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The aim of this study is to histologically and histochemically determine the developmental and involutional stages of bursa of Fabricius of henna partridge (Alectoris chukar). In the study, bursa of Fabricius of 12 3-month-old (6 males, 6 females), 12 6-month-old (6 males, 6 females) henna partridges purchased from a private farm were used. It was observed that bursa of Fabricius was surrounded by a connective tissue capsule and consisted of tunica serosa, tunica muscularis, and tunica mucosa layers from the outside to the inside. It was seen that the tunica muscularis consisted of outer longitudinal and inner circular smooth muscle fibers. It was observed that the tunica mucosa made plicae towards the lumen of the organ and consisted of 10-15 plicae. It was seen that lamina epithelialis and lymph follicles were present in each plica. It was determined that the lamina epithelialis consisted of two parts called FAE (Follicle-Associated Epithelium) and IFE (İnter Follicular Epithelium). It was noted that the lymph follicles contained cortex and medulla sections and were separated locally by capillaries together with cortical medullary boundry cells. In the Methyl Green-pyronin staining method, plasma cells were found in the bursa of Fabricius of the henna partridge, in the connective tissue surrounding the organ, around the blood vessels and inside the follicles. In AB pH=2.5 staining, AB-positive reaction was seen only in the apical part of the epithelial cells forming FAE and IFE in the pre- and post-involution period. In PAS staining, PAS-positive reaction was observed only in the apical part of the epithelial cells forming FAE and IFE in the pre- and post-involution period. In PAS/AB pH=2.5 combined staining method, AB-positive reaction was observed only in the apical part of epithelial cells in the pre- and post-involution period. As a result of this study, it was found that bursa of Fabricius of the henna partridge did not undergo any histochemical changes despite its histologically large differences after involution.

The study aimed to examine and compare the influence of adding synthetic antioxidant butylated hydroxyanisole (BHA), with two herbal medical plants (Oregano germander) on broiler gut microflora, and its immunity. One hundred and forty broilers were raised for three weeks and were distributed into five treatment groups. The prepared dietary treatments were included (w/w):1). Control (without supplement) 2). Germander (GER; inclusion level 1.5 %) 3). Oregano (ORE; inclusion level 2.5 %) 4). Combination of GER and ORE (CM; inclusion levels 1.5 and 2.5 %, respectively)5). BHA (0.02 %). The highest total number of ileal lactobacilli counts was found in broilers fed CM dietary treatment. On the other hand, their disgust samples (i.e. in CM) showed the lowest total count of Escherichia coli compared to other treatments. Among different dietary treatments, CM treatment showed the best positive effect on broiler immune system response, where it showed the highest Bursa Fabricius relative weight, and IgG values. Overall, the results showed that such dietary treatment (i.e. Combination of GER and ORE)positively enhanced gut microflora, and bird's immunity response. [ABSTRACT FROM AUTHOR]

The developmental morphology of the bursa of Fabricius (BF) of broiler chicken was evaluated in this study using gross anatomical, histological, reticulin histo-chemical, and transmission electron microscopic techniques. The result showed that the short plica of the BF at embryonic day (ED) 14 was a mesenchymal tissue that contained cells, including mesenchymal cells and lymphoblasts. The organo-somatic index (OSI) of the BF peaked at ED 17, while the BF of ED 19 showed well delineated follicle-associated and inter-follicular epithelial (IFE) cells. Whereas, the IFE contained apical vacuoles which increased in size with age, the BF contained lymphoid follicles which were first observed at ED 17, and increased steadily in mean diameter from ED 19 to post-hatch day (PD) 28. The framework of the interfollicular areas and the follicular capsules were composed of collagen type III fibres. Moreover, the cortico-medullary basement membranes were well established with peripheral and corticomedullary basement capillaries becoming very consistent between PDs 5 and 7. The lymphoid follicle contained lymphocytes with mitotic figures, and plasma cells which showed extensive network of rough endoplasmic reticulum at PD 21, while macrophages contained increasing evidence of phagocytosis from PDs 35 to 56. In conclusion, the morphological features of the BF of broiler chicken in this study reveals that the key function of B-cell maturation within the BF may occur between the first 3 to 4 weeks after hatching, and thereafter, may primarily produce immunoglobulins until involution occurs. [ABSTRACT FROM AUTHOR]

Some basic indicators of nonspecific immunity in ROSS 308 hybrid broilers receiving a polybacterial immunomodulator were studied by enzyme-linked immunosorbent assay and spectrophotometric methods. The experiments were performed in flocks of broiler breeders and broilers under production conditions. In the control herds- under the same breeding conditions and in compliance with the prophylactic programs in the farms, including the accepted antibiotic therapy. The birds from the experimental flocks were raised without the use of antibiotics. As a result of the performed studies, we found higher concentrations of lysozyme, IFN γ, IL-2; IL-6 in experimental herds receiving the immunomodulator compared to controls. For example, in the experimental broiler herd, we found twice as high levels of serum lysozyme relative to controls: 6.17 ± 0.49 mg / L and 2.99 ± 0.27 mg / L, respectively. The activity of complement (CH50) in the blood serum of broilers treated with AVIGEN - 549.00 ± 19.69, also significantly exceeded the values in the control herd - 377.40 ± 9.58. We received similar results from broiler breeders. Serum IgY concentrations showed a significant difference in adolescent broiler breeders but not in broilers. We tracked the changes in bursa Fabricii by histological methods. Under the influence of the immunomodulator AVIGEN in the bursa of experimental birds, we observed delayed involution and good functional activity, while in the controls, involution processes were advanced and accompanied by follicle death and connective tissue growth. The morphological and functional activity of bursa Fabricii contributes to the increased natural resistance in the birds treated with the immunomodulator, which enabled their breeding without the use of antibiotics in production conditions. [ABSTRACT FROM AUTHOR]

In contrast to mammals, early B cell differentiation and diversification of the antibody repertoire in chickens do not take place in the bone marrow but in a specialized gut associated lymphoid tissue (GALT), the bursa of Fabricius. During embryonic development, B cell precursors migrate to the bursa anlage, where they proliferate and diversify their B cell receptor repertoire. Around hatch these diversified B cells start to emigrate from the bursa of Fabricius and populate peripheral lymphoid organs, but very little is known how the migratory processes are regulated. As CXCL12 (syn. SDF-1) and CXCR4 were shown to be essential for the control of B cell migration during the development of lymphoid tissues in mammals, we analyzed expression and function of this chemokine/chemokine-receptor pair in the chicken bursa. We found a strong variation of mRNA abundance of CXCL12 and CXCR4 in different stages of bursa development, with high abundance of CXCL12 mRNA in the bursa anlage at embryonic day 10 (ED10). In situ hybridization demonstrated disseminated CXCL12 expression in the early bursa anlage, which condensed in the developing follicles and was mainly restricted to the follicle cortex post-hatch. Flow cytometric analysis detected CXCR4 protein already on early B cell stages, increasing during bursal development. Post-hatch, a subpopulation with the hallmarks of emigrating B cells became detectable, which had lower CXCR4 expression, suggesting that downregulation of CXCR4 is necessary to leave the CXCL12-high bursal environment. In vivo blockade of CXCR4 using AMD3100 at the time of B cell precursor immigration strongly inhibited follicle development, demonstrating that CXCL12 attracts pre-bursal B cells into the bursal anlage. Altogether, we show that CXCL12 and its receptor CXCR4 are important for both populating the bursa with B cells and emigration of mature B cells into the periphery post hatch, and that CXCR4 function in primary B cell organs is conserved between mammals and birds.

Abstract Background Cryptosporidium spp. are protozoans that cause diarrheal illness in humans and animals, including birds, worldwide. The present study was aimed to revisit the infectivity and pathogenicity of C. avium, recently considered to be a valid avian-infecting species of Cryptosporidium, and foster further understanding of its biological characteristics. Results Results showed that no Cryptosporidium oocysts were detected in the feces of experimentally inoculated BALB/c mice, Mongolian gerbils, quail or budgerigars within 30 days post-infection (dpi). Oocysts were first detected in feces of 3-day-old and 40-day-old hens at 8 and 9 dpi, respectively. In ducks infected with C. avium, oocysts were first detected at 9 dpi. Oocysts of infected animals were studied using a nested-polymerase chain reaction (PCR) technique for the SSU rRNA gene, actin gene, HSP70 gene and Cryptosporidium oocyst wall protein gene (COWP) detection. Restriction fragment length polymorphism (RFLP), using SspI and VspI restriction enzymes, was carried out to genotype the species and obtained amplification products were sequenced. Cryptosporidium developmental stages were found in the longitudinal plica of the bursa fabricii (BF) of hens, with high levels observed in histological sections and scanning electron microscopy. No pathological changes were observed. Conclusions These findings indicate that the bursa fabricii may be the primary site of C. avium infection. More biological data are needed to support the establishment of new species and contribute to the taxonomy of Cryptosporidium.

Perfluoroalkyl acids (PFAAs) are ubiquitous environmental contaminants and eggs and nestlings of raptors and fish-eating birds often contain high levels of PFAAs. We studied developmental effects of a mixture of ten PFAAs by exposing chicken embryos to 0.5 or 3 μg/g egg of each compound in the mixture. Histological changes of the thyroid gland were noted at both doses and increased expression of mRNA coding for type III deiodinase was found at 0.5 μg/g egg. Serum concentrations of the free fraction of thyroid hormones (T3 and T4) were reduced by the PFAA mixture at 3 µg/g egg, which is in line with a decreased synthesis and increased turnover of thyroid hormones as indicated by our histological findings and the decreased mRNA expression of type III deiodinase. The relative weight of the bursa of Fabricius increased at a dose of 3 μg/g egg in females. The bursa is the site of B-cell development in birds and is crucial for the avian adaptive immune system. Analysis of plasma and liver concentrations of the mixture components showed differences depending on chain length and functional group. Our results highlight the vulnerability of the thyroid hormone and immune systems to PFAAs. [ABSTRACT FROM AUTHOR]

Infectious bursa disease virus (IBDV) pathogenesis is characterized by increased numbers of T cells and decreased numbers of B cells in the bursa. Currently, little is about the key factor that affects T migration into bursa. In humans, CC chemokine ligand 19 (CCL19) recruits monocytes and neutrophils and is usually involved in various inflammatory disorders. The aim of this study was to assess the roles of CCL19 in driving peripheral blood cells infiltration into bursa of Fabricius of chickens infected with IBDV. Bursal samples were collected from chickens of the infection group and the control group on day 1, 3, 5, and 7 post infection (dpi) with IBDV. The mRNA or protein levels of ccl19 and ccr7 genes in bursae were determined by real-time PCR and immunohistochemistry (IHC) methods. Moreover, an in vitro chemotaxis assay was performed to evaluate the chemotaxis ability of CCL19 and bursal total protein. The results have displayed that the mRNA levels of ccl19 were significantly increased on 1, 3, 5, and 7 dpi in the infection group. The highest value amounted to 73.4-fold of the control group. Also, the mRNA levels of CCR7, the receptor of CCL19, began to increase on 3 dpi and reached to the highest value of 206.3-fold on 5 dpi after IBDV infection. Then the gene expression of CCR7 in bursae of the infection group returned to the normal level. IHC results of CCL19 protein level accorded with the mRNA levels of CCL19, with the highest value on 5 dpi. Then, in vitro chemotaxis test demonstrated that the total bursal protein had the ability of recruiting peripheral white blood cells (PWBC) and the migration percentage was a little higher than that of the blank control with only basal medium (P < 0.05). Taken together, these data suggest that CCL19 acts as a chicken PWBC chemotactic factor and facilitate the infiltration of PWBC (especially T cells) into the bursae after IBDV infection. [ABSTRACT FROM AUTHOR]

Abstract The aim of this study was to evaluate the effect of phytogenic additives and glutamine plus glutamic acid, associated or not, on histomorphometry of bursa of Fabricius and small intestine, oocyst count and lesion scores, and carbon turnover of duodenal mucosa of broiler chickens infected with Eimeria acervulina. A total of 450 male broiler chickens was distributed into a completely randomized design with six treatments and three replications. Treatments consisted of control diet (CD); CD + coccidiosis vaccine; CD + antibiotic performance enhancers and anticoccidial (APE/AC); CD + glutamine and glutamic acid (Gln/Glu); CD + phytogenic additives (PA); CD + Gln/Glu + PA. Birds on treatment CD + vaccine were vaccinated via drinking water at three days of age against coccidiosis. At 16 days of age all birds of all treatments were inoculated orally and individually with 500,000 oocysts of Eimeria acervulina. There was no treatment effect on lesion score in the intestinal epithelium of birds. The smaller number of excreted oocysts was observed in groups of birds fed diets containing APE/AC and PA. Were observed better results of villus height and crypt depth for duodenum and ileum of birds of treatments containing Gln/Glu at 7 days of age, and Gln/Glu and PA at 21 days of age. Higher percentage of cortical area from bursa follicles was observed in birds fed diets supplemented with Gln/Glu and PA at 7, 14 and 21 days of age. Increased turnover of intestinal mucosa was observed in treatments containing Gln/Glu, indicating acceleration in development and regeneration of damaged tissue. Glutamine plus glutamic acid and phytogenic additives can provide improvements to structure, and thus to intestinal function, as well as to better immune response against the infectious challenges. Phytogenic additives can be used for coccidiosis control of broiler chickens where the use of antibiotic performance enhancers and anticoccidials is prohibited.

Glycyrrhizinate dipotassium (DG) is a widely used anti-inflammatory, antimicrobial and anti-viral agent isolated from the licorice root. This study aims to investigate the potential antiviral activity of DG and its underlying mechanisms of protection against infectious bursal disease virus (IBDV) in vivo. The international guiding principles for Biomedical Research Involving Animals were followed during animal experiment. Measured the indices of immune organs including spleen, thymus and bursa of Fabricius, level of anti-IBDV antibody (Ab), IFN-γ and IFN-β in serum through ELISA, lymphocyte proliferation and the ratio of CD4+/CD8+ in blood using MTT and flow cytometry respectively and the expression of IBDV VP1 and TLR3 host gene in bursa of Fabricius were also evaluated by qRT-PCR. The DG treatment groups showed increased immunological index of spleen, thymus and bursa of Fabricius, a much higher ratio of CD4+/CD8+, the levels of anti-IBDV Ab, IFN-γ and IFN-β in serum were up-regulated varyingly, inhibit the VP1 expression and also up-regulated the TLR3 expression in bursa of Fabricius. These findings suggested that DG inhibited IBDV infection in vivo through multiple pathways and DG is a promising drug candidate for further development. [ABSTRACT FROM AUTHOR]

Background: The molecular mechanisms underlying stress-influenced immune function of chicken (Gallus Gallus) are not clear. The stress models can be established effectively by feeding chickens corticosterone (CORT) hormone. The bursa of Fabricius is a unique central immune organ of birds. RNA-Seq technology was used to investigate differences in the expression profiles of immune-related genes and associated pathways in the bursa of Fabricius to clarify molecular mechanisms. The aim of this study was to broaden the understanding of the stress-influenced immune function in chickens. Results: Differentially expressed genes (DEGs) in the bursa of Fabricius between experimental group (basal diet with added CORT 30 mg/kg; C_B group) and control group (basal diet; B_B group) were identified by using RNA-seq technology. In total, we found 1434 significant DEGs (SDEGs), which included 199 upregulated and 1235 downregulated genes in the C_B group compared with the B_B group. The immune system process GO term was the top significantly GO term, including MYD88, TLR4, IL15, VEGFA gene and so on. The cytokine-cytokine receptor interaction pathway and the Toll-like receptor signaling pathway were the key pathways affected by stress. The protein-protein interaction (PPI) analysis of the SDEGs showed that VEGFA, MyD88 and IL15 were hub genes and module analysis showed that MYD88, TLR4 and VEGFA play important roles in response to stress. Conclusion: This study showed that the VEGFA and ILs (such as IL15) via the cytokine-cytokine receptor interaction pathway, MYD88 and TLR4 via the Toll-like receptor signaling pathway may play important roles in the regulation of immune function under stress condition with CORT administration. The results of this study provide a reference for further studies of the molecular mechanisms of stress-influenced immune function. [ABSTRACT FROM AUTHOR]

Abstract Hydrogen sulfide (H 2 S) is widely accepted to be a signaling molecule that exhibits some potentially beneficial therapeutic effects at physiological concentrations. At elevated levels, H 2 S is highly toxic and has a negative effect on human health and animal welfare. Studies have shown that H 2 S exposure induces an immune function in mice, but there are few studies of the effect of continuous H 2 S exposure on immune organs in poultry. In this study, one-day-old broilers were selected and exposed to 4 or 20 ppm of H 2 S gas for 14, 28 and 42 days of age. After exposure, the bursa of Fabricius (BF) was harvested. The results showed that continuous H 2 S exposure reduced the body weight, abdominal fat percentage, and antibody titer in broilers. H 2 S exposure also decreased mRNA expression of IgA, IgM and IgG in the broiler BF. A histological study revealed obvious nuclear debris, and a few vacuoles in the BF, and an ultrastructural study revealed mitochondrial and nuclear damage to BF cells after H 2 S exposure for 42 d. Terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay suggested H 2 S exposure remarkably increased the number of TUNEL positive nuclei and significantly increased apoptotic index. The expression of apoptotic genes also confirmed that H 2 S inhalation damaged the broiler BF. Increased cytokines and reduced antioxidant responses were detected in the BF after exposure to H 2 S. Cytokines promoted inflammation and caused a Th1/Th2 imbalance. We suggest that continuous H 2 S intoxication triggers oxidative stress, inflammation, apoptosis and a Th1/Th2 imbalance in the BF, leading to immune injury in broilers. Graphical abstract fx1 Highlights • Excessive H 2 S reduce the growth characteristics of broiler chickens. • H 2 S exposure induce a Th1/Th2 imbalance and affected immunoglobulin production. • Apoptosis is one injury mechanism to the bursa of Fabricius caused by H 2 S. • Oxidative stress and inflammation are involved in H 2 S-induced immune injury in broilers. [ABSTRACT FROM AUTHOR]

The bursa of Fabricius (BF) is a central humoral immune organ unique to birds. Four bursal peptides (BP-I, BP-II, BP-III, and BP-IV) have been isolated and identified from the BF. In this study, the immunoadjuvant activities of BPs I to IV were examined in mice immunized with H9N2 avian influenza virus (AIV) vaccine. The results suggested that BP-I effectively enhanced cell-mediated immune responses, increased the secretion of Th1 (interferon gamma)- and Th2 (interleukin-4)-type cytokines, and induced an improved cytotoxic T-lymphocyte (CTL) response to the H9N2 virus. BP-II mainly elevated specific antibody production, especially neutralizing antibodies, and increased Th1- and Th2-type cytokine secretion. BP-III had no significant effect on antibody production or cell-mediated immune responses compared to those in the control group. A strong immune response at both the humoral and cellular levels was induced by BP-IV. Furthermore, a virus challenge experiment followed by H&E staining revealed that BP-I and BP-II promoted removal of the virus and conferred protection in mouse lungs. BP-IV significantly reduced viral titers and histopathological changes and contributed to protection against H9N2 AIV challenge in mouse lungs. This study further elucidated the immunoadjuvant activities of BPs I to IV, providing a novel insight into immunoadjuvants for use in vaccine design. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the morphological characteristics and to describe some quantitative traits of Bursa Oynarı native pigeon breed in Bursa province in Turkey. The study was carried out on a total of randomly selected 43 Bursa Oynarı pigeons (23 males, 20 females). The morphological characteristics (head type, eye colour, head and bib colour, neck blend colour, beak type and colour, head plumage, ventral abdomen colour and claw colour) and the quantitative traits (body weight and morphometric measurements) were determined from both male and female pigeons. The results indicated that the most frequent morphological characteristics of this pigeon breed were round shaped head (72.09%), dusty rose eye colour (67.44%), veiled head/bib colour (37.21%), purple neck blend colour (53.49%), flat-shaped type beak (67.44%), white beak (51.16%), markless head plumage (69.77%), white ventral abdomen colour (93.02%) and white claw colour (95.35%). Sex significantly (P<0.01) affected the quantitative traits such as the body length, leg length and tail length. Male pigeons had higher means of the mentioned traits than those of female pigeons. Over the past few decades, there has been an increased awareness for the conservation of native breeds for their importance to genetic diversity. Thus, studies conducted on native breeds in various species may provide a noteworthy contribution to this purpose. [ABSTRACT FROM AUTHOR]

Toll like receptor 4 (TLR4), eosinophils and mast cells play significant role in host immunity during several pathogenic infections. However in vivo tissue expression of TLR4 and distribution pattern of eosinophils and mast cells in chicken bursa of Fabricius (BF) during Salmonella enterica serovar Typhimurium (STm) infection is poorly studied. Therefore, herein, following immunostaining, we found localization of TLR4 in follicular cortex and medulla and its expression was statistical increased after 36 h and 72 h of STm stimulation. Chromotrope 2R staining revealed that eosinophils were mostly distributed in follicular cortex, inter-follicular spaces and in or around blood vessels and their number in BF were statistical increased after 72 h of STm stimulation. The presence of eosinophils was confirmed using immunostaining with anti-rabbit eosinophil cationic protein antibody. Toluidine blue stained mast cells were mostly distributed in connective tissues between inter-follicular spaces while some were also present in follicular cortex of BF. However, STm stimulation illustrated non-significant effect on the number of mast cells or their de-granulation, instead their number were gradually decreased in BF with advancement in age of chickens. Hence, this study provided novel information about in vivo tissue distribution of TLR4, eosinophils and mast cells in BF during STm infection. [ABSTRACT FROM AUTHOR]

The Harderian gland is a sparsely characterized immune tissue known to play an important role in local immunity. The function of the Harderian gland, however, is not clearly defined. Measuring the expression of all genes using RNA-seq enables the identification of genes, pathways, or networks of interest. Our relative RNA-seq expression analysis compared the chicken Harderian gland transcriptome to other important primary and secondary immune tissues including the bursa of Fabricius, thymus, and spleen of non-challenged birds. A total of 2,386 transcripts were identified as highly expressed in the Harderian gland. Gene set enrichment showed the importance of G-protein coupled receptor signaling and several immune pathways. Among the genes highly expressed in the Harderian gland were 48 miRNAs, a category of genetic elements involved in regulation of gene expression. Several identified miRNAs have immune related functions. This analysis gives insight to the unique immune processes inherent in the Harderian gland. [ABSTRACT FROM AUTHOR]

To evaluate the antidiarrheal effects of Anacardium occidentale L. leaf powder, 45 two-day old White Leghorn chicks (L-33 hybrid) were studied for 8 hours. A completely randomized design was applied with three treatments. The diet treatments consisted in basal diet (BD), BD + 1.0 % of Anacardium occidentale L. leaf powder, and BD + 1.5 % of A. occidentale leaf powder. Besides, the incidence of diarrhea was calculated 2, 4, 6 and 8 hours after inducing diarrhea with castor oil. Then, five birds were sacrificed per treatment and the accessory immune organs and all the viscera were weighed. The intestinal pH was analyzed, and the hematocrit levels were analyzed. The initial and final live weights and feed consumption of diarrheal newborn birds remained stable (P > 0.05) among the treatments. Likewise, the relative weights of liver, glandular stomach, muscular stomach, and small and large intestine did not have statistical differences (P > 0.05). However, supplementation with the medicinal powder modified (P < 0.05) the relative weight of pancreas, heart, thyme, and bursa of Fabricius. The T2 treatment (1.5 %) decreased the incidence of diarrhea significantly (P < 0.05) compared to the other treatments. However, the experimental treatments did not alter (P > 0.05) the concentration of hematocrits in newborn birds. The supplementation of 1.5 % of Anacardium occidentale L. leaf powder is recommended for newborn birds with metabolic diarrhea. [ABSTRACT FROM AUTHOR]

Coronavirus infection delays the development of the cortico-medullary (CM) capillary network which results in retarded development of bursal follicles. The smaller size of the medulla in the coronavirus-infected birds may lead to a lower number of B lymphocytes and bursal secretory dendritic cells, which negatively affects the reactivity and efficacy of the immune system. Contrary to the wild-type infectious bronchitis virus (IBV) strain, infection induced by H120 vaccine virus exerts only a moderate influence on caveolin-1 expression of the CM capillary web and on follicular development compared to the untreated controls. [ABSTRACT FROM AUTHOR]

In chickens, B cells develop in the bursa of Fabricius, a unique organ for B cell development. Most B cells will die within the bursa, mirroring cell losses seen in mammalian bone marrow as central tolerance is enforced at the transition to mature cells. B cell responses are shaped by a complex interplay of signals. Signals in addition to BCR that impact central tolerance have recently been described. We have been interested in chB6, a novel alloantigen on B cells in the chicken. chB6 is found in close proximity to the BCR and can trigger apoptosis after cross-linking by antibody. chB6 has two Ig domains, placing it within the CD2/SLAM family of molecules, but its cytoplasmic domain is unique. We have used a site-specific mutagenesis approach to show that an SH3 binding site in chB6 is required for the induction of apoptosis, suggesting parallels to CD2 signaling. [ABSTRACT FROM AUTHOR]

The objective of this research was to compare the reverse transcription polymerase chain reaction (RT-PCR) and agar gel immunodiffusion test (AGID) in terms of sensitivity and specificity for the detection of Infectious Bursal disease virus (IBDV) in broiler chickens. 85 samples of Bursa of Fabricius were collected from poultry flocks of Morocco during the period 1991 to 2015. IBDV was isolated from suspected bursa samples. The 604-bp region of hypervariable VP2 gene of IBDV was amplified by using specific primers. Agar gel precipitation test revealed the presence of IBDV in 60 (70, 58%) field infected bursal samples and RT-PCR revealed the IBDV in 81 (95, 29%) samples. RT-PCR is more accurate, sensitive and specific method for rapid detection of infectious bursal disease virus from field samples. In conclusion, the RT-PCR assay described herein can be used to rapidly distinguish IBDV from other pathogens, which is important for diagnosis and control of infectious bursitis outbreaks in Morocco. [ABSTRACT FROM AUTHOR]

The gross anatomical study of thymus and bursa of Fabricius was carried out on 30 Kadaknath birds of different age groups ranging from day old to 26 week. The birds were divided into five equal groups according to age as day old to 2 week, 2 to 4 weeks, 4 to 8 weeks, 8 to 16 weeks and 16 to 26 weeks, each consisted of six birds. The shape, colour and location were observed. The thymus gland in Kadaknath consisted of two long chains having 6-8 irregular shaped lobes. The shape and color of thymic lobes as well as length and width of thymus varied amongst groups. Grossly there was no regression of thymus after 26th week of age. The bursa of Fabricius was located on the dorsal wall of proctodeum of cloaca. The shape and color of bursa of Fabricius varied amongst age groups. Grossly there was complete regression of bursa after 25th week of age. The dissimilarities in these findings might be due to species difference. [ABSTRACT FROM AUTHOR]

A synoptic, annotated catalogue is provided, documenting the long history of vacillated nomenclature usages between leafhopper family-group names Gyponidae Stål 1870c and Scaridae Amyot & Serville 1843a (nec Scaridae Rafinesque 1810b), between genus-group names Gypona Germar 1821a and Scaris Le Peletier & Serville 1828a (nec Scaris Chaudoir 1879), synonyms, and use of Docalidia ferruginea (Fabricius) in the literature for Iassus ferrugineus, beginning at the formation of each taxon and ending at the present. Authors' annotations, where applicable, follow each citation. A photograph of the lectotype of Iassus ferrugineus Fabricius (Coelidiinae) and a misidentified specimen (Gyponinae) by Germar are shown for comparative purposes. [ABSTRACT FROM AUTHOR]

The current experiment was conducted to compare the efficacy of different of Infectious Bursal Disease (IBD) vaccines having different IBD virus strains against field virus. A total of two hundred, one-day old broiler chickens were divided into four groups (50 birds each group). Group A was subcutaneously vaccinated with immune complex vaccine at 1 day of age. The groups B and C were vaccinated with live IBD vaccines D78 and 228E at 20th and 16th day of age according to Deventer formula. The blood samples were taken randomly from five birds of each group at day 7, 14, 21, 28 and 35 to evaluate anti-IBDV antibody titer by ELISA. Five birds from each group were killed on days 14, 21, 28 and 35 to check bursa to body weight ratio, bursometery, gross and histopathological lesions scoring. Ten birds from each treatment group were challenged with virulent field IBDV on 28 day. On day 35 significantly (P<0.05) higher ELISA antibody titer was observed in group A vaccinated with immune complex vaccine. Bursa to body weight ratio of group A was significantly higher (P<0.05) as compared to other vaccinated groups. Mild to moderate histopathological lesions such as lymphocytic depletion, epithelial necrosis and mononuclear cells infiltration, fibrous tissue proliferation and edematous fluid were observed in vaccinated groups. The live and immune complex IBD vaccine induced adequate protection after challenged. The high mortality and morbidity observed in control group D1 in one week of challenge. The morbidity rate in group A1 and Group C1 was 90% and in group B1 was 70%. It concluded that conventional live IBD vaccines cause more severe damage in bursal follicles as compared to immune complex vaccine. Immune complex vaccine can be safer for day-old chick regardless of maternal derived antibody titers. [ABSTRACT FROM AUTHOR]

The study was carried out on bursa of Fabricius and thymus of guinea fowl to elucidate its histochemical features. The tissue samples were collected from day old to six months at monthly interval and the results are discussed. [ABSTRACT FROM AUTHOR]

T lymphocytes and Toll-like receptors have been confirmed to have correlation with the ability to resistance to pathogenic challenges and play an important role in duck immune system. However, the information of ontogeny of T lymphocytes and Toll-like receptors is scarcely in duck. Therefore, to address these questions, we report the development and distribution of CD3 and CD4 by immunocytochemistry and the age-related mRNA level of duck T cell markers (CD3 and CD4) and Toll-like receptors (TLR2, TLR3, TLR4 and TLR7) by real time quantitative PCR in duck lymphoid organs (thymus, bursa of Fabricius and spleen). Results indicated that CD3 and CD4 positive cells can be observed in all test organs and partly change in an age-related way. CD4 positive T cell of duck spleen mainly distributed in periarterial lymphatic sheaths and red pulp, not in white pulp. Both of CD3 and CD4 were experienced significant increased wave twice in duck lymphoid organs and T cell dependent cellular immunity of duck may well established until 5 weeks old. The mRNA expression levels of duck TLRs were age and organ dependent, and duck TLR3 and TLR7 were significantly lower abundance in the spleen but higher in thymus and bursa of Fabricius, respectively. This study provide the essential knowledge of the ontogeny of T cells and Toll-like receptors in duck, which may shed lights on the T-cell mediate immunity and innate immunity in duck. [ABSTRACT FROM AUTHOR]

Objective: The bursa of Fabricius (BF) is a central humoral immune organ belonging specifically to avians. Recent studies had suggested that miRNAs were active regulators involved in the immune processes. This study was to investigate the possible differences of the BF at miRNA level between two genetically disparate duck breeds. Methods: Using Illumina next-generation sequencing, the miRNAs libraries of ducks were established. Results: The results showed that there were 66 differentially expressed miRNAs and 28 novel miRNAs in bursa. A set of abundant miRNAs (i.e., let-7, miR-146a-5p, miR-21-5p, miR-17∼92) which are involved in immunity and disease were detected and the predicted target genes of the novel miRNAs were associated with duck high anti-adversity ability. By gene ontology analysis and enriching KEGG pathway, the targets of differential expressed miRNAs were mainly involved in immunity and disease, supporting that there were differences in the BF immune functions between the two duck breeds. In addition, the metabolic pathway had the maximum enriched target genes and some enriched pathways that were related to cell cycle, protein synthesis, cell proliferation and apoptosis. It indicted that the difference of metabolism may be one of the reasons leading the immune difference between the BF of two duck breeds. Conclusion: This data lists the main differences in the BF at miRNAs level between two genetically disparate duck breeds and lays a foundation to carry out molecular assisted breeding of poultry in the future. [ABSTRACT FROM AUTHOR]

Background Chickens infected with both infectious bursal disease virus (IBDV) and Salmonella had higher mortality. In this work, we investigated the effect of IBDV vaccine (modified live-virus bursal disease vaccine, Nobilis strain 228E®) on experimentally infected chickens with Salmonella Enteritidis (SE). Methods Four experimental groups were included in this study, negative control group, 228E®group, 228E® + SE infected group, and SE infected group. Chickens were ocularly administrated 228E® at 12 days of age and orally infected with S. Enteritidis at 13 days of age. Sera, intestinal fluid, blood, cloacal swabs and tissue samples were collected at 1, 2 and 3 weeks post vaccination (PV). Results The recorded mortalities were higher in the 228E® + SE infected group, compared to the SE infected group. The anti- S. Enteritidis serum antibody titer and the intestinal mucosal IgA level were higher in the SE infected group at 2 and 3 weeks PV, compared to 228E® + SE infected group. S. Enteritidis fecal shedding and organ colonization were significantly higher in the 228E® + SE infected group than the SE infected group at 2 and 3 weeks PV. The 228E® + SE group had significantly lower bursa to body weight ratios at 2 and 3 weeks PV, as well as had higher bursal lesion scores than the SE infected group. IBDV vaccine depressed the specific-SE systemic and mucosal antibody responses, but did not affect the specific-SE cellular immune responses. Conclusion Chickens administrated IBDV vaccine, followed by S. Enteritidis infection, could cause a significant effect on the bursa of Fabricius, resulting in failure of systemic and mucosal antibody responses to the S. Enteritidis and reduce the elimination and the clearance of S. Enteritidis. [ABSTRACT FROM AUTHOR]

Both CCR5 and CXCR4 are important chemokine receptors and take vital role in migration, development and distribution of T cells, however, whether they will influence the process of T cell infiltration into bursa of Fabricius during infectious bursal disease virus (IBDV) infection is unclear. In the current study, CCR5 and CXCR4 antagonists, Maraviroc and AMD3100, were administrated into chickens inoculated with IBDV, and the gene levels of IBDV VP2, CCR5, CXCR4 and related cytokines were determined by real-time PCR. The results showed that large number of T cells began to migrate into the bursae on Day 3 post infection with IBDV and the mRNA of chemokine receptors CCR5 and CXCR4 began to increase on Day 1. Moreover, antagonist treatments have increased the VP2, CCR5 and CXCR4 gene transcriptions and influenced on the gene levels of IL-2, IL-6, IL-8, IFN-γ, TGF- β 4, MHC-I and MDA5. In conclusion, the chemokine receptors CCR5 and CXCR4 might influence virus replication during IBDV infection and further study would focus on the interaction between chemokine receptors and their ligands. [ABSTRACT FROM AUTHOR]

Embryonic tissues contain highly ramified stellate-shaped cells expressing CD45 and MHC II antigens but their origin and immunophenotype are unknown. Using staged avian embryos and cell-type-specific antibodies, we establish a detailed spatiotemporal ontogeny of cells that express CD45, the earliest marker of hematopoietic stem cells in the chick. CD45 immunostaining marks three distinct embryonic cell populations: round, ramified and amoeboid cells. The round and ramified CD45+ cells appear first in yolk-sac blood islands before the onset of circulation. A subpopulation of round cells co-expresses the thrombocyte-specific CD51/CD61 antigen. Amoeboid cells express macrophage-specific antigens and frequently occur in regions of apoptosis. Ramified cells are distributed uniformly in the embryonic mesenchyme, colonize lymphoid and non-lymphoid organs and later express MHC II. To study the origin of CD45+ cells, 2-day-old chick embryos were ablated from the yolk sac before the establishment of circulation and incubated for 2-5 days. Large numbers of CD45+MHC II+ ramified cells differentiated in the yolk sac. Yolk-sac chimeras were generated by grafting embryos into GFP-expressing de-embryonated yolk sacs. GFP/CD45 co-expressing ramified and amoeboid cells colonized all organ primordia in the donor embryo. We also recombined GFP+ yolk sac with the bursa of Fabricius and found ramified GFP+CD45+ cells in the bursa where they differentiated into dendritic cells. Thus, CD45 cells are first present in the yolk sac during primitive hematopoiesis and then migrate from the extra-embryonic yolk sac to give rise to cells throughout all organ primordia, including dendritic cells in the bursa of Fabricius. [ABSTRACT FROM AUTHOR]

Background: The Toll-like receptor 4 (TLR4) pathway involves in the pathogen recognition and defense against infection in mammals. Considering that avian and mammalian TLR are differentially mediated, the action of a natural product on avian TLR4 pathway was unclear. High, medium and low doses of Astragalus polysaccharide (APS), were treated the chicken at 7-days-old age by gavage. The sIgA level in the intestinal fluid, the expression of chTLR4 mRNA/protein in bursa of Fabricius as well as the expression of downstream molecules of chTLR4 (chMyD88, chTRIF, chNF-κB, chIRF3, chIFN-β and chTNF-α) were measured on alternate days. Results: The content of sIgA and the chTLR4 mRNA expression/protein level were increased in non-dose-dependent manner after APS supplement. Also, the expressions of a subset of MyD88-independent pathway genes were more than MyD88-independent, in particular with low doses of APS supplement for 7 days. Conclusions: These suggest that administration of APS activates chTLR4 pathway in bursa of Fabricius in MyD88-independent pathway. Meanwhile, low dose of APS shows better performance regarding the activation of chTLR4 and regulation of MyD88-independent pathway. [ABSTRACT FROM AUTHOR]

Avian neoplastic diseases have been identified as one of the leading causes of mortality and production losses in commercial chickens in Nigeria. Although available reports described the trend of Marek's disease in Zaria, Kaduna state, they did not take cognizance of other neoplastic diseases of poultry hence the need for this study. The clinic records of the Avian Clinic of the Veterinary Teaching Hospital (VTH), Ahmadu Bello University (ABU), Zaria, were examined for cases of all avian neoplastic diseases from 2002 to 2010. The overall prevalence of avian neoplastic diseases was 7.58% (234/3085). Marek's disease (MD) and avian leukosis (AL) were the only avian neoplastic diseases of poultry reported during the period under review. Marek's disease contributed 85.90% (201/234) of the total avian neoplastic diseases outbreaks while AL was responsible for only 14.10% (33/234) of the outbreaks. The overall prevalence of MD was 6.25% (201/3085) while that of AL was 1.07% (33/3085). Chicken (99.57%) and duck (0.43%) were the only species of birds affected by the diseases. The types of chickens that were affected include commercial layers (97.85%), exotic broilers (0.86%), exotic cockerels (0.86%) and Nigerian indigenous chicken (0.43%). The average age of poultry affected was 20.17 (SD=±2.6) weeks for MD and 41.43 (SD=±15.4) weeks for AL. Weight loss (55.98%), ruffled feathers (47.01%), diarrhea (39.79%) and leg paralysis (17.52%) were the most reported clinical signs. The most consistent gross lesions observed were hepatomegaly (76.50%), emaciated carcass (75.64%), renomegaly (52.56%) and splenomegaly (44.87%). Neoplastic growths were mostly observed on the liver (46.58%), kidney (28.2%) and heart (25.21%). The sciatic nerve (20.51%) and bursa of Fabricius (3.85%) were also affected. There is a remarkable increase in the cases of avian neoplastic diseases over the study period which underscores the importance of a National control program for these important diseases of poultry. [ABSTRACT FROM AUTHOR]

We investigated lead (Pb)-induced oxidative stress and immune damage in the chicken bursa of Fabricius (BF) and the ameliorative effect of selenium (Se). Seven-day-old male chickens were randomly divided into four groups and were provided standard diet and drinking water, NaSeO added to the standard diet and drinking water, standard diet and (CHCOO)Pb added to drinking water, and NaSeO added to the standard diet and (CHCOO)Pb added to drinking water for 30, 60, and 90 days. The presence of Pb inhibited total antioxidant capacity (T-AOC), glutathione peroxidase (GPx), glutathione S-transferase (GST), superoxide dismutase (SOD), and catalase (CAT) activities; decreased glutathione (GSH) content; increased malondialdehyde (MDA) and hydrogen peroxide (HO) contents; inhibited interleukin (IL)-2 and interferon-γ (IFN-γ) messenger RNA (mRNA) expression; and increased IL-4, IL-6, IL-10, IL-12β, and IL-17 mRNA expression. The presence of Se relieved all of the above Pb-induced changes. There were close correlations among GSH, CAT, T-AOC, SOD, GPx, MDA, and HO and among IL-2, IL-4, IL-6, IL-12β, IL-17, and IFN-γ. Our data showed that Pb caused oxidative stress and immune damage in the chicken BF. Se alleviated Pb-induced oxidative stress and immune damage in the chicken BF. [ABSTRACT FROM AUTHOR]

Vaccination is recognized to be the most cost-effective means of preventing, controlling, and even eradicating infectious diseases. Conventional poultry are vaccinated through various routes including eye/nose drops, drinking water, vent brush, or injection. Efficient vaccination is an essential part of any good poultry management. The bursa of Fabricius is intimately connected to the cloaca and the intestinal system. It is well-known as a primary lymphoid organ in the chicken and a major channel through which environmental antigens stimulate the immune system. In this study we tested whether direct instillation of various viral vaccines and antigens into the cloaca (per bursam), could stimulate higher antibody titers and generate improved protection. Despite the very rapid absorption of the vaccines or antigens from the cloaca to the lumen of the Bursa of Fabricius, per bursam inoculation failed to generate a satisfactory immune response. In contrast conventional administration of live or inactivated commercial vaccines led to an acceptable level of seroconversion and protection against challenge. An interesting finding in this study was the fact that administration of a single priming dose of antigenic material at age 1 or 5 days, did not improve the response to a second administration at 14 days of age as expected. Instead, in most cases there was a reduced serum antibody response suggesting the induction of tolerance. This was true for all routes of administration (intramuscular, per ocular and per bursam) and for all formulations of vaccine. The current study reveals: 1) no advantage for direct application of live or inactivated vaccines or antigens into the bursa of Fabricius compared to common routes of vaccination, 2) that apparent desensitization or tolerance effects have important implications for poultry management, since in many countries, vaccination of day old chicks is compulsory or a well-accepted part of flock vaccination. According to our results, early vaccination can in fact reduce or inhibit a secondary immune response to subsequent vaccination and increase susceptibility to disease agents. [ABSTRACT FROM AUTHOR]

Copyright of Avian Diseases is the property of American Association of Avian Pathologists, Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The bursa of Fabricius, the central humoral immune organ unique to birds, plays an important role in B-lymphocyte differentiation. In order to gain a better understanding of the molecular mechanism of critical biological processes like Bcell immigration, differentiation, and final emigration, the transcriptional changes during embryonic and posthatch development of this organ were investigated. We generated a cDNA library from total RNA isolated from 3 representative developmental stages (embryonic day [ED] 10, posthatch d 2 and d 21). We generated over 70 million high-quality reads from the cDNA library by using deep sequencing. The uniquely mapped sequences of ED 10, d 2 and d 21 were 71087280, 59167491 and 70263675 respectively. All of the differential expressed genes were involved in Vitamin A metabolism, regulation of actin cytoskeleton, Wnt signaling pathway, MAPK signaling pathway, Jak-STAT signaling pathway, Notch signaling pathway, Toll-like receptor signaling pathway. The RNA-seq analysis provides a powerful method for analyzing the transcriptome and investigating the transcriptional changes of different development stages of bursa of Fabricius. The assembled bursa transcriptome provides an essential resource for future investigations about chicken Bursa development. [ABSTRACT FROM AUTHOR]

This study encompasses the pathology both gross and microscopic, of a recent outbreak of Leucocytozoon caulleryi infection in a commercial broiler flock. Four numbers of 3 3-day-old broilers {Gallus gallus domesticus) were necropsied following a history of depression and sudden death. On necropsy, subcutaneous haemorrhages were observed in the pectoral and thigh muscles, epicardium, pancreas, and kidneys. On histopathology, numerous schizonts, megaloschizonts and merozoites of Leucocytozoon were observed in the heart, liver, lung, kidneys, thymus and bursa of Fabricius. Although L. caulleryi infection was diagnosed previously in Kerala, there are no reports of an outbreak of L. caulleryi in broiler chicken in the state. [ABSTRACT FROM AUTHOR]

The article presents a case study of a 2-month-old, 600-g male Harris hawk with no antemortem signs of illness. Topics discussed include multisystemic hemorrhage as primary cause of death of hawk; Escherichia coli infection that resulted in the septic condition; vector-borne intracellular hemic parasites Leucocytozoon as reason for its death; and hemorrhage in bursa of Fabricius.

The bursa of Fabricius (BF) is a lymphoepithelial organ found only in birds. Differences in morphology of BF could play an important role in immune response. The objective of this study was to investigate the histological and histochemical characteristics of the bursa of Fabricius in the long-legged buzzard (Buteo rufi nus). The material for the study comprised bursa samples obtained from three long-legged buzzards with permission of the General Directorate of Nature Protection and National Parks (Ankara, Turkey). Briefl y, interfollicular epithelium (IFE) was shown to be columnar in shape and not to contain goblet cells. Reticular fi bers were located in interfollicular septae. Each lymphoid follicle in the bursa of Fabricius in the long-legged buzzard was remarkably linked to the follicle associated epithelium (FAE). Namely, FAE has been reported to stimulate antibody production by transferring antigens to the medulla and have a leading role in developing of local immune response. Among the others, the speciesspecifi c differences in bursa of Fabricius morphology of long-legged buzzard (Buteo rufi nus) also might support the continuity of this species in nature. [ABSTRACT FROM AUTHOR]

Growth hormone (GH) is expressed in several extra-pituitary tissues, including the primary and secondary lymphoid organs of the immune system. In birds, GH mRNA and protein expression show a specific developmental distribution pattern in the bursa of Fabricius (BF), particularly in epithelial and B cells. Changes in the bursal concentration and distribution of locally produced GH during ontogeny suggest it is involved in B cell differentiation and maturation, as well as in a functional survival role in this organ, which may be mediated by paracrine/autocrine mechanisms. Here, we analyzed the anti-apoptotic effect of GH in BF and the intracellular signaling pathways involved in this activity. Also, we studied if this effect was exerted directly by GH or mediated indirectly by IGF-I. Bursal cell cultures showed an important loss of their viability after 4 h of incubation and a significant increase in apoptosis. However, treatment with 10 nM GH or 40 nM IGF-I significantly increased B cell viability (16.7 ± 0.67% and 13.4 ± 1.12%, respectively) when compared with the untreated controls. In addition, the presence of apoptotic bodies (TUNEL) dramatically decreased (5.5-fold) after GH and IGF-I treatments, whereas co-incubation with anti-GH or anti-IGF-I, respectively, blocked their anti-apoptotic effect. Likewise, both GH and IGF-I significantly inhibited caspase-3 activity (by 40 ± 2.0%) in these cultures. However, the use of anti-IGF-I could not reverse the GH anti-apoptotic effects, thus indicating that these were exerted directly. The addition of 100 nM wortmannin (a PI3K/Akt inhibitor) blocked the GH protective effects. Also, GH stimulated (3-fold) the phosphorylation of Akt in bursal cells, and adding wortmannin or an anti-GH antibody inhibited this effect. Furthermore, GH was capable to stimulate (7-fold) the expression of Bcl-2. Taken together, these results indicate that the direct anti-apoptotic activity of GH observed in the chicken bursal B cell cultures might be mediated through the PI3K/Akt pathway. [ABSTRACT FROM AUTHOR]

The bursa of Fabricius (BF), which is unique to birds, serves as the central humoral immune organ and plays a significant role in B lymphocyte differentiation. In this study, a new bursal peptide (BP-IV) was isolated from BF, which promoted colony-forming unit pre-B formation and regulated B cell differentiation. BP-IV also exerted immunomodulatory effects on antigen-specific immune responses via both humoral and cellular immunity in chicken and mice that had been immunized with inactivated avian influenza virus (AIV; H9N2 subtype), including enhancing AIV-specific antibody and cytokine production. The results of this study provided novel insights into the use of a potential candidate reagent for B cell development and future immuno-pharmacological use. [ABSTRACT FROM AUTHOR]

The effects of diclazuril on the bursa of Fabricius (BF) structure and secretory IgA (SIgA) expression in chickens infected with Eimeria tenella were examined. The morphology of the BF was observed by hematoxylin and eosin staining, while ultrastructural changes were monitored by transmission electron microscopy. E. tenella infection caused the BF cell volumes to decrease, irregularly arranged, as well as, enlargement of the intercellular space. Diclazuril treatment alleviated the physical signs of damages associated with E. tenella infection. The SIgA expression in BF was analyzed by immunohistochemistry technique. The SIgA expression increased significantly by 350.4% (P<0.01) after E. tenella infection compared to the normal control group. With the treatment of diclazuril, the SIgA was relatively fewer in the cortex, and the expression level was significantly decreased by 46.7% (P<0.01) compared with the infected and untreated group. In conclusion, E. tenella infection in chickens induced obvious harmful changes in BF morphological structure and stimulated the expression of SIgA in the BF. Diclazuril treatment effectively alleviated the morphological changes. This result demonstrates a method to develop an immunological strategy in coccidiosis control. [ABSTRACT FROM AUTHOR]

IgMIgG B cells were detected, by immunofluorescence staining of single cells, in the bursa of Fabricius after hatching. To study the role of maternal IgG (MIgG) in this emergence of IgMIgG B cells, MIgG-free chicks were established from surgically bursectomized hens. Deprivation of MIgG in chicks completely prevented the appearance of IgMIgG B cells in the bursa 1 week after hatching. However, introduction of fluorescein-isothiocyanate-labeled MIgG to MIgG-free chick embryos on day 18 of incubation retrieved IgMIgG B cells in the bursa 1 week after hatching. Thus, IgMIgG B cells are induced by the binding of MIgG to IgM B cells in the bursa after hatching. Nevertheless, no binding of MIgG to IgM B cells was observed in the bursa of chick embryos in which B-cell proliferation and differentiation were independent of external antigens (Ags). Additionally, the binding of MIgG to IgM B cells after hatching was prevented by the isolation of the bursa from environmental stimuli by bursal duct ligation. Therefore, Ag stimulation from the external environment to the bursa is indispensable for the binding of MIgG to IgM B cells in the bursa. Taken together, the data demonstrate that IgMIgG B cells are generated by Ag-dependent binding of MIgG to IgM B cells in the bursa after hatching. [ABSTRACT FROM AUTHOR]

Species of the family Prosthogonimidae are considered the most pathogenic poultry trematodes worldwide, affecting particularly low intensity farming in rural areas. Adults of Prosthogonimus occur mainly in the bursa of Fabricius, oviduct and cloaca of ducks, geese, fowl and other birds feeding at least occasionally on dragonflies or damselflies (Odonata). We analyzed the central European species of the Prosthogonimidae, namely Prosthogonimus cuneatus , Prosthogonimus ovatus , Prosthogonimus pellucidus and Prosthogonimus rarus . We sequenced three nuclear (ITS2) and mitochondrial (CO1, ND1) DNA loci of four species isolated from Anas clypeata , Anas strepera , Anas platyrhynchos , Aythya ferina , Passer domesticus and Turdus merula . Intra- and inter-specific sequence variability revealed that all four species represent distinct well-defined entities. Our data, combined with previously published studies, suggest the return of the name Prosthogonimus rarus Braun, 1901 for Schistogonimus rarus (Braun, 1901). The genus name Schistogonimus Lühe, 1909 is considered a junior synonym of Prosthogonimus Lühe, 1899. We identified the existence of two clades, one represented by P. cuneatus and P. pellucidus , and another one formed by P. ovatus and P. rarus . We also provide comparative measurements of these four central European prosthogonimids, and address their tissue specificity, host-specific prevalence (based on the extensive bird cohort examined in years 1962–2014), and for some bird hosts we address also differences in the prevalence of Prosthogonimus spp. in natural and near-natural wetlands in comparison with fishponds utilized for intense carp production. We provide an updated key to European Prosthogonimus spp. based on their morphological characters. [ABSTRACT FROM AUTHOR]

Several causes may induce change and atrophy in the bursa of Fabricius (BF). Databases on BF standards are available from published studies, however, updated references are needed to adjust the BF standards to present changes in highly specialized broiler genetic lines. The aim of this study was to evaluate BF-related measurements (weight and dimensions) under controlled conditions that would mimic field situations. Chickens were kept in isolation, thus avoiding exposure to disease agents by vaccination or field infections. This study was conducted using male Cobb 500 commercial broilers from the same hatch and source. Absence of disease was confirmed throughout the study. Despite the presence of individual variations, a minimum bursa-to-body weight ratio standard of 0.11 is proposed in broilers from 7 to 42 days of age. [ABSTRACT FROM AUTHOR]

The bursa of Fabricius (BF) is the acknowledged central humoral immune organ in birds. Bursal septpeptide II (BSP-II) is an immunomodulatory bioactive peptide isolated from BF. To understand the effects of BSP-II on immune induction, gene expression profiles of hybridoma cells treated with BSP-II were evaluated. Pathway analysis showed that regulated genes were involved in cytokine-cytokine receptor interactions, T cell receptor signaling pathway, and pathway in cancer. It was observed that BSP-II reduced tumor cells proliferation and stimulated p53 expression. These results indicate potential mechanisms underlying the effects of the humoral immune system on immune induction, including antitumor activities. Our study has provided a novel insight into immunotherapeutic strategies for treating human tumors. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Animal Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)