Identification of the Weevil immune genes and their expression in the bacteriome tissue

Background  

Persistent infections with mutualistic intracellular bacteria (endosymbionts) are well represented in insects and are considered to be a driving force in evolution. However, while pathogenic relationships have been well studied over the last decades very little is known about the recognition of the endosymbionts by the host immune system and the mechanism that limits their infection to the bacteria-bearing host tissue (the bacteriome).     

Short communication: Manipulation of neonatal leptin profile via exogenous glucocorticoids in beef calves

The link between circulating glucocorticoids and leptin in beef calves has not been explored but has been noted in several studies. The aim of this study is to determine the effects of exogenous glucocorticoids given at birth and 1 day of age on serum leptin concentrations in beef calves. Ruminant animals secrete leptin, which is thought to be important for the programming of the hypothalamic appetite centers. Angus crossbred cows (n = 31) bred via natural service were utilized for this experiment. At parturition (day 0), calf BW was recorded and each calf was infused intravenously with either a hydrocortisol sodium succinate solution (HC, 8 males and 8 females) at a dosage of 3.5 μg/kg of BW or a similar volume of saline solution (CONT, 7 males and 8 females). Each calf was given a second infusion of its respective treatment 24 h postpartum at 1.5 μg/kg of BW for HC treatment. Calf treatment was blocked by sex, dam body condition score (BCS), and dam age. Blood samples were taken via jugular venipuncture before infusion, daily from days 0 to 5, then every other day up to day 17. Serum leptin and cortisol concentrations were analyzed via radioimmunoassay. Dam age, dam BCS, calf BW, and serum leptin and cortisol concentrations were analyzed using MIXED procedure of SAS. Dam age was not different (P = 0.81) among HC and CONT calves (4.9±0.5 and 4.7±0.5, respectively). Dam BCS was not different between treatments (5.7±0.2 and 5.6±0.2 HC and CONT, respectively; P = 0.66). There was no difference in calf birth BW between treatments (P = 0.87) and averaged 38.3±1.4 kg. Cortisol concentrations were not different between both treatments (P = 0.23) from birth to day 4 of age. Calves that received the HC treatment showed significantly reduced (P = 0.03) leptin concentrations on days 1 to 13. Calf BW from 60 to 150 days of age was not different between CONT and HC treated calves (P = 0.65). These data indicate that exogenous glucocorticoids can be used to suppress neonatal leptin levels in calves. This could lead to changes in voluntary feed intake of treated calves.     

Brown adipose tissue in obesity: Fractalkine-receptor dependent immune cell recruitment affects metabolic-related gene expression

Brown adipose tissue (BAT) plays essential role in metabolic- and thermoregulation and displays morphological and functional plasticity in response to environmental and metabolic challenges. BAT is a heterogeneous tissue containing adipocytes and various immune-related cells, however, their interaction in regulation of BAT function is not fully elucidated. Fractalkine is a chemokine synthesized by adipocytes, which recruits fractalkine receptor (CX3CR1)-expressing leukocytes into the adipose tissue. Using transgenic mice, in which the fractalkine receptor, Cx3cr1 gene was replaced by Gfp, we evaluated whether deficiency in fractalkine signaling affects BAT remodeling and function in high-fat-diet - induced obesity. Homo- and heterozygote male CX3CR1-GFP mice were fed with normal or fat enriched (FatED) diet for 10 weeks. Interscapular BAT was collected for molecular biological analysis. Heterozygous animals in which fractalkine signaling remains intact, gain more weight during FatED than CX3CR1 deficient gfp/gfp homozygotes. FatED in controls resulted in macrophage recruitment to the BAT with increased expression of proinflammatory mediators (Il1a, b, Tnfa and Ccl2). Local BAT inflammation was accompanied by increased expression of lipogenic enzymes and resulted in BAT “whitening”. By contrast, fractalkine receptor deficiency prevented accumulation of tissue macrophages, selectively attenuated the expression of Tnfa, Il1a and Ccl2, increased BAT expression of lipolytic enzymes (Atgl, Hsl and Mgtl) and upregulated genes involved thermo-metabolism (Ucp1, Pparg Pgc1a) in response to FatED. These results highlight the importance of fractalkine-CX3CR1 interaction in recruitment of macrophages into the BAT of obese mice which might contribute to local tissue inflammation, adipose tissue remodeling and regulation of metabolic-related genes.     

Behaviour of free-ranging beef cows and calves

The aim of this project was to describe the behaviour of free-ranging cows and calves after birth and during growth to the age of 6 months. Ten bull and 10 heifer calves were followed from birth until first suckling. Calves were observed to record their position in the field once a day until 10 days of age. Focal observations of 5 bull and 5 heifer calves were made from 27 to 167 days of age.

Of the cows studied, 2 separated completely from the herd at calving. The calving sites were randomly distributed in the area available. After birth all cows licked their calves. The amount of licking between 0 and 30 min was significantly greater than that between 30 and 60 min after birth. The duration of the first suckling was significantly longer for heifer calves than for bull calves. Eleven of 17 calves changed area during the first day after birth. The duration of cows licking calves did not change significantly from 27 to 167 days of age, and was not correlated to duration of licking immediately after birth. Suckling frequency per hour, suckling time per hour and duration of each suckling did not change significantly from 27 to 167 days of age. Bull calves from 27 to 167 days of age had a significantly higher frequency than heifer calves of sniffings towards adult cows other than the mother and a significantly higher frequency of mountings of adult cows. Cows and calves spent more time together when the calf was a female than when it was a male, and more time when the weaning weight was low than when it was high.     

Effects of severity of dystocia on cold tolerance and serum concentrations of glucose and cortisol in neonatal beef calves

Effects of dystocia on rectal temperature and serum cortisol and glucose concentrations, were studied in neonatal calves exposed to 0 degree C. Primiparous dams were observed continuously during parturition and if Stage II (labor) was not completed within 2 h after appearance of the allantochorion, delivery was completed with obstetrical assistance. Parturitions were scored (CDS) for difficulty and obstetric assistance required: CDS 1, no assistance (n = 8); CDS 2, minor manual assistance (n = 7); CDS 3, use of a mechanical calf puller (n = 5); CDS 4, cesarean section (n = 6). A blood sample, rectal temperature, and body weight were obtained within 30 min after birth. Calves were then fed 38 degrees C pooled colostrum, muzzled to prevent suckling, and placed back with their dam in a heated (22 degrees C) barn. At 4 h of age an indwelling jugular catheter was inserted. At 5 h of age calves were placed in a 0 degree C room for 140 min and blood samples and rectal temperatures were obtained every 10 or 20 min. A shivering score (1 = no shivering; 2 = moderate shivering; 3 = intense shivering) was assigned at each sampling time. Rectal temperatures were higher (P < 0.01) in CDS 1, 2 and 4 calves (39.0, 39.3, and 39.0 +/- .02 degrees C, respectively) than in calves with CDS 3 (38.3 +/- 0.02 degrees C) and were affected by duration of cold exposure (time; P < 0.01). Shivering was not affected by CDS but was affected by time (P < 0.01). Glucose concentrations were higher (P < 0.01) in CDS 3 calves (110.1 +/- 1.6 mg/dL) than in CDS 1, 2, or 4 calves (77.2, 86.4, and 89.0 +/- 1.3 mg/dL, respectively) and changed over time (P < 0.01). Cortisol concentrations were higher in CDS 1 calves (80.0 +/- 1.7 ng/mL) than in CDS 2, 3 or 4 calves (62.7, 58.2, and 57.7 +/- 2.0 ng/mL, respectively) and were affected by time (P < 0.01). We conclude that severe dystocia (CDS 3) resulted in lower calf rectal temperature, reduced serum cortisol, and increased serum glucose which could affect the ability of the calf to withstand cold stress. Minor dystocia did not cause and timely cesarean delivery prevented, the physiological aberrations encountered in severe dystocia.     

Impact of volume,immunoglobulin G concentration,and feeding method of colostrum product on neonatal nursing behavior and transfer of passive immunity in beef calves

One-third of beef calves fail to achieve adequate transfer of passive immunity (TPI) through timely ingestion of colostrum, which substantially increases their risk of preweaning morbidity and mortality. Two randomized clinical trials were designed to assess the impact of volume, immunoglobulin G (IgG) concentration, and feeding method of colostrum product on neonatal nursing behavior and TPI. In Trial 1, 47 calves were randomly assigned to receive one of three colostrum interventions by oro-esophageal tube feeder (OET): 1 L with 100 g/L IgG, 1.4 L with 70 g/L IgG, or 2 L with 100 g/L IgG. In Trial 2, 29 calves were randomly assigned to be fed 1 L of colostrum product with 100 g/L IgG by either nipple bottle (NB) or OET. Colostrum intervention (i.e. feeding of colostrum product) occurred within 60 minutes of birth. Cow-calf pairs were monitored by video surveillance in individual stalls for 24 h. Dam colostrum was collected at 10 minutes and calf serum was collected at 24–36 h after birth to assess IgG concentration. Differences among colostrum intervention groups on latency to stand and nurse were analyzed using Kaplan-Meier survival curves and Cox proportional hazard models. The impact of colostrum intervention group on TPI was assessed using multivariable linear regression modeling. In Trial 1, calves fed 1.4 L with 70 g/L IgG by OET nursed from their dams statistically significantly earlier compared to calves fed 1 L with 100 g/L IgG (P = 0.003) and calves fed 2 L with 100 g/L IgG (P = 0.008). Six of the 15 calves in the NB group in Trial 2 refused to consume part of the colostrum feeding offered by bottle and required follow-up tube feeding of the remaining volume. These calves were analyzed as a separate group (NB + OET). Calves fed 1 L by NB stood and nursed statistically significantly earlier than calves fed by OET (P = 0.005) or a combination of NB + OET (P = 0.003). Calf serum IgG concentrations were not statistically significantly different among colostrum intervention groups (P > 0.1). Overall, the colostrum interventions assessed in this study led to only one calf with failed TPI. While statistically significant differences in serum IgG concentrations were not detected in this study, subsequent nursing behavior did vary and was improved by feeding a moderate volume (1.4 L with 70 g/L IgG) of colostrum when using an OET, and by using the NB when feeding a smaller volume (1 L with 100 g/L IgG).     

Cardiotocography in cows: A method for monitoring calves during delivery

Fetal ECG-electrodes and an intrauterine catheter were inserted into 15 Holstein-Friesian cows during their first stage of labor to make a cardiotocogram. Simultaneously, fetal heart rate and intrauterine pressure were recorded until completion of fetal expulsion. Immediatly post partum the viability of the calf was assessed by clinical evaluation and measurements of blood pH, base excess (BE) and pCO(2). Fetal heart rate patterns and their changes were evaluated according to standards used in human medicine. Basal fetal heart rate (90 to 120) in 10 calves gradually increased towards the end of parturition, with a marked loss of variability. Decelerations, coinciding with periods of increased intrauterine pressure, occurred in all cows. When decelerations occurred beyond the end of a contraction the calf was born in a poor condition. Accelerations were only recorded in two cows. Many of the fetal heart rate changes observed were similar to those which in human cardiotocography are considered to be signs of fetal distress. Further investigation is needed to establish the predictive value of fetal heart rate patterns in cows, which would be a welcome addition to improved fetal diagnostics during parturition.     

In vivo blockade of gamma interferon affects the influenza virus-induced humoral and the local cellular immune response in lung tissue.

Influenza virus infection induces the local production of gamma interferon (IFN-gamma) by T cells and non-T cells in the respiratory tract. To elucidate the possible functions of this cytokine, the humoral and local cellular immune responses to influenza virus were studied in BALB/c mice with or without in vivo neutralization of IFN-gamma by using monoclonal antibodies. Neutralization of IFN-gamma led to a significant reduction in virus-specific titers of immunoglobulins G2a and G3 in serum but had little effect on other isotypes. Studies on cells isolated from the lung parenchyma itself revealed that at the height of the immune response the ability of these cells to produce cytokines after antigen or T-cell receptor/CD3 stimulation was not affected. Ex vivo cytolytic activity by lung parenchyma cells, which is induced by infection with this virus in normal mice, was also found to be undisturbed by this treatment, even though anti-IFN-gamma antibody activity was recovered from lung lavage samples and sera at all days studied. Surprisingly, in vivo neutralization of IFN-gamma led to a significant reduction in the magnitude of the cellular infiltrate in the lung tissue which followed infection, suggesting an involvement of IFN-gamma in the mechanisms that regulate increased leucocyte traffic in the inflamed lung parenchyma. This conclusion was supported by findings of differences between mock-treated and anti-IFN-gamma-treated mice in the number of CD8+ lung T cells expressing CD49d (alpha4-integrin) and CD62L at various times after influenza virus infection. This study therefore demonstrates that IFN-gamma affects the local cellular response in the respiratory tract as well as the systemic humoral response to influenza virus infection.     

Age-dependent lipid peroxidation in neonatal rat lung tissue.

A unique, age-specific pulmonary lipid peroxidation has been found to occur after incubation of neonatal rat lung homogenates in the absence of any added factors. As measured by the formation of malondialdehyde, lipid peroxidation was not detectable in rat lung homogenates prepared from animals immediately after birth but appeared by the second day and reached a maximum at 5 days of age. The effect gradually disappeared by 20 to 21 days after birth. The addition of NADPH did not enhance lipid peroxidation in the sensitive age group nor did it initiate lipid peroxidation when added to lung homogenates from either 1-day-old or adult rats. The activities and concentrations of various endogenous antioxidants were measured in neonatal lung tissue. When measured in lung tissue obtained from rats during the sensitive age period, no concomitant deficiencies of glutathione peroxidase, glutathione reductase, glucose 6-phosphate dehydrogenase, reduced glutathione, or a-tocopherol were observed. With the exception of α-tocopherol, none of these factors inhibited malondialdehyde formation when added to homogenized lung tissue prepared from 5-day-old rats. α-Tocopherol did inhibit malondialdehyde formation in 5-day-old rat lung homogenates but at a concentration much greater than the endogenous concentration found in adult rat lungs. The 21-day neonatal age period during which malondialdehyde is produced following incubation of lung tissue is similar to the 3-week period immediately after birth reported to be the time of maximum proliferation of rat lung fibroblasts, type 1 pneumocytes and type II pneumocytes.     

comE基因缺陷影响肺炎链球菌体内诱导基因的表达

【目的】筛选受comE调控的肺炎链球菌(Streptococcus pneumoniae,S.pn)体内诱导基因。【方法】通过插入失活构建基因comE缺陷的S.pn菌株,与野生菌株分别腹腔注射BALB/c小鼠,经过体内诱导后取小鼠血,分离细菌提取RNA,用RT-PCR法检测13个体内诱导基因mRNA水平差异。【结果】将RT-PCR结果通过Quantity-one灰度分析,进行配对t检验,显示8个体内诱导基因在缺陷菌株和野生菌株中mRNA表达水平具有统计学差异(P0.05),其中spd-0300、spd-0414、spd-0622、spd-1663、spd-1719、spd-0235、spd-0873受转化上调,spd-1672受转化下调。【结论】筛选出受转化调控的体内诱导基因spd-0300、spd-0414、spd-0622、spd-1663、spd-1719、spd-0235、spd-0873、spd-1672,它们可能参与生长调节、温度感应、糖脂代谢等环节,表明细菌转化可通过调节某些体内诱导基因的表达来增强细菌的毒力。     

Influence of formula versus sow milk feeding on trace element status and expression of zinc-related genes in the jejunum,liver and pancreas of neonatal piglets

Increasing litter sizes in modern swine production have raised an urgent need for artificial rearing strategies and formula feeding. The current experiment was conducted to study the influence of formula trace element concentration according to recommendations for weaned piglets on the mRNA concentration of zinc (Zn)-related genes in the jejunum, liver and pancreas of neonatal piglets. Eight artificially reared piglets were fed a cow-milk-based formula (Group FO) containing 100 mg Zn/kg dry matter. Eight of their sow-reared littermates (Group SM) were used as control. After 14 d, all 16 piglets were killed and the jejunum, liver and pancreas were evaluated for Zn, copper, manganese (Mn) and iron (Fe) concentration and mRNA concentration of metal and Zn-specific transporters, metallothioneins (MT) and interleukin 6 (IL-6). In Group FO the Zn concentration in liver tissue was increased (p < 0.05). Furthermore, Fe and Mn concentrations in liver and jejunal tissue were higher (p < 0.05) in Group FO, whereas neither Zn transporters nor MT in jejunal and pancreatic tissue showed differences between both groups. In the liver of Group FO, MT mRNA concentration was higher (p < 0.05), whereas Zn transporter protein 1 and divalent metal-ion transporter 1 (DMT1) mRNA concentration was lower (p < 0.05). Besides Zn-induced expression of transporters and MT, the significantly increased IL-6 expression in Group FO suggests the involvement of cytokine-mediated Mn and Fe sequestration in the liver and jejunum. The results revealed that dietary trace element concentration used in the study likely exceeded the requirements of neonatal pigs as reflected by homeostatic counter-regulation in different organs.     

Mouse genotype affects inducible expression of cytokine genes.

The levels of circulating IFN in mice infected with Newcastle disease virus (NDV) are regulated by the If-1 locus. In this study we show that in NDV-infected C57BL/6 mice, which carry the If-1h allele and produce high levels of IFN, high levels of both IFN-alpha and -beta mRNA can be detected in the spleen. In contrast, only very low levels of IFN mRNA could be detected in spleens of infected BALB/c mice containing the If-1l allele and producing low levels of IFN or in B6.C-H28c mice that are congenic for the If-1l allele. The relative levels of all individual IFN-alpha 1, alpha 4, and alpha 6 mRNA in spleens of infected BALB/c were lower than in spleens of infected C57BL/6 mice, indicating that the If-1 locus affects the expression of all IFN-alpha subtypes and is not associated with the deletion or inactivation of a specific IFN gene. The relative levels of IFN regulatory factor-1 mRNA in infected mice carrying the If-1l and If-1h loci were comparable, suggesting that the If-1 regulation is not associated with the altered expression of the IFN regulatory factor-1 gene. Quantitative difference in the expression of IFN-alpha and -beta genes was also observed in in vitro-infected peritoneal macrophages isolated from either C57BL/6 or BALB/c mice. A surprise finding was that the If-1 locus also affected the NDV-induced expression of two other cytokine genes, TNF-alpha and IL-6. Priming of the macrophage cultures with murine IFN enhanced the expression of all cytokine genes, and the relative levels of IFN, TNF-alpha, and IL-6 mRNA induced by NDV in macrophages derived from C57BL/6 and BALB/c mice were comparable. We propose that the If-1 locus affects the early stages of a signal transduction pathway which are common to the virus-mediated induction of IFN, TNF-alpha, and IL-6 genes.     

Effects of hydrolyzed yeast supplementation in calf starter on immune responses to vaccine challenge in neonatal calves

The effects of hydrolyzed yeast supplementation on growth performance, health and immune-physiological parameters in neonatal calves challenged with vaccine were investigated. Twelve Holstein calves were started in the experiment at 2 ± 1 days of age and were studied for 35 days. Calves were randomly assigned to each of two dietary treatments, a control (CON) and hydrolyzed yeast (HY) group. The calves in the HY group received control calf starter supplemented with 0.2% HY. All calves were given calf starter ad libitum for 5 weeks starting in week 1. Calves were also given whole milk according to a step-down milking protocol. In order to induce immune responses, all calves were challenged with Hog cholera and Erysipelothrix insidiossa live vaccines by intramuscular injection at 3 weeks of age. Growth performance and feed intake were not affected by dietary treatment throughout the experimental period, except that the HY group had significantly higher (P < 0.05) milk intake than did the CON group at 3 weeks of age. Calves in the HY group showed significantly better (P < 0.05) fecal and health scores at 3 weeks compared to those in the control group. After vaccine challenge, neutropenia, lymphophilia and thrombocytopenia were observed in the CON group, but calves in the HY group did not show significant changes of leukocytes. The average concentration of serum haptoglobin in the HY group was significantly higher (P < 0.05) at 1 and 3 days post-vaccine challenge (DPVC) than that of CON group. Feeding HY supplemented calf starter resulted in a higher (P < 0.05) relative amount of bacterial and viral - specific IgA than in the CON group at 5 DPVC. Although the percentage of CD4+ T cells was significantly (P < 0.05) higher in the HY group than in the CON group at -2 DPVC, significant differences between groups after vaccine challenge was not observed during the experimental period. These results suggest that 0.2% HY supplementation in calf starter can improve the health status and immune-related serum protein production and affect blood cell composition in neonatal calves after vaccine challenge.     

The iscS gene deficiency affects the expression of pyrimidine metabolism genes

Inactivation of iscS encoding cysteine desulfurase results in a slow growth phenotype associated with the deficiency of iron-sulfur clusters, thiamine, NAD, and tRNA thionucleosides in Escherichia coli. However, the other roles of iscSin vivo are unknown. By using differential screening strategies, we identified 2 pyrimidine salvage enzymes, namely, uridine phosphorylase and cytidine deaminase, which were down-regulated in the iscS mutant. Both enzymes are positively regulated by the cAMP receptor protein (CRP). We also identified a novel protein complex, namely, YeiT-YeiA, whose expression level was decreased in the iscS mutant. The recombinant YeiT-YeiA complex exhibited NADH-dependent dihydropyrimidine dehydrogenase activity, indicating its role in pyrimidine metabolism. The presence of a CRP-binding consensus sequence on the 5′-upstream of the yeiT-YeiA gene suggests its regulation by CRP. These results provide a clue to the possible role of iscS in pyrimidine metabolism by gene regulation.