

Trichomonas vaginalis

Pathogenesis of respiratory Klebsiella pneumoniae infection in rats: bacteriological and histological findings and metabolic alterations.

Gram-negative bacterial pneumonias have been increasingly important as nosocomial infections. The following model was developed to study the pathogenesis and evaluate therapy of such infections. Intranasal instillation of rats with a suspension of 5 x 10(6) Klebsiella pneumoniae caused bronchopneumonia with 24 h. Bacteria were isolated from the lungs in large numbers (greater than 10(5) colony-forming units [CFU] for at least 13 days after inoculation. Thereafter, the viable concentration decreased to about 10(3) CFU at 21 days but increased to 10(4) CFU at 25 days. Mortality rarely exceeded 25%. Plasma zinc concentration decreased, and plasma seromucoid, lysozyme, and alpha2-macrofetoprotein increased during respiratory K. pneumoniae infection in rats. There seemed to be a linear relationship between seromucoid concentration and the concentration of K. pneumoniae in the lung expressed in log10 units. Plasma zinc, alpha2-macrofetoprtoein, or lysozyme levels, however, did not change until the concentration of bacteria retrieved fron lungs exceeded 4 to 5 logs, Analysis of blood samples obtained serially from the orbital sinuses revealed that rats that succumbed to infection had significantly higher levels of seromucoid, alpha2-macrofetoprotein, and lysozyme and lower levels of plasma zinc than infected rats that survived. Progressive increases in seromucoid and particularly in lysozyme and alpha2-macrofetoprotein appeared to be predicative of death. It is postulated that the threshold effect observed for alpha2-macrofetoprotein and lysozyme reflect significant damage to lung tissue, and thus these two variables are good indexes of the severity of this infection. We propose that this model may be of value in elucidating the pathogenesis of respiratory K. pneumoniae as well as in assessing various models of therapy.

Animals

Gut microbiota dysbiosis and host metabolite-immune crosstalk drives the pathogenesis of neonatal lupus erythematosus: a multi-omics analysis.

BACKGROUND: Neonatal lupus erythematosus (NLE) is a rare autoimmune condition triggered by the transplacental transfer of maternal antibodies. Despite its recognized clinical manifestations, the underlying pathogenesis remains incompletely understood. This study seeks to explore the disruption of the gut microbiota-host metabolism-immune axis in anti-Ro/La-positive neonates, and to assess its potential role in the development of NLE. METHODS: This multicenter, cross-sectional study included 90 neonates, divided into three groups: 30 with neonatal lupus erythematosus (NLE), 30 with positive antibodies but without clinical manifestations (No-NLE), and 30 healthy controls. We performed 16 S rRNA sequencing to analyze gut microbiota composition, untargeted plasma metabolomic profiling, and proteomic analysis to identify alterations associated with the pathogenesis of NLE. RESULTS: We identified significant alterations in the gut microbiota, plasma metabolome, and proteome profiles of anti-Ro/La-positive neonates. NLE infants exhibited marked enrichment of Enterobacteriaceae and depletion of Bifidobacterium and Clostridium butyricum. Metabolomic analysis revealed hyperactivation of β-alanine and purine metabolism, along with impaired α-linolenic acid metabolism and endocannabinoid signaling. Proteomic profiling indicated aberrant protein expression that modulated IFN signaling, particularly within the C-type lectin receptor pathway. Dysregulation of the spleen tyrosine kinase (SYK) and high-affinity immunoglobulin epsilon receptor subunit gamma (FCER1G) decoupling was observed, correlating with elevated IFN-α and NF-κB p65 levels. Integrated correlation analysis revealed significant associations among differential microbial taxa, plasma metabolites, and proteins. Notably, E. coli-associated metabolites and proteins displayed inverse relationships with those associated with C. butyricum. CONCLUSIONS: These findings represent comprehensive evidence of dysregulation along the "gut microbiota-host metabolism-immune" axis in neonatal lupus erythematosus (NLE), providing novel insights into the disease's underlying heterogeneity.

Humans

Causal effect of three autoimmune diseases on brain functional networks and cerebrospinal fluid metabolites to underlie the pathogenesis of autoimmune psychosis: a two-sample mendelian randomization analysis.

BACKGROUND: Autoimmune diseases such as Systemic Lupus Erythematosus (SLE), Sj&#xf6;gren's Syndrome (SS), and Hashimoto's Thyroiditis (HT) frequently exhibit neuropsychiatric manifestations, including cognitive impairment, depression, anxiety, and so on, yet the exact pathogenesis underlying this association remain incompletely understood. Dysfunction of brain resting-state functional networks and cerebrospinal fluid (CSF) metabolite disturbances have been widely reported in psychiatric disorders. However, the application of resting-state functional magnetic resonance imaging (rsfMRI) and CSF metabolomics in the diagnosis and monitoring of autoimmune psychosis is still limited. METHODS: A two-sample Mendelian randomization (MR) analysis was performed to investigate the causal relationships between three autoimmune diseases (SLE, SS, and HT, n&#x2009;=&#x2009;14,267 to 402,090 individuals) and 191 rsfMRI phenotypes (n&#x2009;=&#x2009;47,276 individuals), as well as 338 CSF metabolites. The genome-wide association study (GWAS) of three autoimmune diseases was used as the exposure, whereas rsfMRI phenotypes and 338 CSF metabolites were treated as the outcome. Inverse variance weighted (IVW) with P value&#x2009;<&#x2009;0.05 was regarded as the primary approach for calculating causal estimates. Additionally, the false discovery rate (FDR)-adjusted P value (PFDR)&#x2009;<&#x2009;0.05 was utilized to account for multiple testing. MR Egger method, weighted median method, simple mode method and weighted mode method were used for sensitive analysis. RESULTS: Our analyses identified 5 causal relationships between SLE and the 191 rsfMRI phenotypes, 48 between SS and the 191 rsfMRI phenotypes, and 4 between HT and the 191 rsfMRI phenotypes. Additionally, we found 8 causal relationships between HT and CSF metabolites. Furthermore, all three diseases were significantly associated with the temporal lobe and triple networks (default mode network (DMN), salience network (SN), and central executive network (CEN)), which are the core brain regions and functional networks for cognition. Following FDR correction, 6 causal relationships between SS and the 191 rsfMRI phenotypes were further validated. CONCLUSIONS: Our study pinpoints important brain functional networks and CSF metabolites potentially implicated in the pathogenesis of psychiatric disorders associated with autoimmune diseases and highlights critical brain regions for the development of novel therapeutics.

Humans

Influence of Major Histocompatibility Complex (MHC) Diversity on Immune Modulation, Pathogenesis, and Control of Lumpy Skin Disease Virus.

INTRODUCTION: Lumpy Skin Disease Virus (LSDV), a member of the genus Capripoxvirus within the family Poxviridae, is an economically important transboundary viral pathogen affecting cattle and water buffalo. The disease causes severe production losses through decreased milk yield, infertility, hide damage, reduced growth performance, and occasional mortality. The rapid geographic spread of LSDV, together with its vectorborne transmission and emerging recombinant strains, has intensified the need for improved understanding of viral pathogenesis, host immune responses, and effective prevention strategies. In particular, the role of the bovine Major Histocompatibility Complex (BoLA/MHC) in regulating antiviral immunity, disease susceptibility, and vaccine responsiveness has gained increasing scientific attention. METHODS: This review summarises the published literature related to the epidemiology, transmission, structure, pathogenesis, diagnosis, prevention, and control of LSDV, with special emphasis on the immunological and molecular role of bovine MHC molecules. Relevant studies concerning BoLA-mediated antigen presentation, immunoinformaticsbased epitope prediction, vaccine development, antiviral drug repurposing, molecular docking, genomic surveillance, and diagnostic approaches, including PCR- and ELISAbased assays, were critically evaluated. Recent advances in computational biology, molecular virology, and host-pathogen interaction studies were also reviewed. RESULTS: The reviewed studies demonstrate that Lumpy Skin Disease Virus (LSDV) possesses a complex double-stranded DNA genome enabling immune modulation and efficient transmission through arthropod vectors such as mosquitoes, ticks, and biting flies. Disease progression involves systemic viral replication, vascular injury, dermal necrosis, and inflammatory skin lesions. Real-time PCR remains the most sensitive diagnostic method for early detection, while ELISA supports surveillance. Evidence highlights the central role of bovine Major Histocompatibility Complex (BoLA) molecules in antigen presentation and T-cell activation. Computational studies identified promising BoLA-binding epitopes and repurposed antiviral candidates, including ivermectin, theaflavin, canagliflozin, and tepotinib, for future therapeutic development. DISCUSSION: Current evidence indicates that effective LSDV control requires integration of molecular diagnostics, vector management, vaccination, and host immunogenetics. BoLAguided immunoinformatics provides promising opportunities for developing multi-epitope vaccines, although experimental validation remains essential. Similarly, repurposed antiviral candidates require comprehensive in vivo and pharmacological evaluation before clinical application. Future research should focus on elucidating viral immune-evasion mechanisms, validating predicted epitopes, and translating computational findings into practical vaccines and therapeutics for sustainable disease control. CONCLUSION: Lumpy Skin Disease continues to pose a major threat to global cattle health and livestock economies. Advances in molecular diagnostics, genomic surveillance, antiviral drug discovery, and BoLA-guided vaccine design provide promising opportunities for improved disease control. Understanding the interaction between LSDV and the bovine MHC system is essential for developing next-generation vaccines, immunotherapeutics, and precision disease-management strategies. Future research should prioritise experimental validation of predicted epitopes, large-scale vaccine trials, and mechanistic studies on host-virus immune interactions to establish effective and sustainable global control programs for LSDV.

BoLA

Pathogenesis of diabetic ketoacidosis: a reappraisal.

This study reviews the pathogenic hormonal abnormalities (insulin deficiency and stress hormone excess) in diabetic ketoacidosis. The data both supporting and negating a primary role for insulin deficiency in the pathogenesis of diabetic ketoacidosis are examined. Evidence implicating excess stress hormone secretion as a necessary event in the development of severe metabolic decompensation is discussed. The data suggest that diabetic ketoacidosis may be prevented by correcting either the relative deficiency of insulin or the excess secreation of one or a combination of the stress hormones. Studies supporting a primary role for insulin deficiency in the pathogenesis of diabetic ketoacidosis include the beneficial therapeutic response to insulin administration in ketoacidosis, development of ketoacidosis; and (3) stress hormone excess is necessary for fulminant ketoacidosis to be manifested.s following insulin withdrawal from diabetic man and animals, and hypoglycemic and hypoketonemic effects of insulin. Studies negating a primary role for insulin deficiency in ketoacidosis include the "normal" plasma insulin concentration in the majority of ketoacidotic cases, delayed onset of ketoacidosis after insulin withdrawal from diabetic man, and lack of hypolipolytic and hypoketonemic effect of insulin without prior stress hormone adipocyte and hepatocyte stimulation. Evidence that stress hormones (glucagon, catecholamines, cortisol, and growth hormone) contribute to the metabolic decompensation of ketoacidosis includes: (1) in all cases of ketoacidosis, at least one stress hormone is always elevated; (2) pharmacologic blockade of each of the stress hormones reduces the rate and/or frequency of metabolic decompensation in diabetic man; (3) removal of the pituitary and/or the adrenal gland in diabetic animals completely prevents the development of ketoacidosis after insulin withdrawal; and (4) administration of each of the four stress hormones under appropriate conditions induces metabolic decompensation in diabetic man with "normal" circulating levels of plasma insulin concentration. From these studies, the following conclusions are supported: (1) absolute insulin deficiency is an unusual cause of ketoacidosis; (2) the presence of relative insulin deficiency is necessary for the development of ketoacidosis; and (3) stress hormone excess is necessary for fulminant ketoacidosis to be manifested.

Adolescent

Deep learning-assisted, pathogenesis-informed lung histopathology scoring in preclinical mouse models of SARS-CoV-2 and influenza A infection.

INTRODUCTION: SARS-CoV-2 and influenza A virus (IAV) cause viral pneumonia, yet their lung lesions evolve with distinct spatial organization and resolution-phase architecture. In preclinical murine studies, H&E histopathology is a primary endpoint, but burden-focused semiquantitative scoring can miss pathogen- and phase-specific differences in lesion topology, compartmental involvement, inflammatory organization, and repair. We aimed to define virus- and phase-specific morphologic signatures and translate them into a practical, pathogenesis-informed scoring guide, supported by whole-slide convolutional neural network (CNN) analysis with class activation mapping (CAM). METHODS: Mice were infected under standardized conditions and evaluated during the early, peak-injury, and late phases of infection, corresponding to 2~3, 5~8, and 14 days post-infection (dpi), respectively. Lungs were assessed by H&E with semiquantitative scoring and by immunostaining to map viral antigen distribution and epithelial tropism. Whole-slide CNN models were trained for virus- and phase-specific classification, and CAM localized discriminative regions. RESULTS: Dose titration established reproducible lethal and sublethal infection conditions for both viruses. Viral antigen kinetics diverged, with SARS-CoV-2 peaking early and declining toward clearance by the resolution phase, whereas IAV peaked later and declined by the resolution phase, paralleling distinct injury-repair trajectories. CNN/CAM analysis distinguished virus- and phase-specific histologic patterns across the early, peak-injury, and resolution phases of infection and highlighted spatial signatures consistent with expert review. At the peak-injury phase, SARS-CoV-2 lungs showed broad alveolar/interstitial involvement, whereas IAV exhibited bronchocentric inflammatory organization. During the resolution phase, IAV showed prominent epithelial regeneration with remodeling-forward architecture, while SARS-CoV-2 more often retained localized residual inflammatory foci. Across both infections, tissue inflammatory composition shifted over time, with higher neutrophil representation during the peak-injury phase and a relative increase in lymphocytic representation during the resolution phase. Integrating lesion topology/distribution, edema, epithelial injury-regeneration, remodeling features, and lymphocyte predominance, we proposed a pathogen-resolved, phase-informed histopathology scoring guide with recommended evaluation windows for each model. CONCLUSION: Together, these findings define virus- and phase-specific morphologic programs that inform respiratory virus pathogenesis in mice and can be translated into practical scoring criteria for preclinical respiratory virus studies.

Animals