The transcription factor XBP1 in dendritic cells promotes the TH2 cell response in airway allergy.

Dendritic cells (DCs) that express T cell immunoglobulin domain molecule-4 (TIM4), a cell surface receptor for phosphatidylserine, induce T helper 2 (TH2) cell responses and allergic reactions. We elucidated the role of the transcription factor X-box-binding protein-1 (XBP1) in the induction of the TH2 cell response through its role in generating TIM4+ DCs. We found that XBP1 was required for TIM4 mRNA and protein expression in airway DCs in response to the cytokine interleukin-2 (IL-2) and that this pathway was required for TIM4 expression on DCs in response to the allergens PM2.5 and Derf1. The IL-2-XBP1-TIM4 axis in DCs contributed to Derf1/PM2.5-induced, aberrant TH2 cell responses in vivo. An interaction between the guanine nucleotide exchange factor Son of sevenless-1 (SOS1) and the GTPase RAS promoted XBP1 and TIM4 production in DCs. Targeting the XBP1-TIM4 pathway in DCs prevented or alleviated experimental airway allergy. Together, these data suggest that XBP1 is required for TH2 cell responses by inducing the development of TIM4+ DCs, which depends on the IL-2-XBP1-SOS1 axis. This signaling pathway provides potential therapeutic targets for the treatment of TH2 cell-dependent inflammation or allergic diseases.

Early life microbiota transplantation from highly feed-efficient broiler improved weight gain by reshaping the gut microbiota in laying chicken.

Starting phase of laying chicken life is the building stone for rearing and production stages. Since, fecal microbial transplantation (FMT) regulates the gut microbial diversity and affects the productive performance of the bird. The aim of this study is to evaluate the effect of FMT from feed-efficient broiler chicken could program the diversity of gut microbiota and growth of recipient native slow growing egg-laying chicks. For this, a total of 150 (one-day-old) Jing Hong chicks were randomly assigned into two groups, each group consisted of 5 replicates (n = 15 bird/ replicate). The control group (CON) and FMT recipient birds (FMT) fed on basal diet, the FMT group received an oral daily dose of FMT prepared from Cobb-500 chickens. The FMT performed from the 1d to 28d of age, through the experimental period, feed intake and body weight were recorded weekly. At the end of a 28-day trial, carcass traits were assessed and cecal samples were collected for microbiome assessment via 16S rRNA-based metagenomic analysis to characterize the diversity and functions of microbial communities. The data were statistically analyzed using R software. Body weight and body weight gain increased, and FCR decreased (p = 0.01) in FMT group. The relative abundance of Firmicutes and the Firmicutes/Bacteroidetes (F/B) ratio were increased due to FMT administration (p = 0.01). A higher relative abundance of Lactobacillus, Lactococcus, and Bifidobacterium were presented in the FMT group. Meanwhile, Enterococcus, Helicobacter, and Bacteroides were more abundant in the CON group (p < 0.01). Kyoto encyclopedia of genes and genomes (KEGG) pathways for microbial functions regarding amino acid metabolism, secondary metabolites biosynthesis, carbohydrate metabolism, energy metabolism, and enzyme families, cofactors, and vitamins were significantly annotated in the FMT group. Overall, FMT administration from the donor of highly feed-efficient broilers improved weight gain by reshaping a distinct gut microbiome, which may be related to the metabolism and health in the recipients laying chicks, providing new insight on the application of the FMT technique for early life programming of laying chickens.

Characterization of allergic inflammation in chronic uterine cervicitis.

Female genital tract chronic inflammation is common in clinics; the pathogenesis is not fully understood yet. House dust mite (HDM) involves the pathogenesis of many chronic diseases in human. This study aims to identify HDM-specific allergic response in the cervix of patients with cervical inflammation. Patients (n = 80) with chronic cervicitis (CC) and non-CC control (NC) subjects (n = 80) were recruited into this study. Vaginal lavage fluids (VLF) were collected from CC patients and NC subjects. Cellular components and fluid part of VLF were separated by centrifugation, and analyzed by flow cytometry and enzyme-linked immunosorbent assay. We found that a portion (52 out of 80) of CC patients responded to HDM, manifesting positive skin prick test, and HDM-specific IgE and IgG was detected in the VLF (designated CCp patients). VLF of CCp patients showed a Th2-dominant profile. HDM-specific Th2 cells were detected in VLF in CCp patients. Exposure to HDM in the culture induced proinflammatory cytokine release from CCp VLF CD4+ T cells. Exposure to CCp VLF CD4+ T cell-conditioned medium induced de novo Th2 response. Direct exposure to HDM induced allergic response in the cervix of CCp patients. In summary, a portion of CC patients respond to HDM challenge in the cervix. Exposure to HDM induces an allergy-like response in the cervix of CCp patients.

Flagellin maintains eosinophils in the intestine.

Eosinophils (Eos) are the major effector cells in allergic response. The regulation of Eo is not fully understood yet. Flagellin (FGN) has immune regulatory functions. This study aims to elucidate the role of FGN in maintaining Eo at the static status in the intestinal tissues. A mouse food allergy (FA) model was developed. Eo mediator levels in the serum or culture supernatant or intestinal lavage fluids were assessed and used as an indicator of Eo activation. The results showed that less FGN amounts were detected in the FA mouse intestinal tissues, that were negatively correlated with the Eo activation. Mast cell-derived chymase bound FGN to induce FGN degradation. FGN formed complexes with FcγRI on Eos to prevent specific antigens from binding FcγRI, and thus, to prevent Eo activation. Administration of FGN efficiently alleviated experimental FA. In conclusion, FGN plays a critical role in maintaining Eos at static status in the intestine. Administration of FGN can alleviate experimental FA. FGN may be a novel drug candidate to be used in the treatment of Eo-related diseases.

Impact of Maternal Selenium Supplementation from Late Gestation and Lactation on Piglet Immune Function.

The present work aimed at assessing passive, innate, and acquired immunity in piglets from sows supplemented with either organic or inorganic selenium (Se). A total of 12 multiparous pregnant sows were randomly allocated to three groups: selenium-deficient, corn and soy-based diet base diet (BD), 0.3 mg Se/kg as hydroxy-selenomethionine (OH-SeMet), and 0.3 mg Se/kg as sodium selenite (SS). The feeding trial was carried out from gd 84 to weaning on postpartum day 21 (ppd 21). On gd 98 and 105, sows were vaccinated with hen egg white lysozyme (HEWL) to assess passive immunity. On ppd 23, weaned piglets were intramuscularly challenged with lipopolysaccharide (LPS) to trigger an acute-phase response. On ppd 14, 28, and 35, piglets were vaccinated with ovalbumin (OVA) to assess OVA-specific immunoglobulin G (IgG) and dermal hypersensitivity responses. Se levels in piglet plasma, muscle, and liver on ppd 21 were higher in OH-SeMet group. On ppd 2, piglet HEWL-specific IgG levels in OH-SeMet group were significantly increased. IL-10 and haptoglobin (HP) levels in OH-SeMet group were significantly increased 2 h and 48 h post-LPS simulation, respectively. The OVA-specific IgG levels in BD group were significantly higher than the other two groups, and the IL-4 concentration following whole blood ex vivo challenge with either OVA or mitogen was significantly increased in OH-SeMet group. OVA-specific skin swelling was lower in OH-SeMet and SS groups at 3 h and 6 h. This suggests that sow supplementation with OH-SeMet enhances mainly passive immunity through IgG maternal transfer and can influence piglet innate and acquired immunity.

The capability of L-carnitine-mediated antioxidant on cock during aging: evidence for the improved semen quality and enhanced testicular expressions of GnRH1, GnRHR, and melatonin receptors MT 1/2.

Precise natural anti-oxidative compounds have facilitated the research of infertile gametes and the development of novel bio-therapeutics, especially the molecules that are based on the reduction of oxidative stress, such as L-carnitine (LC). In addition to, the defect in the functioning of sperm mitochondrial and the decreasing seminal antioxidant ability due to aging, its essential role in permitting the mitochondrial import and oxidation of long chain fatty acids is worthy. Therefore, current study was designed to investigate the effects of dietary LC on semen quality, seminal antioxidant activity, and their implications for the fertility in aged cocks for 12 wk. Supplementation of the feed with two different doses of LC (50 and 150 mg/kg body weight/day) for 12 wk showed significantly increased in the reproductive activity of cock, in comparison to the control group. Seminal analysis showed that supplementation of LC significantly increased (P < 0.05) the sperm motility, concentration, livability, semen quality factor, seminal malondialdehyde concentration, catalase, and glutathione peroxidase activities. In addition, addition of LC significantly increased (P < 0.05) the plasma concentration of testosterone and prostaglandin E2 but posed no significant effect on the concentration of follicle-stimulating hormone. Furthermore, the findings of artificial insemination showed significant increased (P < 0.05) in the percentage of fertility in LC groups, while the percentage hatchability and mortality remained unchanged. Immunohistochemistry analysis revealed that LC significantly increased (P < 0.05) the testicular immunopositivity of MT1 and MT2. Moreover, the administration of LC to the aged cocks enhanced (P < 0.05) GnRH1 and GnRHR mRNA levels when compared with untreated cocks. The results of the present study suggest that LC treatment of aged cocks increases the seminal antioxidant enzymes and sexual hormones levels, which may improve the semen quality by increasing the expression of GnRH1 and melatonin receptors (MT1 and MT2) activities. Collectively, LC could be a suitable feed supplementation to increase reproductive activities through enhancing semen quality in aging cocks.

A Time-Series Analysis of Severe Burned Injury of Skin Gene Expression Profiles.

BACKGROUND/AIMS: Major burn injury is one of the main severe forms of wound which lead to a mass of clinical debilitation, this study was to identify core biomarkers for the recovery of severe burned injury. METHODS: Gene expression profiles (GSE19743) from the Gene Expression Omnibus (GEO) was downloaded, followed by background correction, normalization of raw microarray dataset and identification of differential expression genes (DEGs) . Soft clustering of DEGs was used for the screening of gene clusters that with sustained increasing (SIG) and decreasing expression (SDG) profiles along with the recovery process of burned injury. The significantly enriched Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways of SIGs and SDGs were obtained through the Database for Annotation, Visualization, and Integrated Discovery (DAVID), based on which the miRNA-gene regulation network for SIGs and SDGs were constructed from the miRWalk database. RESULTS: Ten clusters were obtained through soft clustering. The SIGs and SDGs were found to be closely associated with the biological processes of immune system. The miRNA-gene regulation network analysis suggested different roles between SIGs and SDGs in the recovery of severe burned injury. Furthermore, a bunch of important biomarkers were identified, which would be helpful in the treatment of burned patients. CONCLUSION: Our current findings suggest an interesting molecular link between transcriptional regulation potentially involved in immunosuppressive state after major burn injury, which warrants further exploration for their utilization in the treatment of major burn injury.

Salmonella infection may alter the expression of toll like receptor 4 and immune related cells in chicken bursa of Fabricius.

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.

Effects of Boron Supplementation on Expression of Hsp70 in the Spleen of African Ostrich.

Increased synthesis of heat shock protein 70 (Hsp70) occurs in prokaryotes and eukaryotes in response to physiological, environmental, and chemical exposures, thus allowing the cell survival from fatal conditions. Hsp70 cytoprotective properties may be clarified by its anti-apoptotic function. Boron has been reported to play an essential role in various organ developments and metabolisms. However, it is not known if boron is also able to modulate the Hsp70. In the present study, the actions of boron on ostrich spleen and expression level of Hsp70 were investigated. Thirty healthy ostrich chicks were randomly assigned to six groups: groups I, II, III, IV, V, and VI and fed the basal diet spiked with 0-, 40-, 80-, 160-, 320-, and 640-mg boric acid (BA)/L, respectively, in drinking water. The histomorphological examination in the spleen was done by hematoxylin and eosin (HE) staining. The expression level of Hsp70 was analyzed by immunohistochemistry (IHC) and western blotting, and mRNA expression of Hsp70 was investigated by quantitative real-time PCR (qPCR). In order to investigate apoptosis, TUNEL assay reaction in all treatment groups was analyzed. Our results showed that the histological structure of spleen up to 160 mg/L BA supplementation groups well developed. The Hsp70 expression level first induced at low-dose groups (up to group IV) and then inhibited dramatically in high-dose groups (V and VI) while comparing with the group I (0 mg BA). The TUNEL assay reaction revealed that the cell apoptosis amount was decreased in group IV, but in group V and especially in group VI, it was significantly increased (P < 0.01). Taken altogether, proper dietary boron treatment might stimulate ostrich chick spleen development by promoting the Hsp70 expression level and inhibiting apoptosis, while a high amount of boron supplementation would impair the ostrich spleen structure by inhibiting Hsp70 expression level and promoting cell apoptosis.

Lipopolysaccharide mediates immuno-pathological alterations in young chicken liver through TLR4 signaling.

BACKGROUND: Lipopolysaccharide (LPS) induces acute liver injury and the complex mechanisms include the activation of toll like receptor 4 (TLR4) signaling pathway in many species. However, immuno-pathological changes during TLR4 signaling under LPS stress in acute liver injury is poorly understood in avian species. The present investigation was therefore carried out to evaluate these alterations in TLR4 signaling pathway during acute liver injury in young chickens. RESULTS: After intraperitoneal injection of LPS or saline, liver samples were harvested at 0, 2, 6, 12, 24, 36, 72 and 120 h (n = 6 at each time point) and the microstructures were analyzed by hematoxylin and eosin (H&E) staining. Alanine aminotransferase (ALT) and caspase-3 enzyme activity was assessed by enzyme-linked immunosorbent assay (ELISA). Proliferative cell nuclear antigen (PCNA), single stranded DNA (ssDNA) and TLR4 protein expressions were determined by immunohistochemistry. Gene expressions of PCNA, caspase-3, caspase-8, TLR4 and its downstream molecules were analyzed by quantitative polymerase chain reaction (qPCR). LPS injection induced significantly higher ALT activity, severe fatty degeneration, necrotic symptoms, ballooning degeneration, congestion, enhanced inflammatory cell infiltration in liver sinusoids, decreased proliferation, increased apoptosis and significant up-regulation in TLR4 and its downstream molecules (MyD88, NF-κB, TNF-α, IL-1ß and TGF-ß) expression at different time points. CONCLUSIONS: This study indicated that TLR4 signaling and its downstream molecules along with certain cytokines play a key role in acute liver injury in young chickens. Hence, our findings provided novel information about the histopathological, proliferative and apoptotic alterations along with changes in ALT and caspase-3 activities associated with acute liver injury induced by Salmonella LPS in avian species.

Effect of Dendrobium officinale on D-galactose-induced aging mice.

OBJECTIVE: To examine the effect of Dendrobium officinale (DO) on D-galactose-induced aging mice. METHODS: Aging mice was induced by D-galactose at 0.125 g/kg for 10 weeks through subcutaneous injection except for the negative control group. After 10 days, according to complete random design, the aging modeling mice were randomized into 4 groups: aging control group (10 ML·kg-1·d-1) of distilled water), positive control group (vitamin B6 and ganodema lucidum tablets with a dose of 1 tablet/kg), DO-1 treatment group (DO juice with a dose of 1 g/kg), DO-2 treatment group (DO Polysaccharide with a dose of 0.32 g/kg), 14 mice in each group. All the animals were orally medicated daily for 9 weeks. Cognitive function assessment was performed using the maze test and step-down test. At the end of experiment, the superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and total antioxidant capacity (T-AOC) levels in the serum, the SOD, GSH-Px and nitric oxide (NO) levels in the cerebrum, the SOD and catalase (CAT) levels in the liver, the SOD and NO levels in the heart, and the SOD level in the kidney, were determined using commercial kits. The spleen, liver, heart, cerebrum and kidney were excised for histological study. RESULTS: Compared to aging control group, DO shortened the time of passing through the maze and prolong the step-down latency of aging mice (P <0.05 or P<0.01). DO markedly up-regulated serum levels of SOD, GSH-Px and T-AOC, and restored SOD levels in the heart, liver, kidney and cerebrum to normal status (P<0.05 or P<0.01). DO at the dose of 1 g/kg also signififi cantly improved the degree of spleen lesions (P<0.01). CONCLUSIONS: DO had marked anti-aging effect on D-galactose-induced model of aging. The underlying mechanism could be related to modulation on antioxidation system and immune system. The results indicated that DO could potentially be used as natural drugs or functional foods for preventing aging.

Lipopolysaccharide induces acute bursal atrophy in broiler chicks by activating TLR4-MAPK-NF-κB/AP-1 signaling.

We investigated the mechanisms that induce atrophy of the chicken bursa of Fabricius (BF) upon lipopolysaccharide (LPS) treatment in young chicks. LPS treatment resulted in ∼36% decrease in bursal weight within 36 h (P < 0.01). Histological analysis showed infiltration of eosinophilic heterophils and nucleated oval shaped RBCs in or near blood vessels of the BF from LPS-treated chicks. Scanning electron micrographs showed severe erosion and breaks in the mucosal membrane at 12 h and complete exuviation of bursal mucosal epithelial cells at 36 h. We observed decreased cell proliferation (low PCNA positivity) and increased apoptosis (high TUNEL and ssDNA positivity) in the BF 12-72 h after LPS treatment. RNA-seq analysis of the BF transcriptome showed 736 differentially expressed genes with most expression changes (637/736) 12 h after LPS treatment. KEGG pathway analysis identified TLR4-MAPK-NF-κB/AP-1 as the key signaling pathway affected in response to LPS stimulation. These findings indicate LPS activates the TLR4-MAPK-NF-κB/AP-1 signaling pathway that mediates acute atrophy of the chicken bursa of Fabricius by inducing inflammation and apoptosis.

Dendrobium officinale Prevents Early Complications in Streptozotocin-Induced Diabetic Rats.

Background. Dendrobium officinale (DO) Kimura et Migo is a precious Chinese herb that is considered beneficial for health due to its antioxidant and antidiabetes properties, and so on. In this research, we try to determine the preventive effect of DO on the early complications of STZ-induced diabetic rats. Methods. Type 1 diabetic rats were produced with a single intraperitoneal injection of STZ (50 mg/kg). DO (1 g/kg/day) was then orally administered for 5 weeks. Blood glucose, TC, TG, BUN, CREA, and GSH-PX levels were determined, and electroretinographic activity and hypoalgesia were investigated. Pathological sections of the eyes, hearts, aortas, kidneys, and livers were analyzed. Results. Treatment with DO significantly attenuated the serum levels of TC, TG, BUN, and CREA, markedly increased the amplitudes of ERG a- and b-waves and Ops, and reduced the hypoalgesia and histopathological changes of vital organs induced by hyperglycemia. The protective effect of DO in diabetic rats may be associated with its antioxidant activity, as evidenced by the marked increase in the serum level of glutathione peroxidase. However, DO had no significant effect on blood glucose levels and bodyweight of diabetic rats. Conclusions. DO supplementation is an effective treatment to prevent STZ-induced diabetic complications.

Effects of lipopolysaccharide on the histomorphology and expression of toll-like receptor 4 in the chicken trachea and lung.

Endotoxin or lipopolysaccharide (LPS) exposure can cause injury to the respiratory airways and in response, the respiratory epithelia express toll-like receptors (TLRs) in many species. However, its role in the innate immunity in the avian respiratory system is poorly understood. The aim of the present study was to evaluate the effects of LPS on the chicken trachea and lung. After intraperitoneal LPS or saline injection, the trachea and lungs were harvested at 0, 12, 36 and 72 h (n = 6 at each time point) and histopathologically analysed using haematoxylin and eosin and periodic acid-Schiff staining, while TLR4 expression was determined by immunohistochemistry and secretory Immunoglobulin A (SIgA) levels by enzyme-linked immunosorbent assay. After LPS stimulation, we observed a remarkable decrease in the number of goblet cells along with obvious disruption and desquamation of the ciliated epithelium in the trachea, blurring of the boundary between pulmonary lobules, narrowed or indistinguishable lumen of the pulmonary atria and leukostasis in the lungs. Following LPS stimulation, TLR4 protein expression was up-regulated in both the trachea and the lungs and was found on the ciliated columnar cells as well as in the submucosa of the trachea, and in the lungs on parenchymal and immune cells. However, SIgA levels were only up-regulated in the trachea at 12 h following LPS stimulation. Hence, this report provides novel information about the effects of LPS on the microstructure of the lower respiratory tract and it is concluded that its intra-peritoneal administration leads to TLR4-mediated destruction of the tracheal epithelium and pulmonary inflammation along with increased SIgA expression in the tracheal mucosa.

Increased Thymic Cell Turnover under Boron Stress May Bypass TLR3/4 Pathway in African Ostrich.

Previous studies revealed that thymus is a targeted immune organ in malnutrition, and high-boron stress is harmful for immune organs. African ostrich is the living fossil of ancient birds and the food animals in modern life. There is no report about the effect of boron intake on thymus of ostrich. The purpose of present study was to evaluate the effect of excessive boron stress on ostrich thymus and the potential role of TLR3/4 signals in this process. Histological analysis demonstrated that long-term boron stress (640 mg/L for 90 days) did not disrupt ostrich thymic structure during postnatal development. However, the numbers of apoptotic cells showed an increased tendency, and the expression of autophagy and proliferation markers increased significantly in ostrich thymus after boron treatment. Next, we examined the expression of TLR3 and TLR4 with their downstream molecular in thymus under boron stress. Since ostrich genome was not available when we started the research, we first cloned ostrich TLR3 TLR4 cDNA from thymus. Ostrich TLR4 was close to white-throated Tinamou. Whole avian TLR4 codons were under purify selection during evolution, whereas 80 codons were under positive selection. TLR3 and TLR4 were expressed in ostrich thymus and bursa of fabricius as was revealed by quantitative real-time PCR (qRT-PCR). TLR4 expression increased with age but significantly decreased after boron treatment, whereas TLR3 expression showed the similar tendency. Their downstream molecular factors (IRF1, JNK, ERK, p38, IL-6 and IFN) did not change significantly in thymus, except that p100 was significantly increased under boron stress when analyzed by qRT-PCR or western blot. Taken together, these results suggest that ostrich thymus developed resistance against long-term excessive boron stress, possibly by accelerating intrathymic cell death and proliferation, which may bypass the TLR3/4 pathway. In addition, attenuated TLRs activity may explain the reduced inflammatory response to pathogens under boron stress.

Lipopolysaccharide stimulation upregulated Toll-like receptor 4 expression in chicken cerebellum.

Toll-like receptors (TLRs) play crucial roles in innate and adaptive immune responses to invading pathogens. TLR4 is responsible for the recognition of bacterial lipopolysaccharide (LPS) in different parts of central nervous system of many vertebrates. To better understand the functions of TLR4 in cerebellum of chicken, present study was designed to identify the cell types that express TLR4 during postnatal stages as well as the changes in its expression in response to LPS challenge. For this purpose, cerebella were collected from chicken aged 1, 14 and 40 days (n=7 in each group) to analyze TLR4 distribution pattern. The cerebella from 14 chickens injected with LPS or sterilizing saline were also collected at Day 14 (n=7 in each group) to investigate changes in TLR4 expression. This expression was analyzed by immunohistochemistry using an anti-TLR4 antibody. TLR4 was constitutively expressed in the Purkinje cell layer, pia mater, neurons in medulla and blood vessels in the cerebellum and LPS stimulation significantly up-regulated TLR4 expression on Day 14 in the chicken cerebellum. This study provides evidence that neurons in chicken cerebellum can express TLR4 in vivo and suggests that these neurons may play an important role in initiating a defense reaction via activation of TLR4.

TLR4 is constitutively expressed in chick thymic epithelial cells.

Toll-like receptor 4 (TLR4) has been suggested to play a regulatory role in immune cell development; however, studies regarding the role of TLR4 in the development of the chick thymus are scarce. In this study, we investigated the distribution and expression pattern of TLR4 in normal chick thymi at different stages of development, in order to better understand the role of TLR4 in chick thymus development. We studied the thymi from 15 chicks, collected at days 7, 21 and 35 of age. The relative change in TLR4 mRNA expression in the chick thymus at different ages was determined by quantitative real-time PCR, and changes in protein expression were analyzed by immunohistochemistry and Western blotting. Furthermore, the distribution of TLR4 in the chick thymus was analyzed by immunohistochemistry, and compared with the distribution of TLR4 expression in juvenile female pigs (gilts). Our results indicated that TLR4 was constitutively expressed in the chick thymus. TLR4 was primarily expressed in the thymic cortico-medullary junction and the medulla, particularly in the epithelial cells of Hassall's corpuscles. The mRNA and protein expression level of TLR4 increased in the thymus with increasing age (p<0.05). Taken together, these results indicate that TLR4 is constitutively expressed by epithelial cells in the chick thymus, suggesting it may participate in thymic development by inducing factors affecting its development.

Distribution patterns of stromal eosinophil cells in chick thymus during postnatal development.

Eosinophils are a type of thymic stromal cell that are present in the thymus of both humans and mice. They participate in regulating T-cell development under non-pathological conditions. However, studies are scarce regarding the role of eosinophils in the development of the thymus in chickens. Therefore, this study investigated the distribution of eosinophils in normal chicken thymi at different stages of development. Seven thymi were obtained from chickens at days 1, 21 and 35 of development. The distribution of eosinophils in the thymi was analyzed by histological and immunohistochemical techniques using Lendrum's chromotrope 2R method and an antibody against eosinophilic cationic protein (ECP), respectively. Eosinophils were constitutively located in the chick thymus. They were mainly distributed in the thymic corticomedullary junction and medulla, especially around vessels and Hassall's corpuscles, and only a few were in the trabeculae among thymic lobules and around vessels. There were none in the cortex. The number of thymic eosinophils decreased with increasing age (P<0.01). These results indicated that eosinophils comprise a type of thymic stromal cells in the chick, which may regulate thymic development, especially during the early stages of development.

Distribution and morphology of argyrophilic cells in the digestive tract of the African ostrich.

We used light microscopy to elucidate the morphological features of argyrophilic cells in the digestive tract of the African ostrich (Struthio camelus). The results indicated that argyrophilic cells were found to be distributed among the epithelial cells of the mucosa or glands throughout the digestive tract, except for the esophagus; two types of argyrophilic cells were found; i.e., closed-type cells and cells with triangular or elongated shapes and with their apical cytoplasmic process in contact with the lumen (open-type cells); the greatest number of argyrophilic cells was found in the proventriculus, and the argyrophilic cell density gradually decreased from the proventriculus to the rectum; Furthermore, the number of argyrophilic cells in the duodenum and ileum was higher than that in the jejunum. This text still combined the characteristics that the argyrophilic cells in digestive tract of ostrich maybe related to different digestive function of different region and the basis of their morphology to carry on a discussion. It was speculated that argyrophilic cells in the digestive tract may have both endocrine and exocrine functions.