Study on immunoregulation function of peony seed proteolysis product in mice

To explore the immunoregulatory function of peony seed proteolysis product in mice, the protein from peony seed meal was extracted and hydrolyzed with bromelain. The peony seed proteolysis product was fed to mice at three different doses of 0.25, 0.5, and 1.0 g/kg for 21 days. The immunoregulation abilities of peony seed proteolysis product after each of these doses were evaluated in mice. Our results showed that all immune indices were higher in mice that had received a lavage with peony seed proteolysis product than in control mice. The immune indices of immune organs, delayed-type hypersensitivity reaction (DTH), phagocytosis of peritoneal macrophages, serum hemolysin levels, lymphocyte proliferation (SI value), and levels of IFN-γ and IL-4 in the middle dose and high dose groups were significantly higher (p < .05) or extremely significant (p < .01) in comparison with the control group. These results indicate that the peony seed proteolysis product enhances immunological functions in mice. PRACTICAL APPLICATIONS: Peony seed is rich in proteins and can be extracted and hydrolyzed using bromelain. The peony seed proteolysis product can enhance the nonspecific, humoral, and cellular immune responses. Thus, peony seed could be of potential value to obtain peony seed protein, which can be further developed and utilized in the manufacture of functional health products.

Identification of 2'-5'-Oligoadenylate Synthetase-Like Gene in Goose: Gene Structure, Expression Patterns, and Antiviral Activity Against Newcastle Disease Virus

2'-5'-oligoadenylate synthetase-like (OASL) is a kind of antiviral protein induced by interferons (IFNs), which plays an important role in the IFNs-mediated antiviral signaling pathway. In this study, we cloned and identified OASL in the Chinese goose for the first time. Goose 2'-5'-oligoadenylate synthetase-like (goOASL), including an ORF of 1527bp, encoding a protein of 508 amino acids. GoOASL protein contains 3 conserved motifs: nucleotidyltransferase (NTase) domain, 2'-5'-oligoadenylate synthetase (OAS) domain, and 2 ubiquitin-like (UBL) repeats. The tissue distribution profile of goOASL in 2-week-old gosling and adult goose were identified by Real-Time quantitative PCR, which revealed that the highest level of goOASL mRNA transcription was detected in the blood of adult goose and gosling. The mRNA transcription level of goOASL was upregulated in all tested tissues of duck Tembusu virus (DTMUV)-infected 3-day-old goslings, compared with control groups. Furthermore, using the stimulus Poly(I: C), ODN2006, R848, and lipopolysaccharide (LPS) as well as the viral pathogens DTMUV, H9N2 avian influenza virus (AIV), and gosling plague virus (GPV) to treat goose peripheral blood mononuclear cells (PBMCs) for 6 h, goOASL transcripts level was significantly upregulated in all treated groups. To further investigate the antiviral activity of goOASL, pcDNA3.1(+)-goOASL-His plasmid was constructed, and goOASL was expressed by the goose embryo fibroblast cells (GEFs) transfected with pcDNA3.1(+)-goOASL-His. Our research data suggested that Newcastle disease virus (NDV) replication (viral copies and viral titer) in GEFs was significantly reduced by the overexpression of goOASL protein. These data were meaningful for the antiviral immunity research of goose and shed light on the future prevention of NDV in fowl.

Cross-species antiviral activity of goose interferon lambda against duck plague virus is related to its positive self-regulatory feedback loop

Duck plague virus (DPV) is a virus of the Herpesviridae family that leads to acute disease with a high mortality rate in ducks. Control of the disease contributes to the development of poultry breeding. Type III IFN family (IFN-λs) is a novel member of the IFN family, and goose IFN-λ (goIFN-λ) is a newly identified gene whose antiviral function has only been investigated to a limited extent. Here, the cross-species antiviral activity of goIFN-λ against DPV in duck embryo fibroblasts (DEFs) was studied. We found that pre-treatment with goIFN-λ greatly increased the expression of IFN-λ in both heterologous DEFs and homologous goose embryo fibroblasts (GEFs), while differentially inducing IFNα- and IFN-stimulated genes. Additionally, a positive self-regulatory feedback loop of goIFN-λ was blocked by a mouse anti-goIFN-λ polyclonal antibody, which was confirmed in both homologous GEFs and goose peripheral blood mononuclear cells (PBMCs). The suppression of the BAC-DPV-EGFP by goIFN-λ in DEFs was confirmed by fluorescence microscopy, flow cytometry (FCM) analysis, viral copies and titre detection, which can be rescued by mouse anti-goIFN-λ polyclonal antibody incubation. Finally, reporter gene assays indicated that the cross-species antiviral activity of goIFN-λ against BAC-DPV-EGFP is related to its positive self-regulatory feedback loop and subsequent ISG induction. Our data shed light on the fundamental mechanisms of goIFN-λ antiviral function in vitro and extend the considerable range of therapeutic applications in multiple-poultry disease.

Molecular identification and immunological characteristics of goose suppressor of cytokine signaling 1 (SOCS-1) in vitro and vivo following DTMUV challenge

Purpose suppressor of cytokine signaling 1 (SOCS-1) is inducible feedback inhibitors of cytokine signaling and involved in viral infection through regulation of both innate and adaptive immunity. In this study, we firstly cloned SOCS-1 (goSOCS-1) from duck Tembusu virus (DTMUV) infected goose. The full-length sequence of goSOCS-1 ORF is 624bp and encoded 108 amino acids. Structurally, the mainly functional regions (KIR, SH2, SOCS-box) were conserved between avian and mammalian. The tissues distribution data showed SOCS-1 highly expressed in immune related tissues (SP, LU, HG) of both gosling and adult goose. Moreover, the goSOCS-1 transcripts were induced by goIFNs in GEFs and by TLR ligands in PBMCs. Notably, upon DTMUV infection, highly expression level of goSOCS-1 was detected in vitro and in vivo with high viral load. Our results indicated that goSOCS-1 might involve in both innate and adaptive antiviral immunity of waterfowl.

Identification of linear B-cell epitopes on goose parvovirus non-structural protein

Goose parvovirus (GPV) infection can cause a highly contagious and lethal disease in goslings and muscovy ducklings which is widespread in all major goose (Anser anser) and Muscovy duck (Cairina moschata) farming countries, leading to a huge economic loss. Humoral immune responses play a major role in GPV immune protection during GPV infection. However, it is still unknown for the localization and immunological characteristics of B-cell epitopes on GPV non-structural protein (NSP). Therefore, in this study, the epitopes on the NSP of GPV were identified by means of overlapping peptides expressed in Escherichia coli in combination with Western blot. The results showed that the antigenic epitopes on the GPV NSP were predominantly localized in the C-terminal (aa 485-627), and especially, the fragment NS (498-532) was strongly positive. These results may facilitate future investigations on the function of NSP of GPV and the development of immunoassays for the diagnosis of GPV infection.

Molecular identification and comparative transcriptional analysis of myxovirus resistance GTPase (Mx) gene in goose (Anser cygnoide) after H9N2 AIV infection

Interferon (IFN)-induced myxovirus resistance (Mx) GTPases belong to the family of dynamin-like GTPases and control a diverse range of viruses. In this study, the identified goose Mx (goMx) mRNA is 2009bp long, shares partially conserved exons with other homologues, and shares highly conserved domains in its primary structure. The amino acid position 629 (629aa) of the goMx protein was identified as serine (Ser), in contrast to the Ser located at 631aa in chicken Mx, which is considered to be responsible for the lack of chicken Mx antiviral activity. In addition, the goMx 142aa residue in the dynamin family signature differs from that of other functional Mx proteins. Transcriptional analysis revealed that goMx was mainly expressed in the digestive, respiratory and immune systems in an age-specific manner. GoMx transcript levels in goose peripheral blood mononuclear cells (PBMCs) were found to be significantly up-regulated by various agonists and avian viruses. Furthermore, a time course study of the effects of H9N2 avian influenza virus (AIV) on goMx expression in infected goslings suggested that H9N2 AIV affected goMx expression. However, significant changes in goMx expression were observed in the trachea, lung and small intestine of infected birds. Altogether, these results indicate that goMx protein may have acquired its broad antiviral activity by changing only a few amino acids at select sites, even as it shares a conserved architectures with species.

Antigen distribution of TMUV and GPV are coincident with the expression profiles of CD8α-positive cells and goose IFNγ

Both Tembusu virus (TMUV) and goose parvovirus (GPV) are causative agents of goose disease. However, the host immune response of the goose against these two different categories of virus has not been well documented. Here, we compared the clinical symptoms and pathological characteristics, antigen distribution and intensity, and expression of immune-related genes in TMUV- and GPV- infected goose. The immunohistochemistry analysis demonstrated that GPV was primarily located in the liver, lung, small intestine, and rectum, while TMUV was situated in the liver, brain, spleen, and small intestine. The induction of IFNγ and proinflammatory cytokines is highly associated with the distribution profiles of antigen and CD8α+ molecules. The effector function of CD8 T cells may be accomplished by the secretion of IFNγ together with high expression of proinflammatory cytokines such as IL1 and IL6. Remarkably, significant increases in the transcription of immune genes were observed after infection, which suggested that both GPV and TMUV can effectively induce immune response in goose PMBCs. This study will provide fundamental information for goose molecular immunology in defending against pandemic viruses.