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BACKGROUND: The neuroimmune network plays a crucial role in regulating mucosal immune homeostasis within the digestive tract. Synaptosome-associated protein 25 (SNAP-25) is a presynaptic membrane-binding protein that activates ILC2s, initiating the host's anti-parasitic immune response. METHODS: To investigate the effect of Moniezia benedeni (M. benedeni) infection on the distribution of SNAP-25 in the sheep's small intestine, the recombinant plasmid pET-28a-SNAP-25 was constructed and expressed in BL21, yielding the recombinant protein. Then, the rabbit anti-sheep SNAP-25 polyclonal antibody was prepared and immunofluorescence staining was performed with it. The expression levels of SNAP-25 in the intestines of normal and M. benedeni-infected sheep were detected by ELISA. RESULTS: The results showed that the SNAP-25 recombinant protein was 29.3 KDa, the titer of the prepared immune serum reached 1:128,000. It was demonstrated that the rabbit anti-sheep SNAP-25 polyclonal antibody could bind to the natural protein of sheep SNAP-25 specifically. The expression levels of SNAP-25 in the sheep's small intestine revealed its primary presence in the muscular layer and lamina propria, particularly around nerve fibers surrounding the intestinal glands. Average expression levels in the duodenum, jejunum, and ileum were 130.32 pg/mg, 185.71 pg/mg, and 172.68 pg/mg, respectively. Under conditions of M. benedeni infection, the spatial distribution of SNAP-25-expressing nerve fibers remained consistent, but its expression level in each intestine segment was increased significantly (P < 0.05), up to 262.02 pg/mg, 276.84 pg/mg, and 326.65 pg/mg in the duodenum, jejunum, and ileum, and it was increased by 101.06%, 49.07%, and 89.16% respectively. CONCLUSIONS: These findings suggest that M. benedeni could induce the SNAP-25 expression levels in sheep's intestinal nerves significantly. The results lay a foundation for further exploration of the molecular mechanism by which the gastrointestinal nerve-mucosal immune network perceives parasites in sheep.

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The concentration of immunoglobulin (Ig) E is the lowest among serum Igs, but it can induces type I hypersensitivity and plays an important role in anti-parasitic infection. The present study aimed to explore the residence characteristics of IgE+ cells in the sheep small intestine and the impact of Moniezia benedeni infection on them. The recombinant plasmids pET-28a-IgE were constructed and induced and expressed in Escherichia coli. BL21 (DE3). The rabbit anti-sheep IgE polyclonal antibody was prepared using the obtained recombinant protein as antigen. Finally, the levels of IgE+ cells in the small intestine of healthy (Control group) and naturally M. benedeni-infected (Infected group) sheep were detected analyzed. The results showed that the rabbit anti-sheep IgE polyclonal antibody with good immunogenicity (titer = 1: 128000) could specifically bind to the heavy chain of natural sheep IgE. In the Control group, the IgE+ cells were mainly distributed in lamina propria of the small intestine, and the densities were significantly decreased from duodenum to ileum (P<0.05), with respective values of (4.28 cells / 104 µm2, 1.80 cells / 104 µm2, and 1.44 cells / 104 µm2 in duodenum, jejunum, and ileum. In the Infected group, IgE+ cells density were 6.26 cells / 104 µm2, 3.01 cells / 104 µm2, and 2.09 cells / 104 µm2 in duodenum, jejunum and ileum respectively, which were significantly higher in all segments compared to the Control group (P<0.05), increasing by 46.26%, 67.22% and 45.14%, respectively. In addition, compared with the Control group, the IgE protein levels were significantly increased in all intestinal segments of the Infected group (P<0.01), however, there was no significant differences among the different intestinal segments within the same group (P>0.05). The results demonstrated that M. benedeni infection could significantly increase the content of IgE and the distribution density of its secreting cells in sheep small intestine. The intestinal mucosal immune system of sheep presented obvious specificity against M. benedeni infection. This lays a good foundation for further exploring molecular mechanisms of the intestinal mucosal immune system monitoring and responding to M. benedeni infection.

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Introduction: T cells are the core of the cellular immunity and play a key role in the regulation of intestinal immune homeostasis. In order to explore the impact Moniezia benedeni (M. benedeni) infection on distributions of CD3+ T cells in the small intestine of the sheep. Methods: In this study, sheep pET-28a-CD3 recombinant plasmid were constructed and expressed in BL21 receptor cells, then the rabbit anti-sheep CD3 polyclonal antibody was prepared through recombinant protein inducing. The M. benedeni-infected sheep (infection group, n = 6) and healthy sheep (control group, n = 6) were selected, and the distributions of CD3+ T cells in intestinal laminae propria (LP) and mucous epitheliums were observed and analyzed systematically. Results: The results showed that the rabbit anti-sheep CD3 polyclonal antibody had good potency and specificity. In the effector area of small intestine, a large number of CD3+ T cells were mainly diffusely distributed in the intestinal LP as well as in the mucous epitheliums, and the densities of intestinal LP from duodenum to jejunum to ileum were 6.01 cells/104 µm2, 7.01 cells/104 µm2 and 6.43 cells/104 µm2, respectively. Their distribution densities in mucous epitheliums were 6.71 cells/104 µm2, 7.93 cells/104 µm2 and 7.21 cells/104 µm2, respectively; in the infected group, the distributions of CD3+ T cells were similar to that of the control group, and the densities in each intestinal segment were all significantly increased (p < 0.05), meanwhile, the total densities of CD3+ T cells in duodenum, jejunum and ileum were increased by 33.43%, 14.50%, and 34.19%. In LP and mucous epitheliums, it was increased by 33.57% and 27.92% in duodenum; by 25.82% and 7.07% in jejunum, and by 27.07% and 19.23% in ileum, respectively. Discussion: It was suggested that M. benedeni infection did not change the spatial distributions of CD3+ T cells in the small intestine of sheep, but significantly increased their densities, which lays a foundation for further research on the regulatory mechanism of sheep intestinal mucosal immune system against M. benedeni infection.

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In order to investigate the anti-aging performance of nano-modified natural ester insulating oils, in this paper, two different types of nanoparticles are selected to modify insulating oils. We studied the microscopic mechanism of nano-modified models using molecular simulation techniques. Three models were established: an oil-water model without the addition of nanoparticles and two which contained nano-Fe3O4 and nano-Al2O3 particles, where the concentration of water was 1 wt.%. The research found that the diffusion of water molecules in the nano-modified model was slow, and the water molecules generated from transformer insulation aging were adsorbed around the nanoparticles, which inhibited the diffusion of water molecules, reduced the hydrolysis of ester molecules, and effectively enhanced the anti-aging performance of natural ester insulating oil. Compared with two different types of nano-modified models, the interface compatibility between nano-Fe3O4 and natural ester insulating oil is better, the composite model is stable, the change rate of the diffusion coefficient with temperature is small, there are more hydrogen bonds generated by nano-Fe3O4 and water molecules, and the anti-aging performance of the nano-Fe3O4-modified oil model is better.

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Secreted immunoglobulin A (SIgA), IgG, and IgM play a crucial role in forming the intestinal mucosal immune barrier, and parasites could disturb the host's immune response by releasing various immunomodulatory molecules. Moniezia benedeni is an important pathogen parasitizing in the sheep small intestine. It is aimed to explore the residence characteristics of IgA+, IgG+, and IgM+ cells in the sheep small intestine, and the influence of Moniezia benedeni infection on them. Control group (n = 6) and infected group (n = 6) were selected, respectively, and the three subtype cells residing in the small intestine were systematically observed and analyzed. The results showed that in the Control group, the three types of positive cells were all distributed diffusely, and the total densities in jejunum, duodenum and ileum was gradually declined in turn. Notably, the change trend of IgA+ and IgG+ cells densities were both congruent with the total densities, and the differences among them were significant, respectively (P < 0.05); the IgM+ cells density was the highest in duodenum, followed by jejunum and ileum, there was no significant difference between duodenum and jejunum (P > 0.05), but both significantly higher than in ileum (P < 0.05). In the Infected group, their total densities in duodenum, jejunum and ileum were gradually declined in turn. Notably, the IgA+ and IgM+ cells densities change trend was the same as the total densities, and the differences among them were significant, respectively (P < 0.05). The IgG+ cells density in duodenum was the highest, followed by ileum and jejunum and there was significantly difference among them (P < 0.05). The comparison results between Control and Infected groups showed that from the duodenum, jejunum to ileum, IgA+, IgG+, and IgM+ cells were all reduced significantly, respectively. The results suggest that the three types of positive cells were resided heterogeneously in the small intestinal mucosa, that is, significant region-specificity; Moniezia benedeni infection could not change their diffuse distribution characteristics, but strikingly, reduce their resident densities, and the forming mucosal immune barrier were significantly inhibited. It provided powerful evidence for studying on the molecular mechanism of Moniezia benedeni evasion from immune surveillance by strongly inhibiting the host's mucosal immune barrier.

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BACKGROUND: Neuromedin U (NMU) plays an important role in activating the group 2 innate lymphoid cells (ILC2s) and initiating the host's anti-parasitic immune responses. It is aimed to explore the distribution characteristics of NMU in the sheep small intestine and the influence of Moniezia benedeni infection on them. In the present study, the pET-28a-NMU recombinant plasmids were constructed, and Escherichia coli. BL21 (DE3) were induced to express the recombinant protein. And then, the rabbit anti-sheep NMU polyclonal antibody was prepared and immunofluorescence staining was performed with it. The expression levels of NMU in the intestine of normal and Moniezia benedeni-infected sheep were detected by ELISA. RESULTS: The results showed that the molecular weight of the obtained NMU recombinant protein was consistent with the expected molecular (13 kDa) and it was expressed in the form of inclusion body. The titer and specificity of obtained rabbit anti-sheep NMU polyclonal antibody were good. The results of immunofluorescence analysis showed that the nerve fibers which specifically expressed NMU mainly extended from the ganglion in the submucosal to lamina propria (LP) in the sheep small intestine, and the expression level was relatively high; especially on the nerve fibers of LP around the intestinal glands. The expression levels were gradually increased from the duodenum to the ileum, and the levels in the jejunum and ileum were significantly higher than that in the duodenum (P < 0.05). In addition, scattered NMU positive cells were distributed in the epithelium of the jejunal crypts. Moniezia benedeni infection increased the expression of NMU in each intestinal segment, especially in the jejunum and ileum there were significant increase (P < 0.05). CONCLUSIONS: It was suggested that Moniezia benedeni infection could be detected by the high expression of NMU in sheep enteric nervous, and which laid the foundation for further studies on whether NMU exerts anti-parasitic immunity by activating ILC2s. In addition, NMU was expressed in some intestinal gland epitheliums, which also provided a basis for studying its roles in regulation of the immune homeostasis. The present study laid the foundation for further revealing the molecular mechanism of sheep's neural-immune interaction network perceiving the colacobiosis of parasites.

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OBJECTIVE: To observe the microstructure and ultrastructure of Multiceps multiceps from the artificially infected dogs. METHEDS: Two male dogs were infected with the coenurus of M. multiceps from naturally-infected sheep (about 80-100 per dog). The adult worms of M. multiceps were recovered from the intestine, and fixed by the conventional method. The scolex, neck, immature proglottid, mature proglottid, and gravid proglottid were prepared for paraffin section and ultrathin sections with HE staining and uranyl acetate staining, and observed under light microscope and electron transmission microscope, respectively. RESULTS: Under light microscope, each proglottid consisted of cortical layer and parenchymal layer. The cortical layer was composed of microvilli, syncytium, and substrate layer. The parenchymal layer mainly consisted of muscle tissue, excretory system, and reproductive system. The microvilli layer of scolex was thinner than that of neck and mature proglottid, and the longest microvilli were mainly distributed in the binding site between the proglottids. The scolex was extremely muscular. The nervous system and excretory system were repeated in each proglottid. Mature proglottid had both male and female reproductive systems. Gravid proglottid had uterus and egg, and atrophic male reproductive organs. CONCLUSION: The special microstructure of Multiceps multiceps are that most microvilli in the cortex is cylindrical; the microvilli length in the binding sites between mature proglottids is longer than that of other parts.

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