Innate Immune Genes Research Articles

Transcriptome analysis reveals mechanisms of metabolic detoxification and immune responses following farnesyl acetate treatment in Metisa plana

Metisa plana is a widespread insect pest infesting oil palm plantations in Malaysia. Farnesyl acetate (FA), a juvenile hormone analogue, has been reported to exert in vitro and in vivo insecticidal activity against other insect pests. However, the insecticidal mechanism of FA on M. plana remains unclear. Therefore, this study aims to elucidate responsive genes in M. plana in response to FA treatment. The RNA-sequencing reads of FA-treated M. plana were de novo-assembled with existing raw reads from non-treated third instar larvae, and 55,807 transcripts were functionally annotated to multiple protein databases. Several insecticide detoxification-related genes were differentially regulated among the 321 differentially expressed transcripts. Cytochrome P450 monooxygenase, carboxylesterase, and ATP-binding cassette protein were upregulated, while peptidoglycan recognition protein was downregulated. Innate immune response genes, such as glutathione S-transferases, acetylcholinesterase, and heat shock protein, were also identified in the transcriptome. The findings signify that changes occurred in the insect’s receptor and signaling, metabolic detoxification of insecticides, and immune responses upon FA treatment on M. plana. This valuable information on FA toxicity may be used to formulate more effective biorational insecticides for better M. plana pest management strategies in oil palm plantations.

Involvement of mitochondrial fatty acid β-oxidation in the antiviral innate immune response in head kidney macrophages of large yellow croaker (Larimichthys crocea)

As a vital pathway for cellular energy production, mitochondrial fatty acid β-oxidation (FAO) is essential in regulating immune responses to bacterial pathogens and maintaining intracellular homeostasis in vertebrates. However, the specific role of FAO in antiviral innate immune response in macrophages remains insufficiently understood. In this study, virus infection simulated by poly(I:C) inhibited FAO, as indicated by the reduced expression of FAO-related genes and proteins in the head kidney of large yellow croaker, with similar results observed in poly(I:C)-stimulated macrophages. Then, inhibition of FAO by supplementary mildronate in vivo and etomoxir treatment in vitro revealed varying increases in the mRNA expression of antiviral innate immune response genes after stimulated by poly(I:C) in the head kidney and macrophages. Notably, etomoxir significantly facilitated the transcriptional up-regulation of the IFNh promoter by IRF3. Moreover, inhibiting FAO by knockdown of cpt1b promoted antiviral innate immune response triggered by poly(I:C) in macrophages. Conversely, activating FAO through overexpression of cpt1b or cpt2 significantly reduced the mRNA levels of antiviral response genes in macrophages stimulated by poly(I:C). Unlike etomoxir, cpt1b overexpression inhibited the transcriptional up-regulation of the IFNh promoter by IRF3. Furthermore, in vivo dietary palm oil feeding and in vitro exposure to palmitic acid inhibited the antiviral innate immune response triggered by poly(I:C) in the head kidney and macrophages, respectively. These effects were partly associated with FAO activation, as evidenced by etomoxir. In summary, this study elucidates FAO's critical role in regulating antiviral innate immune response in head kidney macrophages. These findings not only deepen insights into the interaction between metabolic remodeling and host immune responses, but also offer valuable guidance for developing nutritional strategies to improve antiviral immunity in aquaculture.

Genome Restructuring around Innate Immune Genes in Monocytes in Alcohol-associated Hepatitis.

Many inflammatory genes in the immune system are clustered in the genome. The 3D genome architecture of these clustered genes likely plays a critical role in their regulation and alterations to this structure may contribute to diseases where inflammation is poorly controlled. Alcohol-associated hepatitis (AH) is a severe inflammatory disease that contributes significantly to morbidity in alcohol associated liver disease. Monocytes in AH are hyper-responsive to inflammatory stimuli and contribute significantly to inflammation. We performed high throughput chromatin conformation capture (Hi-C) technology on monocytes isolated from 4 AH patients and 4 healthy controls to better understand how genome structure is altered in AH. Most chromosomes from AH and healthy controls were significantly dissimilar from each other. Comparing AH to HC, many regions of the genome contained significant changes in contact frequency. While there were alterations throughout the genome, there were a number of hotspots containing a higher density of changes in structure. A few of these hotspots contained genes involved in innate immunity including the NK-gene receptor complex and the CXC-chemokines. Finally, we compare these results to scRNA-seq data from patients with AH challenged with LPS to predict how chromatin conformation impacts transcription of clustered immune genes. Together, these results reveal changes in the chromatin structure of monocytes from AH patients that perturb expression of highly clustered proinflammatory genes.

Sustained mucosal colonization and fecal metabolic dysfunction by Bacteroides associates with fecal microbial transplant failure in ulcerative colitis patients

Fecal microbial transplantation (FMT) offers promise for treating ulcerative colitis (UC), though the mechanisms underlying treatment failure are unknown. This study harnessed longitudinally collected colonic biopsies (n = 38) and fecal samples (n = 179) from 19 adults with mild-to-moderate UC undergoing serial FMT in which antimicrobial pre-treatment and delivery mode (capsules versus enema) were assessed for clinical response (≥ 3 points decrease from the pre-treatment Mayo score). Colonic biopsies underwent dual RNA-Seq; fecal samples underwent parallel 16S rRNA and shotgun metagenomic sequencing as well as untargeted metabolomic analyses. Pre-FMT, the colonic mucosa of non-responsive (NR) patients harbored an increased burden of bacteria, including Bacteroides, that expressed more antimicrobial resistance genes compared to responsive (R) patients. NR patients also exhibited muted mucosal expression of innate immune antimicrobial response genes. Post-FMT, NR and R fecal microbiomes and metabolomes exhibited significant divergence. NR metabolomes had elevated concentrations of immunostimulatory compounds including sphingomyelins, lysophospholipids and taurine. NR fecal microbiomes were enriched for Bacteroides fragilis and Bacteroides salyersiae strains that encoded genes capable of taurine production. These findings suggest that both effective mucosal microbial clearance and reintroduction of bacteria that reshape luminal metabolism associate with FMT success and that persistent mucosal and fecal colonization by antimicrobial-resistant Bacteroides species may contribute to FMT failure.

Assessing a respiratory toxic infectious bronchitis virus (IBV) strain: isolation, identification, pathogenicity, and immunological failure insights.

Infectious bronchitis virus (IBV) is caused by avian coronavirus and poses a global economic threat to the poultry industry. In 2023, a highly pathogenic IBV strain, IBV/CN/GD20230501, was isolated and identified from chickens vaccinated with IBV-M41 in Guangdong, China. This study comprehensively investigated the biological characteristics of the isolated IBV strain, including its genotype, whole genome sequence analysis of its S1 gene, pathogenicity, host immune response, and serum non-targeted metabolomics. Through the analysis of the S1 gene sequence, serum neutralization tests, and comparative genomics, it was proven that IBV/CN/GD20230501 belongs to the GI-I type of strain and is serotype II. One alanine residue in the S1 subunit of the isolated strain was mutated into serine, and some mutations were observed in the ORF1ab gene and the terminal region of the genome. Animal challenge experiments using the EID50 and TCID50 calculations showed that IBV/CN/GD20230501 possesses strong respiratory pathogenicity, with early and long-term shedding of viruses and rapid viral spread. Antibody detection indicated that chickens infected with IBV/CN/GD20230501 exhibited delayed expression of early innate immune genes, while those infected with M41 showed rapid gene induction and effective viral control. Metabolomics analysis demonstrated that this virus infection led to differential expression of 291 ions in chicken serum, mainly affecting the citric acid cycle (tricarboxylic acid cycle).IMPORTANCEThis study identified an infectious bronchitis virus (IBV) strain isolated from vaccinated chickens in an immunized population that had certain sequence differences compared to IBV-M41, resulting in significantly enhanced pathogenicity and host defense. This strain has the potential to replace M41 as a more suitable challenge model for drug research. The non-targeted metabolomics analysis highlighting the citric acid cycle provides a new avenue for studying this highly virulent strain.

Proliferative arrest induces neuron differentiation and innate immune responses in control and Creutzfeldt-Jakob Disease agent infected rat septal neurons.

Rat post-mitotic septal (SEP) neurons, engineered to conditionally proliferate at 33°C, differentiate when arrested at 37.5°C and can be maintained for weeks without cytotoxic effects. Nine independent cDNA libraries were made to follow arrest-induced neural differentiation and innate immune responses in normal (Nl) uninfected and CJ agent infected SEP cells. Proliferating Nl versus latently infected (CJ-) cells showed few RNA-seq differences. However arrest induced major changes. Normal cells displayed a plethora of anti-proliferative transcripts. Additionally, known neuron differentiation transcripts, e.g., Agtr2, Neuregulin-1, GDF6, SFRP4 and Prnp were upregulated. These Nl neurons also displayed many activated IFN innate immune genes, e.g., OAS1, RTP4, ISG20, GTB4, CD80 and cytokines, complement, and clusterin (CLU) that binds to misfolded proteins. In contrast, arrested highly infectious CJ+ cells (10 logs/gm) downregulated many replication controls. Furthermore, arrested CJ+ cells suppressed neuronal differentiation transcripts, including Prnp which is essential for CJ agent infection. CJ+ cells also enhanced IFN stimulated pathways, and analysis of the 342 CJ+ unique transcripts revealed additional innate immune and anti-viral-linked transcripts, e.g., Il17, ISG15, and RSAD2 (viperin). These data show: 1) innate immune transcripts are produced by normal neurons during differentiation; 2) CJ infection can enhance and expand anti-viral responses; 3) latent CJ infection epigenetically imprints many proliferative pathways to thwart complete arrest. CJ+ brain microglia, white blood cells and intestinal myeloid cells with shared transcripts may be stimulated to educe latent CJD infections that can be clinically silent for >30 years.

Comparative assessment of interferon activity in influenza and COVID-19

Among respiratory viruses, the most serious complications are caused by influenza A and B viruses, as well as coronaviruses. Most studies determined the absolute content of interferons (IFNs) of different types in blood serum. However, serum IFN protein concentrations do not always reflect the level of antiviral protection. The purpose of this study was a comparative assessment of interferon status in patients with ARVI: influenza and the acute stage of COVID-19. Materials and methods. We used biomaterial in the form of whole blood samples from 113 patients with influenza and 110 patients in the acute phase of moderate COVID-19. The body’s antiviral defense during ARVI was assessed by determining the activity of type I and II interferons produced by blood leukocytes using the “Interferon status” method in a cell-virus system simulated in vitro. Results. This work reveals a statistically significant decrease in the biological activity of interferons produced by blood leukocytes in influenza and a deficiency of IFN activity in COVID-19, compared with reference values, and also shows possible prospects for the treatment of these nosologies with such immunoactive drugs as IFN inducers (cycloferon, Kagocel) and immunomodulators (ingavirin, multicomponent vaccine Immunovac-VP-4). Conclusion. The results of IFN activity are necessary to assess the antiviral potential of the body, especially with COVID-19, given the “novelty” of the infection, the severity and variety of its clinical manifestations. Today it is known that the SARS-CoV-2 virus is capable of penetrating not only into the epithelial cells of the upper respiratory tract, epithelial cells of the stomach and intestines, but also into the cells of the esophagus, heart, adrenal glands, bladder, brain, as well as into the vascular endothelium and macrophages. Coronavirus SARS-CoV-2 inhibits the expression of cellular genes, including innate immune genes, and has a negative effect on the IFN system. The use of IFN inducers and immunomodulators for influenza and COVID-19 has shown immunological feasibility and clinical promise.

Mitochondrial antioxidants abate SARS-COV-2 pathology in mice

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection inhibits mitochondrial oxidative phosphorylation (OXPHOS) and elevates mitochondrial reactive oxygen species (ROS, mROS) which activates hypoxia-inducible factor-1alpha (HIF-1α), shifting metabolism toward glycolysis to drive viral biogenesis but also causing the release of mitochondrial DNA (mtDNA) and activation of innate immunity. To determine whether mitochondrially targeted antioxidants could mitigate these viral effects, we challenged mice expressing human angiotensin-converting enzyme 2 (ACE2) with SARS-CoV-2 and intervened using transgenic and pharmacological mitochondrially targeted catalytic antioxidants. Transgenic expression of mitochondrially targeted catalase (mCAT) or systemic treatment with EUK8 decreased weight loss, clinical severity, and circulating levels of mtDNA; as well as reduced lung levels of HIF-1α, viral proteins, and inflammatory cytokines. RNA-sequencing of infected lungs revealed that mCAT and Eukarion 8 (EUK8) up-regulated OXPHOS gene expression and down-regulated HIF-1α and its target genes as well as innate immune gene expression. These data demonstrate that SARS-CoV-2 pathology can be mitigated by catalytically reducing mROS, potentially providing a unique host-directed pharmacological therapy for COVID-19 which is not subject to viral mutational resistance.

Ileal Paneth Cell Phenotype is a Cellular Biomarker for Pouch Complications in Ulcerative Colitis.

Biomarkers that integrate genetic and environmental factors and predict outcome in complex immune diseases such as inflammatory bowel disease (IBD; including Crohn's disease [CD] and ulcerative colitis [UC]) are needed. We showed that morphologic patterns of ileal Paneth cells (Paneth cell phenotype [PCP]; a surrogate for PC function) is one such cellular biomarker for CD. Given the shared features between CD and UC, we hypothesized that PCP is also associated with molecular/genetic features and outcome in UC. Because PC density is highest in the ileum, we further hypothesized that PCP predicts outcome in UC subjects who underwent total colectomy and ileal pouch-anal anastomosis (IPAA). Uninflamed ileal resection margins from UC subjects with colectomy and IPAA were used for PCP and transcriptomic analyses. PCP was defined using defensin 5 immunofluorescence. Genotyping was performed using Immunochip. UC transcriptomic and genotype associations of PCP were incorporated with data from CD subjects to identify common IBD-related pathways and genes that regulate PCP. The prevalence of abnormal ileal PCP was 27%, comparable to that seen in CD. Combined analysis of UC and CD subjects showed that abnormal PCP was associated with transcriptomic pathways of secretory granule maturation and polymorphisms in innate immunity genes. Abnormal ileal PCP at the time of colectomy was also associated with pouch complications including de novo CD in the pouch and time to first episode of pouchitis. Ileal PCP is biologically and clinically relevant in UC and can be used as a biomarker in IBD.

Molecular basis of neurodegeneration in a mouse model of Polr3-related disease.

Pathogenic variants in subunits of RNA polymerase (Pol) III cause a spectrum of Polr3-related neurodegenerative diseases including 4H leukodystrophy. Disease onset occurs from infancy to early adulthood and is associated with a variable range and severity of neurological and non-neurological features. The molecular basis of Polr3-related disease pathogenesis is unknown. We developed a postnatal whole-body mouse model expressing pathogenic Polr3a mutations to examine the molecular mechanisms by which reduced Pol III transcription results primarily in central nervous system phenotypes. Polr3a mutant mice exhibit behavioral deficits, cerebral pathology and exocrine pancreatic atrophy. Transcriptome and immunohistochemistry analyses of cerebra during disease progression show a reduction in most Pol III transcripts, induction of innate immune and integrated stress responses and cell type-specific gene expression changes reflecting neuron and oligodendrocyte loss and microglial activation. Earlier in the disease when integrated stress and innate immune responses are minimally induced, mature tRNA sequencing revealed a global reduction in tRNA levels and an altered tRNA profile but no changes in other Pol III transcripts. Thus, changes in the size and/or composition of the tRNA pool have a causal role in disease initiation. Our findings reveal different tissue- and brain region-specific sensitivities to a defect in Pol III transcription.

Insights into Prime Editing Technology: A Deep Dive into Fundamentals, Potentials, and Challenges.

As the most versatile and precise gene editing technology, prime editing (PE) can establish a durable cure for most human genetic disorders. Several generations of PE have been developed based on an editor machine or prime editing guide RNA (pegRNA) to achieve any kind of genetic correction. However, due to the early stage of development, PE complex elements need to be optimized for more efficient editing. Smart optimization of editor proteins as well as pegRNA has been contemplated by many researchers, but the universal PE machine's current shortcomings remain to be solved. The modification of PE elements, fine-tuning of the host genes, manipulation of epigenetics, and blockage of immune responses could be used to reach more efficient PE. Moreover, the host factors involved in the PE process, such as repair and innate immune system genes, have not been determined, and PE cell context dependency is still poorly understood. Regarding the large size of the PE elements, delivery is a significant challenge and the development of a universal viral or nonviral platform is still far from complete. PE versions with shortened variants of reverse transcriptase are still too large to fit in common viral vectors. Overall, PE faces challenges in optimization for efficiency, high context dependency during the cell cycling, and delivery due to the large size of elements. In addition, immune responses, unpredictability of outcomes, and off-target effects further limit its application, making it essential to address these issues for broader use in nonpersonalized gene editing. Besides, due to the limited number of suitable animal models and computational modeling, the prediction of the PE process remains challenging. In this review, the fundamentals of PE, including generations, potential, optimization, delivery, invivo barriers, and the future landscape of the technology are discussed.

HIV-1 Vpr combats the PU.1-driven antiviral response in primary human macrophages

HIV-1 Vpr promotes efficient spread of HIV-1 from macrophages to T cells by transcriptionally downmodulating restriction factors that target HIV-1 Envelope protein (Env). Here we find that Vpr induces broad transcriptomic changes by targeting PU.1, a transcription factor necessary for expression of host innate immune response genes, including those that target Env. Consistent with this, we find silencing PU.1 in infected macrophages lacking Vpr rescues Env. Vpr downmodulates PU.1 through a proteasomal degradation pathway that depends on physical interactions with PU.1 and DCAF1, a component of the Cul4A E3 ubiquitin ligase. The capacity for Vpr to target PU.1 is highly conserved across primate lentiviruses. In addition to impacting infected cells, we find that Vpr suppresses expression of innate immune response genes in uninfected bystander cells, and that virion-associated Vpr can degrade PU.1. Together, we demonstrate Vpr counteracts PU.1 in macrophages to blunt antiviral immune responses and promote viral spread.

Dietary vitamin C reduces mortality of pacific white shrimp (Penaeus vannamei) post-larvae by Vibrio parahaemolyticus challenge

This study was conducted to investigate whether optimal vitamin C (VC) levels can enhance non-specific immune response and antioxidant capacity and reduce mortality of Pacific white shrimp (Penaeus vannamei) post-larvae when infected with Vibrio parahaemolyticus. Six experimental diets were formulated to contain six different VC levels of 0, 40, 80, 120, 160 and 320 mg/kg diet (designated as C0, C40, C80, C120, C160 and C320, respectively). Shrimp post-larvae (39.1 ± 0.47 mg) were randomly distributed to 24 tanks with 40 shrimp per tank. Four replicate groups of shrimp were fed one of the diets for 43 days. VC supplemented groups showed significantly higher growth performance than C0 group. Shrimp fed C120 diet had significantly improved feed utilization efficiency than shrimp fed C0 diet. VC concentrations in hepatopancreas and gills were significantly higher with the increase in dietary VC levels. Optimal dietary VC levels significantly upregulated the expressions of growth and digestive enzyme-related genes such as IGF-1, IGF-BP, amylase, trypsin and chymotrypsin, and also upregulated the expressions of innate immunity and antioxidant-related genes such as prophenoloxidase, crustin, penaiedin-3a, superoxide dismutase, glutathione peroxidase and catalase in hepatopancreas. Shrimp fed C80, C120 and C160 diets showed significantly increased resistance to V. parahaemolyticus than shrimp fed C0 diet. The optimum dietary VC level for the shrimp post-larvae was established to be 80.2 mg/kg diet by a broken-line regression analysis based on the growth. The findings from the challenge test indicated that VC levels over 83.0 mg/kg diet could enhance disease resistance of the shrimp against V. parahaemolyticus.

Bacterial sepsis triggers stronger transcriptomic immune responses in larger primates.

Empirical data relating body mass to immune defence against infections remain limited. Although the metabolic theory of ecology predicts that larger organisms would have weaker immune responses, recent studies have suggested that the opposite may be true. These discoveries have led to the safety factor hypothesis, which proposes that larger organisms have evolved stronger immune defences because they carry greater risks of exposure to pathogens and parasites. In this study, we simulated sepsis by exposing blood from nine primate species to a bacterial lipopolysaccharide (LPS), measured the relative expression of immune and other genes using RNAseq, and fitted phylogenetic models to determine how gene expression was related to body mass. In contrast to non-immune-annotated genes, we discovered hypermetric scaling in the LPS-induced expression of innate immune genes, such that large primates had a disproportionately greater increase in gene expression of immune genes compared to small primates. Hypermetric immune gene expression appears to support the safety factor hypothesis, though this pattern may represent a balanced evolutionary mechanism to compensate for lower per-transcript immunological effectiveness. This study contributes to the growing body of immune allometry research, highlighting its importance in understanding the complex interplay between body size and immunity over evolutionary timescales.

Physiochemical interaction between osmotic stress and a bacterial exometabolite promotes plant disease

Various microbes isolated from healthy plants are detrimental under laboratory conditions, indicating the existence of molecular mechanisms preventing disease in nature. Here, we demonstrated that application of sodium chloride (NaCl) in natural and gnotobiotic soil systems is sufficient to induce plant disease caused by an otherwise non-pathogenic root-derived Pseudomonas brassicacearum isolate (R401). Disease caused by combinatorial treatment of NaCl and R401 triggered extensive, root-specific transcriptional reprogramming that did not involve down-regulation of host innate immune genes, nor dampening of ROS-mediated immunity. Instead, we identified and structurally characterized the R401 lipopeptide brassicapeptin A as necessary and sufficient to promote disease on salt-treated plants. Brassicapeptin A production is salt-inducible, promotes root colonization and transitions R401 from being beneficial to being detrimental on salt-treated plants by disturbing host ion homeostasis, thereby bolstering susceptibility to osmolytes. We conclude that the interaction between a global change stressor and a single exometabolite from a member of the root microbiome promotes plant disease in complex soil systems.

Chicken intestinal organoids: a novel method to measure the mode of action of feed additives.

There is a rapidly growing interest in how the avian intestine is affected by dietary components and feed additives. The paucity of physiologically relevant models has limited research in this field of poultry gut health and led to an over-reliance on the use of live birds for experiments. The development of complex 3D intestinal organoids or "mini-guts" has created ample opportunities for poultry research in this field. A major advantage of the floating chicken intestinal organoids is the combination of a complex cell system with an easily accessible apical-out orientation grown in a simple culture medium without an extracellular matrix. The objective was to investigate the impact of a commercial proprietary blend of organic acids and essential oils (OA+EO) on the innate immune responses and kinome of chicken intestinal organoids in a Salmonella challenge model. To mimic the in vivo prolonged exposure of the intestine to the product, the intestinal organoids were treated for 2 days with 0.5 or 0.25 mg/mL OA+EO and either uninfected or infected with Salmonella and bacterial load in the organoids was quantified at 3 hours post infection. The bacteria were also treated with OA+EO for 1 day prior to challenge of the organoids to mimic intestinal exposure. The treatment of the organoids with OA+EO resulted in a significant decrease in the bacterial load compared to untreated infected organoids. The expression of 88 innate immune genes was investigated using a high throughput qPCR array, measuring the expression of 88 innate immune genes. Salmonella invasion of the untreated intestinal organoids resulted in a significant increase in the expression of inflammatory cytokine and chemokines as well as genes involved in intracellular signaling. In contrast, when the organoids were treated with OA+EO and challenged with Salmonella, the inflammatory responses were significantly downregulated. The kinome array data suggested decreased phosphorylation elicited by the OA+EO with Salmonella in agreement with the gene expression data sets. This study demonstrates that the in vitro chicken intestinal organoids are a new tool to measure the effect of the feed additives in a bacterial challenge model by measuring innate immune and protein kinases responses.

Unveiling the dynamics of embryogenesis and immune genes expression pattern in the amur common carp (Cyprinus carpio haematopterus)

Amur common carp (Cyprinus carpio haematopterus), is a commercially important fish species that has been genetically improved over the years through selective breeding. Despite its significance in aquaculture, limited knowledge exists regarding its embryogenesis and immune genes associated with its early stages of life. This article represents a detailed study of the embryogenesis and innate immune gene expression analysis of the Amur common carp during its ontogenic developments. The entire embryonic developmental process of ∼44 h could be divided into eight periods, beginning with the formation of the zygote, followed by cleavage, morula, blastula, segmentation, pharyngula, and hatching. The segmentation period, which lasted for ∼ 6 h, exhibited the most significant changes, such as muscle contraction, rudimentary heart formation, increased somites number, and the initiation of blood circulation throughout the yolk. The expression of immune-related genes, namely toll-like receptor (TLR)4, nucleotide-binding oligomerization domain (NOD)1, NOD2 and interleukin (IL)-8 showed stage-specific patterns with varying levels of expression across the developmental stages. The TLR4 gene exhibited the highest expression during the neurella stage, while NOD1 and NOD2 peaked during hatching and IL-8 reached its maximum level during the gastrula stage. This is the first report of the innate immune gene expression during the embryogenesis of Amur common carp.

Probiotics Mitigate Exercise Fatigue, Memory Deficits, Depression and Neuro/inflammation in a Mouse Model of Gulf War Illness

We have previously found learning/memory, exercise intolerance, metabolic disturbance, gut dysbiosis and deregulation of neuroinflammatory genes, suggesting a possible microbiota-gut-brain interaction in GWI pathology (Kozlova et al., 2022a PMID: 34710444; 2022b PMID: 34801513). Here, we tested the hypothesis that probiotic treatment (P) prevents GWI symptoms. Adult male C57Bl/6N mice were separated into 4 groups (n=16/group): GW receiving pyridostigmine bromide (8.7 mg/kg, PB, po), permethrin (1.3 mg/kg, PER, top), DEET (33%, top); CON/S (vehicle plus stress); CON/S+P and GW+P. Probiotic groups received a gut-protective probiotic (P) cocktail of L. reuteri, L. rhamnosus, L. casei, B. longum (po, 108 CFU/mL, 3 times/wk) for 2 wk prior to and during GW agent treatment and until sacrifice 5 months later. Fecal RT-qPCR showed colonization of all strains except L. rhamnosus after 6-7 doses when compared to saline sham. Colonization after GW agent exposure was strain-specific and varied with time post-exposure. On an exercise endurance (EE) test GW (but not GW+P) mice tired faster relative to CON/S at PT56 (p<0.05) but not at PT150. Repeat testing on the passive avoidance apparatus (15 wk after previous test) showed that GW but not GW+P mice displayed reduced latency to enter aversive chamber on day 1 of acquisition trials, indicating deficient memory (p<0.05). Depressive-like behavior (mean percent time spent mobile) on tail suspension test (TST) showed less time spent mobile for GW (p<0.05) but not GW+P mice than controls at PT50 (but not PT150). Probiotics protected against the GW-induced rise in liver C-reactive protein (CRP) (p<0.05) and brain interleukin-6 (IL-6) (p<0.05). Immunofluorescence probing in the hippocampal CA1 and dentate gyrus showed significantly greater counts of Iba-1 positive cells in GW (but not GW+P) vs CON/S (p<0.05). NeuN immunostaining on the same sections showed abnormal neuronal phenotype indicative of reorganized RNA in GW but not GW+P) vs CON/S (p<0.05). Multi-gene profiling of innate and adaptive immunity genes in brain homogenates (prefrontal cortex, hypothalamus, hippocampus) identified GW agent-induced deregulation (>1.5-fold; p<.05) of pro-inflammatory genes, i.e., upregulation of C5ar1 and Cxcl10 and downregulation of Tlr4; changes prevented by probiotic treatment. In the gut, M1 proinflammatory macrophages appeared to be more abundant in GW (but not GW+P) vs CON/S (p<0.05). We used 16S next generation sequencing to examine probiotic treatment effects on gut microbial communities. In combination, our findings indicate that GW mice can be used to model multi-symptom illness and support previous evidence that the underlying pathophysiology in GWI likely involve systemic, gut and neuroinflammation and bacterial dysbiosis. Importantly, we show for the first time that probiotic treatment protects against some GWI symptom domains. Further study is needed to uncover pathophysiological pathways through which the microbiota-gut-brain axis impacts gut and brain health and toxicant-related pathology. DoD grant GW-180072 to M.C.C. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Ocular A-to-I RNA editing signatures associated with SARS-CoV-2 infection.

Ophthalmic manifestations have recently been observed in acute and post-acute complications of COVID-19 caused by SARS-CoV-2 infection. Our precious study has shown that host RNA editing is linked to RNA viral infection, yet ocular adenosine to inosine (A-to-I) RNA editing during SARS-CoV-2 infection remains uninvestigated in COVID-19. Herein we used an epitranscriptomic pipeline to analyze 37 samples and investigate A-to-I editing associated with SARS-CoV-2 infection, in five ocular tissue types including the conjunctiva, limbus, cornea, sclera, and retinal organoids. Our results revealed dramatically altered A-to-I RNA editing across the five ocular tissues. Notably, the transcriptome-wide average level of RNA editing was increased in the cornea but generally decreased in the other four ocular tissues. Functional enrichment analysis showed that differential RNA editing (DRE) was mainly in genes related to ubiquitin-dependent protein catabolic process, transcriptional regulation, and RNA splicing. In addition to tissue-specific RNA editing found in each tissue, common RNA editing was observed across different tissues, especially in the innate antiviral immune gene MAVS and the E3 ubiquitin-protein ligase MDM2. Analysis in retinal organoids further revealed highly dynamic RNA editing alterations over time during SARS-CoV-2 infection. Our study thus suggested the potential role played by RNA editing in ophthalmic manifestations of COVID-19, and highlighted its potential transcriptome impact, especially on innate immunity.

Innate immune response of snakehead fish to Indian strain of snakehead rhabdovirus (SHRV-In) infection and the infectivity potential of the virus to other freshwater fishes

A new virus known as snakehead rhabdovirus (SHRV-In) was discovered in South India in striped snakehead (Channa striata) that had hemorrhagic patches and cutaneous ulcerations. The virus is the most potentially harmful pathogen of snakehead because it could cause 100% mortality within 5 days. The goal of the current investigation was to evaluate the infectivity of rhabdovirus in freshwater fishes and to analyze the immune response in snakehead fish after challenge with SHRV-In. The infectivity study of SHRV-In against three freshwater fish such as tilapia, grass carp and loach showed that the virus could not induce mortality in any of them. Snakehead fish challenged with SHRV-In showed significant (p < 0.05) changes in haematological parameters such as red blood cell (RBC), haemoglobin (HGB), haematocrit (HCT), mean corpuscular haemoglobin concentration (MCHC), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), white blood cell (WBC), total platelet (PLT) counts, mean platelet volume (MPV) and immunological markers such as respiratory burst, superoxide dismutase, catalase activity and myeloperoxidase activity at 6, 12, 24 and 48 hpi. Real time PCR was executed to examine the expression profile of innate immune genes such as IRF-7, IL-8 and IL-12 in Snakehead fish at 6, 12, 24 and 48 h post SHRV-In infection. Immune gene expression of IRF-7, IL-8 and IL-12 were up-regulated in the spleen when compared to kidney at 6 and 12 hpi. However, the expression level of all the genes was down-regulated at 24 and 48 hpi. The down regulation of innate immune genes after 24 hpi in these tissues may be the result of increased multiplication of SHRV-In by interfering with the immune signaling pathway.