Enhancement of chicken macrophage cytokine response to Salmonella Typhimurium when combined with bacteriophage P22

Immune-Related Gene Expression Profiling of Broiler Chickens Fed Diets Supplemented with Vinification Byproducts: A Valorization Approach II

Simple Summary

The valorization of grape byproducts appears to be a sustainable bioeconomic strategy that could promote the substitution of synthetic with natural antioxidant compounds in the food and feed industry. The nutritional physiology of broiler chickens requires special attention to the interactions between nutrients and antioxidant mechanisms since the stressor signals of factory farming could impair the immune status, resulting in detrimental effects on broilers’ performance. The objective of this study was to assess the inclusion of grape byproducts (grape pomace, wine lees, and stem extract) on the transcriptional profiling of genes regulating the immune system in the liver, bursa of Fabricius, and spleen. The dietary supplementation of grape byproducts rich in polyphenolic compounds decreased the mRNA levels of the predominant pro-inflammatory receptor in the liver, while in the spleen, the stem extract diet upregulated the aforementioned receptor. Upregulation of interleukin 8 was observed in the bursa of Fabricius and spleen of the stems extract-fed broilers. Although grape byproducts depicting a sustainable source of bioactive compounds with vast antioxidant potential, there were unveiled preliminary insights for immune stimulation at the transcriptional level.

Abstract

The valorization of vinification byproducts portrays a promising bioprocess for the enrichment of animals’ diet with bioactive compounds, such as polyphenols, which could regulate the immune response. Therefore, the impact of dietary grounded grape pomace (GGP), wine lees extract (WYC), and grape stem extract (PE) on the relative transcript level of immune related genes of broiler chickens were examined. Two hundred forty, one-day-old as hatched (male/female) chicks (Ross 308) were allocated to four dietary groups, with four replicate pens each with 15 birds. Birds were fed either a basal diet (CON) or the basal diet supplemented with 2.5% GGP, or 0.2% WYC, or 0.1% PE for 42 d. The relative expression of immune-related genes was investigated using a real-time PCR platform. The mRNA levels of Toll-like Receptor 4 (TLR4) were downregulated (p = 0.039) in the liver of broilers fed the GGP-containing diet compared to the CON, while in the spleen of PE-fed broilers, TLR4 was significantly upregulated (p = 0.043). The mRNA levels of interleukin 8 (IL8) tended to upregulate (p = 0.099) in the bursa of Fabricius and were significantly increased (p = 0.036) in the spleen of broilers fed the PE diet. Vinification byproducts depict a promising sustainable source of polyphenols for the poultry feed industry, but more research is needed under field conditions.

gga-miR-200b-3p Promotes Macrophage Activation and Differentiation via Targeting Monocyte to Macrophage Differentiation-Associated in HD11 Cells

MicroRNAs (miRNAs) play a critical role in various biological processes through regulation of gene expression post-transcriptionally. Although miRNAs are involved in cell proliferation and differentiation in mammals, few reports regarding the effects of host miRNAs on macrophage activation and differentiation are available in birds. Here, we reported that gga-miR-200b-3p acts as a positive regulator, enhancing macrophage activation and differentiation using an avian model. We found that ectopic expression of gga-miR-200b-3p in HD11 cells enhances the amount of MHC-II-positive cells and promotes the expression of pro-inflammatory cytokines and that gga-miR-200b-3p directly targets monocyte to macrophage differentiation-associated (MMD). The inhibition of MMD by gga-miR-200b-3p enhances the activation and differentiation of HD11 cells and increases the expression of pro-inflammatory cytokines. Collectively, these findings highlight a crucial role of gga-miR-200b-3p in macrophage activation and differentiation in birds.

Evaluation of Ascorbic Acid or Curcumin Formulated in a Solid Dispersion on Salmonella Enteritidis Infection and Intestinal Integrity in Broiler Chickens

Two experimental models were conducted to evaluate and compare the effect of ascorbic acid (AA) or curcumin formulated in a solid dispersion (SD-CUR) as prophylactic or therapeutic alternatives to prevent or control S. Enteritidis (SE) infection in broiler chickens. In the prophylactic model, dietary administration of AA showed a significant reduction in SE counts in crop compared to the positive control (PC) group (p < 0.05), whereas in cecal tonsils (CT), SD-CUR significantly reduced SE recovery. Superoxide dismutase (SOD) activity was significantly higher in chickens supplemented with AA or SD-CUR, and total intestinal IgA levels were significantly lower in both treatments when compared to the PC group. Serum fluorescein isothiocyanate-dextran (FITC-d) levels were reduced by SD-CUR compared to PC, while AA presented significantly lower total aerobic bacteria. In the therapeutic model, only the dietary administration of AA significantly decreased SE in crop and CT on days 3 and 10 post-challenge. FITC-d levels were significantly lower in both treated groups in comparison to PC, but IgA levels were significantly reduced only by AA. The results suggest that dietary AA and SD-CUR have different modes of action to reduce SE intestinal colonization in two different challenge models in broiler chickens.

Avian Leukosis Virus Subgroup J Attenuates Type I Interferon Production Through Blocking IκB Phosphorylation

Avian leukosis virus subgroup J (ALV-J) is an oncogenic retrovirus that causes immunosuppression and enhances susceptibility to secondary infection, resulting in great economic losses. Although ALV-J-induced immunosuppression has been well established, the underlying molecular mechanism for such induction is still unclear. Here, we report that the inhibitory effect of ALV-J infection on type I interferon expression is associated with the down-regulation of transcriptional regulator NF-κB in host cells. We found that ALV-J possess the inhibitory effect on type I interferon production in HD11 cells and that ALV-J causes the up-regulation of IκBα and down-regulation of NF-κB p65, and that ALV-J blocks the phosphorylation of IκBα on Ser32/36 amino acid residues. Collectively, our findings provide insights into the pathogenesis of ALV-J.

Influence of bacteriophage P22 on the inflammatory mediator gene expression in chicken macrophage HD11 cells infected with Salmonella Typhimurium

This study was designed to evaluate the effects of bacteriophage on the intracellular survival and immune mediator gene expression in chicken macrophage-like HD11 cells. The invasive ability and intracellular survival of Salmonella Typhimurium (ST(P22-) ) and lysogenic S. Typhimurium (ST(P22+) ) in HD11 cells were evaluated at 37 °C for 24 h postinfection (hpi). The expression of inflammatory mediator genes was determined in ST(P22-) - and ST(P22+) -infected HD11 cells treated with and without bacteriophage P22 at 1 and 24 hpi using quantitative RT-PCR. The ability of ST(P22-) and ST(P22+) to invade HD11 cells was significantly decreased by bacteriophage P22 at 1 hpi. The numbers of intracellular ST(P22-) and ST(P22+) were significantly decreased from 2.39 to 1.62 CFU cm(-2) and from 3.40 to 1.72 CFU cm(-2) in HD11 cells treated with bacteriophage P22, respectively, at 24 hpi. The enhanced expression of inflammatory mediators was observed in ST(P22-) - and ST(P22+) -infected HD11 cells treated with and without bacteriophage P22. These results suggest that the application of bacteriophage could be an effective way to control the intracellular infection.