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.
"More recently, Michailidis et al. (2012) reported that 11 AvBD genes were expressed in hen ovaries, and their expression increased with sexual maturation and the age of birds. Inoculation of birds with SE or LPS increased the expression of several AvBDs in the theca tissue or ovarian tissues (Subedi et al., 2007; Michailidis et al., 2012), suggesting that pathogenic agents affect AvBD expression . Furthermore, the density of ir-AvBD12 showed a tendency to decrease with LPS injection in the granulosa cells (Subedi et al., 2008). "
"Scale bars represent 20 µm. (Abdelsalam et al., 2010) increased expression of several AvBDs (Michailidis et al., 2012). Injection of birds with LPS resulted in an increase in the expression of several AvBDs in the theca tissue, although no response was observed in the granulosa layer (Subedi et al., 2007). "
[Show abstract][Hide abstract] 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 · 0.93 Impact Factor
"Initially such peptides were characterized as antimicrobial effectors of heterophils in the chicken and turkey (Evans et al., 1995). In recent years they have been shown to be key responders to infection at mucosal surfaces including Salmonella and Campylobacter infection of the intestinal tract (Akbari et al., 2008; Hasenstein and Lamont, 2007; van Dijk et al., 2007; Crhanova et al., 2011; Meade et al., 2009), Salmonella infection of the reproductive tract (Michailidis et al., 2012) and have been shown to have considerable antimicrobial activity towards Salmonella (Milona et al., 2007). The role of NK cells in avian bacterial infections is poorly described beyond that NK-lysin has anti-bacterial activity (Lee et al., 2012b). "
[Show abstract][Hide abstract] ABSTRACT: Bacterial infections remain important to the poultry industry both in terms of animal and public health, the latter due to the importance of poultry as a source of foodborne bacterial zoonoses such as Salmonella and Campylobacter. As such, much focus of research to the immune response to bacterial infection has been to Salmonella. In this review we will focus on how research on avian salmonellosis has developed our understanding of immunity to bacteria in the chicken from understanding the role of TLRs in recognition of bacterial pathogens, through the role of heterophils, macrophages and γδ lymphocytes in innate immunity and activation of adaptive responses to the role of cellular and humoral immunity in immune clearance and protection. What is known of the immune response to other bacterial infections and in particular infections that have emerged recently as major problems in poultry production including Campylobacter jejuni, Avian Pathogenic Escherichia coli, Ornithobacterium rhinotracheale and Clostridium perfringens are discussed.
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