Biology subjects

Jensen, H. E.

Publications and source records attributed to Jensen, H. E..

8 recordsLinked to original sources

bioRxiv2026

TMEM119+ microglia MHC class I restricted antigen presentation impacts CD8 T cell memory, effector status, and blood-brain barrier disruption during neurotropic virus infection

The impact of microglia antigen presentation on CNS infiltrating CD8 T cells responses during neurotropic virus infection has been difficult to define. Using Theilers murine encephalomyelitis virus (TMEV) infection of neurons as a model system, our laboratory has previously determined that H-2Db restricted, but not H-2Kb restricted CD8 T cells are required for viral clearance, demonstrating the role of discrete MHC class I alleles. To determine the extent microglia antigen presentation impacts brain-infiltrating CD8 T cells, our laboratory generated novel single MHC class I conditional knockout mice in which H-2Kb or H-2Db can be specifically deactivated in TMEM119+ microglia with tamoxifen administration. During TMEV infection, conditional knockout of H-2Kb in microglia reduced antigen-specific CD8 T cell proliferation in the brain. Meanwhile, mice with deletion of Db in microglia had reduced levels of perforin in antigen-specific CD8 T cells. Furthermore, microglia specific deletion of H-2Db reduced CD8 T cell numbers in the brain and preserved blood-brain barrier (BBB) integrity. Microglial Db restricted antigen presentation was also essential for the reactivation of CD8 tissue resident memory (TRM) cells and BBB integrity during memory recall responses. These findings further our understanding of how brain infiltrating antiviral CD8 T cell responses are impacted by microglia, as well as define how this cellular interaction contributes to BBB disruption during neuroinflammation. These findings also have high significance to our understanding of how microglia impact CD8 TRM cell populations that reside in the brain long after virus infection is cleared. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=111 SRC="FIGDIR/small/722741v1_ufig1.gif" ALT="Figure 1"> View larger version (42K): org.highwire.dtl.DTLVardef@1f53d89org.highwire.dtl.DTLVardef@19af9a8org.highwire.dtl.DTLVardef@17cb8b5org.highwire.dtl.DTLVardef@1428440_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

bioRxiv2025

Gene expression profiling for forensic age assessment of porcine skin wounds

Determining the age of wounds is of utmost importance in both veterinary and human forensic pathology. The aim of this study was to design and optimize quantitative polymerase chain reaction (qPCR) primers for use on degraded RNA samples obtained in veterinary forensic cases, hereby ensuring assay robustness. Moreover, the aim was to evaluate if an expression signature, based on optimized short-amplicon primers, was able to differentiate porcine experimental granulation tissue according to age and if this could be used for wound age assessment in veterinary forensic cases. Initially, 12 samples of experimental granulation tissue (n=6) and skin (n=6) from two pigs were deliberately exposed to RNA degrading conditions before being stored in RNAlater. A panel of 24 robust primers were selected based on the intentionally degraded samples. Granulation tissue (5, 10, 15, 20, 25, 30, and 35 days of age) (n=94) and control skin (n=47) from 47 experimental pigs was sampled and stored in RNAlater. Furthermore, granulation tissue and fibrous scar tissue were sampled from 14 veterinary forensic cases. Microfluidic qPCR was performed to evaluate the gene expression of 24 genes. An expression signature of 14 genes reflected the age of the experimental wounds. The 5-day old wounds displayed the biggest divergence from the control skin. As the granulation tissue matured, gene expression gradually approached the levels observed in intact skin. The forensic samples clustered somewhat separately from the experimental samples. In conclusion, granulation tissue from the experimental wounds displayed a time-dependent expression profile based on 14 short-amplicon primers suitable for use with low-quality RNA. However, an expression profile of 14 genes cannot be used as the sole method for forensic age assessments of porcine wounds.

genetics↗

bioRxiv2025

A multidisciplinary approach for the study of age-dependent expression patterns in porcine experimental wounds

Determining the age of wounds in both human and veterinary subjects is a critical aspect of forensic pathology. Gross and histopathological evaluations are used for age estimations, however, these evaluations are subjective as they rely on the opinion and experience of the examining pathologist. Therefore, the aim of the study was to create a multidisciplinary approach to discover accurate and objective indicators of wound age in veterinary forensic cases. In the present study we utilized a porcine experimental wound healing model. Granulation tissue from wounds at different ages (5, 10, 15, 20, 25, 30, and 35 days) (n=188) and control skin samples (n=47) from 47 experimental pigs were evaluated macroscopically, histologically, immunohistochemically, combined with digital pathology, and flow cytometry. Granulation tissue thickness peaked on day 10 post wounding. Full epithelialization was observed at the earliest on day 20 and the percentage of wound surface covered by epithelium increased with age. Leukocytes including hemosiderophages, neutrophils and accumulation of macrophages all displayed time-dependent infiltration into the wound bed. CD34 showed no time-dependent expression. CD105 expression peaked on day 15. CD45 showed a time-dependent expression pattern in the superficial part of the granulation tissue, with highest expression on day 5 and a decrease with increasing wound age. The findings of this multidisciplinary approach indicate the potential to achieve accurate and objective wound age estimations in veterinary and human forensic investigations.

cell biology↗

bioRxiv2025

Experimental inoculation of pigs with porcine respirovirus type 1 revealed pathological manifestations in the upper respiratory tract

Several pathogens are known to affect the respiratory tract of pigs resulting in decreased health and welfare. Virological investigations and the use of metagenomic sequencing of samples allowed the identification of new viruses in pigs, such as porcine respirovirus type 1 (PRV1) and swine orthopneumovirus (SOV). The pathogenicity of PRV1 has been investigated experimentally by one research group, whereas SOV is yet to be studied. In this experimental trial, groups of weaners were inoculated with a European isolate of PRV1 (n = 8), a pool of SOV RNA-positive clinical nasal swab material (n = 8) or culture medium serving as controls (n = 4). Four days post inoculation (DPI), two controls and four pigs from each of the PRV1 and SOV groups were euthanized and necropsied. All SOV inoculated pigs tested negative for SOV at DPI 4 and therefore four of these pigs were transferred to the stable with the PRV1- infected pigs to assess direct-contact transmission. Nasal swab samples were collected at regular intervals after challenge and blood samples were collected at DPI 0, 4, and 14. At 14 DPI, the remaining pigs (n = 10) were euthanized and necropsied. Nasal swab samples and tissues from the respiratory tract were examined for PRV1 RNA by reverse transcriptase real- time PCR and blood samples were investigated for PRV1 antibodies by ELISA. Respiratory tissues were also evaluated macro- and microscopically and selected tissues were investigated for in situ detection of PRV1 mRNA by RNAscope. No clinical signs, except for nasal discharge, were observed in any of the pigs. PRV1-shedding was observed from DPI 2 to 11 with peaks between DPI 4 and 7, and PRV1 was transmitted horizontally to all direct-contact pigs. The highest viral load was detected in the upper respiratory tract, i.e. nose, upper and lower trachea compared to the lower respiratory tract, i.e., bronchioles, and alveoli. Generally, a chronic tracheitis at 4 DPI, developing into chronic, erosive tracheitis at 14 DPI was observed in the PRV1 groups and was supported by in situ detection of PRV1 by RNAscope. Three pigs also developed mild, bronchointerstitial pneumonia at 14 DPI. In conclusion, these results showed that PRV1 is a primary porcine respiratory pathogen. Author summaryRespiratory diseases in pigs impair porcine health and welfare and are often caused by a complex interaction between pathogens. We investigated the pathogenesis of two recently discovered viruses: porcine respirovirus type 1 (PRV1) and swine orthopneumovirus (SOV). An experimental model in weaner pigs showed that PRV1 is capable of efficient replication, horizontal transmission and caused pathological manifestations mainly in the upper respiratory tract. The lesions consisted of chronic, erosive tracheitis in all PRV1 infected pigs, resulting in a breakage of the tracheal epithelial barrier, and a few pigs developed bronchointerstitial pneumonia. These findings confirm that PRV1 should be considered a primary porcine respiratory pathogen, but in contrast, SOV did not result in a successful infection, and the reasons why remain to be elucidated. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=100 SRC="FIGDIR/small/666573v1_ufig1.gif" ALT="Figure 1"> View larger version (41K): org.highwire.dtl.DTLVardef@d93a11org.highwire.dtl.DTLVardef@17341e9org.highwire.dtl.DTLVardef@1ec4ca4org.highwire.dtl.DTLVardef@9bd42f_HPS_FORMAT_FIGEXP M_FIG C_FIG Graphical abstract created with Biorender.com

microbiology↗

bioRxiv2025

New high accuracy diagnostics for avian Aspergillus fumigatus infection using Nanopore methylation sequencing of host cell-free DNA and machine learning prediction

Avian aspergillosis is a detrimental fungal infection affecting wild and domestic birds yet sensitive antemortem diagnostics for early clinical infections are lacking. Here we present new diagnostics for Aspergillus fumigatus (Af) infection developed from cell-free DNA (cfDNA) methylation markers. Broiler chickens were experimentally infected with either Af, a non-Af agent (Escherichia coli or Gallibacterium anatis) or assigned as controls. Oxford Nanopore (ONT) sequencing was performed on serum cfDNA (n = 124), and machine learning (ML) models were trained on infection-specific markers. Three tests were developed: A High Accuracy test for best performance (sensitivity: 100%, specificity: 89.2%) and robustness (ROC-AUC: 0.92) as well as Fast- and In situ tests for rapid turnaround and methylation PCR. Diagnostic accuracies were 92.3%, 82.7%, and 73.1%, respectively. In conclusion, new tests using on ML- and host cfDNA methylation markers demonstrated high diagnostic performance comparable to microbial cfDNA (mcfDNA) tests but without concern for environmental contamination. Key highlightsO_LIWe present three new high accuracy diagnostic tests for Aspergillus fumigatus infection in chickens that use methylation markers from serum cell-free DNA (cfDNA). C_LIO_LIDifferentially methylated cfDNA regions (DMRs) were detected by Oxford Nanopore sequencing (ONT) in experimentally infected chickens and used as markers to train machine learning (ML) models for development of three diagnostic tests. C_LIO_LIThe highest accuracy was found with 83 markers of 10 kilobases (KB) using the glmnet algorithm for the ML model, which classified 92.3% blinded samples correctly. C_LIO_LIA Fast test designed for cheap <1h sequencing using adaptive sampling could correctly classify 82.7% samples with 22 markers using a random forest (rf) model. C_LIO_LIAn In situ test with only four markers, envisioned for use in a simple methylation-specific PCR (MSP-PCR) assay, could correctly classify 73.1% blinded samples. C_LIO_LIReference values with associated probabilities of infection were calculated for each of the three tests and are presented for further evaluation. C_LI

microbiology↗

bioRxiv2025

Refining the adjuvant-induced rat model of monoarthritis by optimizing the induction volume and injection site

Arthritis is a highly prevalent and disabling condition characterized by pathological joint-damage, clinical symptoms of pain and loss of normal joint function. Monoarthritis can be modelled in rodents via intraarticular injection of complete Freund's Adjuvant (CFA), inducing both joint inflammation and pain-like behaviours. This study aimed to compare the outcome of different injection-volumes and joint-locations, to refine the model's use and to improve its validity. Male and female rats were injected with CFA into the ankle (10, 20 or 50 {micro}l) or knee (10, 50 or 100 {micro}l), and assessed on dynamic weight bearing, locomotor activity, depressive- and anxiety-like behaviours, histology, and a variety of welfare and model-specific parameters. Induction of monoarthritis resulted in relatively similar behavioural profiles regardless of the injected joint. The animals were highly affected in the acute phase, while less in the chronic phase. Greater volumes of CFA were associated with more profound behavioural changes and joint swelling. The largest volumes induced a pronounced local spread of inflammation to adjacent joints, which was reduced with intermediate volumes without attenuating the model validity. Reducing induction volumes to 20 and 50 {micro}l CFA for ankle and knee injections, respectively, appears to be valuable refinement of these models.

neuroscience↗

bioRxiv2024

Reduced glucose supply during neonatal infection attenuates neurological and renal pathology via modulation of innate and Th1 immunity

BackgroundPremature infants are highly susceptible to infections that can lead to sepsis with life-threatening organ dysfunctions. The clinical practice of high parenteral glucose supply in preterm infants can exacerbate infection outcomes through excessive glycolysis-induced inflammatory response. This in turn can affect the health of vital preterm organs, including the brain and kidneys. We hypothesized that reducing glucose supply in infected preterm newborns may help protect against pathology in these two key organs. MethodsCaesarean-delivered preterm pigs were nourished with high or low parenteral glucose levels, infected with Staphylococcus epidermidis or saline, and cared for until 22h. Blood, brain, and kidney samples were collected at the end of the study for analyses. ResultsInfection led to multiple pathological changes, increased inflammation and tissue injury and dysfunction in both brain and kidneys of preterm piglets. Reduced glucose supply in infected animals alleviated neurological degradation, hyperemia and enhanced M2 microglial phenotype in the brain. This intervention also reduced plasma creatinine, renal edema, tubular vacuolization and dilatation. Multiple genes related to innate and Th1 immunity in both organs were highly correlated and dampened by reduced glucose supply, but there were clear signs that renal inflammation was closely connected to systemic inflammation while neuroinflammation was likely driven by immune response to the bacteria translocated into the brain. ConclusionReduced glucose supply can protect brain and kidney health in infected preterm neonates.

immunology↗

bioRxiv2024

The avian and human influenza A virus receptors sialic acid (SA)-α2,3 and SA-α2,6 are widely expressed in the bovine mammary gland

An outbreak of H5N1 highly pathogenic influenza A virus (HPIAV) has been detected in dairy cows in the United States. Influenza A virus (IAV) is a negative-sense, single-stranded, RNA virus that has not previously been associated with widespread infection in cattle. As such, cattle are an extremely under-studied domestic IAV host species. IAV receptors on host cells are sialic acids (SAs) that are bound to galactose in either an 2,3 or 2,6 linkage. Human IAVs preferentially bind SA-2,6 (human receptor), whereas avian IAVs have a preference for 2,3 (avian receptor). The avian receptor can further be divided into two receptors: IAVs isolated from chickens generally bind more tightly to SA-2,3-Gal-{beta}1,4 (chicken receptor), whereas IAVs isolated from duck to SA-2,3-Gal-{beta}1,3 (duck receptor). We found all receptors were expressed, to a different degree, in the mammary gland, respiratory tract, and cerebrum of beef and/or dairy cattle. The duck and human IAV receptors were widely expressed in the bovine mammary gland, whereas the chicken receptor dominated the respiratory tract. In general, only a low expression of IAV receptors was observed in the neurons of the cerebrum. These results provide a mechanistic rationale for the high levels of H5N1 virus reported in infected bovine milk and show cattle have the potential to act as a mixing vessel for novel IAV generation. Graphical abstractCreated with Biorender.com O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=60 SRC="FIGDIR/small/592326v1_ufig1.gif" ALT="Figure 1"> View larger version (24K): org.highwire.dtl.DTLVardef@1d6493org.highwire.dtl.DTLVardef@1b60585org.highwire.dtl.DTLVardef@1247e69org.highwire.dtl.DTLVardef@e75da1_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗