Xiaohan Cao

Enhancement of the immune responses to foot-and-mouth disease vaccination in mice by oral administration of a Novel polysaccharide from the roots of Radix Cyathulae officinalis Kuan (RC)

Foot-and-mouth disease (FMD) is a kind of the important animal infectious disease caused by the foot-and-mouth disease virus (FMDV). Thus, the aim of this study was to determine the effects of the polysaccharide from the Radix Cyathulae officinalis Kuan (RCPS) for its adjuvant potential on the FMDV-specific cellular and humoral immune responses in mice. In this study, our findings shows that oral administration of RCPS significantly enhanced the phagocytic capacity of peritoneal macrophage, splenocyte proliferation, the activity of natural killer (NK) cells and cytotoxic T lymphocytes (CTL) and IgG, IgG1, IgG2a, and IgG2b antibody titers. Furthermore, RCPS promoted the level of IL-2, IFN-γ and IL-4 in CD4(+)T cells and level of IFN-γ in CD8(+)T cells. In addition, RCPS enhanced the expression of CD40(+), CD80(+) and CD86(+) on DCs. Importantly, RCPS could up-regulated the mRNA level of MHC I, MHC II, TLR-2, TLR-4. Interestingly, RCPS down-regulated the frequency of CD4(+)CD25(+)Foxp3(+)Treg cells. Taken together, these results demonstrate that RCPS can enhance both cellular and humoral immune responses via up-regulating DCs maturation through TLR2, TLR4 signaling pathway, and suppressing Treg frequency.

Novel polysaccharide from Radix Cyathulae officinalis Kuan can improve immune response to ovalbumin in mice.

This study was designed to investigate the effects of oral administration of the polysaccharide from the Radix Cyathulae officinalis Kuan (RCPS) for its adjuvant potential on the specific cellular and humoral immune responses in mice. In this study, our data demonstrated that oral administration of RCPS significantly enhanced the phagocytic capacity of peritoneal macrophage, splenocyte proliferation, the activity of natural killer (NK) cells and cytotoxic T lymphocytes (CTL) and OVA-specific IgG, IgG1, IgG2a, and IgG2b antibody titers. Furthermore, RCPS promoted the level of interleukin-2(IL-2), IFN-γ and IL-4 in CD4(+)T cells and level of IFN-γ in CD8(+)T cells. In addition, RCPS enhanced the expression of CD40(+), CD80(+) and CD86(+) on the dendritic cells (DCs). Importantly, RCPS down-regulated the frequency of CD4(+)CD25(+)Foxp3(+)Treg cells. Taken together, these results suggested that RCPS could increase both cellular and humoral immune responses via up-regulating DCs maturation, and suppressing Treg frequency.

Characterization and antioxidant activities of the polysaccharides from Radix Cyathulae officinalis Kuan

A water-soluble polysaccharide (PSRC) was extracted and purified from the roots of Radix Cyathulae officinalis Kuan, and its chemical characteristics, monosaccharide composition and antioxidant activities were characterized. The average of molecular weight (Mw) of PSRC was 182 kDa. The majority of monosaccharide components of PSRC was glucose (relative mass 48.8%) with lower levels of mannose, rhamnose, galactose, fructose and arabinose (relative mass of 15.7, 14.3, 10.6, 6.1 and 4.5%, respectively). In vitro assays revealed that RSRC possessed potent scavenging activities against DPPH, hydroxyl and superoxide anion radicals. Oral administration of PSRC significantly enhanced antioxidant enzyme activities (including total superoxide dismutase, copper-zinc superoxide dismutase (Cu,Zn-SOD), manganese superoxide dismutase (Mn-SOD), glutathione peroxidase and catalase (CAT)) and capacities of scavenging superoxide anion and hydroxyl radicals, markedly lowered lipid peroxidation formation of malondialdehyde and significantly up-regulated mRNA expressions of Cu,Zn-SOD, Mn-SOD, CAT, glutathione peroxidase 1, thioredoxin 1 and thioredoxin 2, in a d-galactose-induced aging mouse model. Taken together, these findings demonstrate that PSRC could be used as a novel promising source of natural antioxidants and antiaging drugs.

Active immunization against GnRH reduces the synthesis of GnRH in male rats

We sought to determine the effects of active anti-GnRH immunization on GnRH synthesis in the hypothalamus. Adult male rats (n = 36) were randomly and equally allocated into three groups: Control (no treatment), surgically castrated, or immunized against 50 μg D-Lys6-GnRH-tandem-dimer peptide conjugated to ovalbumin in Specol adjuvant at 12 week of age (with a booster 8 week later). Blood samples (for antibody titers and hormone concentrations) were collected at 2-week intervals until rats were killed (20 week). Compared with intact controls, immunocastration reduced (P < 0.05) serum concentrations of testosterone, LH, and FSH, and GnRH content in the median eminence, reduced the weight of the hypohysis (P < 0.01), and induced testicular atrophy (suppression of spermatogenesis). Furthermore, mRNA expression of GnRH in the hypothalamus, GnRH receptor, LH-β and FSH-β in the pituitary, LH receptor and FSH receptor in the testes, and genes in sex steroid feedback loops (androgen receptor [AR], kisspeptin encoded gene (Kiss-1), and kisspeptin receptor (GPR54) in the hypothalamus were decreased in immunocastrated rats compared with intact controls (P < 0.05). Similarly, surgical castration reduced GnRH in the median eminence as well as mRNA expression of GnRH, AR, Kiss-1, and GPR54 in the hypothalamus (P < 0.05). We concluded that anti-GnRH immunization in adult rats reduced synthesis of hypothalamic GnRH by decreasing androgen-AR-Kisspeptin-GPR54 signaling pathways, and caused dysfunction of the pituitary-testicular axis, thereby suppressing spermatogenesis, resulting in testicular atrophy.

Transcriptome profiling of spleen provides insights into the antiviral mechanism in Schizothorax prenanti after poly (I: C) challenge

ABSTRACT Schizothorax prenanti (S. prenanti) is an important economical cold‐water fish species in southwestern China, but it is susceptible to various pathogens infection. In order to clearly elucidate the antiviral mechanism, in this study, we have analyzed the transcriptome of S. prenanti spleen after challenge with the virus mimic, poly (I:C) (pIC), using next generation sequencing technology (RNA‐seq). A total of 313 differential expressed genes (DEGs) in spleen at 12 h were obtained after pIC treatment, including 268 significantly up‐regulated unigenes (fold change > 2) and 45 significantly down‐regulated unigenes (fold change > 2). Through the immune‐related DEGs (IRDs) screening, 47 IRDs were used to establish heat map, which intuitively showed a significantly difference after pIC treatment. To validate the RNA‐seq data and observe gene expression, the expression levels of 14 IRDs were detected by qPCR after pIC treatment at 0, 4, 8, 12, and 24 h. The results indicated that the qPCR data presented a positive line correlation with RNA‐seq data, and the 14 IRDs were responsive to pIC stimulation except IL‐1&bgr;. Thus, based on the RNA‐seq and qPCR data, we inferred that MDA5‐ and Jak‐mediated signaling pathways may involve in the antiviral signaling transduction, and induce type I IFNs and ISGs to block virus invasion, respectively. Unfortunately, TLR3 and TLR22, as receptors of virus dsRNA, were no significantly expressed in this study. Nonetheless, our study still provides useful mRNA sequences of antiviral immunity for further immunological research, and facilitates improving disease restriction in S. prenanti. HighlightsWe constructed the transcriptome library of Schizothorax prenanti after poly(I:C) treatment.We obtained 313 DEGs after poly(I:C) treatment.We screened 41 immune‐related DEGs after poly(I:C) treatment.We validated the transcriptome data and tested expression level of IRDs by qPCR at the different time points.We predicated the possible mechanism of anti‐virus in Schizothorax prenanti.

Mucosal and systemic immunity in mice after intranasal immunization with recombinant Lactococcus lactis expressing ORF6 of PRRSV

The purpose of the study was to construct mucosal vaccine of a recombinant Lactococcus lactis expressing PRRSV ORF6 gene and evaluate mucosal and systemic immune response against PRRSV in mice after intranasal immunization. The result show that the vaccine can stimulate mice to produce specific IgG in serum and remarkable special s-IgA in lung lavage fluid, at the same time, the contents of cytokines IL-2 and IFN-γ of the experimental group were significant higher than those of the control group (P < 0.01), however, the contents of cytokines IL-4 was not different to the all groups. In summary, the constructed mucosal vaccine can significantly induce mucosal immune, humoral immunity and cellular immunity involved Th1 type cytokines, which will lay a theoretical foundation on immune mechanism and new efficient vaccines for PRRSV.

Active immunization with GnRH-tandem-dimer peptide in young male rats reduces serum reproductive hormone concentrations, testicular development and spermatogenesis.

GnRH sterilization vaccines have been developed for various practical and clinical reasons. However, conjugation of GnRH peptide to carrier protein has many drawbacks, hampering the further commercialization of GnRH vaccines. In this study, a new nonconjugated GnRH vaccine, D-Lys6-GnRH-tandem-dimer peptide (TDK), emulsified in Specol adjuvant was investigated for its immunocastration efficacy in young male rats. Prepubertal male rats were randomly allocated into three groups (n = 12): control (no treatment), surgically castrated or immunized against 100 μg TDK in Specol adjuvant at 6 weeks of age (with a booster 8 weeks later). Blood samples (for antibody titers and hormone concentrations) were collected at 2-week intervals until rats were killed (18 weeks of age). Compared to intact controls, active immunization against TDK reduced (P < 0.05) serum concentrations of testosterone, inhibin B, LH and FSH, prevented the onset of spermatogenesis at puberty. Furthermore, mRNA expressions of GnRH receptor, LH-β and FSH-β in the pituitary, LH receptor, FSH receptor, inhibin α, βA and βB subunit in the testes were decreased in immunocastrated rats compared to intact controls (P < 0.05). These results demonstrate for the first time that GnRH-tandem-dimer peptide emulsified in Specol is a promising veterinary sterilization medicine.

Whole-genome sequences of 89 Chinese sheep suggest role of RXFP2 in the development of unique horn phenotype as response to semi-feralization

Abstract Background Animal domestication has been extensively studied, but the process of feralization remains poorly understood. Results Here, we performed whole-genome sequencing of 99 sheep and identified a primary genetic divergence between 2 heterogeneous populations in the Tibetan Plateau, including 1 semi-feral lineage. Selective sweep and candidate gene analysis revealed local adaptations of these sheep associated with sensory perception, muscle strength, eating habit, mating process, and aggressive behavior. In particular, a horn-related gene, RXFP2, showed signs of rapid evolution specifically in the semi-feral breeds. A unique haplotype and repressed horn-related tissue expression of RXFP2 were correlated with higher horn length, as well as spiral and horizontally extended horn shape. Conclusions Semi-feralization has an extensive impact on diverse phenotypic traits of sheep. By acquiring features like those of their wild ancestors, semi-feral sheep were able to regain fitness while in frequent contact with wild surroundings and rare human interventions. This study provides a new insight into the evolution of domestic animals when human interventions are no longer dominant.

Single Nucleotide Polymorphisms in the HIRA Gene Affect Litter Size in Small Tail Han Sheep

Simple Summary Litter size is one of the most important reproductive traits in sheep. Two single nucleotide polymorphisms (SNPs), g.71874104G>A and g.71833755T>C, in the Histone Cell Cycle Regulator (HIRA) gene, were identified by whole-genome sequencing (WGS) and may be correlated with litter size in sheep. The two SNPs were genotyped and expression patterns of HIRA was determined in sheep breeds with different fecundity and in groups of Small Tail Han sheep producing large or small litters. Association analysis indicated that both SNPs were significantly correlated with litter size in Small Tail Han sheep. Furthermore, high levels of HIRA expression may have a negative effect on litter size in Small Tail Han sheep. Abstract Maintenance of appropriate levels of fecundity is critical for efficient sheep production. Opportunities to increase sheep litter size include identifying single gene mutations with major effects on ovulation rate and litter size. Whole-genome sequencing (WGS) data of 89 Chinese domestic sheep from nine different geographical locations and ten Australian sheep were analyzed to detect new polymorphisms affecting litter size. Comparative genomic analysis of sheep with contrasting litter size detected a novel set of candidate genes. Two SNPs, g.71874104G>A and g.71833755T>C, were genotyped in 760 Small Tail Han sheep and analyzed for association with litter size. The two SNPs were significantly associated with litter size, being in strong linkage disequilibrium in the region 71.80–71.87 Mb. This haplotype block contains one gene that may affect litter size, Histone Cell Cycle Regulator (HIRA). HIRA mRNA levels in sheep with different lambing ability were significantly higher in ovaries of Small Tail Han sheep (high fecundity) than in Sunite sheep (low fecundity). Moreover, the expression levels of HIRA in eight tissues of uniparous Small Tail Han sheep were significantly higher than in multiparous Small Tail Han sheep (p < 0.05). HIRA SNPs significantly affect litter size in sheep and are useful as genetic markers for litter size.

Physiological interactions between the hypothalamic-pituitary-gonadal axis and spleen in rams actively immunized against GnRH.

Hypothalamic-pituitary-gonadal (HPG) axis is strongly implicated in the regulation of immune system. The objective was to determine the effects of immunocastration on splenic reproduction- and immunity-related gene expressions, and serum cytokine profiles in rams. Forty rams were randomly allocated into three groups: control (n=14); surgically castrated (n=13); or immunized (n=13) against 100μg D-Lys6-GnRH-tandem-dimer peptide conjugated to ovalbumin in Specol adjuvant at 6months of age (with a booster 2months later). Blood samples (for hormone and immune cytokine profiles) were collected at 1-month intervals until rams were slaughtered (10months). Compared to intact controls, anti-GnRH immunization reduced (P<0.05) serum concentrations of LH, FSH, and testosterone. Reduced testosterone abrogated its inhibitor feedback effect on the synthesis of GnRH in spleen, as evidenced by increased (P<0.05) protein content and mRNA expressions of GnRH, and simultaneously decreased (P<0.05) mRNA expressions of androgen receptor in spleen. In parallel with the increased GnRH production in spleen, the mRNA expressions of interleukin (IL)-2, IL-4, IL-6 and tumor necrosis factor alpha (TNF-α) as well as lymphocyte marker CD4, CD8 and CD19 molecules were increased (P<0.05) in spleen. Consistently, serum concentrations of IL-2, IL-4, IL-6, TNF-α were increased (P<0.05) in rams following immunization. Similarly, deprivation of testosterone by surgical castration also increased (P<0.05) GnRH and thus immune cytokine expressions in spleen. Collectively, our data suggested that immunocastration increased GnRH production in spleen by abrogating the inhibitory feedback effects from testosterone, consequently improving the immune markers of spleen and serum immune cytokines in rams.