Transcriptional profiling of antimicrobial peptides avian β-defensins in the chicken ovary during sexual maturation and in response to Salmonella enteritidis infection.
ABSTRACT Avian β-defensins (AvβDs) are antimicrobial peptides that play significant roles in the innate immune system in chickens. The aim of this study was to identify the types of AvβDs expressed in the chicken ovary, to investigate the effects of sexual maturation in the ovarian mRNA abundance and to determine the changes in their expression levels as a result to Salmonella enteritidis (SE) infection. RNA was extracted from the ovary of healthy prepubertal, sexually mature and aged birds, as well as from sexually mature and aged SE infected birds. Real-time PCR analysis revealed that 11 AvβDs genes were expressed in the chicken ovary. A significant up regulation of AvβD1, 3, 4, 5, 7 and 11 was observed in the ovary of sexually mature and aged birds. Furthermore, a significant up-regulation of AvβD4, 5, 7, 11 and 12 was observed in the ovary of SE infected sexually mature birds. These results suggest that the mRNA expression of at least six AvβDs increase with age in the ovary of laying hens, and that at least five AvβDs show an induction in their expression in response to SE infection, indicating an AvβD-mediated immune response mechanism in the chicken ovary.
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ABSTRACT: Abstract 1. This study was to evaluate the effects of supplementary dietary selenium (Se) given as sodium selenite on host immune response against necrotic enteritis (NE) in commercial broiler chickens. 2. Chicks were fed from hatching on a non-supplemented diet or diets supplemented with different levels of Se (0.25, 0.50 and 1.00 Se mg/kg). To induce NE, broiler chickens were orally infected with Eimeria maxima at 14 d of age and then with Clostridium perfringens 4 d later using our previously established NE disease model. 3. NE-associated clinical signs and host protective immunity were determined by body weight changes, intestinal lesion scores, and serum antibodies against α-toxin and NetB toxin. The effects of dietary Se on the gene expression of pro-inflammatory cytokines (interleukin (IL)-1β, IL-6, IL-8LITAF, tumour necrosis factor (TNF) SF15, and inducible nitric oxide synthase (iNOS), glutathione peroxidase 7 (GPx7), and avian β-defensins (AvBD) 6, 8, and 13 (following NE infection) were analysed in the intestine and spleen. 4. The results showed that dietary supplementation of newly hatched broiler chicks with 0.25 Se mg/kg from hatch significantly reduced NE-induced gut lesions compared with infected birds given a non-supplemented diet. The levels of serum antibody against the Necrotic enteritis B (NetB) toxin in the chicks fed with 0.25 and 0.50 mg/kg Se were significantly higher than the non-supplemented control group. The transcripts for IL-1β, IL-6, IL-8, iNOS, LITAF and GPx7, as well as AvBD6, 8 and 13 were increased in the intestine and spleen of Se-supplemented groups, whereas transcript for TNFSF15 was decreased in the intestine. 5. It was concluded that dietary supplementation with optimum levels of Se exerted beneficial effects on host immune response to NE and reduced negative consequence of NE-induced immunopathology.British Poultry Science 11/2014; 56(1). DOI:10.1080/00071668.2014.984160 · 0.78 Impact Factor
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ABSTRACT: The ovary and oviduct of the hen are susceptible to various pathogenic microorganisms, and infections in these organs may not only contaminate the eggs, but also disorder the egg formation. The immune function of the ovary and oviduct is essential to protect these tissues from infection as well as for the production of hygienic eggs. This paper reviews recent studies on the host defence system in the reproductive organs with reference to their innate immune functions, with emphasis on the important role of Toll-like receptors and avian β-defensins in this defence system.Avian biology research 02/2014; 7(1). DOI:10.3184/175815514X13902927945697 · 0.90 Impact Factor
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ABSTRACT: Salmonella infection of the chicken is important both as a source of foodborne human salmonellosis and as a source of disease in the chicken itself. Vaccination and other control strategies require an understanding of the immune response and as such have been important in understanding both mucosal immunity and more generally the response to bacterial infection. In this review, we discuss the contribution the study of avian salmonellosis has made to understanding innate immunity including the function of phagocytic cells, pattern recognition receptors, and defensins. The mucosal response to Salmonella infection and its regulation and the contribution this makes in protection against infection and persistence within the gut and future directions in better understanding the role of TH17 and Tregs in this response. Finally, we discuss the role of the immune system and its modulation in persistent infection and infection of the reproductive tract. We also outline key areas of research required to fully understand the interaction between the chicken immune system and Salmonella and how infection is maintained in the absence of substantive gastrointestinal disease.Frontiers in Immunology 09/2014; 5:482. DOI:10.3389/fimmu.2014.00482