Avian Beta-defensin Research Articles

Identification and Structural Characterization of Avian Beta-Defensin 2 Peptides from Pheasant and Quail

Rates of tobacco use among adolescents in China and other lower and middle-income countries remain high despite notable prevention and intervention programs. One reason for this may be the lack of theory-based research in tobacco use prevention in these countries. In the current study, a culturally appropriate 21-item measurement scale for cigarette smoking was developed based on the core constructs of Protection Motivation Theory (PMT). The scale was assessed among a sample of 553 Chinese vocational high school students. Results from correlational and measurement modeling analysis indicated adequate measurement reliability for the proposed PMT scale structure. The two PMT Pathways and the seven PMT constructs were significantly correlated with adolescent intention to smoke and actual smoking behavior. This study is the first to evaluate a PMT scale for cigarette smoking among Chinese adolescents. The scale provides a potential tool for assessing social cognitive processes underlying tobacco use. This is essential for understanding smoking behavior among Chinese youth and support more effective tobacco use prevention efforts. Additional studies are needed to assess its utility for use with Chinese youth in other settings.

Expression and regulation of beta-defensin 11 in the oviduct in response to estrogen and in ovarian tumors of chickens

Avian beta-defensins (AvBDs), also known as gallinacins, are small cationic peptides having three cysteine disulfide bonds between their cysteine residues. They play essential roles in the innate immune system as well as stimulate proliferation of epithelial cells and fibroblasts. Although we found the avian homolog of human beta-defensin 11 to be highly expressed in chicks treated with the diethylstilbestrol (DES, a synthetic estrogen agonist), little is known about the hormonal and transcriptional regulation of AvBD-11 in the chicken oviduct and its expression in cancerous ovaries of chickens. Results of this study of young chicks revealed that DES induced AvBD-11 mRNA and protein in the oviduct, specifically luminal and glandular epithelial cells. In addition, microRNA-1615 was discovered to influence AvBD-11 expression via its 3′-UTR which suggests post-transcriptional regulation of AvBD-11 expression in chickens. Furthermore, we compared the expression patterns of the AvBD-11 gene in normal and cancerous ovaries from laying hens which are models for human epithelial ovarian cancer. Our results demonstrated that AvBD-11 is most abundant in the glandular epithelium of endometrioid-type ovarian tumors, but not normal ovaries of laying hens. Collectively, these results suggest that AvBD-11 is an estrogen-induced gene during oviduct development and that it may be used as a biomarker for diagnosis of ovarian cancer and for monitoring effects of therapeutics on progression of ovarian carcinogenesis.

The effect of microbial-nutrient interaction on the immune system of young chicks after early probiotic and organic acid administration1

The combined effects of probiotics (Lactobacillus acidophilus, Lactobacillus casei, Streptococcus faecium, and Saccharomyces cerevisiae) and organic acids (sorbic and citric acid) on intestinal morphology and expression of immune-related genes were investigated. One-day-old chicks were randomly assigned to 1 of 3 groups: birds not receiving probiotic or organic acids (control; T1), or birds receiving an oral combination (1 g/L in water) of 10(8) CFU/g of each of the aforementioned probiotics and organic acids (1% sorbic acid and 0.2% citric acid) for 7 (T2) or 14 d (T3). Each group was divided into 5 replicate pens of 20 birds each, and 5 birds from each group (1 from each pen) were killed on d 11 and 22. Intestinal sections were collected for histological assessment, and reverse transcriptase-PCR analysis was used to assess defensin and cathelicidins expression. Quantitative real-time PCR was used to assess toll-like receptors (TLR) and cytokine expression. Duodenal villus height was greater in T2 and T3 at d 11 (P ≤ 0.036) and 22 (P ≤ 0.015) compared with T1. At d 11, duodenal goblet cell/unit area was less in T3, whereas it was greater in T2 compared with T1 in the jejunum (P = 0.009). Ileal goblet cell/unit area was greater in T3 at d 22 compared with T1 (P < 0.001). Avian beta-defensin-3 was expressed in all tissues except the bursa of T3 birds at d 11, and TLR-2 was down regulated in the cecal tonsil of birds in T2 and T3 at d 11 compared with T1 (P = 0.020 and 0.003, respectively). Expression of IL-12p35 in the ileum at d 11 was down regulated in T2 and T3 compared with T1 (P = 0.030 and 0.012, respectively). Reduced expression of INF-γ was observed in the ileum in T3 compared with T1 at d 11 (P = 0.047). Ileal IL-6 and IL-10 and cecal tonsil interferon-gamma (INF-γ) expressions were greater T2 at d 22 (P ≤ 0.047) than T1. In conclusion, supplementation of combined probiotics and organic acids resulted in inconsistent gut morphology associated responses, and avian beta-defensins and cathelicidins expression were not associated with combined probiotics and organic acids supplementation. Birds supplemented with combined probiotics and organic acids for 7 d showing similar responses in TLR-2, IL-12p35, and IFN-γ compared with those supplemented for 14 d indicates that shorter periods of supplementation might be enough to elicit beneficial responses.

Probiotic Lactobacilli stimulate avian beta-defensin 9 expression in cultured chicken small intestinal epithelial cells

Probiotic <i>Lactobacilli</i> stimulate avian beta-defensin 9 expression in cultured chicken small intestinal epithelial cells

Bioinformatic and molecular characterization of beta-defensins-like peptides isolated from the green lizard Anolis carolinensis

The high resistance of lizards to infections indicates that anti-microbial peptides may be involved. Through the analysis of the green lizard ( Anolis carolinensis) genome and the expressed sequence tag (EST) libraries 32 beta-defensin-like-peptides have been identified. The level of expression of some of these genes in different tissues has been determined by semi-quantitative RT-PCR. Gene expression and structure analysis suggest the presence of alternative splicing mechanisms, with a number of exons ranging from two to four, similar to that for beta-defensins genes in mammals. Lizard beta-defensin-like peptides present the characteristic cysteine-motif identified in mammalian and avian beta-defensins. Phylogenetic analysis indicates that some lizard beta-defensins-like peptides are related to crotamine and crotamin-like peptides of snakes and lizards suggesting that beta-defensins and venomous peptides have a common ancestor gene.

Detection of Avian Beta-defensins mRNA and Proteins in Male Reproductive Organs in Chicken

The aim of this study was to investigate the innate immune system in male chicken reproductive organs by analyzing the expression of avian beta-defensins (avBDs) genes and localizing the avBDs proteins. The expression of avBDs were analysed by RT-PCR and selected avBDs proteins, including avBD-11 and -12, were localized by immunohistochemistry in the testis and epidihymis. The RT-PCR analysis showed the expression of 9 types of avBDs (avBD-3 to-5, -7 and -9 to -13) in the testis. In the epididymis, expression of 10 types of avBDs (avBD-1 to -5, -7 and -9 to -12) were identified. In the testis, the immu-noreaction products for immunoreactive (ir)-avBD-11 were found in the cytoplasm of Sertoli cells. In the epididymis, the epithelial cells of efferent ducts contained dense ir-avBD-11 and ir-avBD-12. The immunoreaction products of these avBDs were negligible in the epithelium of epididymal ducts. These results suggest that the testis and epididymis are able to syn-thesize avBDs to form innate immune system in chickens. It may play significant roles in the host defense against patho-gens in these tissues.

Identification and characterization of an avian β-defensin orthologue, avian β-defensin 9, from quails

In this study, a newly identified avian beta-defensin (AvBD) orthologue was isolated from Chinese painted quail (Coturnix chinensis) lung and bone marrow tissues. The complete nucleotide sequence of the gene contained a 204-bp open-reading frame encoding 67 amino acids. Homology, characterization, and comparison of the gene with AvBD from other avian species confirmed that it was quail AvBD9. To analyze and compare the expression pattern of AvBD9 in tissues from young and adult quails, layer hens, and broilers, reverse transcription polymerase chain reaction was performed using mRNA isolated from 21 different tissues. The AvBD9 expression pattern distribution was differed among quails of different ages, layer hens, and broilers. It was widely expressed in all the tissues except the trachea, liver, and kidney and was highly expressed in the lung and heart of young quails. Similarly, it was widely expressed in all the tissues of adult quails except for the liver, kidney, spleen, thymus, and Harderian gland. In layer hens, AvBD9 was widely expressed in all the tissues except the trachea, glandular stomach, and cecum. Similarly, it was widely expressed in all the tissues of broilers except for the trachea, glandular stomach, rectum, cecum, bone marrow, and cecal tonsil. Recombinant AvBD9 (rAvBD9) was produced and purified by expressing the gene in Escherichia coli. Additionally, peptide according to quail AvBD9 sequence was synthesized, named sAvBD9. As expected, both rAvBD9 and sAvBD9 exhibited strong bactericidal properties against 11 strains of bacteria, including Gram-positive and Gram-negative forms.

Gallin; an antimicrobial peptide member of a new avian defensin family, the ovodefensins, has been subject to recent gene duplication

BackgroundEgg white must provide nutrients and protection to the developing avian embryo. One way in which this is achieved is an arsenal of antimicrobial proteins and peptides which are essentially extensions of the innate immune system. Gallin is a recently identified member of a family of peptides that are found in egg white. The function of this peptide family has not been identified and they are potentially antimicrobial.ResultsWe have confirmed that there are at least 3 forms of the gallin gene in the chicken genome in 3 separate lines of chicken, all the forms are expressed in the tubular cells of the magnum region of the oviduct, consistent with its presence in egg white. mRNA expression levels are in the order 10,000 times greater in the magnum than the shell gland. The conservation between the multiple forms of gallin in the chicken genome compared with the conservation between gallin and other avian gallin like peptides, suggests that the gene duplication has occurred relatively recently in the chicken lineage. The gallin peptide family contains a six cysteine motif (C-X5-C-X3-C-X11-C-X3-C-C) found in all defensins, and is most closely related to avian beta-defensins, although the cysteine spacing differs. Further support for the classification comes from the presence of a glycine at position 10 in the 41 amino acid peptide. Recombinant gallin inhibited the growth of Escherischia coli (E. coli) at a concentration of 0.25 μM confirming it as part of the antimicrobial innate immune system in avian species.ConclusionsThe relatively recent evolution of multiple forms of a member of a new defensin related group of peptides that we have termed ovodefensins, may be an adaptation to increase expression or the first steps in divergent evolution of the gene in chickens. The potent antimicrobial activity of the peptide against E. coli increases our understanding of the antimicrobial strategies of the avian innate immune system particularly those of the egg white and the evolution of the defensin family. The potential of this peptide and others in the family can now be investigated in a number of novel antimicrobial roles.

Changes in the Localization of Immunoreactive Avian Beta-Defensin-8, -10 and -12 in Hen Ovarian Follicles during Follicular Growth

Avian beta-defensins (avBDs) play significant roles in the innate immune system. The aim of this study was to identify immunoreactive (ir) avBDs proteins in the hen ovarian follicles and the changes in their localization with follicular growth. The ovarian follicles at different growth stages, namely the largest (F1), second and third largest (F2 and F3), prehierarchal small yellow and cortical follicles, were collected. The presence of ir-avBD-8, -10, and -12 were examined by immunohistochemistry and Western blot. The three ir-avBDs showed a similar pattern of immunostainings in the follicular tissues at different growth stages. In the granulosa cells, the ir-avBDs were identified in the cortical follicles, whereas their density was reduced in small yellow follicles. The granulosa cells of yellow follicles (F3-F1) showed dense immunolabelings. The interstitial cells showed a faint immunolabeling for avBD-12 but not for avBD-8 and -10 in the cortical follicles, whereas they were weakly stained in the small yellow follicles. Dense immunoreaction products were noticed in the theca interna cells of F3F1 follicles. Western blot analysis showed a single band for each defensin. These results suggest that avBD-8, -10 and -12 proteins are expressed in the specific cells in the follicles, namely interstitial or theca interna cells and granulosa cells, where their amounts are likely increased with follicular growth. These avBDs may play significant roles in the host innate immune system in the follicles.

Molecular dynamics simulation studies and in vitro site directed mutagenesis of avian beta-defensin Apl_AvBD2

BackgroundDefensins comprise a group of antimicrobial peptides, widely recognized as important elements of the innate immune system in both animals and plants. Cationicity, rather than the secondary structure, is believed to be the major factor defining the antimicrobial activity of defensins. To test this hypothesis and to improve the activity of the newly identified avian β-defensin Apl_AvBD2 by enhancing the cationicity, we performed in silico site directed mutagenesis, keeping the predicted secondary structure intact. Molecular dynamics (MD) simulation studies were done to predict the activity. Mutant proteins were made by in vitro site directed mutagenesis and recombinant protein expression, and tested for antimicrobial activity to confirm the results obtained in MD simulation analysis.ResultsMD simulation revealed subtle, but critical, structural variations between the wild type Apl_AvBD2 and the more cationic in silico mutants, which were not detected in the initial structural prediction by homology modelling. The C-terminal cationic 'claw' region, important in antimicrobial activity, which was intact in the wild type, showed changes in shape and orientation in all the mutant peptides. Mutant peptides also showed increased solvent accessible surface area and more number of hydrogen bonds with the surrounding water molecules. In functional studies, the Escherichia coli expressed, purified recombinant mutant proteins showed total loss of antimicrobial activity compared to the wild type protein.ConclusionThe study revealed that cationicity alone is not the determining factor in the microbicidal activity of antimicrobial peptides. Factors affecting the molecular dynamics such as hydrophobicity, electrostatic interactions and the potential for oligomerization may also play fundamental roles. It points to the usefulness of MD simulation studies in successful engineering of antimicrobial peptides for improved activity and other desirable functions.

Identification and characterization of a novel antibacterial peptide, avian β-defensin 2 from ducks

In this study, a novel avian beta-defensin (AvBD) was isolated from duck pancreas. The complete nucleotide sequence of the gene contained an 195 bp open reading frame encoding 64 amino acids. Homology, characterization and comparison of the gene with AvBD from other avian species confirmed that it was duck AvBD2. The mRNA expression of the gene was analyzed in 17 tissues from 21-day-old ducks. AvBD2 was highly expressed in the trachea, crop, heart, bone marrow, and pancreas; moderately expressed in the muscular stomach, small intestine, kidney, spleen, thymus, and bursa of Fabricius; and weakly expressed in skin. We produced and purified recombinant AvBD2 by expressing the gene in Escherichia coli. As expected, the recombinant peptide exhibited strong bactericidal properties against Bacillus cereus, Staphylococcus aureus, and Pasteurella multocida, and weak bactericidal properties against E. coli and Salmonella choleraesuis. In addition, the recombinant protein retained antimicrobial activity against S. aureus under different temperatures (range, -20 degrees C to 100 degrees C) and pH values (range, 3 to 12).

Evaluation of beta defensin 2 production by chicken heterophils using direct MALDI mass spectrometry

Beta defensins (BD) are cysteine rich, cationic antimicrobial peptides (AMP) produced mainly by epithelial and myeloid cells such as neutrophils. In birds, the neutrophil equivalent heterophils produce avian beta defensins (AvBD) of which AvBD2 is the major isoform. Heterophils recognize pathogens or their derived products through a series of pattern recognition receptors called toll-like receptors (TLR) leading to their antimicrobial activities. This work is the first report of TLR modulation of AvBD2 expression in chickens. To measure the effect of TLR activation on AvBD2 production, the heterophils were cultured with different TLR agonists for 6h. Modulation of AvBD2 levels by TLR activation was measured using direct MALDI mass spectrometry without stable isotopic labeling or chromatographic separation. Chemical modification of the conditioned media was performed using reduction/alkylation with dithiothreitol/iodoacetamide to distinguish TLR treated AvBD2 (reduced/alkylated) from controls (non-reduced). Changes in corrected ion intensity ratios were assumed to reflect AvBD2 modulation in heterophils upon activation with different TLR agonists. In general, TLR agonists increased AvBD2 production with LPS showing the greatest induction and CpG-ODN showing little or no effect. These data show that the direct MALDI-MS coupled with reduction/alkylation may provide a rapid relative quantitative approach to the measurement of agonist-induced differential expression of AvBD2.

Transcriptional profiling avian beta-defensins in chicken oviduct epithelial cells before and after infection with Salmonella enterica serovar Enteritidis

BackgroundSalmonella enterica serovar Enteritidis (SE) colonizes the ovary and oviduct of chickens without causing overt clinical signs which can lead to SE-contamination of the content and membrane of shell-eggs as well as hatchery eggs. The organism utilizes the Salmonella Pathogenicity Island-2 encoded type III secretion system (T3SS-2) to promote persistence in the oviduct of laying hens. In this study, reverse transcriptase-polymerase chain reaction (RT-PCR) was carried out to determine the expression profiles of 14 known avian beta defensins (AvBDs) in primary chicken oviduct epithelial cells (COEC) before and after infections with a wild type SE strain and T3SS mutant SE strains carrying an inactivated sipA or pipB gene.ResultsBased on the expression levels in uninfected COEC, AvBDs can be loosely grouped into three categories with AvBD4-5 and AvBD9-12 being constitutively expressed at high levels; AvBD1, AvBD3, and AvBD13-14 at moderate levels; and AvBD2 and AvBD6-8 at minimal levels. Infection with the wild type SE strain temporarily repressed certain highly expressed AvBDs and induced the expression of minimally expressed AvBDs. The pipB mutant, compared to the wild type strain, had reduced suppressive effect on the expression of highly expressed AvBDs. Moreover, the pipB mutant elicited significantly higher levels of the minimally expressed AvBDs than the wild type SE or the sipA mutant did.ConclusionChicken oviduct epithelial cells express most of the known AvBD genes in response to SE infection. PipB, a T3SS-2 effector protein, plays a role in dampening the β-defensin arm of innate immunity during SE invasion of chicken oviduct epithelium.

Two novel duck antibacterial peptides, avian beta-defensins 9 and 10, with antimicrobial activity

Two novel duck antibacterial peptides, avian beta-defensins 9 and 10, with antimicrobial activity

The avian Toll-Like receptor pathway—Subtle differences amidst general conformity

The Toll-Like receptor (TLR) pathway plays a core role in innate immunity and is maintained with remarkable consistency across all vertebrate species. Amidst this background of overall conservation, subtle differences in the components that make up this pathway may have important implications for species-specific defense against key pathogens. Here we employ a homology-based comparative method to characterize the TLR pathway in the recently sequenced chicken and zebra finch genomes, which represent two distantly related bird species. The key features of the TLR pathway are conserved in birds and mammals, although some clear differences exist. The TLR receptors show a pattern of gene duplication and gene loss in both avian species when compared to mammals. In particular, we observe avian specific duplication of both TLR1 and TLR2 as well and a recent duplication of the TLR7 gene in the zebra finch lineage. Both positive selection and gene conversion shape the evolution of the avian specific TLR2 genes. In addition, there are notable differences in the zebra finch repertoire of antimicrobial peptides (AMPs) when compared to those of the chicken. Bioinformatic analysis reveals no evidence of cathelicidins in the zebra finch genome but does identify a cluster of 12 novel defensins which map to the avian beta-defensin locus on chromosome 3. These findings contribute to the characterization of the differing immune response systems that have evolved in individual vertebrate species in response to their microbiological environment.

Two Novel Duck Antibacterial Peptides, Avian β-Defensins 9 and 10, with Antimicrobial Activity

Two novel avian beta-defensins (AvBDs) isolated from duck liver were characterized and their homologies with other AvBDs were analyzed. They were shown to be duck AvBD9 and AvBD10. The mRNA expression of the two genes was analyzed in 17 different tissues from 1-28-dayold ducks. AvBD9 was differentially expressed in the tissues, with especially high levels of expression in liver, kidney, crop, and trachea, whereas AvBD10 was only expressed in the liver and kidney of ducks at all the ages investigated. We produced and purified GST-tagged recombinant AvBD9 and AvBD10 by expressing the two genes in Escherichia coli. Both recombinant proteins exhibited antimicrobial activity against several bacterial strains. The results revealed that both recombinant proteins retained their antimicrobial activities against Staphylococcus aureus under a range of different temperatures (-70 degrees C -100 degrees C) and pH values (pH 3-12).

Comparative in vivo infection models yield insights on early host immune response to Campylobacter in chickens

Salmonella typhimurium and Campylobacter jejuni pose significant risks to human health and poultry are a major vector for infection. Comparative in vivo infection models were performed to compare the avian host immune response to both bacterial species. Forty-five commercial broiler chickens were orally challenged with either C. jejuni or S. typhimurium whilst 60 similar control birds were mock challenged in parallel. Birds were sacrificed at 0, 6, 20 and 48 h post-infection and cloacal swabs, blood and tissue samples taken. Peripheral blood leukocytes were isolated for flow cytometric analyses and RNA was extracted for gene expression profiling. Colonisation patterns were markedly different between the two bacterial species, with systemic colonisation of Campylobacter outside the gastrointestinal tract. Salmonella infection induced significant changes in circulating heterophil and monocyte/macrophage populations, whilst Campylobacter infection had no effect on the heterophil numbers but caused a significant early increase in circulating monocytes/macrophages. Toll-like receptor 1 (TLR1) gene expression was decreased, and avian beta-defensin (AvBD) gene expression (AvBD3, AvBD10 and AvBD12) was significantly increased in response to Salmonella infection (P < 0.05). In contrast, Campylobacter infection induced increased TLR21 gene expression but significantly reduced expression of seven antimicrobial peptide (AMP) genes (AvBD3, AvBD4, AvBD8, AvBD13, AvBD14, CTHL2 and CTHL3; P < 0.05). Considered together, microbiological, cellular and gene expression profiles indicate that the innate immune system responds differently to Salmonella and to Campylobacter infection. Furthermore, reduction in the expression of AMPs may play a role in the persistence of high level colonisation of the host by Campylobacter.

Expression of Avian β-Defensin 3, an Antimicrobial Peptide, by Sperm in the Male Reproductive Organs and Oviduct in Chickens: An Immunohistochemical Study

The aim of this study was to determine whether chicken sperm express avian beta-defensin 3 (AvBD-3), an antimicrobial peptide, and retain it during the residence in the male and female reproductive tract. Immunocytochemistry to identify AvBD-3 was performed in the testis, epididymis, ductus deferens, ejaculated sperm, and utero-vaginal junction of the oviduct of inseminated hens. Reverse transcription-PCR analysis was also performed to confirm the synthesis of AvBD-3 by testicular cells and ejaculated sperm. The immunoreaction products for AvBD-3 were identified in the elongated spermatids attached to the seminiferous epithelium and in the sperm in the lumen of seminiferous tubules. Immunoreaction products were found in the sperm in the epididymal ducts and ductus deferens. In the ejaculated sperm, immunoreaction products were distributed in the midpiece and cephalic region of the tail of sperm, but not in the head. The AvBD-3 immunoreaction products were also identified in the sperm stored in the sperm storage tubules in the utero-vaginal junction. Reverse transcription-PCR analysis showed the expression of AvBD-3 mRNA in the testicular tissue, but not in the ejaculated sperm. These results suggest that AvBD-3 is synthesized by late stage of spermatids in the testis, and this molecule is retained by the sperm during the passage of male reproductive tract, and even in the sperm storage tubules of oviduct. The sperm AvBD-3 is assumed to play roles in protecting the sperm from the microbial infection and enable to survive in the male and female reproductive tracts.

Expression of Antimicrobial Peptides in Cecal Tonsils of Chickens Treated with Probiotics and Infected with Salmonella enterica Serovar Typhimurium

Several strategies currently exist for control of Salmonella enterica serovar Typhimurium colonization in the chicken intestine, among which the use of probiotics is of note. Little is known about the underlying mechanisms of probiotic-mediated reduction of Salmonella colonization. In this study, we asked whether the effect of probiotics is mediated by antimicrobial peptides, including avian beta-defensins (also called gallinacins) and cathelicidins. Four treatment groups were included in this study: a negative-control group, a probiotic-treated group, a Salmonella-infected group, and a probiotic-treated and Salmonella-infected group. On days 1, 3, and 5 postinfection (p.i.), the cecal tonsils were removed, and RNA was extracted and used for measurement of avian beta-defensin 1 (AvBD1), AvBD2, AvBD4, AvBD6, and cathelicidin gene expression by real-time PCR. The expressions of all avian beta-defensins and cathelicidin were detectable in all groups, irrespective of treatment and time point. Probiotic treatment and Salmonella infection did not affect the expression of any of the investigated genes on day 1 p.i. Furthermore, probiotic treatment had no significant effect on the expression of the genes at either 3 or 5 days p.i. However, the expression levels of all five genes were significantly increased (P < 0.05) in response to Salmonella infection at 3 and 5 days p.i. However, administration of probiotics eliminated the effect of Salmonella infection on the expression of antimicrobial genes. These findings indicate that the expression of antimicrobial peptides may be repressed by probiotics in combination with Salmonella infection or, alternatively, point to the possibility that, due to a reduction in Salmonella load in the intestine, these genes may not be induced.

Expression of Avian β-Defensins in the Oviduct and Effects of Lipopolysaccharide on Their Expression in the Vagina of Hens

The aims of this study were to (i) determine the types of avian beta-defensin genes (AvbetaD) expressed in the hen oviduct and (ii) to examine the effects of lipopolysaccharide (LPS) treatment in vivo on their expression in the vagina. Birds were i.v. treated with LPS (1 mg/kg of BW), and subsequently the oviducts were analyzed 0, 3, 6, 12, or 24 h after LPS administration. The mRNA expression for AvbetaD was examined by reverse transcription-PCR using RNA preparations from the mucosal tissues of all the oviductal segments. Furthermore, changes in their mRNA expression profiles in the vagina were analyzed by semiquantitative reverse transcription-PCR. The AvbetaD-1, -2, -3, -4, -5, -7, -8, -9, -10, -11, and -12 were identified in each oviductal segment from infundibulum to vagina. Among these AvbetaD, the expression of AvbetaD-3, -5, -10, -11, and -12 in the vagina were significantly increased in response to LPS treatment, whereas the others did not show significant changes. These results suggest that all 11 types of AvbetaD are expressed in the hen oviduct and at least 5 of them in the vagina show increased expression in response to LPS.