Molecular mechanism of enhancing the immune effect of the Newcastle disease virus vaccine in broilers fed with Bacillus cereus PAS38.

The aim of this study was to explore the molecular mechanism of enhancing the immune effect of the Newcastle disease virus (NDV) vaccine in broilers fed with Bacillus cereus PAS38. The results showed that the NDV antibody titer of broilers in the treatment group supplemented with B. cereus PAS38 was higher than that of the control group, and the difference was significant at 28 days of age (P < 0.05). The spleen, thymus and bursa of fabricius of 42-day-old broilers were quickly collected to construct a differentially expressed gene library of suppression subtractive hybridization (SSH). A total of 31 immune-related differentially expressed genes were screened from three immune organs, of which 15 were up-regulated and 16 were down-regulated. After silencing the up-regulated genes MIF, CD74, DOCK2 and KLHL6, the expression levels of cytokines (Akirin2, NF-κB, IL-2, IL-4, IL-6, IFN-γ and TNF-α) in lymphocytes were reduced to varying degrees. B. cereus PAS38 might be involved in the proliferation, differentiation, activation, migration of B lymphocytes and vaccine antigen presentation by up-regulating the expression of MIF, CD74, DOCK2, KLHL6 and other genes. Moreover, it also stimulated plasma cells to produce immunoglobulins and specific antibodies, thereby improving the humoral immune function of broilers and enhancing the immune effect of the NDV vaccine.

Mulberry leaf polysaccharide supplementation contributes to enhancing the respiratory mucosal barrier immune response in Newcastle disease virus-vaccinated chicks.

Despite high global vaccination coverage, Newcastle disease (ND) remains a constant threat to poultry producers owing to low antibody levels. Given the respiratory mucosa is the important site for Newcastle disease virus (NDV) vaccination, enhancing respiratory mucosal immunity may help control ND. Our previous study showed that mulberry leaf polysaccharide (MLP) is very promising in delivering a robust balanced immune response, but the effects of it on respiratory immunity in chicks are unknown. In this study, we evaluated the potential of MLP to activate respiratory mucosal immunity and revealed the possible mechanism of MLP as an immunopotentiator for ND vaccines. Chicks were randomly divided into 5 groups: blank control, vaccination control (VC), and low-, middle-, and high-dose MLP (MLP-L, MLP-M, and MLP-H) (n = 30). The serum results of humoral and cell-mediated immune responses showed significant increases in NDV hemagglutination inhibition antibody titer, IgG and IgA antibody levels, and the T-lymphocyte population in the MLP-M group compared with the VC group. Validation of results also indicated remarkable increases in tracheal antibody-mediated immunity and a mucosal immune response in the MLP-M group. Furthermore, the upregulation of TLR7 revealed a possible mechanism. Our findings provided evidence to consider MLP as a potential mucosal vaccine adjuvant candidate against ND in chickens.

Sunflower seed oil containing ginseng stem-leaf saponins (E515-D) is a safe adjuvant for Newcastle disease vaccine.

Vaccination is an effective method to prevent Newcastle disease (ND) in chickens. Marcol 52 and #10 white oil are mineral-based adjuvants and can be found in commercial inactivated ND virus vaccines. The present study demonstrated that a vegetable origin oil E515-D had lower polycyclic aromatic hydrocarbons and higher flash point than the commercial products Marcol 52 and #10 white oil. E515-D could be mixed with an aqueous phase containing ND virus antigen to form a stable water-in-oil vaccine emulsion and exhibited more potent adjuvant effects on the immune response than Marcol 52 and #10 white oil. Moreover, the absorption of E515-D-adjuvanted vaccine was faster than absorption of Marcol 52- and #10 white oil-adjuvanted vaccines when ND virus vaccines were injected in broilers. Therefore, E515-D was safe and could be a suitable adjuvant used in vaccines for food animals. In addition，E515-D is not easy to be flammable during shipping and storage owing to its higher flash point.

Sunflower seed oil combined with ginseng stem-leaf saponins as an adjuvant to enhance the immune response elicited by Newcastle disease vaccine in chickens.

The present study was to evaluate the adjuvant effect of sunflower seed oil containing saponins extracted from the stem and leaf of Panax ginseng C.A. Meyer (E515-D) on the immune response induced by an inactivated Newcastle disease virus (NDV) in chickens. The results showed that E515-D promoted significantly higher serum NDV-specific HI and neutralizing antibody responses, IFN-γ and IL-4 levels, and lymphocyte proliferative responses to Con A, LPS, and NDV antigen than the conventional adjuvant Marcol 52. Different adjuvant effect between E515-D and Marcol 52 may be attributed to different genes expressed in two groups. Transcriptome analysis of splenocytes showed that there were 1198 differentially expressed genes (DEGs) with 539 up and 659 down regulated in E515-D group while 1395 DEGs with 697 up and 698 down regulated in Marcol 52 group in comparison with the control group. Analysis of gene ontology (GO) term and kyoto encyclopedia of Genes and Genomes (KEGG) pathways showed that the predominant immune related pathways included "Toll-like receptor signaling pathway", "NOD-like receptor signaling pathway", "C-type lectin receptor signaling pathway", and "Phosphatidylinositol signaling system" in E515-D group while Marcol 52 were "NOD-like receptor signaling pathway", "Phagosome", and "Lysosome", and the most relevant DEGs in E515-D group were STAT1, STAT2, PI3K, and IL-6. Considering the excellent adjuvant activity and vegetable origin, E515-D deserves further study as an adjuvant for vaccines used in food animals.

Immunomodulatory effect of ginseng stem-leaf saponins and selenium on Harderian gland in immunization of chickens to Newcastle disease vaccine.

Our previous study demonstrated that ginseng stem-leaf saponins (GSLS) in combination with selenium (GSLS-Se) have adjuvant effect on the live vaccine of Newcastle disease virus (NDV) and infectious bronchitis virus (IBV) in intraocular-and-intranasal immunization in chickens. The present study was to investigate the potential molecular mechanisms involved in the immunomodulation of GSLS-Se on the Harderian gland (HG). It was found that the window allowing animals susceptible to infections due to low antibody titers became smaller or even completely closed because of increased NDV-specific HI titers when NDV vaccine and GSLS-Se were coadministered for immunization at early life in chickens. In addition, NDV-specific sIgA and the numbers of IgG+, IgA+, IgM+ plasma cells were significantly more in GSLS-Se group than the control in the HGs. Transcriptome analysis of HGs identified 1184 differentially expressed genes (DEGs) between GSLS-Se treated and non-treated groups. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses identified 42 significantly enriched GO terms and 13 canonical immune pathways. These findings indicated that GSLS-Se might exert immunomodulatory effects through influencing the antioxidant regulation and modulating the activity of immune related enzymes. Besides, Toll-like receptor (TLR) signaling pathway and mitogen-activated protein kinase (MAPK) signaling pathway might be involved primarily in the immunomodulation. Therefore, enhanced antibody responses in GSLS-Se group may be attributed to the immunomodulatory effects of GSLS-Se on the immune-related gene profile expressed in the immunocompetent cells of the HGs.

Effect of zinc oxide nanoparticles on broilers' performance and health status.

The current study investigated the effects of zinc oxide nanoparticles (ZONPs) and oxytetracycline (OTC) supplementation on broilers' behavior, performance, carcass quality, biochemical parameters, and intestinal microbial populations and birds' response to Newcastle disease (ND) vaccine. A total of 336 seven-day-old IR broiler chicks were randomly allotted to six dietary treatments containing 0, 10, 20, 30 and 40 ppm ZONPs or 50 ppm OTC. Each diet was fed to 7 replicates (8 birds/pen). The results clarified that 10 ppm ZONPs significantly improved the body weight gain and feed conversion in comparison to the control. No changes in behavior were recorded. The 10 ppm and 30 ppm ZONPs and OTC significantly reduced the gizzard weight in comparison to the control. While, 10 ppm ZONPs significantly increased the spleen weight, and all ZONPs doses increased bursa weight in comparison to the control and OTC groups. 20 ppm ZONPs increased the eviscerated yield and edible yield in comparison to the control and OTC groups. 40 ppm ZONPs increased pH, reduced meat color and overall acceptability in comparison to the control. In addition, results revealed that the 20 ppm ZONPs increased Calcium (Ca), High density low cholesterol (HDL-C), reduced urea (UA) and triglyceride (TG). Also, 40 ppm ZONPs and OTC increased creatinine (Cr) and reduced ND-HI titer in comparison to the control. For microbial population, OTC group was significantly lower than ZONPs groups in the total anaerobic, aerobic and lactobacilli count. In conclusion, the dietary inclusion of ZONPs can be applied as antibiotic growth promoter substitutions in broilers' diet. However, further investigations are still needed.

Ginseng stem-leaf saponins in combination with selenium enhance immune responses to an attenuated pseudorabies virus vaccine.

Pseudorabies, a herpesvirus infection, is mainly controlled by using attenuated live vaccines. In this study, the effect of ginseng stem and leaf saponins (GSLS) in combination with selenium (Se; in the form of sodium selenite) on vaccination against attenuated pseudorabies virus (aPrV) was evaluated. It was found that GSLS and Se have an adjuvant effect and that a combination of GSLS and Se stimulates significantly enhanced immune responses than does GSLS or Se alone. Following oral administration of GSLS, mice immunized with an attenuated PrV vaccine diluted in Se-containing physiological saline solution (PSS) provoked a significantly stronger gB-specific serum antibodies response (IgG, IgG1 and IgG2a), enhanced lymphocyte proliferation and cytolytic activity of NK cells, along with higher production of cytokines (IFN-γ, IL-12, IL-5 and IL-10) by splenocytes. Notably, the combination of GSLS and Se conferred a much higher resistance to fPrV challenge after immunization of the mice with aPrV vaccine. This study offers convincing experimental evidence that an injection of Se with oral GSLS is a promising adjuvant combination that improves the efficacy of vaccination against PrV and deserves further study regarding improvement of responses to other animal vaccines.

Efficacy of CpG-ODN Administration Routes on Humoral Responses against Newcastle disease in Broilers.

Un-methylated cytosine-phosphate-guanosine oligodeoxynucleotides (CpG-ODN) has been considered as a powerful vaccine adjuvant and recognition of CpG-ODN by chicken leukocytes promotes their ability to fight against infections. In our study, efficacy of different routes of CpG-ODN application as an adjuvant on immune responses (antibody titer together with leukogram) following vaccination against Newcastle disease (ND) has been evaluated in broiler chickens (Ross-308). The results indicated that routes of CpG-ODN administration influence immune responses and comparison effectiveness of CpG-OND delivery routes showed that group vaccinated by eye-drop application had the highest antibody titer than that of the group injected intramuscularly (im) and the difference was significant (p = 0.04) on day 35 of age. Antibody titer of the group treated with Clone 30 plus CpG-ODN via eye-drop route was higher than that of the group vaccinated with clone 30 alone on days 28 and 35 of age and the difference was significant (p = 0.04). Co-administration of both vaccine and CpG improved outcome of leukogram of the chickens on days 21 to 42 of age and among the treated groups, WBC of the group received both vaccine and CpG by eye-drop route significantly (p &lt; 0.05) differed from that of the group vaccinated with clone 30 alone on days 28 and 35 but not on day 42 of age. Average final body weight of the control group did not significantly differ from those of the treated groups at end of the experiment. In conclusion, co-administration of ND vaccine plus CpG-ODN via eye-drop route improves immune responses.

Effects of beta-1,3-glucan (AletaTM) on vaccination response in broiler chickens.

This 42-day study evaluated the effects of dietary supplementation with ß-1,3-glucan (Aleta™) on the vaccination response to Newcastle disease virus (NDV), avian infectious bronchitis virus (IBV), and infectious bursal disease (IBD) in a non-challenged environment. This trial included 600 chicks (all vaccinated with IBD at the hatchery) which were assigned to 1 of 3 treatments: vaccination (NDV, IBV), no vaccination, or vaccination combined with feed supplemented with Aleta (100 g/MT of feed). The vaccination with Aleta treatment group showed a trend for improved FCR that was not statistically significant. Control birds that were not vaccinated for IBV had significantly lower IBV titers on day 21 compared to birds that were vaccinated (both with and without Aleta). Surprisingly, there was significant separation among treatment groups for NDV titer levels, especially on day 21, where birds vaccinated and supplemented with Aleta had significantly higher titer levels compared to vaccination alone or no vaccination at all. Critically, only 14% of the birds receiving the vaccine plus Aleta had titer levels below the critical titer threshold for immunity compared to 28% of the birds receiving the vaccine alone and 40% of the unvaccinated birds. This suggests that Aleta supplementation may help to improve the vaccination response by birds, especially for NDV.

Explore the potential effect of natural herbals to resist Newcastle Disease Virus.

In this study, we examined the dose-dependent effects of the formula on Newcastle disease virus (NDV). In in-vitro test, the formula within safety concentration scope and NDV were added into cultured chick embryo fibroblast in 3 modes, and the cellular A570 values were determined by MTT (3-(4, 5-dimethyithiazol-2-yl)-2, 5-diphenyltetrazolium bromide) method. In in-vivo test, we examined the expression of interferon-induced transmembrane protein 3 (IFITM3) and Interferons (IFNs) in NDV-infected chickens. The results showed that the highest virus inhibitory rates of the formula at optimal concentration group were the highest (15.625 mg/mL) in post-adding and simultaneous-adding drug and virus modes, whereas medium concentration (7.813 mg/mL) showed the highest virus inhibitory rates in pre-adding drug mode. In vivo, the formula significantly upregulated the expression of IFITM3 in NDV-infected chickens at 3-D post-infection. However, the levels of IFNs were significantly downregulated. On days 5 and 7 post-infection, the levels of IFNs quickly upregulated. Moreover, the formula can significantly upregulate the antibody to resist the NDV compared with model control group on days 5 and 7 post-infection. In animals treated with the formula, the survival rate was nearly 37% higher at 7 d post-infection. We also found that the formula had a significantly stronger effect than a single herb on upregulating the expression of IFITM3. It confirmed that the formula could significantly inhibit the infectivity of NDV to chick embryo fibroblast. Also, the formula could significantly upregulated IFITM3 expression and inhibited virus replication in NDV-infected chickens. During the early stage of infection, IFNs were consumed to stimulate IFITM3 to inhibit virus replication, whereas during later stages of the infection, the formula upregulated the levels of IFNs and their antibodies to maintain a high level of immunity.

Newcastle disease vaccine adoption by smallholder households in Tanzania: Identifying determinants and barriers.

BACKGROUND: Food security is critical to achieving sustainable growth, poverty reduction, and political and economic stability. Livestock have the potential to improve the food security of smallholder households in developing countries, but livestock productivity is constrained by disease. The extent to which households adopt innovations such as vaccines impacts disease control; however, the behavioral and economic drivers underlying household decisions to adopt or forgo vaccination are not well understood. We address this gap with a study of adoption of Newcastle disease (ND) vaccines by chicken-owning households in Tanzania. METHODS: A cross-sectional survey was administered to 535 households owning indigenous chickens in Arusha, Singida, and Mbeya regions in Tanzania. We measured potential predictors of ND vaccine adoption including knowledge, attitudes, and practices. Logistic regression was used to identify predictors correlated with three stages of household adoption: awareness of ND vaccines, previous vaccination, and recent vaccination (within four months) consistent with veterinary guidelines. RESULTS: Eighty percent of households were aware of ND vaccines, 57% had previously vaccinated, and 26% had recently vaccinated. Knowing someone who vaccinated increased the odds of a household previously vaccinating [adjusted odds ratio (AOR): 1.32, 95% CI: 1.1-1.5]. Larger flock size was also associated with higher odds of previous vaccination (AOR: 1.03 for a one chicken increase, 95% CI: 1.01-1.05). Usage of traditional medicine decreased the odds of previously vaccination (AOR: 0.58, 95% CI: 0.36-0.95). CONCLUSION: Our findings suggest that encouraging the flow of professional-level knowledge within the community by vaccine adopters is a strategy to increase vaccine adoption. Enhancing local chicken productivity through increased vaccine coverage would strengthen a key smallholder household resource for food and economic security.

Oral administration of tea saponins to relive oxidative stress and immune suppression in chickens.

The present study was designed to evaluate the effects of tea saponins on oxidative stress induced by cyclophosphamide in chickens. One hundred twenty chickens were randomly divided into 5 groups. Groups 3 to 4 received intramuscular injection of cyclophosphamide to induce oxidative stress and immunosuppression. After that, groups 2 and 4 were orally administered tea saponins in drinking water for 7 d. Then, groups 1 to 4 were immunized with a live, bivalent vaccine of Newcastle disease virus and infectious bronchitis virus. Blood samples were collected for analysis of oxidative parameters and specific antibody titers, and splenocytes were prepared for lymphocyte proliferative assay. The results showed that administration of tea saponins significantly increased total antioxidant capacity, total superoxide dismutase, catalase, glutathione peroxidase, glutathione, ascorbic acid, and α-tocopherol, and decreased malondialdehyde and protein carbonyl. Enhanced immune responses, such as lymphocyte proliferation induced by concanavalin A and lipopolysaccharides, and serum Newcastle disease virus- and infectious bronchitis virus-specific antibodies were also observed in chickens injected with or without cyclophosphamide. In addition, no side effects were found in chickens throughout the study. Therefore, tea saponins may be a potential agent to improve imunosuppression induced by oxidative stress in chickens.

Effects of pidotimod soluble powder and immune enhancement of Newcastle disease vaccine in chickens.

The aims of this study were to prepare pidotimod (PDM) soluble powder and to investigate the immune enhancement properties of PDM in chickens vaccinated with Newcastle disease virus vaccine. In vivo experiment, 360 6-day-old chickens were averagely divided into 6 groups. The chickens, except blank control (BC) group, were vaccinated with Newcastle disease vaccine (NDV). At the same time of the vaccination, the chickens in three PDM groups were given water with PDM for 5days, respectively, with the PDM at low, medium and high concentrations (0.25g/L, 0.5g/L, 1g/L), in control drug group was treated with 0.2ml/PDM dose via drinking water, in vaccination control (VC) and BC group, with equal volume physiological saline, once a day for five successive days. On days 14, 21 and 28 after the vaccination, the growth performance, the lymphocyte proliferation, serum antibody titer, the CD4/CD8 cell ratios and interleukin-2 (IL-2) and interferon-gamma (IFN-γ) were measured. The results showed that PDM at suitable dose could significantly promote growth performance, lymphocyte proliferation, enhance serum antibody titer, CD4/CD8 cell ratios and improve serum IL-2 and IFN-γ concentrations. It indicated that PDM could significantly improve the immune efficacy of Newcastle disease vaccine using doses of 0.5g/L, these results are consistent with the drug acting as an immunopotentiator.

Modification of lily polysaccharide by selenylation and the immune-enhancing activity.

Lily polysaccharide (LP) was extracted, purified and selenizingly modified by HNO3-Na2SeO3 method according to L9(3(4)) orthogonal design. Nine selenizing LPs, sLP1-sLP9, were obtained and their immune-enhancing activities were compared taking unmodified LP as control. The results in vitro test showed that sLP6 presented the strongest activity in promoting lymphocytes proliferation in single and synergetic with PHA, and the relative expression level of IL-2, IL-6 and IFN-γ mRNA of chicken peripheral lymphocytes. The results in vivo test showed that sLP6 could promote lymphocytes proliferation and enhance the serum antibody titers and serum IL-2, IL-6, IFN-γ contents more significantly than LP in chickens vaccinated with Newcastle Disease (ND) vaccine. These results indicate that polysaccharide selenizing can significantly enhance the immune-enhancing activity of LP and the optimal modification conditions are 400 mg of Na2SeO3 per 500 mg of LP, the reaction temperature of 70 °C and the reaction time of 6 h.

Improved immune responses to a bivalent vaccine of Newcastle disease and avian influenza in chickens by ginseng stem-leaf saponins.

Our previous investigation demonstrated that ginseng stem-leaf saponins (GSLS) derived from the stems and leaves of Panax ginseng C.A. Meyer promoted humoral and gut mucosal immunity in chickens vaccinated with live infectious bursa disease vaccine. The present study was designed to evaluate the effect of GSLS on the immune response to a bivalent inactive vaccine of Newcastle disease (ND) and avian influenza (AI) in chickens immunosuppressed by cyclophosphamide (Cy). One hundred and sixty-eight specific-pathogen-free (SPF) chickens were randomly divided into 7 groups, each containing 24 birds. Chickens in groups 3-7 received intramuscular injection of Cy at 100mg/kg BW for 3 days to induce immunosuppression. Groups 1 and 2 were injected with saline solution in the same way as groups 3-7. Following injection of Cy, groups 4-7 were orally administrated GSLS (2.5, 5 and 10mg/kg BW) or astragalus polysaccharide (APS) (200mg/L) in drinking water for 7 days; groups 1-3 were not medicated and served as control birds. After administration of GSLS or APS, groups 2-7 were subcutaneously injected with a bivalent inactive vaccine of ND and AI. After that, serum was sampled for detecting antibody titers by HI, spleen was collected for lymphocyte proliferation assay, and duodenum tissues were collected for measurement of IgA-secreting (IgA+) cells and intestinal intraepithelial lymphocytes (iIELs). The results showed that injection of Cy significantly suppressed immunity in chickens; oral administration of GSLS before immunization recovered splenocyte proliferation induced by ConA and LPS, and the numbers of IgA+ cells and iIELs as well as the specific antibody response to a bivalent inactive vaccine of ND and AIin immunosuppressed chickens treated with Cy. Therefore, GSLS may be the potential agent to improve vaccination in immunosuppressed chickens.

Sulphated polysaccharides from Ulva clathrata and Cladosiphon okamuranus seaweeds both inhibit viral attachment/entry and cell-cell fusion, in NDV infection.

Sulphated polysaccharides (SP) extracted from seaweeds have antiviral properties and are much less cytotoxic than conventional drugs, but little is known about their mode of action. Combination antiviral chemotherapy may offer advantages over single agent therapy, increasing efficiency, potency and delaying the emergence of resistant virus. The paramyxoviridae family includes pathogens causing morbidity and mortality worldwide in humans and animals, such as the Newcastle Disease Virus (NDV) in poultry. This study aims at determining the antiviral activity and mechanism of action in vitro of an ulvan (SP from the green seaweed Ulva clathrata), and of its mixture with a fucoidan (SP from Cladosiphon okamuranus), against La Sota NDV strain. The ulvan antiviral activity was tested using syncytia formation, exhibiting an IC50 of 0.1 µg/mL; ulvan had a better anti cell-cell spread effect than that previously shown for fucoidan, and inhibited cell-cell fusion via a direct effect on the F0 protein, but did not show any virucidal effect. The mixture of ulvan and fucoidan showed a greater anti-spread effect than SPs alone, but ulvan antagonizes the effect of fucoidan on the viral attachment/entry. Both SPs may be promising antivirals against paramyxovirus infection but their mixture has no clear synergistic advantage.

Adjuvant effects of chitosan and calcium phosphate particles in an inactivated Newcastle disease vaccine.

The adjuvant activity of chitosan (CS) and calcium phosphate (CAP) particles was studied following intranasal (mucosal) administration to commercial chickens with inactivated Newcastle disease virus (NDV) vaccine. After three vaccinations with inactivated NDV in combination with CS or CAP an increase in antibody titers in blood and mucosal samples in chickens was observed when compared with the administration of NDV antigen only. A lower level of humoral immunity was observed in broiler chickens compared to layer-type birds. The CS-based vaccine demonstrated higher antigenic and protective activity following lethal challenge than the vaccine containing CAP. Because CS particles efficiently changed mucosal and humoral immunity and protective activity, CS may in the future be considered for use as a potential adjuvant for production of vaccines for poultry.

The immunological adjuvant activity of gypenosides liposome against Newcastle disease vaccine.

The adjuvant activity of gypenosides liposome (GPSL) encapsulated with liposome was investigated in vitro and in vivo. In vitro, different concentrations of GPSL were added into chicken's peripheral blood lymphocytes and splenic lymphocyte. The results showed that GPSL could significantly enhance T and B lymphocytes proliferation singly or synergistically with PHA and LPS and the efficacy were superior to those of gypenosides (GPS) and blank liposome (BL) at most of concentrations. In vivo, three hundred and fifty 14-day-old chickens were assigned to 7 groups randomly and vaccinated with Newcastle disease (ND) vaccine. Simultaneously, the chickens in experimental groups were, respectively, oral administration with the GPSL at three doses, GPS and BL. The results showed that GPSL could significantly enhance lymphocyte proliferation, increase antibody titer, and promote cytokine secretion in vitro and in vivo, moreover, the adjuvant activity of GPSL was better than those of GPS and BL. These indicated that formulations of GPS and liposome can further enhance the immune response against ND vaccine compared with the adjuvant alone.

Effects of Taishan Robinia pseudoacacia Polysaccharides on immune function in chickens.

To determine the immune function of Taishan Robinia pseudoacacia Polysaccharide (TRPPS) on chickens, 240 chickens were selected as experimental animals and treated with various doses of TRPPS by hypodermic injection before immunized NDV inactivated vaccine. The results indicated that any dose of TRPPS could significantly promote the development of the immune organs, increase the quantity of leukocyte and the ratio of lymphocyte, and improve the antibody titers against Newcastle disease. Meanwhile, it also increased the magnitude of SIgA in duodenum. However, the dose of 200 mg/ml showed to be the most effective. Therefore, in terms of improving immunologic function and production performance, TRPPS could be used as a vaccine immunopotentiator for immune responses.

Effect of epimedium polysaccharide-propolis flavone immunopotentiator on immunosuppression induced by cyclophosphamide in chickens.

Two hundred and fifty 11-day-old chickens were randomly assigned into 5 groups and except normal control group injected with cyclophosphamide once a day for 3 successive days. At day-14-old, all chickens were vaccinated with Newcastle disease vaccine. At the same time of the first vaccination, the chickens in three experimental groups were injected respectively with epimedium polysaccharide-propolis flavone immunopotentiator (EPI) at three dosages, once a day for 3 successive days. On days 7, 14, 21 and 28 after the first vaccination, the serum antibody titer and IgG, IgM, IFN-γ and IL-6 concentrations, peripheral lymphocyte proliferation, including immune organ index on day 28, were measured. The results demonstrated that EPI at high and medium doses could significantly enhance antibody titer and IgG, IgM, IFN-γ and IL-6 concentrations, promote lymphocyte proliferation and enlarge immune organ index as compared with model control group. This indicated that EPI could effectively resist the immunosuppression.