Pyroptosis: a new insight into intestinal inflammation and cancer.

Pyroptosis is an innate immune response triggered by the activation of inflammasomes by various influencing factors, characterized by cell destruction. It impacts the immune system and cancer immunotherapy. In recent years, the roles of pyroptosis and inflammasomes in intestinal inflammation and cancer have been continuously confirmed. This article reviews the latest progress in pyroptosis mechanisms, new discoveries of inflammasomes, mutual regulation between inflammasomes, and their applications in intestinal diseases. Additionally, potential synergistic treatment mechanisms of intestinal diseases with pyroptosis are summarized, and challenges and future directions are discussed, providing new ideas for pyroptosis therapy.

The effect of ghrelin on bursa and cecal tonsils of chickens infected with an attenuated virus strain of infectious bursal disease virus.

Infectious bursal disease (IBD) significantly affects the poultry industry, causing substantial economic losses. This study aimed to investigate the effects of ghrelin on chicks infected with an attenuated virus strain of IBDV (aIBDV). Chicks were divided into 3 groups: a control group (group I), an aIBDV infection group (group II), and a ghrelin + aIBDV infection group (group III). Mice in groups II and III were fed until they reached 19 d of age and then inoculated with aIBDV to establish a subclinical infection model. Group III received an intraperitoneal injection of 0.5 nmol/100 g ghrelin from d 17 to 23. The present study utilized paraffin sectioning, H&E staining, and immunohistochemical staining to examine the effects of ghrelin on the bursa of fabricius and cecum tonsils in aIBDV-infected chicks. The results indicated that at 3 d postinfection (dpi), the average body weight of group III was significantly greater than that of group II (P < 0.05). At 3 and 7 dpi, the proportion of large lymphoid follicles in the bursa of fabricius in group III was notably greater than that in group II (P < 0.05). aIBDV infection resulted in bleeding, edema, and fibrosis in the cecal mucosal layer of chicks, but ghrelin administration mitigated these pathological changes. At 3 and 7 dpi, the thickness of the lamina propria in the cecal tonsils of group III was significantly lower than that in the cecal tonsils of group II (P < 0.05). Additionally, the percentage of large lymphoid follicles in the cecal tonsils of group III was significantly greater than that in group II at 3 and 5 dpi (P < 0.05). There were significantly fewer macrophages in the cecal tonsils of group III than in those of group II at 1, 3, and 5 dpi (P < 0.05). In conclusion, ghrelin supplementation improved performance and mitigated bursal atrophy in aIBDV-infected chicks. It also reduced histological lesions and immune responses in the cecum tonsil. Notably, the reduction in macrophages in the cecum tonsil following ghrelin administration may decrease the risk of aIBDV spread.

Effects of dietary supplementation of fermented Artemisia argyi on growth performance, slaughter performance, and meat quality in broilers.

Artemisia argyi (AA) is promising as a potential feed additive. Microbial fermentation is beneficial to the degradation of cell walls and the better release of bioactive compounds of AA. However, there are few reports on the application of fermented AA as a feed additive for broilers. The present study intended to evaluate the application value of fermented AA as a feed additive for broilers by examining the effects of the dietary supplementation of Aspergillus niger-fermented AA and unfermented AA on growth performance, slaughter performance, and meat quality of brokers. A total of 360 newly hatched (1-day-old) broilers with similar body weight were randomly divided into the following 5 groups: basal diet group as control (C) group, basal diet +3% unfermented AA (E1) group, basal diet + 1% fermented AA (E2) group, basal diet + 3% fermented AA (E3) group, basal diet + 5% fermented AA (E4) group. Each group included 6 replicates with 12 broilers per replicate, and the feeding trail lasted for 48 d. Body weight and feed intake were recorded every 2 wk, and the feed gain ratio was calculated to assess growth performance. At 42 d, 6 broilers from each group were slaughtered, and the carcass traits were calculated. The results showed that compared with the control group, Aspergillus Niger could effectively destroy AA fiber, which contributed to better release of AA bioactive compounds. Moreover, dietary supplementation with AA could improve the growth performance of broilers (P < 0.05), and the effect of fermented AA was better than unfermented AA, especially 3% fermented AA. From 28 to 42 d, compared with the control group, the average daily gain of broilers in the group supplementation with 3% fermented AA was significantly increased (P < 0.05), and the feed-to-gain ratio was decreased (P < 0.05). At 42 d, the dressing percentage, half-eviscerated carcass percentage, eviscerated carcass percentage, and breast muscle percentage of broilers in the groups of 1, 3, and 5% fermented AA diets were significantly improved (P < 0.05), and the thigh muscle percentage of broilers in the group with 3% fermented AA diets was significantly improved (P < 0.05). Meanwhile, the meat quality of broilers in the group with fermented AA diets was also significantly improved. Birds in AA groups had higher a* value and lower shear force of breast muscle, especially the group supplementation with 3% fermented AA (P < 0.05). In conclusion, fermented AA has good application value as a potential feed additive for broilers, dietary supplementation of fermented AA can improve the production performance and meat quality of broiler chickens, of which 3% fermented AA is more effective.

ADP-ribosylation factor 6 promotes infectious bursal disease virus replication by affecting the internalization process via clathrin.

ADP-ribosylation factor 6 (ARF6) is a small G protein with extensive functions, including regulation of cellular membrane transport and viral infection. Infectious bursal disease (IBD) is caused by infectious bursal disease virus (IBDV), which mainly invades the bursa of Fabricius and causes low immunity in poultry. Our study demonstrated that IBDV infection could promote the expression of ARF6; however, the underlying mechanism remains unclear. Herein, the function of ARF6 in IBDV infection was explored, and it was revealed that viral replication was significantly promoted by ARF6 overexpression and hampered by siRNA-mediated inhibition of ARF6. Using two site mutants of ARF6 (ARF6-T27N and ARF6-Q67L), we found that IBDV replication was repressed by ARF6-T27N, indicating that ARF6 promotes IBDV replication. Further exploration of its mechanism revealed that ARF6 affects the copy number of IBDVs entering cells. A clathrin inhibitor (pitstop 2) impeded the early replication of IBDV, even when ARF6 was overexpressed. These results indicated that ARF6 promotes viral replication by affecting the internalization of IBDV, which may involve clathrin-dependent endocytosis. Our findings improve the understanding of the processes governing IBDV infection and provide insights into its prevention and control.

Utilizing Electrochemical Biosensors as an Innovative Platform for the Rapid and On-Site Detection of Animal Viruses.

Animal viruses are a significant threat to animal health and are easily spread across the globe with the rise of globalization. The limitations in diagnosing and treating animal virus infections have made the transmission of diseases and animal deaths unpredictable. Therefore, early diagnosis of animal virus infections is crucial to prevent the spread of diseases and reduce economic losses. To address the need for rapid diagnosis, electrochemical sensors have emerged as promising tools. Electrochemical methods present numerous benefits, including heightened sensitivity and selectivity, affordability, ease of use, portability, and rapid analysis, making them suitable for real-time virus detection. This paper focuses on the construction of electrochemical biosensors, as well as promising biosensor models, and expounds its advantages in virus detection, which is a promising research direction.

Salmonella Pullorum effector SteE regulates Th1/Th2 cytokine expression by triggering the STAT3/SOCS3 pathway that suppresses NF-κB activation.

Salmonella enterica serovar Pullorum (S. Pullorum) can regulate host immunity via special effectors that promote persistent infection and its intracellular survival. SteE as an anti-inflammatory effector is involved in the systemic infection of Salmonella in host macrophages. Macrophage activation can indirectly reflect the immune regulatory function of T helper type 1 (Th1)/T helper type 2 (Th2) cytokines. However, information concerning the regulation of Th1/Th2 cytokine expression by steE in S. Pullorum infection is limited. This study evaluates the effects of steE on the Th1/Th2 balance, STAT3/SOCS3 pathway, and NF-κB P65 activation in S. Pullorum-infected HD-11 cells and in chicken models. We demonstrated that steE diminished the expression of Th1-related cytokines (IFN-γ and IL-12) and promoted the expression of Th2-related cytokines (IL-4 and IL-10) in HD-11 cells and chicken models of S. Pullorum infection. SOCS3 silencing suppressed the function of steE in HD-11 cells and led to the imbalance of Th1/Th2-related cytokines. SteE promoted SOCS3 expression by activating STAT3 in HD-11 cells. Moreover, steE inhibited NF-κB P65 expression and blocked its translocation to the nucleus by promoting SOCS3 expression. Our results illustrated that steE regulated the expression of Th1/Th2 cytokines via modulation of the STAT3/SOCS3 and NF-κB axis, which might be associated with Th1/Th2 cell differentiation and could, therefore, be a novel therapeutic strategy against salmonellosis.

The collectin subfamily member 11 (Ca-Colec11) from Qihe crucian carp (Carassius auratus) agglutinates and inhibits Aeromonas hydrophila and Staphylococcus aureus.

The collectin subfamily member 11 (Colec11), plays an important role in innate immunity as a pattern recognition molecule. In the present study, a colec11 homolog was identified and characterised from Qihe crucian carp, namely, Ca-colec11. The full-length cDNA of Ca-colec11 was composed of 1129 bp, with a 99 bp 5'-untranslated region (UTR), 816 bp open reading frame (ORF) encoding a 271-aa protein and 214 bp 3'-UTR with a polyadenylation signal sequence (aataaa) and a poly(A) tail. The deduced amino acid sequence of Ca-Colec11 contained a si gnal peptide, collagen domain, neck region and carbohydrate-recognition domain (CRD), which had four conserved cysteine residues (Cys170-Cys256 and Cys242-Cys264) and an EPN/WND motif required for carbohydrate-binding specificity. Tissue expression profile analysis by quantitative real-time polymerase chain reaction (RT-qPCR) showed that Ca-colec11 was ubiquitously distributed in the tested tissues and highly expressed in the liver. The gene expression levels of Ca-colec11 were evidently up-regulated in the liver, spleen, kidney and head kidney after infection with A. hydrophila and S. aureus. The recombinant Ca-Colec11 (rCa-Colec11) purified from Escherichia coli BL21 (DE3) could agglutinate A. hydrophila and S. aureus, and it possessed haemagglutination activity against rabbit erythrocytes, which was inhibited by various carbohydrates, including d-Mannose, N-Acetyl-d-mannosamine, l-Fucose, d-Glucose, N-Acetyl-d-glucosamine, d-Galactose, LPS and PGN. Furthermore, rCa-Colec11 could inhibit the growth of A. hydrophila and S. aureus. These findings collectively demonstrated that Ca-Colec11, as a PRR, could play a role in the immune defence of Qihe crucian carp.

Colonoscopy-induced acute appendicitis: A case report.

BACKGROUND: Colonoscopy is widely used for examination, diagnosis, and treatment because of its low incidence of associated complications. Post-colonoscopy appendicitis (PCA) is very rare and is easily misdiagnosed as electrocoagulation syndrome or colon perforation. Therefore, clinicians should pay close attention to this complication. CASE SUMMARY: A 47-year-old female patient underwent a colonoscopy for a systematic physical examination, and the procedure was uneventful with normal endoscopic and histologic findings. However, the bowel preparation was suboptimal (Boston 2-3-2). After the examination, the patient experienced pain in the lower abdomen, which progressively worsened. Computed tomography of the lower abdomen and pelvis revealed appendiceal calcular obstruction and appendicitis. As the patient refused surgery, she was managed with antibiotics and recovered well. CONCLUSION: In the current literature, the definition of PCA remains unclear. However, abdominal pain after colonoscopy should be differentiated from acute appendicitis.

Expression patterns of AMPK and genes associated with lipid metabolism in newly hatched chicks during the metabolic perturbation of fasting and refeeding.

Fasting-refeeding perturbation has been extensively used to reveal specific genes and metabolic pathways that control energy metabolism in chickens. In this study, 200 chickens were randomly assigned to 2 groups after hatching: the control group (C, fed ad libitum) and the fasting-refeeding group (T, water ad libitum). The chicks in Group T were fasted for 72 h, and then fed for another 48 h. Liver, hypothalamus, and adipose samples were collected at 0 (F0), 24 (F24), 48 (F48), and 72 h (F72) after fasting and 4 (FR4), 12 (FR12), 24 (FR24), and 48 h (FR48) after refeeding, respectively. Results showed that Group T had a significantly higher number of liver vacuoles (P < 0.05 or P < 0.01) and a significantly lower gray value of Sudan IIIstained sections (P < 0.05 or P < 0.01) than Group C at F48-FR48. In addition, compared with the Group C, fasting and refeeding reduced the expression of stearoyl CoA desaturase (SCD) mRNA (P < 0.05 or P < 0.01) in the liver and adipose tissues, the expression of glucocorticoid receptor (GR) mRNA (P < 0.05 or P < 0.01) in the liver, adipose, and hypothalamus tissues, and the expression of fatty acid synthase (FAS) mRNA (P < 0.05 or P < 0.01) in the liver at F24-FR24. Moreover, relative to those in Group C, fasting and refeeding increased the mRNA expression levels of adenosine monophosphate-activated protein kinase (AMPK) α, AMPKß, and AMPKγ in the hypothalamus (P < 0.05 or P < 0.01) at F24-FR24. In conclusion, fasting and refeeding increased the fat content of the liver, and the expression of lipolytic genes in the hypothalamus (e.g., AMPKα, AMPKß, and AMPKγ) but decreased the expression of fat synthesis genes in the liver (e.g., SCD, GR, and FAS), adipose (SCD and GR), and hypothalamus (GR).

SteE Enhances the Virulence of Salmonella Pullorum in Chickens by Regulating the Inflammation Response.

Salmonella enterica serovar Pullorum (S. Pullorum) is a host-specific pathogen, which causes acute gastroenteritis with high mortality in poultry. However, the association between steE, encoded by type III secretion system 2, and Salmonella virulence is not well-understood. To elucidate the functions of steE in S. Pullorum, ΔsteE strain was constructed using the λ-Red recombination technology. Compared to that in the wild-type, the deletion of steE in S. Pullorum reduced bacterial invasion, proliferation, and late apoptosis in the infected HD-11 cells. In addition, we analyzed the mRNA expression levels of effector genes and cytokines by qRT-PCR. SteE was associated with the regulation of various effector genes and inflammatory cytokines in HD-11 cells during S. Pullorum infection. The wild-type effector steE promoted the expression of anti-inflammatory cytokines (IL-4 and IL-10) and reduced that of pro-inflammatory cytokines (IL-1ß, IL-6, and IL-12) compared to that in the ΔsteE-infected HD-11 cells and chicken spleens. Results from the chicken infection model showed that the deletion of steE resulted in significantly decreased colonization and long-term survival of the bacteria and alleviated pathological lesions compared to those in the wild-type. Further, steE increased the virulence of S. Pullorum in chickens by regulating the expression of inflammatory cytokines. Our findings provide insights into the persistent infection and autoimmunity associated with steE in S. Pullorum.

Infectious bursal disease virus replication is inhibited by avain T cell chemoattractant chemokine CCL19.

Chemokine CCL19, together with its receptor CCR7, is one of the most important factors recruiting immune cells into target organ during virus infection. Our previous study has shown that CCL19 played a vital role in the process of T cell trafficking into bursae during bursal disease virus (IBDV) infection. In this study, we hypothesized that CCL19 could exert direct influences on IBDV replication other than recruiting immune cells. A eukaryotic expression vector of pEGFP-N1/CCL19 was successfully constructed and identified by PCR, double enzymes digestion, and sequencing. Different concentrations of pEGFP-N1/CCL19 plasmids were transfected into DF1 cells and CCL19 protein was highly expressed. Then, DF1 cells were infected with IBDV B87 strain post-transfection. Based on PCR and Western blot results, CCL19 could obviously decrease the gene levels of VP1 and VP2 and the protein levels of VP2 and VP3. When CCL19 was knocked down, the gene levels of VP1 and VP2 were significantly upregulated. Moreover, indirect immunostaining revealed that the IBDV content was largely decreased after CCL19 overexpression. Additionally, CCL19 inhibitory effects might rely on activation of the JNK signal pathway. Taken together, chemokine CCL19 directly blocks IBDV replication in DF1 cells, indicating that CCL19 could play crucial functions other than recruiting T cells during the pathogenesis of IBDV.

Betaine Alleviates LPS-Induced Chicken Skeletal Muscle Inflammation with the Epigenetic Modulation of the TLR4 Gene.

Betaine was found to alleviate inflammation in different studies. Here, newly hatched broilers were randomly divided into control and betaine consumptive groups, who had access to normal drinking water and water with betaine at a dose of 1000 mg/L, respectively. At the age of two weeks, the boilers were intraperitoneally treated with LPS. The protective effects of betaine against LPS-induced skeletal muscle inflammation were studied. Betaine attenuated the LPS-induced overexpression of IL-6 significantly in the leg muscle. Furthermore, LPS lowered the expression of TLR4 and TLR2 but increased the expression of MyD88. Betaine eliminated the effect of LPS on the expression of TLR4 but not TLR2 and MyD88. LPS also increased the expression of Tet methylcytosine dioxygenase 2 (Tet2), and this effect was also eliminated by betaine consumption. MeDIP-qPCR analysis showed that the methylation level in the promoter region of IL-6 was decreased by LPS treatment, whilst betaine cannot prevent this effect. On the contrary, LPS significantly increase the methylation level in the promoter region of TLR4, which was decreased by the consumption of betaine. Our findings suggest that betaine can alleviate LPS-induced muscle inflammation in chicken, and the regulation of aberrant DNA methylation might be a possible mechanism.

Multiplex PCR assay based on the citE2 gene and intergenic sequence for the rapid detection of Salmonella Pullorum in chickens.

Salmonella is one of the most common Gram-negative pathogens and seriously threatens chicken farms and food safety. This study aimed to establish a multiplex polymerase chain reaction (PCR) approach for the identification of different Salmonella enterica subsp. enterica. The citE2 gene and interval sequence of SPS4_00301-SPS4_00311 existed in all S. enterica subsp. enterica serovars by genomic comparison. By contrast, a 76 bp deletion in citE2 was found only in Salmonella Pullorum. Two pairs of special primers designed from citE2 and interval sequence were used to establish the multiplex PCR system. The optimized multiplex PCR system could distinguish Salmonella Pullorum and non-Salmonella Pullorum. The sensitivity of the optimized multiplex PCR system could be as low as 6.25 pg/µL and 104 colony-forming units (CFU)/mL for genomic DNA and Salmonella Pullorum cells, respectively. The developed multiplex PCR assay distinguished Salmonella Pullorum from 33 different Salmonella enterica subsp. enterica serotypes and 13 non-target species. The detection of egg samples artificially contaminated with Salmonella Pullorum, Salmonella Enteritidis, and naturally contaminated 69 anal swab samples showed that results were consistent with the culture method. These features indicated that the developed multiplex PCR system had high sensitivity and specificity and could be used for the accurate detection of Salmonella Pullorum in clinical samples.

m6A mRNA Methylation Was Associated With Gene Expression and Lipid Metabolism in Liver of Broilers Under Lipopolysaccharide Stimulation.

Hepatic inflammation is always accompanied with abnormal lipid metabolism. Whether N6-methyladenosine (m6A) mRNA methylation affects irregular inflammatory lipid level is unclear. Here, the m6A modification patterns in chicken liver at the acute stage of LPS-stimulated inflammation and at the normal state were explored via m6A and RNA sequencing and bioinformatics analysis. A total of 7,815 m6A peaks distributed in 5,066 genes were identified in the normal chicken liver and were mostly located in the CDS, 3'UTR region, and around the stop codon. At 2 h after the LPS intraperitoneal injection, the m6A modification pattern changed and showed 1,200 different m6A peaks. The hyper- and hypo-m6A peaks were differentially located, with the former mostly located in the CDS region and the latter in the 3'UTR and in the region near the stop codon. The hyper- or hypo-methylated genes were enriched in different GO ontology and pathways. Co-analysis revealed a significantly positive relationship between the fold change of m6A methylation level and the relative fold change of mRNA expression. Moreover, computational prediction of protein-protein interaction (PPI) showed that genes with altered m6A methylation and mRNA expression levels were clustered in processes involved in lipid metabolism, immune response, DNA replication, and protein ubiquitination. CD18 and SREBP-1 were the two hub genes clustered in the immune process and lipid metabolism, respectively. Hub gene AGPAT2 was suggested to link the immune response and lipid metabolism clusters in the PPI network. This study presented the first m6A map of broiler chicken liver at the acute stage of LPS induced inflammation. The findings may shed lights on the possible mechanisms of m6A-mediated lipid metabolism disorder in inflammation.

Tissue distribution and developmental changes of PTEN in the immune organs of chicken and effect of IBDV infection on it.

Phosphatase and tensin homolog (PTEN), a tumor suppressor gene, functions in antiviral innate immunity and regulates the development and function of T cells and B cells. However, limited information about PTEN is available in poultry. In the present study, quantitative real-time polymerase chain reaction and immunohistochemistry staining were used to study the tissue distribution and developmental changes of PTEN in the main immune organs of chicken. The effects of infectious bursal disease virus (IBDV) infection on PTEN mRNA expression in the bursa of Fabricius (BF) of chickens were also investigated. The results are as follows. 1) The order of PTEN mRNA expression levels at the 18th d of hatching (E18) was: muscle and immune organs (spleen and thymus) > visceral organs (heart, lung, kidney, and liver) > hypothalamus and digestive tracts (duodenum, jejunum, ileum, cecum, proventriculus, BF [originates from cloaca], and cecum tonsil [locates at the lamina propria of cecum]). However, at the 15th d of raising (D15), the PTEN mRNA expression in the heart was the highest among all the tissues, followed by those in the liver, proventriculus, and kidney. The PTEN mRNA expression levels in the rest tissues were very low and were only 1.20 to 19.47% as much as that in the heart (P < 0.05). 2) The changes in the expression of PTEN mRNA in the BF, spleen, and thymus from E15 to D15 had no obvious regularity. PTEN-immunopositive (PTEN-ip) cells in the BF were distributed in epithelium mucosa, bursal follicles and interfollicles before hatching, but only in bursal follicles after hatching. PTEN-ip cells in the spleen were expressed in the periarterial lymphatic sheath from E18 to D15. Most of PTEN-ip cells distributed in the thymic medulla and only a few distributed in the thymic cortex during the whole experiment. 3) Chicken with IBDV infection had a remarkable decrease in PTEN mRNA expression from 1 d postinfection (dpi) to 7 dpi. Although PTEN mRNA level was reversed at 7 dpi, it was still significantly lower than that at 0 dpi (P < 0.05). These findings suggest that the PTEN of chicken might play important roles in the development of embryos and T/B lymphocytes, and the downregulation of PTEN in chickens infected with IBDV might be a mechanism of IBDV evasion from host immunity. Strategies designed to restore PTEN expression may be a therapy for preventing chickens from IBDV infection.

The N- and C-terminal carbohydrate recognition domains of galectin-9 from Carassius auratus contribute differently to its immunity functions to Aeromonas hydrophila and Staphylococcus aureus.

Galectin-9, an important pathogen recognition receptor (PRR), could recognize and bind pathogen-associated molecular patterns (PAMPs) on the surface of invading microorganisms, initiating the innate immune responses. A galectin-9 was identified from Qihe crucian carp Carassius auratus and designated as CaGal-9. The predicted CaGal-9 protein contained two non-identical carbohydrate recognition domains (CRDs), namely, N-CRD and C-CRD. The recombinant proteins (rCaGal-9, rN-CRD and rC-CRD) were purified from Escherichia coli BL21 (DE3) and exhibited strong agglutinating activity with erythrocytes of rabbit. The haemagglutination was inhibited by D-galactose, α-lactose and N-acetyl-D-galactose. Results of microbial agglutination assay showed that three recombinant proteins agglutinated Gram-negative bacterium Aeromonas hydrophila and Gram-positive bacterium Staphylococcus aureus. With regard to the binding activity, each recombinant protein could bind to LPS, PGN and the examined microorganisms (A. hydrophila and S. aureus) with different binding affinities. The integrated analyses suggested that CaGal-9 with two CRD domains could play an important role in immune defence against pathogenic microorganisms for C. auratus.

The effect of ghrelin on the fibrosis of chicken bursa of fabricius infected with infectious bursal disease virus.

The present study aimed to investigate the effect of ghrelin on the degree of bursa of Fabricius (BF) fibrosis in infectious bursal disease virus-infected chickens. Specific pathogen free (SPF) chicks were divided into four groups. One group was used as the control ("C"). The other three groups were inoculated with IBDV on the 19th day, of which two were injected intraperitoneally with 0.5 nmol ("LG") or 1.0 nmol ("HG") ghrelin/100 g weight from the 18th day to the 22nd day, and one was injected intraperitoneally with PBS ("I"). Hematoxylin-eosin staining, Masson's staining, and quantitative real-time PCR were used to determine the effects of ghrelin on the degree of inflammatory cell infiltration, the bursal fibrosis degree, and the expression of TGF-ß and MMP-9 mRNA in IBDV-infected SPF chicks. The results showed that ghrelin administration reduced the number of infiltrated inflammatory cells in BF from 5 dpi and significantly attenuated the degree of fibrosis induced by IBDV from 2 dpi to 7 dpi (P < 0.05). Moreover, the TGF-ß expression in the LG and HG groups were significantly or highly significantly lower (P < 0.05 or P < 0.01) than those of I group from 2 dpi to 5 dpi. In addition, ghrelin administration downregulated MMP-9 expression evoked by IBDV from 2 dpi to 7 dpi (P < 0.05 or P < 0.01). These results suggested that ghrelin attenuated the bursal fibrosis degree of IBDV-infected SPF chicks by reducing the number of inflammatory cells and by decreasing the expression of TGF-ß and MMP-9, which shortened the process of bursa recovery.

Tissue distribution and developmental changes of interferon regulatory factors in chickens and effects of infectious bursal disease virus infection.

Interferon regulatory factors (IRFs) are a family of transcription factors that play a role in a variety of biological processes including immune regulation of interferon and expression of inflammatory cytokines. However, the data on IRFs are rather limited in chickens. In the present study, qRT-PCR was used to study the tissue distribution of IRFs in chickens at D15 (the 15th day of raising) and developmental changes of all chIRFs (Chicken interferon regulatory factors) in BF from E15 (the 15th day of incubation) to D15. The effects of IBDV infection with chickens on the transcriptional level of chIRFs were also investigated. The results showed: (1) chIRF1 mRNA was expressed much more abundantly in intestinal tract, chIRF2, chIRF6, chIRF7, chIRF8 and chIRF10 distributed mainly in liver or/and kidney. The expression of chIRF5 was mainly in spleen and chIRF4 distributed uniquely abundantly in BF. (2) The mRNA expression levels of chIRF5, chIRF7, chIRF8 and chIRF10 was low before hatching of chicken and at D1 and increased significantly from D5 till to the experiment end and the fold change of chIRF5 at D10 and chIRF7 at D5 reached 41.0-fold and 15.7-fold compared to that of E15, respectively (P < 0.05). ChIRF4 mRNA level was always high during the whole experiment except for E15 and it was 11.9-fold at the highest time point than that of E15 (the lowest time point). (3) When chicken was infected with IBDV, the expression levels of chIRF2, chIRF7 and chIRF10 mRNA had the tendency of increasing first and then decreasing but they peaked at 1dpi, 2 dpi, and 3dpi, respectively. The expression of chIRF5 mRNA was suppressed obviously during the whole experiment stage in IBDV-infected chicken. And chIRF4 expression was up-regulated transitorily at 1dpi and then was suppressed on a very low level till to the experiment end. Conclusion: The chIRFs were constitutively expressed in different tissues examined and has tissue-specific expression. Of them, chIRF2, chIRF4, chIRF5, chIRF7, chIRF8 and chIRF10 were related closely with the development or immune response of BF, and when chicken was infected with IBDV, some of them were activated, earlier or later on, some of them were suppressed. These findings would help to sieve out a few antiviral chIRF candidate gene to improve the host's innate immune and provide a foundation of the further exploiting a new vaccine adjuvant.

Ghrelin attenuates infectious bursal disease virus-induced early inflammatory response and bursal injury in chicken.

Studies demonstrated that chicken ghrelin mRNA was expressed in immune organs of chicken. However, it was not known for its functions in chicken immune system. This study aimed to investigate the effects of ghrelin on infectious bursal disease virus (IBDV)-induced acute inflammatory and bursal injury. Chickens were divided into 4 groups. One group was used as control ("C"). The other three groups incubated with IBDV on the 19th d, of which 2 were injected intraperitoneally with 0.5 nmol ("LG") or 1.0 nmol ("HG") ghrelin/100g body weight from 18th to 22nd d, respectively, and one was injected intraperitoneally with PBS ("I"). Results showed that cytokines including interleukin (IL)-6, IL-1ß, and IL-8 mRNA expression in I group were upregulated significantly after chickens infected with IBDV from 1 d post-infection (dpi) to 3 dpi (P < 0.05). However, the expression level of IL-6, IL-1ß, and IL-8 mRNA in LG and HG groups was 7.3, ∼43.3% as much as that of the I group at 2 dpi and 3 dpi (P < 0.05). Moreover, ghrelin administration attenuated significantly the bursal injury from 1 dpi to 7 dpi and prevents the reduction of bird weight gain at 5 dpi and 7 dpi, which were induced by IBDV (P < 0.05). The results indicated that ghrelin could play an important role in the immune system of chicken.