Xingfa Han

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.

Chuanminshen violaceum polysaccharides improve the immune responses of foot-and-mouth disease vaccine in mice

Water-soluble polysaccharides from Chuanminshen violaceum (CVPS) were evaluated for their physicochemical properties, monosaccharide composition, and adjuvant potential to specific cellular and humoral immune responses in a mouse model of foot-and-mouth disease virus (FMDV) vaccination. The average molecular weight (Mw) of the CVPS was 968.31 kDa. The monosaccharide components of the CVPS was rhamnose, arabinose, fucose, mannose, glucose, and galactose with a relative mass of 6.29%, 21.87%, 16.59%, 12.54%, 13.07%, and 28.05%, respectively. Administering CVPS as an adjuvant significantly enhanced the phagocytic capacity of peritoneal macrophages, splenocyte proliferation, and the activity of NK cells and CTL as well as increased FMDV-specific IgG and IgG subclass antibody titers. Moreover, CVPS increased the expression of IL-2, IFN-γ, and IL-4 in CD4(+) T cells and IFN-γ expression in CD8(+) T cells. Additionally, CVPS enhanced CD40(+), CD80(+), and CD86(+) expression on DCs. Moreover, CVPS upregulated MHC-I/II, TLR-2/4 mRNA levels. In contrast, CVPS downregulated TGF-β mRNA expression and the frequency of CD4(+)CD25(+)Foxp3(+) Treg cells. Taken together, these results indicate that administering CVPS as an adjuvant enhances both cellular and humoral immune responses via the TLR-2 and TLR-4 signalling pathways, thereby promoting DC maturation and suppressing TGF-β expression and 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.

Sulfated Radix Cyathulae officinalis Polysaccharides Act as Adjuvant via Promoting the Dendritic Cell Maturation and Suppressing Treg Frequency

This study was conducted to evaluate the adjuvant potential of sulfated Radix Cyathulae officinalis Kuan polysaccharides (sRCPS) and their effects on specific cellular and humoral immune responses to hepatitis B subunit vaccine in mice. Our data demonstrated that sRCPS significantly promoted the rHBsAg-specific IgG, IgG1, IgG2a, and IgG2b antibody titers, the activities of natural killer cells (NK) and cytotoxic T lymphocytes (CTL), T cells proliferation, and phagocytic capacity of peritoneal macrophages. Furthermore, sRCPS increased the levels of IL-4, IL-2, and IFN-γ in CD4+T cells and the level of IFN-γ in CD8+T cells. In addition, sRCPS enhanced the expression of CD40+, CD80+, CD86+, MHC I and MHC II in dendritic cells (DCs) and upregulated the mRNA levels of MHC I, MHC II. sRCPS downregulated the frequency of CD4+CD25+Foxp3+ Treg cells. sRCPS increased both cellular and humoral immune responses by upregulating DC maturation, and suppressing the frequency of Treg cells.

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.

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.

Active immunisation against pregnenolone reduces testicular steroidogenesis and GnRH synthesis in rabbits

To investigate the effects of active immunisation against pregnenolone on reproductive traits in rabbits, 16 early pubertal male rabbits (4mo old) were randomly and equally allocated into two groups, control or immunised against pregnenolone-hemisuccinate-BSA in Freunds adjuvant (with a booster 4wk later). Blood samples (for antibody titres and hormone concentrations) were collected at 2 or 4wk-intervals after immunisation until rabbits were killed, 24wk after the primary immunisation. Compared to controls, rabbits immunised against pregnenolone had increased serum antibody titres (P<0.01) and decreased serum concentrations of both testosterone and LH (P<0.01 for each). At 24wk after the primary immunisation, testes were severely atrophied, spermatogenesis was arrested and steroidogenesis was suppressed, as evidenced by lesser amounts of testicular cholesterol side-chain cleavage cytochrome P-450 and 17α-hydroxylase cytochrome P-450 mRNA (P<0.05). Furthermore, the amounts of mRNA for GnRH in the arcuate nucleus (Arc), of the hypothalamus and GnRH receptor and LH-β in the pituitary and genes in sex-hormone negative feedback loops (androgen receptor, oestrogen alpha receptor, kisspeptin encoded gene and kisspeptin receptor) in the Arc were decreased in pregnenolone-immunised rabbits compared to controls (P<0.05). It was concluded that immunisation against pregnenolone directly blocked testicular steroidogenesis, which reduced synthesis of hypothalamic GnRH and subsequently synthesis of pituitary LH by abolishing the permissive action of sex steroids on hypothalamic GnRH neurons, thereby disrupting spermatogenesis. This was apparently the first report that active immunisation against pregnenolone was a means of immunological castration.

Transcriptome analysis of spleen reveals the signal transduction of toll-like receptors after Aeromonas hydrophila infection in Schizothorax prenanti

Schizothorax prenanti (S. prenanti), an important species of economical fish in Southwest China, is susceptible to Aeromonas hydrophila (Ah). To understand the immune response to Ah, the transcriptome profiling of spleen of S. prenanti was analyzed after Ah infection. A total of 6, 213 different expression genes (DEGs) were obtained, including 3, 066 up-regulated DEGs and 3, 147 down-regulated DEGs. These DEGs were annotated by KEGG and GO databases, so that the immune-related DEGs (IRDs) can be identified and classified. Then, the interesting IRDs were screened to build heat map, and the reliability of the transcriptome data was validated by qPCR. In order to clarify the mechanism of signal transduction in the anti-bacterial immunity, the signaling pathway initiated by TLRs was predicted. In this pathway, TLR25 and TLR5 mediate the NF-κB and AP-1 signals via MyD88-dependent pathway. Meanwhile, the type I IFN (IFNα/β) induced by IRF1 and IRF3/7 may play an important role in the anti-bacterial immunity. In conclusion, this study preliminarily provides insights into the mechanism of signal transduction after Ah infection in S. prenanti, which contributes to exploring the complex anti-bacterial immunity.