Transcriptome profile in bursa of Fabricius reveals potential mode for stress-influenced immune function in chicken stress model

Social isolation promotes tumor immune evasion via β2-adrenergic receptor

Social isolation is a recognized risk factor for tumor initiation and mortality, but the role and mechanisms responsible for social isolation on tumor progression are poorly understood. In this study, we found that social isolation contributed to accelerated tumor growth and induced a remodeling of the tumor immune microenvironment, resulting in immunosuppression. Mechanistically, social isolation triggered the activation of the sympathetic nervous system, leading to impaired CD8+ T cell antitumor immune responses by activating β-adrenergic receptor 2 (β2-AR), which highly expressed on tumor-infiltrating CD8+ T cells. Pharmacological inhibition of β2-AR signaling effectively enhanced CD8+ T cell anti-tumor immune responses and improved the efficacy of anti-PD-1 immunotherapy in the context of social isolation. Thus, our study uncovers a mechanism through which social isolation induces tumor immune evasion and offers potential directions for cancer immunotherapy in socially isolated patients.

The Effects of Dietary Pterostilbene on the Immune Response, Antioxidant Function, and Jejunal Structure of Broilers

This experiment was carried out to investigate the effect of pterostilbene (PTE) supplementation in feed on Arbor Acres broilers in terms of serum biochemical parameters, immune and inflammatory responses, antioxidant status, and intestinal morphological structure. For a duration of 42 days, a total of 480 1-day-old Arbor Acres broilers were randomly divided into four groups. Each group was assigned to receive either the basal diet or the basal diet supplemented with 200, 400, or 600 mg/kg of PTE. Each treatment consisted of eight replicates, with 15 chicks per replicate. In comparison with the control group, three PTE treatments significantly increased the lymphocyte transformation rate in the spleen of broilers. The automated biochemical analysis, enzyme-linked immunosorbent assay, and RT-qPCR analysis kits found that 400 mg/kg of PTE significantly increased the serum levels of complement C3, IL-4, and iNOS; reduced the serum levels of IL-6, TNF-α, and mRNA levels of the genes IL-6, IL-8, TNF-α, NLRP3, and IFN-γ; significantly improved the activities of antioxidant enzymes including CAT, GSH-Px, and T-SOD in the jejunum; and significantly reduced the MDA contents in the serum and jejunum of broilers. Nikon microscope observations and ImagePro Plus 6.0 measure results found that 400 mg/kg of PTE supplementation significantly reduced the relative length and weight of the jejunum and improved the jejunal villi structure, resulting in increased intestinal villi, deepened crypt, and an enhanced ratio of villi height to crypt depth (VH/CD). RT-qPCR and Western blot found that dietary PTE also resulted in increased mRNA levels of the genes Claudin-2, Occludin, ZO-1, and Sirt1, and decreased NF-κB protein levels in the jejunum. The results of this study demonstrated that dietary PTE improved the immune function and intestinal health of broilers by reducing inflammation and increasing the antioxidant capacity of the animals.

BPA and low-Se exacerbate apoptosis and autophagy in the chicken bursa of Fabricius by regulating the ROS/AKT/FOXO1 pathway

Bisphenol A (BPA) is a ubiquitous environmental pollutant that can have harmful effects on human and animal immune systems by inducing oxidative stress. Selenium (Se) deficiency damages immune organ tissues and exhibits synergistic effects on the toxicity of environmental pollutants. However, oxidative stress, cell apoptosis, and autophagy caused by the combination of BPA and low-Se, have not been studied in the bursa of Fabricius of the immune organ of poultry. Therefore, in this study, BPA and/or low-Se broiler models and chicken lymphoma cells (MDCC-MSB-1 cells) models were established to investigate the effects of BPA and/or low-Se on the bursa of Fabricius of poultry. The data showed that BPA and/or low-Se disrupted the normal structure of the bursa of Fabricius, BPA (60 μM) significantly reduced the activity of MDCC-MSB-1 cells and disrupted normal morphology (IC50 = 192.5 ± 1.026 μM). Compared with the Control group, apoptosis and autophagy were increased in the BPA or low-Se groups, and the generation of reactive oxygen species (ROS) was increased. This inhibited the AKT/FOXO1 pathway, leading to mitochondrial fusion/division imbalance (Mfn1, Mfn2, OPA1 were increased, DRP1 was decreased) and dysfunction (CI-NDUFB8, CII-SDHB, CIII-UQCRC2, CIV-MTCO1, CV-ATP5A1, ATP). Furthermore, combined exposure of BPA and low-Se aggravated the above-mentioned changes. Treatment with N-acetylcysteine (NAC) reduced ROS levels and activated the AKT/FOXO1 pathway to further alleviate BPA and low-Se-induced apoptosis and autophagy. Apoptosis induced by low-Se + BPA was exacerbated after 3-Methyladenine (3-MA, autophagy inhibitor) treatment. Together, these results indicated that BPA and low-Se aggravated apoptosis and autophagy of the bursa of Fabricius in chickens by regulating the ROS/AKT/FOXO1 pathway.

Transcriptome identification and characterization of long non-coding RNAs in the ovary of hens at four stages

Long non-coding RNAs (lncRNAs) play important roles in transcriptional and post-transcriptional regulation. LncRNAs, which are defined as non-coding RNAs more than 200 bp in length, are involved in key biological processes, such as cell proliferation and differentiation, epigenetic regulation, and gene transcriptional translation. Recent studies have shown that lncRNAs also play major regulatory roles in the reproduction of mammals. However, knowledge of the roles of lncRNAs in the chicken ovary lacking. In this study, we performed RNA-seq analyses of ovarian tissue from Hy-Line brown laying hens at four physiological stages [15, 20, 30, and 68 weeks of age (W)]. We identified 657 lncRNA transcripts that were differentially expressed during ovarian development, the number of down-regulated lncRNAs was higher than the number of up-regulated lncRNAs during development. We predicted the cis and trans target genes of the DE lncRNAs and constructed a lncRNA-mRNA interaction network, which indicated that the DE genes (DEGs) and the target genes of the DE lncRNAs are mainly involved in signaling pathways associated with ovarian development, including oocyte meiosis, calcium signaling pathways, ECM-receptor interactions, and ribosome and focal adhesion. Overall, we found that twelve lncRNAs were strongly involved in ovarian development: LNC_013443, LNC_001029, LNC_005713, LNC_016762, ENSGALT00000101857, LNC_003913, LNC_013692, LNC_012219, LNC_004140, ENSGALT00000096941, LNC_009356, and ENSGALT00000098716. In summary, our study utilized RNA-seq analysis of hen ovaries to explore key lncRNAs involved in ovarian development and function. Furthermore, the comprehensive analysis identified the target genes of these lncRNAs providing a better understanding of the mechanisms underlying ovarian development in hens and a theoretical basis for further research.

Effect of HSPA8 gene on the proliferation, apoptosis and immune function of HD11 cells

HSPA8 (Heat shock 70 kDa protein 8) is a molecular chaperone involved in a variety of cellular processes. This gene may affect the proliferation, apoptosis and immune function of chicken macrophages, but the specific mechanism remains unclear. The purpose of this study was to explore the effect of the HSPA8 gene on the proliferation, apoptosis and immune function of chicken macrophages. In this study, a chicken HSPA8 overexpression plasmid, interference fragment and corresponding controls were transfected into HD11 cells, and then the expression of the HSPA8 gene, cell proliferation, cell cycle, apoptosis rate and immune function of each group were detected. The results showed that transfection of the HSPA8 overexpression plasmid significantly upregulated the level of HSPA8 expression in HD11 cells compared with the control; significantly promoted the proliferation of HD11 cells and the expression of PCNA, CCND1 and CCNB3; decreased the number of cells in the G1 phase and increased the number of cells in the S phase; decreased the rate of apoptosis and upregulated the expression of Bcl-2; and promoted the expression of the LPS-induced cytokines IL-1β, IL-6 and TNF-α. Transfection of the HSPA8 interference fragment significantly downregulated the level of HSPA8 expression in HD11 cells; significantly inhibited the proliferation of HD11 cells and the expression of PCNA, CCND1 and CDK1; increased the number of cells in the G1 phase and decreased the number of cells in the S phase; increased the rate of apoptosis, downregulated the expression of Bcl-2 and upregulated the expression levels of Fas and FasL; and inhibited the expression of the LPS-induced cytokines IL-1β and NF-κB. The results suggested that HSPA8 promotes the proliferation of and inhibits the apoptosis of HD11 cells and has a proinflammatory effect.

Circular RNA circAKIRIN2 participates in the process of stress-induced immunosuppression affecting immune response to infectious bursal disease virus vaccine in chicken

At present, stress-induced immunosuppression is still a hidden threat that leads to immunization failure and outbreaks of poultry diseases, and causes huge economic losses to the modern poultry industry. However, the molecular mechanisms of stress-induced immunosuppression affecting viral vaccine immunity are still poorly understood. Here, we identified circAKIRIN2 as a conserved circular transcript in chicken, and explored its expression patterns in different immune states by quantitative real-time PCR (qRT-PCR), then conducted bioinformatics analysis. The results showed that circAKIRIN2 actively participated in the process of stress-induced immunosuppression affecting the immune response to infectious bursal disease virus (IBDV) vaccine. The key time points for circAKIRIN2 involving in the process were 2 day post immunization (dpi), 5 dpi, and 28 dpi, especially at the acquired immune stage. The important tissues that responded to the process included the heart, liver, and lung, all of which changed significantly. In addition, circAKIRIN2 as a competing endogenous RNA (ceRNA) sponging zinc finger and BTB domain containing 20 (ZBTB20) was a potential molecular mechanism for regulating immune functions in the process. In conclusion, circAKIRIN2 is a key regulatory factor for stress-induced immunosuppression affecting the IBDV vaccine immune response, and this study can provide a new perspective for exploring the molecular regulatory mechanisms of stress-induced immunosuppression affecting immune response.

The SIRT1-HMGB1 axis: Therapeutic potential to ameliorate inflammatory responses and tumor occurrence

Inflammation is a common complication of many chronic diseases. It includes inflammation of the parenchyma and vascular systems. Sirtuin 1 (SIRT1) is a nicotinamide adenine dinucleotide (NAD)-dependent histone deacetylase, which can directly participate in the suppression of inflammation. It can also regulate the activity of other proteins. Among them, high mobility group box 1 (HMGB1) signaling can be inhibited by deacetylating four lysine residues (55, 88, 90, and 177) in quiescent endothelial cells. HMGB1 is a ubiquitous nuclear protein, once translocated outside the cell, which can interact with various target cell receptors including the receptor for advanced glycation end-products (RAGE), toll-like receptor (TLR) 2, and TLR4 and stimulates the release of pro-inflammatory cyto-/chemokines. And SIRT1 has been reported to inhibit the activity of HMGB1. Both are related to the occurrence and development of inflammation and associated diseases but show an antagonistic relationship in controlling inflammation. Therefore, in this review, we introduce how this signaling axis regulates the emergence of inflammation-related responses and tumor occurrence, providing a new experimental perspective for future inflammation research. In addition, it explores diverse upstream regulators and some natural/synthetic activators of SIRT1 as a possible treatment for inflammatory responses and tumor occurrence which may encourage the development of new anti-inflammatory drugs. Meanwhile, this review also introduces the potential molecular mechanism of the SIRT1-HMGB1 pathway to improve inflammation, suggesting that SIRT1 and HMGB1 proteins may be potential targets for treating inflammation.

Intergrated Transcriptomic and Proteomic Analysis Revealed the Differential Responses to Novel Duck Reovirus Infection in the Bursa of Fabricius of Cairna moschata

The bursa of Fabricius is an immunologically organ against the invasion of duck reovirus (DRV), which is a fatal bird virus belonging to the Reoviridae family. However, responses of the bursa of Fabricius of Cairna moschata to novel DRV (NDRV) infection are largely unknown. Transcriptomes and proteomes of the samples from control and two NDRV strain (HN10 and JDm10) with different virulence were analyzed. Differentially expressed genes and differential accumulated proteins were enriched in the serine protease system and innate immune response clusters. Most of the immune-related genes were up-regulated under both JDm10/HN10 infections. However, the immune-related proteins were only accumulated under HN10 infection. For the serine protease system, coagulation factor IX, three chains of fibrinogen, and complements C8, C5, and C2s were significantly up-regulated by the HN10 infection, suggesting that the serine protease-mediated immune system might be involved in the resistance to NDRV infection. For the innate and adaptive immune system, RIG-I, MDA5, MAPK20, and IRF3 were significantly up-regulated, indicating their important roles against invaded virus. TLR-3 and IKBKB were only up-regulated in the liver cells, MAPK20 was only up-regulated in the bursa of Fabricius cells, and IRAK2 was only up-regulated in the spleen samples. Coagulation factor IX was increased in the bursa of Fabricius, not in the liver and spleen samples. The data provides a detailed resource for studying the proteins participating in the resistances of the bursa of Fabricius of duck to NDRV infections.

Transcriptome analysis revealed the roles of long non-coding RNA and mRNA in the bursa of Fabricius during pigeon (Columba livia) development

The bursa of Fabricius (BF) is the critical humoral immune organ to birds, playing an essential role in B lymphocyte differentiation. However, unlike other poultries, surgical removal of pigeon BF did not limit humoral immune responsiveness. To investigate the expression profiles and the potential role of mRNA and long non-coding RNA (LncRNA) in squab BFs, transcriptome analysis was performed by RNA-Sequencing (RNA-Seq) over three developmental stages (1-day, 13 and 26 days old). We identified 13,072 mRNAs and 19,129 lncRNAs, of which 2,752 mRNAs and 1,515 lncRNAs were differential expressed (DE) in pigeon BFs over three developmental stages. Cluster analysis presented different expression patterns in DE mRNAs and lncRNAs. Functional enrichment analysis revealed that DE lncRNAs and mRNAs with distinct expression patterns might play crucial roles in the immune system process and tissue morphogenesis. In particular, some DE genes and lncRNAs with higher expression levels in 13D or 26D are related to lymphocyte activation and differentiation, adaptive immune response, positive regulation of immune response, leukocyte migration, etc. Protein-protein interaction (PPI) network and Molecular Complex Detection (MCODE) analysis sreened six significant modules containing 37 genes from immune-related DE gene cluster, which is closely linked in B cell activation, lymphocyte differentiation, B cell receptor signaling pathway, etc. Our study characterizes mRNA and lncRNA transcriptomic variability in pigeon BFs over different developmental stages and enhances understanding of the mechanisms underlying physiological functions of pigeon BF.

Divergent selection for natural antibodies in poultry in the presence of a major gene

Background

Natural antibodies (NAb) are antibodies that are present in a healthy individual without requiring previous exposure to an exogenous antigen. Selection for high NAb levels might contribute to improved general disease resistance. Our aim was to analyse the genetic background of NAb based on a divergent selection experiment in poultry, and in particular the effect of a polymorphism in the TLR1A gene.

Methods

The study population consisted of a base population from a commercial pure-bred elite white leghorn layer line and seven generations of birds from a High and Low selection line. Birds were selected for total KLH-binding NAb titer (IgTotal). An enzyme-linked immunosorbent assay was performed to determine NAb titers in blood plasma for IgTotal and the antibody isotypes IgM and IgG. NAb titers were available for 10,878 birds. Genotypes for a polymorphism in TLR1A were determined for chickens in generations 5, 6 and 7. The data were analysed using mixed linear animal models.

Results

The heritability estimate for IgM was 0.30 and higher than that for IgG and IgTotal (0.12). Maternal environmental effects explained 2 to 3% of the phenotypic variation in NAb. Selection for IgTotal resulted in a genetic difference between the High and Low line of 2.4 titer points (5.1 genetic standard deviation) in generation 7. For IgM, the selection response was asymmetrical and higher in the Low than the High line. The frequency of the TLR1A C allele was 0.45 in the base population and 0.66 and 0.04 in generation 7 of the High and Low line, respectively. The TLR1A polymorphism had large and significant effects on IgTotal and IgM. Estimated genotypic effects suggest full dominance of the TLR1A C allele. Significant TLR1A by generation interactions were detected for IgM and IgTotal.

Conclusions

The effect of a polymorphism in the TLR1A gene on IgTotal and IgM NAb was confirmed. Furthermore, we provide experimental verification of changes in allele frequencies at a major gene with dominant gene action on a quantitative trait that is subjected to mass selection. TLR1A by generation interactions indicate sensitivity to environmental factors.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12711-022-00715-9.

Use of transcriptomic analysis to identify microRNAs related to the effect of stress on thymus immune function in a chicken stress model

In modern poultry production, stress-induced immunosuppression leads to serious economic losses and harm to animals, but the molecular mechanisms governing the effects of stress on the chicken thymus have not been elucidated. In this study, we successfully constructed a stress model of 7-day-old Gushi chickens by adding exogenous corticosterone (CORT) to their diet and determined the microRNA (miRNA) expression profile of thymus tissues using RNA-seq technology. The results identified 51 differentially expressed miRNAs (DEMs), including 30 upregulated miRNAs and 21 downregulated miRNAs. A total of 164 target genes of the DEMs were predicted based on bioinformatic analysis methods, and Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses of these target genes were performed. The results from the GO enrichment analysis of the target genes identified 349 significantly enriched terms, including terms associated with the stress response and immune function that are primarily involved in the negative regulation of phagocytosis, the response to stress and the cellular response to stimulus. The KEGG pathway analysis indicated that the enriched pathways related to immunity or stress included the MAPK signaling pathway, lysosomes, endocytosis, and the RIG-I-like receptor signaling pathway. Among these pathways, DEMs (such as gga-miR-2954, gga-miR-106-5p, and gga-miR-16-5p) and corresponding target genes (such as IL11Ra, SIKE1, and CX3CL1) might be strongly correlated with thymic immunity in chickens. The results of this study provide a reference for further research on the molecular regulatory mechanisms governing the effect of stress on the immune function of the chicken thymus.

Stress and immunity in poultry: light management and nanotechnology as effective immune enhancers to fight stress

The poultry industry plays a significant role in boosting the economy of several countries, particularly developing countries, and acts as a good, cheap, and affordable source of animal protein. A stress-free environment is the main target in poultry production. There are several stressors, such as cold stress, heat stress, high stocking density, and diseases that can affect birds and cause several deleterious changes. Stress reduces feed intake and growth, as well as impairs immune response and function, resulting in high disease susceptibility. These effects are correlated with higher corticosteroid levels that modulate several immune pathways such as cytokine-cytokine receptor interaction and Toll-like receptor signaling along with induction of excessive production of reactive oxygen species (ROS) and thus oxidative stress. Several approaches have been considered to boost bird immunity to overcome stress-associated effects. Of these, dietary supplementation of certain nutrients and management modifications, such as light management, are commonly considered. Dietary supplementations improve bird immunity by improving the development of lymphoid tissues and triggering beneficial immune modulators and responses. Since nano-minerals have higher bioavailability compared to inorganic or organic forms, they are highly recommended to be included in the bird's diet during stress. Additionally, light management is considered a cheap and safe approach to control stress. Changing light from continuous to intermittent and using monochromatic light instead of the normal light improve bird performance and health. Such changes in light management are associated with a reduction of ROS production and increased antioxidant production. In this review, we discuss the impact of stress on the immune system of birds and the transcriptome of oxidative stress and immune-related genes, in addition, how nano-minerals supplementations and light system modulate or mitigate stress-associated effects.

Nephropathogenic Infectious Bronchitis Virus Infection Altered the Metabolome Profile and Immune Function of the Bursa of Fabricius in Chicken

Infectious bronchitis is a highly contagious, acute viral respiratory disease of chickens, regardless of the strain, and its infection may lead to considerable economic losses to the poultry industry. New nephropathogenic infectious bronchitis virus (NIBV) strains have increasingly emerged in recent years; hence, evaluating their infection-influenced immune function changes and the alteration of metabolite profiling is important. Initially, chickens were randomly distributed into two groups: the control group (Con) and the disease group (Dis). Here, the partial cytokines were examined, and the metabolome alterations of the bursa of Fabricius (BF) in NIBV infections in chickens were profiled by gas chromatography time-of-flight/mass spectrometry (GC-TOF/MS). The results revealed that the NIBV infection promotes the mRNA expression of inflammatory cytokines. Metabolic profile analysis indicated that clustering differed between the two groups and there were 75 significantly different metabolites detected between the two groups, suggesting that the host metabolism was significantly changed by NIBV infection. Notably, the following 12 metabolites were identified as the potential biomarkers: 3-phenyllactic acid, 2-deoxytetronic acid, aminomalonic acid, malonamide 5, uric acid, arachidonic acid, 2-methylglutaric acid, linoleic acid, ethanolamine, stearic acid, N-alpha-acetyl-l-ornithine, and O-acetylserine. Furthermore, the results of the correlation analysis showed that a strong correlation existed between metabolic biomarkers and inflammatory cytokines. Our results describe an immune and metabolic profile for the BF of chickens when infected with NIBV and provide new biomarkers of NIBV infection as potential targets and indicators of indicating therapeutic efficacy.

Whole Transcriptome Analysis of Chicken Bursa Reveals Candidate Gene That Enhances the Host's Immune Response to Coccidiosis

Coccidiosis is a major hazard to the chicken industry, but the host’s immune response to coccidiosis remains unclear. Here, we performed Eimeria coccidia challenge in 28-day-old ROSS 308 broilers and selected the bursa from the three most severely affected individuals and three healthy individuals for RNA sequencing. We obtained 347 DEGs from RNA-seq and found that 7 upregulated DEGs were enriched in Cytokine-cytokine receptor interaction pathway. As the DEGs with the highest expression abundance in these 7 genes, TNFRSF6B was speculated to participate in the process of host’s immune response to coccidiosis. It is showed that TNFRSF6B can polarize macrophages to M1 subtype and promote inflammatory cytokines expression. In addition, the expression of TNFRSF6B suppressed HD11 cells apoptosis by downregulating Fas signal pathway. Besides, TNFRSF6B-mediated macrophages immunity activation can be reversed by apoptosis. Overall, our study indicates that TNFRSF6B upregulated in BAE, is capable of aggravating the inflammatory response by inhibiting macrophages apoptosis via downregulating Fas signal pathway, which may participate in host’s immune response to coccidiosis.

Integrative analysis of long non-coding RNA and mRNA in broilers with valgus-varus deformity

BACKGROUND

Bone abnormality and leg disease in commercial broiler flocks are increasingly prominent, causing serious economic losses to the broiler breeding industry. Valgus-varus deformity (VVD) is a common deformity of the long bone in broilers that manifests as an outward or inward deviation of the tibiotarsus or tarsometatarsus. There is a paucity of studies on the molecular mechanisms of VVD.

RESULTS

In this study, 6 cDNA libraries were constructed from spleen samples from VVD birds and normal birds. A total of 1951 annotated lncRNAs, 7943 novel lncRNAs and 30252 mRNAs were identified by RNA-sequencing. In addition, 420 differentially expressed (DE) mRNAs and 124 differentially expressed lncRNAs (adjusted P-value < 0.05) were obtained. A total of 16 dysregulated genes were confirmed by qPCR to be consistent with the results of the RNA-Seq. The functional lncRNA-mRNA co-expression network was constructed using differentially expressed mRNAs and target genes of the differentially expressed lncRNAs. 11 DE genes were obtained from the analysis. In order to gain insight into the interactions of genes, lncRNAs and pathways associated with VVD, we focused on the following pathways, which are involved in immunity and bone development: the Jak-stat signaling pathway, Toll-like receptor signaling pathway, Wnt-signaling pathway, mTOR signaling pathway, VEGF signaling pathway, Notch signaling pathway, TGF-beta signaling pathway and Fanconi anemia pathway. All together, 30 candidate DE genes were obtained from these pathways. We then analyzed the interaction between the DE genes and their corresponding lncRNAs. From these interaction network analyses we found that GARS, NFIC, PIK3R1, BMP6, NOTCH1, ACTB and CREBBP were the key core nodes of these networks.

CONCLUSION

This study showed that differentially expressed genes and signaling pathways were related to immunity or bone development. These results increase the understanding of the molecular mechanisms of VVD and provide some reference for the etiology and pathogenesis of VVD.

Study on the osmoregulation of "Halomonas socia" NY-011 and the degradation of organic pollutants in the saline environment

"Halomonas socia" NY-011, a new species of moderately halophilic bacteria isolated and identified in our laboratory, can grow in high concentrations of salt ranging from 0.5 to 25%. In this study, the whole genome of NY-011 was sequenced and a detailed analysis of the genomic features was provided. Especially, a series of genes related to salt tolerance and involved in xenobiotics biodegradation were annotated by COG, GO and KEGG analyses. Subsequently, RNA-Seq-based transcriptome analysis was applied to explore the osmotic regulation of NY-011 subjected to high salt stress for different times (0 h, 1 h, 3 h, 6 h, 11 h, 15 h). And we found that the genes related to osmoregulation including excluding Na⁺ and accumulating K⁺ as well as the synthesis of compatible solutes (alanine, glutamate, ectoine, hydroxyectoine and glycine betaine) were up-regulated, while the genes involved in the degradation of organic compounds were basically down-regulated during the whole process. Specifically, the expression trend of genes related to osmoregulation increased firstly then dropped, which was almost opposite to that of degrading organic pollutants genes. With the prolongation of osmotic up-shock, NY-011 survived and gradually adapted to osmotic stress, the above-mentioned two classes of genes slowly returned to normal expression level. Then, the scanning electron microscope (SEM) and transmission electron microscope (TEM) were also utilized to observe morphological properties of NY-011 under hypersaline stress, and our findings showed that the cell length of NY-011 became longer under osmotic stress, at the same time, polyhydroxyalkanoates (PHAs) were synthesized in the cells. Besides, physiological experiments confirmed that NY-011 could degrade organic compounds in a high salt environment. These data not only provide valuable insights into the mechanism of osmotic regulation of NY-011; but also make it possible for NY-011 to be exploited for biotechnological applications such as degrading organic pollutants in a hypersaline environment.

Transcriptomic Analysis of Spleen Revealed Mechanism of Dexamethasone-Induced Immune Suppression in Chicks

Stress-induced immunosuppression is a common problem in the poultry industry, but the specific mechanism of its effect on the immune function of chicken has not been clarified. In this study, 7-day-old Gushi cocks were selected as subjects, and a stress-induced immunosuppression model was successfully established via daily injection of 2.0 mg/kg (body weight) dexamethasone. We characterized the spleen transcriptome in the control (B_S) and model (D_S) groups, and 515 significant differentially expressed genes (SDEGs) (Fragments Per Kilobase of transcript sequence per Millions base pairs sequenced (FPKM) > 1, adjusted p-value (padj) < 0.05 and Fold change (|FC|) ≥ 2) were identified. The cytokine-cytokine receptor interaction signaling pathway was identified as being highly activated during stress-induced immunosuppression, including the following SDEGs-CXCL13L2, CSF3R, CSF2RB, CCR9, CCR10, IL1R1, IL8L1, IL8L2, GHR, KIT, OSMR, TNFRSF13B, TNFSF13B, and TGFBR2L. At the same time, immune-related SDEGs including CCR9, CCR10, DMB1, TNFRSF13B, TNFRSF13C and TNFSF13B were significantly enriched in the intestinal immune network for the IgA production signaling pathway. The SDEG protein-protein interaction module analysis showed that CXCR5, CCR8L, CCR9, CCR10, IL8L2, IL8L1, TNFSF13B, TNFRSF13B and TNFRSF13C may play an important role in stress-induced immunosuppression. These findings provide a background for further research on stress-induced immunosuppression. Thus, we can better understand the molecular genetic mechanism of chicken stress-induced immunosuppression.

Mycoplasma gallisepticum Infection Impaired the Structural Integrity and Immune Function of Bursa of Fabricius in Chicken: Implication of Oxidative Stress and Apoptosis

Mycoplasma gallisepticum (MG) induces a dysregulated immune response in the lungs and air ways of poultry. However, the mechanism of MG-induced immune dysregulation is still not completely understood. In the present study, the effect of MG-infection on chicken bursa of fabricius (BOF) is investigated. Histopathology, electron microscopy, TUNEL assay, qRT-PCR and western blot were employed to examine the hallmarks of oxidative stress and apoptosis. The data revealed that MG-infection induced oxidative stress and decreased antioxidant responses in BOF tissues compared to control group. Histopathological study showed pathological changes including reduction in lymphocytes and increased inflammatory cell infiltration in MG-infection group. Ultrastructural assessment represents obvious signs of apoptosis such as mitochondrial swelling, shrinkage of nuclear membrane and fragmentation of nucleus. Increased cytokine activities were observed in MG-infection group compared to control group. Meanwhile, the mRNA and protein expression level of apoptosis-related genes were significantly (p < 0.05) upregulated in MG-infection group. Terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay further confirmed that MG induced apoptosis in BOF tissues as TUNEL-stained positive nuclei were remarkably increased in MG-infection group. In addition, MG-infection significantly reduced the number of CD8⁺ lymphocytes in chicken BOF at day 7. Moreover, bacterial load significantly increased at day 3 and day 7 in MG-infection group compared to control group. These results suggested that MG-infection impaired the structural integrity, induced oxidative stress and apoptosis in chicken BOF tissues, which could be the possible causes of damage to immune function in chicken BOF.

High-throughput transcriptome analysis reveals potentially important relationships between lncRNAs and genes in broilers affected by Valgus-varus Deformity (Gallus gallus)

Valgus-varus Deformity (VVD) is an outward or inward deviation of the tibiotarsus or tarsometatarsus, which results in physical distress of chickens and economic loss in poultry industry. While the etiology and pathogenesis of VVD at the molecular level are still not fully understood so far. Here, based on a case/control design with VVD birds and normal birds, we identified genes and lncRNAs which associated with VVD using RNA sequencing. Transcriptome analysis revealed 231 differentially expressed mRNAs and 23 differentially expressed lncRNAs between case and control of leg cartilage. We identified the cis- and trans-regulatory targets of the differentially expressed lncRNAs, and we constructed a functional lncRNA-mRNA co-expression network. Analysis of the network showed that the differentially expressed mRNAs and the target genes of the differentially expressed lncRNAs were enriched in the signaling pathways associated with bone development, including p53, MAPK, Toll-like receptor, Jak-STAT, Hedgehog, and PPAR. The expression levels of DENND4A, FGF10, FGF12 and BMP3 were also determined in cartilage and other six tissues. Overall, our study predicted the mRNAs and lncRNAs related with leg diseases by transcriptome analyses, which might contribute to understand the etiology and pathogenesis of VVD. It established the foundation for the further research on the function of -mRNAs and lncRNAs in skeleton development.

The morphological basis of the development of the chick embryo immune system

The chick immune system is a fundamental model in basic immunology. In birds, the bone marrow derived pluripotent stem cells after entering the circulation, migrate to bursa of Fabricius to benefit from a microenvironment which supports the differentiation and maturation of B lymphocytes by the help of its resident cells and tissues. Delivering sufficient functional B cells is required to maintain their peripheral population and normal peripheral humoral responses. Additionally, bursa acts as an active site for the generation of antibody diversity through gene conversion. Being consisted of 98% B lymphocytes, the organ is occupied by other cell types including T cells, macrophages, eosinophils and mast cells. Thymus, which is an epithelial organ is the main site of T cell development where positive and negative selections contribute to the development of functional and not autoreactive T cell repertoire. Bursectomy and thymectomy are surgical exercises through which the involvement of cells of specific immunity including B cells and T cells can be determined.