Developing ovine mammary terminal duct lobular units have a dynamic mucosal and stromal immune microenvironment.

The human breast and ovine mammary gland undergo striking levels of postnatal development, leading to formation of terminal duct lobular units (TDLUs). Here we interrogate aspects of sheep TDLU growth as a model of breast development and to increase understanding of ovine mammogenesis. The distributions of epithelial nuclear Ki67 positivity differ significantly between younger and older lambs. Ki67 expression is polarised to the leading edge of the developing TDLUs. Intraepithelial ductal macrophages exhibit periodicity and considerably increased density in lambs approaching puberty. Stromal macrophages are more abundant centrally than peripherally. Intraepithelial T lymphocytes are more numerous in older lambs. Stromal hotspots of Ki67 expression colocalize with immune cell aggregates that exhibit distinct organisation consistent with tertiary lymphoid structures. The lamb mammary gland thus exhibits a dynamic mucosal and stromal immune microenvironment and constitutes a valuable model system that provides new insights into postnatal breast development.

Genes involved in immune, gene translation and chromatin organization pathways associated with Mycoplasma ovipneumoniae presence in nasal secretions of domestic sheep.

Mycoplasma ovipneumoniae contributes to polymicrobial pneumonia in domestic sheep. Elucidation of host genetic influences of M. ovipneumoniae nasal detection has the potential to reduce the incidence of polymicrobial pneumonia in sheep through implementation of selective breeding strategies. Nasal mucosal secretions were collected from 647 sheep from a large US sheep flock. Ewes of three breeds (Polypay n = 222, Rambouillet n = 321, and Suffolk n = 104) ranging in age from one to seven years, were sampled at three different times in the production cycle (February, April, and September/October) over four years (2015 to 2018). The presence and DNA copy number of M. ovipneumoniae was determined using a newly developed species-specific qPCR. Breed (P<0.001), age (P<0.024), sampling time (P<0.001), and year (P<0.001) of collection affected log10 transformed M. ovipneumoniae DNA copy number, where Rambouillet had the lowest (P<0.0001) compared with both Polypay and Suffolk demonstrating a possible genetic component to detection. Samples from yearlings, April, and 2018 had the highest (P<0.046) detected DNA copy number mean. Sheep genomic DNA was genotyped with the Illumina OvineHD BeadChip. Principal component analysis identified most of the variation in the dataset was associated with breed. Therefore, genome wide association analysis was conducted with a mixed model (EMMAX), with principal components 1 to 6 as fixed and a kinship matrix as random effects. Genome-wide significant (P<9x10-8) SNPs were identified on chromosomes 6 and 7 in the all-breed analysis. Individual breed analysis had genome-wide significant (P<9x10-8) SNPs on chromosomes 3, 4, 7, 9, 10, 15, 17, and 22. Annotated genes near these SNPs are part of immune (ANAPC7, CUL5, TMEM229B, PTPN13), gene translation (PIWIL4), and chromatin organization (KDM2B) pathways. Immune genes are expected to have increased expression when leukocytes encounter M. ovipneumoniae which would lead to chromatin reorganization. Work is underway to narrow the range of these associated regions to identify the underlying causal mutations.

Effects of spirulina supplementation on lipid metabolism disorder, oxidative stress caused by high-energy dietary in Hu sheep.

The aim of this study was to investigate the effect of spirulina supplementation in a high-energy (HE) diet on lipid metabolism, oxidative status and immunity in Hu lambs. The lambs were assigned to two groups receiving either a standard diet (ST) or a HE diet. Each group was divided into three subgroups: no spirulina supplementation (control), 1% spirulina supplementation, or 3% spirulina supplementation. The body fat, serum cholesterol, triacylglycerol and oxidative stress increased in lambs fed the HE diet. However, 3% spirulina supplementation in the HE diet reduced above parameters and enhanced antioxidant capacity, including increased SOD activity and T-AOC content in serum and Longissimus thoracis et lumborum (LTL). Additionally, lambs receiving 3% spirulina supplementation showed an improvement in immunity-related parameters, including increased IgG concentration in serum and red and white blood cell counts. In conclusion, 3% spirulina supplementation in HE diet ameliorated lipid metabolic disorder and oxidative stress caused by a HE diet.

RIG-I Has a Role in Immunity Against Haemonchus contortus, a Gastrointestinal Parasite in Ovis aries: A Novel Report.

Retinoic acid inducible gene I (RIG-I) is associated to the DExD/H box RNA helicases. It is a pattern recognition receptor (PRR), playing a crucial role in the system and is a germ line encoded host sensor to perceive pathogen-associated molecular patterns (PAMPs). So far, reports are available for the role of RIG-I in antiviral immunity. This is the first report in which we have documented the role of RIG-I in parasitic immunity. Haemonchus contortus is a deadly parasite affecting the sheep industry, which has a tremendous economic importance, and the parasite is reported to be prevalent in the hot and humid agroclimatic region. We characterize the RIG-I gene in sheep (Ovis aries) and identify the important domains or binding sites with Haemonchus contortus through in silico studies. Differential mRNA expression analysis reveals upregulation of the RIG-I gene in the abomasum of infected sheep compared with that of healthy sheep, further confirming the findings. Thus, it is evident that, in infected sheep, expression of RIG-I is triggered for binding to more pathogens (Haemonchus contortus). Genetically similar studies with humans and other livestock species were conducted to reveal that sheep may be efficiently using a model organism for studying the role of RIG-I in antiparasitic immunity in humans.

Effect of maternal cottonseed feed on the immune and antioxidant status of Santa Ines lambs.

Cottonseed has been used as a nutritional alternative in animal production. However, consequences of this nutrient in the progeny is not well characterized. Thus, this work evaluated the effect on the immune and antioxidant status of the progeny of feeding Santa Ines ewe with or without cottonseed. Twenty-four Santa Ines ewes were distributed in two feeding regimes: cottonseed (CS) concentrate (n = 12) and soybean (SB) concentrate (n = 12). After birth, lambs remained with their mothers and blood samples were collected at 1st, 3rd, 7th, 15th, 30th and 60th day of life of 24 lambs born from mothers fed with (CS, n = 12) or without (SB, n = 12) cottonseed. Serum total protein, albumin, alpha beta globulin, gamma globulin, immunoglobulin G and M, activity of glutathione peroxidase (GPx), catalase (CAT), oxygen radical absorbance capacity (ORAC) and variables related to iron metabolism were affected only by sampling times (P < 0.05). The concentration of serum total protein, alpha beta globulin, gamma globulin and immunoglobulin G and M, GPx activity and ORAC values decreased as lamb age increased. Serum albumin concentration and CAT activity, in turn, increased as lamb age increased. In this work, maternal feeding with cottonseed did not affect the serum protein profile and antioxidant status of progeny during the lactation period, indicating no transfer of gossypol effects by milk secretions. Thus, the alternative in ruminants feeding with cottonseed can be used without maternal-descendant effects to immunity and oxidative stress in lambs.

Kisspeptin recombinant oral vaccine: A master gene vaccine inhibiting the reproductive physiology and behavior of ram lambs.

The KISS1 gene product, kisspeptin, stimulates gonadotrophic steroid hormone (GNRH) neuronal signaling through the G-protein coupled receptor, kiss1r. Disturbance of this signaling pathway causes hypogonadotropic hypogonadism in mammals. As part of this cutting-edge research project, we analyzed the efficacy of an oral kisspeptin recombinant vaccine on the reproductive physiology and behavior of ram lambs. Ten 56-day old ram lambs were randomly divided into treatment and control groups to receive the experimental recombinant vaccines, C500/pKS-asd or C500/pVAX-asd (aspartate-ß semialdehyde dehydrogenase), respectively. The vaccines were orally administered at day 0, 28 and 56 and blood samples were taken and scrotal circumference data recorded at 14-day intervals (days 0, 14, 28, 42, 56, 70, and 84). At the end of the experimental period, day 98, sexual behaviors were assessed, scrotal circumferences were measured, and blood samples were collected. Testicular samples were also collected after the animals were sacrificed. Anti-kisspeptin antibody and testosterone serum levels were measured by indirect ELISA. Results demonstrated that the levels of anti-kisspeptin antibodies were significantly higher in the treatment group compared to controls (P<0.05, P<0.01 and P<0.001). However, serum testosterone levels were lower in the treatment group (P<0.01). Interestingly, vaccine administration contributed to a significant reduction (P<0.01) in sexual behavior propensity. These results suggest that the kisspeptin recombinant oral vaccine regulates and inhibits the reproductive physiology and behavior of ram lambs.

Molecular Signature of Aluminum Hydroxide Adjuvant in Ovine PBMCs by Integrated mRNA and microRNA Transcriptome Sequencing.

There have been few in vivo studies on the effect of aluminum hydroxide adjuvant and its influence on the immune response to vaccination. In this study, lambs received a parallel subcutaneous treatment with either commercial vaccines containing aluminum hydroxide or an equivalent dose of this compound only with the aim of identifying the activated molecular signature. Blood samples were taken from each animal at the beginning and at the end of the experiment and PBMCs isolated. Total RNA and miRNA libraries were prepared and sequenced. After alignment to the Oar3.1 reference genome and differential expression with 3 programs, gene enrichment modeling was performed. For miRNAs, miRBase and RNAcentral databases were used for detection and characterization. Three expression comparisons were made: vaccinated animals at the beginning and at the end of the treatment, adjuvanted animals at the same times, and animals of both treatments at the end of the experiment. After exposure to both treatments, a total of 2,473; 2,980 and 429 differentially expressed genes were identified in vaccinated animals, adjuvanted animals and animals at the end of both treatments, respectively. In both adjuvant and vaccine treated animals the NF-κB signaling pathway was enriched. On the other hand, it can be observed a downregulation of cytokines and cytokine receptors in the adjuvanted group compared to the vaccinated group at the final time, suggesting a milder induction of the immune response when the adjuvant is alone. As for the miRNA analysis, 95 miRNAs were detected: 64 previously annotated in Ovis aries, 11 annotated in Bos taurus and 20 newly described. Interestingly, 6 miRNAs were differentially expressed in adjuvant treated animals, and 3 and 1 in the other two comparisons. Lastly, an integrated miRNA-mRNA expression profile was developed, in which a miRNA-mediated regulation of genes related to DNA damage stimulus was observed. In brief, it seems that aluminum-containing adjuvants are not simple delivery vehicles for antigens, but also induce endogenous danger signals that can stimulate the immune system. Whether this contributes to long-lasting immune activation or to the overstimulation of the immune system remains to be elucidated.

Evidence for the existence of regulatory and effector B cell populations in Peyer's patches of sheep.

IL-10 secreting CD21(+) B cells exist in sheep Peyer's patches (PP). It's not known however, whether all PP B cells are regulatory or whether an effector population also exists in this tissue. To further characterize the subpopulations of B cells in PP's, highly purified B cells were negatively sorted from jejunal PP and fractionated according to co-expression of CD72(+)CD21(+)or CD72(+)CD21(-) molecules and then stimulated with the TLR9-agonist, CpG ODN. IL-10, IL-12, IFN-γ, and IgM production were then assayed. We observed that only highly purified CD72(+)CD21(+) B cells spontaneously secreted high levels of IL-10, but they did not produce any IL-12, IFN-γ or IgM suggesting that this cell population contains regulatory B cells. In contrast, CD72(+)CD21(-) B cells did not secrete IL-10, but secreted IL-12, IFN-γ, and IgM, suggesting they include effector cells. In addition, B cells expressing surface IgA, IgM and IgG1 all secreted similar levels of IL-10. We further confirmed that only B cells produce IL-10, while other cells in the PP including DCs and T cells do not. Our investigations may provide evidence for the existence of two sub-populations in sheep PP; IL-10 secreting regulatory (CD72(+)CD21(+)) cells, and IL-12/IFN-γ/IgM-secreting effector (CD72(+)CD21(-)) cells.

Dietary polyunsaturated fatty acids from flaxseed affect immune responses of dairy sheep around parturition.

The objective of the study was to characterize the immune profile of dairy ewes fed flaxseed, rich in polyunsaturated fatty acids (PUFA), around parturition. The hypothesis to be verified was that a physiological stressor, such as parturition, could be overcome with a nutritional manipulation in the diet of the animal in order to guarantee welfare of animals and to sustain their immune responses. Twenty Comisana ewes were divided in two groups (10 ewes/group), and fed a supplementation of whole flaxseed in the diet (FS group) or no supplementation (CON group). Blood samples were collected at parturition and then 7, 14, 21, 28, and 42 day post partum. Plasma samples were used to assess the humoral immune response after ovalbumin (OVA) immunization. At parturition, at 14 day, and 42 day post partum the level of plasma cytokines was assessed. The sheep showed a reduced responsiveness to OVA immunization. In FS ewes the IL-6 level remained unchanged until 14 day post partum and then significantly decreased from 14 day to 42 day post partum. IL-10 level was significantly higher in FS ewes than in CON ewes at 14 day. At parturition IL-1ß level was significantly lower in FS ewes than in CON ewes and significantly decreased in both groups from parturition to 42 day. In conclusion, PUFA from flaxseed, as supplement in the diet of ewes around parturition can modulate sheep immune reactivity by influencing cytokine production.

An Immediate Innate Immune Response Occurred In the Early Stage of E. granulosus Eggs Infection in Sheep: Evidence from Microarray Analysis.

BACKGROUND: Cystic Echinococcosis(CE), caused by infection with the larval stage of the cestode Echinococcus granulosus (E. granulosus), is a chronic parasitic zoonosis, with highly susceptible infection in sheep. However, the comprehensive molecular mechanisms that underlie the process of E. granulosus infection in the early stage remain largely unknown. The objective of this present study was to gain a cluster of genes expression profiles in the intestine tissue of sheep infected with CE. METHODS: Nine healthy sheep were divided into infection group and healthy controls, with six infected perorally 5000 E. granulosus eggs suspended in 1000 µl physiological saline and three controls perorally injected 1000 µl physiological saline. All animals were sacrificed at 4 hours post-infection, respectively. The intestine tissue was removed and the RNA was extracted. In the infection group, the biology replicates were designed to make sure the accuracy of the data. The ovine microarrays were used to analyze changes of gene expression in the intestine tissue between CE infected sheep and healthy controls. Real-time PCR was used to assess reliability of the microarray data. RESULTS: By biology repeats, a total of 195 differentially expressed genes were identified between infected group and controls at 4 hours post-infection, with 105 genes related to immune responses, while 90 genes associated with functions including energy metabolism, fat soluble transport, etc. Among the 105 immunity genes, 72 genes showed up-regulated expression levels while 33 showed down-regulation levels. Function analysis showed that most of up-regulated genes were related to innate immune responses, such as mast cell, NK cell, cytokines, chemokines and complement. In addition, Real-time PCR analysis of a random selection of nine genes confirmed the reliability of the microarray data. CONCLUSION: To our knowledge, this is the first report describing gene expression profiles in the intestine tissue of CE infection sheep. These results suggested that the innate immune system was activated to elicit immediate defense in the intestine tissue where E. granulosus invaded in at 4 hour-post infection. Furthermore, future interest will also focus on unraveling similar events, especially for the function of adaptive immunity, but at late stage infection.

Comparative analysis of cellular immune responses and cytokine levels in sheep experimentally infected with bluetongue virus serotype 1 and 8.

Protective immunity in sheep with bluetongue virus (BTV) infection as well as the role of BTV-induced cytokines during immune response remains unclear. Understanding the basis immunological mechanisms in sheep experimentally infected with serotypes 1 and 8 (BTV-1 and -8) was the aim of this study. A time-course study was carried out in order to evaluate cell-mediated immune response and serum concentrations of cytokines (IL-1ß, TNFα, IL-12, IFNγ, IL-4 and IL-10) with inflammatory and immunological functions. Depletion of T cell subsets (mainly CD4(+), γδ and CD25(+)) together with the absence of cytokines (IFNγ and IL-12) involved in the regulation of cell-mediated antiviral immunity at the first stage of the disease suggested that both BTV-1 and BTV-8 might impair host's capability against primary infections which would favor viral replication and spreading. However, cellular immune response and cytokines elicited an immune response in sheep that efficiently reduced viremia in the final stage of the experiment. Recovery of T cell subsets (CD4(+) and CD25(+)) together with a significant increase of CD8(+) T lymphocytes in both infected groups were observed in parallel with the decrease of viremia. Additionally, the recovery of CD4(+) T lymphocytes together with the significant increase of IL-4 serum levels at the final stage of the experiment might contribute to humoral immune response activation and neutralizing antibodies production against BTV previously described in the course of this experiment. These results suggested that both cellular and humoral immune response may contribute to protective immunity against BTV-1 and BTV-8 in sheep. The possible role played by IL-10 and CD25(+) cells in controlling inflammatory and immune response in the final stage of the experiment has also been suggested.

Design, synthesis and evaluation of a gonadotropin releasing hormone-based subunit vaccine in rams (Ovis aries).

Immunocastration using gonadotropin-releasing hormone (GnRH)-based vaccines has been investigated in rams to reduce aggressive and sexual behaviour and to control meat quality. Despite considerable efforts, a practical GnRH vaccine has yet to be developed for rams. In the present study, a A GnRH-lipopeptide vaccine (GnRH-LP) including two copies of GnRH, 2-amino-d,l-hexadecanoic acid (C16), and a unique T helper epitope, was examined in rams. Rams received a primary and secondary vaccination of GnRH-LP without additional adjuvant (Group 1) or with the adjuvant AdjuVac™ (Group 2). In both Group 1 and 2 anti-GnRH antibody titres increased after secondary vaccination, however, the antibody titres were higher (p<0.01) for rams in Group 2. The latter rams showed a marked decrease in testicular size. The marked and sustained reduction in testicular size in rams treated with GnRH-LP+AdjuVac™ provides the basis for an effective immunocastration vaccine in rams.

The respiratory syncytial virus fusion protein formulated with a novel combination adjuvant induces balanced immune responses in lambs with maternal antibodies.

Respiratory syncytial virus (RSV) causes severe respiratory illness in infants. There are no licensed vaccines to prevent RSV infection. The neonate receives short-term protection from maternally derived antibodies, which, however, can also interfere with the active response to vaccination. A RSV vaccine consisting of a truncated version of the fusion protein formulated with polyI:C, innate defense regulator peptide and polyphosphazene (ΔF/TriAdj), was evaluated in two to three week-old lambs. When delivered intrapulmonary, ΔF/TriAdj elicited IgA production in the lung in addition to a robust systemic response similar to that induced by intramuscular immunization. To investigate potential interference by maternal antibodies, pregnant ewes were vaccinated with ΔF/TriAdj. Lambs born to RSV F-immune or non-immune ewes were then given three vaccinations with ΔF/TriAdj at 3 days, 4 weeks and 8 weeks post-birth. Lambs immunized intramuscularly with ΔF/TriAdj vaccine developed high-affinity ΔF-specific serum IgG and virus neutralizing antibodies, and displayed an increase in the frequency of IFN-γ-secreting cells by in vitro restimulated peripheral blood mononuclear cells. Maternal antibodies did not interfere with the development of an immune response to ΔF/TriAdj in the newborn lambs. These results indicate that immunization of neonates with ΔF/TriAdj is effective even in the face of maternal antibodies.

Pathogenesis of scrapie in ARQ/ARQ sheep after subcutaneous infection: effect of lymphadenectomy and immune cell subset changes in relation to prion protein accumulation.

It is well established that the infectious agent of scrapie can replicate in the lymphoreticular system (LRS). However, the effects of removal of LRS target tissues on the pathogenesis of the infection and the accumulation of disease-associated prion protein (PrP(d)) in LRS tissues on specific immune cell subsets are poorly understood aspects. To address these questions 16 ARQ/ARQ sheep were subcutaneously inoculated in the drainage area of the prefemoral lymph node with brain homogenate derived from Suffolk sheep naturally infected with scrapie. Fourteen sheep were then subjected to either early (14-17 days post-inoculation [dpi]) or late (175-201 dpi) lymphadenectomy and culled at preclinical or clinical stages of infection. Neither late nor even early lymphadenectomy prevented infection or had any effect on the accumulation of PrP(d) in the LRS or CNS suggesting a rapid organic dissemination of the infectious agent after inoculation. Lymph nodes from eight scrapie inoculated sheep selected on the basis of the amount of PrP(d) in their LRS tissues (negative, low or high) were examined for six different immune cell markers. The PrP(d) negative lymph nodes from two sheep with no evidence of scrapie infection showed lower numbers of cluster of determination (CD) 21 positive cells than PrP(d) positive nodes, irrespective of their location (hind leg or head). However, quantitative differences in the expression of this marker were not detected when comparing lymph nodes with low and high levels of PrP(d) accumulation, suggesting that proliferation of CD21 positive cells is related to scrapie infection, but not directly linked to the magnitude of PrP(d) accumulation. An additional observation of the study was that sheep that were methionin-threonine at codon 112 of the prion protein gene showed lower attack rates than methionine homozygotes (67% and 100%, respectively) and also generally lower levels of PrP(d) accumulation in the LRS and brain and increased survival times, suggesting an influence of such polymorphism in the susceptibility to scrapie.

Induction of a protective immune response to rabies virus in sheep after oral immunization with transgenic maize, expressing the rabies virus glycoprotein.

The introduction of exogenous genes into plants permits the development of a new generation of biological products, i.e., edible vaccines. Cereals, especially maize, have been the systems of choice for the expression of antigenic proteins because the proteins can be expressed at high levels in the kernel and stored for prolonged periods without excessive deterioration. The utilization of plant-derived antigens for oral delivery provides an alternative strategy for the control of pathogens in animals compared to the current vaccine administration methods, such as injection. However, there is some doubt about the efficacy of these types of vaccines in polygastric animals due to the features of their digestive system. Here, we report the efficacy of an edible vaccine against rabies evaluated in sheep. Kernels containing different doses of G protein (0.5, 1, 1.5 and 2mg) were given in a single dose by the oral route. Cumulative survival was better in groups that received 2mg of G protein and for the positive control (inactivated rabies vaccine); this observation was supported by the presence of neutralizing antibodies. Animals in the control group died after challenge. The degree of protection achieved for 2mg of G protein was comparable to that conferred by a commercial vaccine. In conclusion, this is the first study in which an orally administered edible vaccine showed efficacy in a polygastric model.

Neuroimmune connections in ovine pharyngeal tonsil: potential site for prion neuroinvasion.

Recent studies have established the involvement of nasal-associated lymphoid tissues, mainly the pharyngeal tonsil, in prion pathogenesis. However, the mechanisms of the associated neuroinvasion are still debated. To determine potential sites for prion neuroinvasion inside the ovine pharyngeal tonsil, the topography of heavy (200 kDa) and light (70 kDa) neurofilaments and of glial fibrillar acidic protein has been semi-quantitatively analysed inside the various compartments of the tonsil. The results show that the most innervated areas are the interfollicular area and the connective tissue located beneath the respiratory epithelium. The existence of rare synapses between follicular dendritic cells and nerve fibres inside the germinal centre indicates that this mechanism of neuroinvasion is possible but, since germinal centres of lymphoid follicles are poorly innervated, other routes of neuroinvasion are likely. The host PRNP genotype does not influence the pattern of innervation in these various tonsil compartments, unlike ageing during which an increase of nerve endings occurs in a zone of high trafficking cells beneath the respiratory epithelium. A minimal age-related increase of innervation inside the lymphoid follicles has also been observed. An increase in nerve fibre density around the lymphoid follicles, in an area rich in mobile cells such as macrophages and dendritic cells capable of capturing and conveying pathogen prion protein (PrPd), might ensure more efficient infectivity, not in the early phase but in the advanced phase of lymphoinvasion after the amplification of PrPd; alternatively, this area might even act as a direct site of entry during neuroinvasion.

Myxomavirus as a vector for the immunisation of sheep: protection study against challenge with bluetongue virus.

Recombinant poxviruses are well suited for the development of new vaccine vectors. Our previous data supported the idea that Myxomavirus (MYXV) is efficient at priming antibody responses in sheep. To provide definitive evidence on the potential of MYXV for vaccination against infectious diseases in ruminants, we investigated the immune protection provided by recombinant MYXV against bluetongue, a devastating disease in sheep. To test this concept, sheep were injected twice with an MYXV expressing the immunodominant VP2 protein (SG33-VP2). The SG33-VP2 vector promoted the production of neutralising antibodies and partially protected sheep against disease after challenge with a highly virulent strain of serotype-8 bluetongue virus (BTV-8). In contrast, an MYXV expressing both VP2 and VP5 proteins (SG33-VP2/5) elicited very little protection. The expression levels of the VP2 and VP5 proteins suggested that, greater than the co-expression of the VP5 protein which was previously thought to favour anti-VP2 antibody response, the high expression of VP2 may be critical in the MYXV context to stimulate a protective response in sheep. This highlights the requirement for a careful examination of antigen expression before any conclusion can be drawn on the respective role of the protective antigens. As a proof of principle, our study shows that an MYXV vaccine vector is possible in ruminants.

Effects of maternal plane of nutrition and increased dietary selenium in first-parity ewes on inflammatory response in the ovine neonatal gut.

Many areas of the western United States have soils that have increased Se content, and ruminants grazing these rangelands may ingest increased quantities of Se. In addition, high-energy diets or increased Se intake may induce gut inflammation. The objective of this study was to evaluate the effects of maternal plane of nutrition and increased dietary Se during gestation on inflammatory responses in neonatal lamb ileal tissue, a major immune organ. Rambouillet ewes (age = 240 ± 17 d; initial BW = 52.1 ± 6.2 kg) were allocated to 4 treatments arranged in a 2 × 2 factorial. Factors included Se [adequate Se (ASe, 11.5 µg/kg of BW) or high Se (HSe, 77.0 µg/kg of BW)] initiated at breeding, and nutritional plane [100% (CON) or 140% (HIH) of requirements] initiated at d 40 of gestation. Ewes were fed individually from d 40, and lambs were removed at parturition and fed artificial colostrum and milk replacer. Lambs were necropsied at 20 d of age, and ileal tissues were sampled for immunoblotting and real-time quantitative reverse-transcription PCR analyses. The ASe-HIH and HSe-CON treatments had no effect (P = 0.179) on inflammatory signaling compared with ASe-CON. However, greater inflammatory signaling was detected in the HSe-HIH group, as shown by increased (P < 0.05) mRNA expression of tumor necrosis factor-α and chemotaxis IL-8. Consistently, phosphorylation of c-Jun N-terminal kinase, a primary inflammatory signaling mediator, was greater (P < 0.05) in the HSe-HIH group compared with other treatments. Consistent with cytokine expression, mast cell density was less in the HSe-CON group than in other treatments. The expression of transforming growth factor ß mRNA was greater (P < 0.05) in the HSe-HIH group; consistently, collagen content was increased in the HSe-HIH group compared with the ASe-CON group (P < 0.05). In conclusion, independently, neither HSe nor HIH had major effects on inflammation, but in combination, these maternal treatments induced an inflammatory response in the neonatal intestine.

The recombinant gut-associated M17 leucine aminopeptidase in combination with different adjuvants confers a high level of protection against Fasciola hepatica infection in sheep.

Fasciola hepatica M17 leucine aminopeptidase (FhLAP) is thought to play a role in catabolizing peptides generated by the concerted activity of gut-associated endopeptidases on host polypeptides, thus releasing amino acids to be used in protein anabolism. In this study, a recombinant functional form of this homo hexameric metallopeptidase produced in Escherichia coli was used in combination with adjuvants of different types in a vaccination trial in Corriedale sheep against experimental challenge with F. hepatica metacercariae. The experimental assay consisted of 6 groups of 10 animals; 5 of the groups (1-5) were subcutaneously inoculated at weeks 0 and 4 with 100 µg of rFhLAP mixed with Freund's complete plus incomplete adjuvant (group 1), Alum (group 2), Adyuvac 50 (group 3), DEAE-D (group 4) and Ribi (group 5); the adjuvant control group (group 6) received Freund's adjuvant. Two weeks after the booster, the sheep were orally challenged with 200 metacercariae. Immunization with rFhLAP induced significant reduction in fluke burdens in all vaccinated groups: 83.8% in the Freund's group, 86.7% in the Alum group, 74.4% in the Adyuvac 50 group, 49.8% in the Ribi group and 49.5% in the DEAE-D group compared to the adjuvant control group. Morphometric analysis of recovered liver flukes showed no significant size modifications in the different vaccination groups. All vaccine preparations elicited specific IgG, IgG1 and IgG2 responses. This study shows that a liver fluke vaccine based on rFhLAP combined with different adjuvants significantly reduced worm burden in a ruminant species that was high in animals that received the enzyme along with the commercially approved adjuvants Alum and Adyuvac 50.

Naringin and vitamin E influence the oxidative stability and lipid profile of plasma in lambs fed fish oil.

Thirty two Merino lambs (15 weeks old) fed barley straw and fish oil enriched concentrate were used to assess the effect of vitamin E (6 g kg(-1) DM) and naringin (1.5-3 g kg(-1) DM) on plasma lipid peroxidation (TBARS), total antioxidant status (TAS), immune response, plasma cholesterol, and triglycerides. After 21 days feeding the experimental diets, lambs were subjected to a 4 h transportation stress period and then held 4 more hours without feed. TBARS values before stress were lower for animals consuming vitamine E and naringin when compared to control lambs (P<0.05). However, after stress all groups presented similar levels of TBARS. TAS decreased (P<0.05) in all groups in response to stress with values recovering (P<0.05) to pre-stress values following 4 h of rest. A rise (P<0.05) in serum concentrations of triacylglycerol following 21 d of fish oil supplementation was dampened in lambs consuming vitamin E or naringin. Both pre-stress TBARS and triacylglycerol-reducing effects of naringin added to fish oil enriched concentrate for fattening lambs are reported.