左旋咪唑在猪瘟疫苗接种猪中免疫调节作用的研究

本研究采用 2 0头 40— 45日龄仔猪 ,随机分为试验组和对照组。两组猪只均肌肉接种猪瘟疫苗 1头份。从疫苗接种的当日开始 ,在试验组猪只饲料内按每天每公斤体重 8mg计算 ,拌入盐酸左旋咪唑 ,连服三日 ;对照组不服左旋咪唑。于接苗后的 10、40、70和 10 0天 ,分别由两组猪只耳静脉采血 ,分离血清 ,供测定血清抗体用。同时 ,分别取两组猪只血样作成血涂片 ,供检测T淋巴细胞用。试验结果 :除接苗后 40天 ,试验组与对照组血清抗体效价的几何平均数相同外 ,于接苗后的 10和10 0天 ,试验组血清抗体效价稍高于对照组 ,但两组间的差异不显著 (p >0 .0 5 )。于接苗后 10天 ,试验组T淋巴细胞的百分率显著高于对照组 (P <0 .0 5 )。由此可见 ,猪只在接种猪瘟疫苗的同时 ,服用左旋咪唑 ,可以促进T淋巴细胞的增殖 ,增强其免疫力。

左旋咪唑对鸡传染性法氏囊病疫苗接种鸡的免疫调节作用的研究

本研究采用 70只无母源抗体的 14日龄雏鸡 ,随机分为试验组和对照组。两组雏鸡均口服接种IBD疫苗 1只份。从疫苗接种的当日开始 ,在试验组雏鸡的饲料内按每天每公斤体重 15mg计算 ,拌入盐酸左旋咪唑 ,连服三日 ;对照组不服左旋咪唑。于接苗后的 10、2 0、30、40和 5 0天 ,从两组雏鸡中随机各取 30只由翅静脉采血 ,析出血清 ,供测定血清抗体用。同时 ,从各组鸡血样中随机各取 10份 ,作成血涂片 ,供检查T淋巴细胞用。试验结果 :试验组琼脂扩散抗体出现的时间似比对照组稍早、抗体阳性率下降略迟 ,但两组间差幅不大。试验组T淋巴细胞明显高于对照组。由此可见 ,雏鸡在接种IBD疫苗的同时 ,服用左旋咪唑 ,可以促进T淋巴细胞增殖 。

丰城市某镇2000-2009年乙肝疫苗接种概况及乙肝流行病学分析

目的:分析尚庄街办2000年-2009年乙肝疫苗接种、乙肝发病率、1-15岁人群乙肝免疫状况。方法:对尚庄2000年-2009年乙肝接种资料、发病资料、免疫状况进行流行病学分析。结果:乙肝疫苗接种率已提高、发病率下降、乙肝表面抗体阳性率随年龄增加而下降。结论:控制乙肝发生的主要方法应当是加强乙肝疫苗接种、管理好乙肝表面抗原阳性人群。

探讨单侧下回风局部百级洁净区的影响因素

本文运用CFD技术以疫苗车间接毒无菌室为例,探讨了干扰采用FFU单侧下回风形式的局部百级洁净区流场的各种因素和影响程度,这对类似局部百级洁净区的优化设计具有较重要的理论意义与工程应用价值。

An effective vaccine against colon cancer in mice:Use of recombinant adenovirus interleukin-12 transduced dendritic cells

AIM： To investigate the effect of a vaccine with recombinant adenovirus interleukin-12 （AdVIL-12） transduced dendritic cells （DCs） against colon cancer in mice. METHODS： DCs and AdVIL-12 were incubated together at different time intervals and at different doses. Supernatant was collected and tested for IL-12 by enzyme-linked immunosorbent assay （ELISA）. In order to determine whether tumor cell lysate-pulsed （TP） AdVIL-12/DCs enhance therapeutic potential in the established tumor model, CT26 colon tumor cells were implanted subcutaneously （s.c.） in the midflank of naive BALB/c mice. Tumor-bearing mice were injected with a vaccination of CT26 TP AdVIL-12/DCs on d 3 and 10. As a protective colon tumor model, naive BALB/c mice were immunized s.c. in their abdomens with CT26 TP AdVIL-12/DCs twice at seven day intervals. After the immunization on d 7, the mice were challenged with a lethal dose of CT26 tumor cells and survival times were evaluated. Subsequently, cytotoxic T lymphocyte （CTL） activity and interferon gamma （IFNy） secretion was evaluated in the immunized mice, and assayed CTL ex vivo. RESULTS： Murine DCs were retrovirally transduced with AdVIL-12 efficiency, and the AdVIL-12 transduced DCs secreted a high level of IL-12 （AdVIL-12/DCs, 615.27 ± 42.3 pg/mL vs DCs, 46.32 ± 7.29 pg/mL, P 〈 0.05）. Vaccination with CT26 TP AdVIL-12/DCs could enhance anti-tumor immunity against CT26 colon tumor in murine therapeutic models （tumor volume on d 19：CT26 TP AdVIL-12/DCs 107 ± 42 mm^3 vs CT26 TP DCs 383± 65 mm^3, P 〈 0.05） and protective models. Moreover, the CT26 TP AdVIL-12/DC vaccination enhances tumor-specific CTL activity, producing high levels of IFN7 in immunized mice. Ex vivo primed T cells with AdVIL-12/DCs were able to induce more effective CTL activity than in primed T cells with CT26 TP/DCs （E：T = 100：1, 69.49% ± 6.11% specific lysis vs 37.44% ＋ 4.32% specific lysis, P 〈 0.05）.CONCLUSION： Vaccination with recombinant AdVIL-12 transduced DC pulsed tumor cell lysate enhance antitumor immunity specific to colon cancer in mice.

Immune response to an indigenously developed r-Hepatitis B vaccine in mixed population: Study of an accelerated vaccination schedule

AIM: To establish the safety and efficacy of an indigenously developed r-hepatitis B vaccine using an accelerated schedule and to highlight the social awareness and commitment in preventing the spreading of hepatitis B virus infection. METHODS: The study was a multicentric, double blind, randomized (3:1) study using three doses of vaccine immunization schedule (20μg for those above 10 years old and 10 μg for those below 10 years old) on d 0, 30 and 60. One hundred and sixty-six subjects were enrolled (87 males and 76 females aged 5-35 years). The main outcome measure was assessment of immunogenicity and safety. RESULTS: A 100% seroconversion response was observed on the 30th d after the 1st injection in both the experimental groups. The sero-protection data reported a 41.2-65.6% response on the 30th d after the 1st injection and reached 100% on the 60th d. Descriptive statistical analysis showed a geometric mean titer value of 13.77 mIU/mL in the test (BEVAC) group and 10.95 mlU/mL in the commercial control (ENGERIX-B) group on the 30th d after the 1st injection. The response on the 60th d showed a geometric mean titre value (GMT) of 519.84 mlU/mL in the BEVAC group and 475.46 mlU/mL in the ENGERIX-B group. On the 90th d, the antibody titer response was observed to be 2627.58 mlU/mL in the BEVAC group and 2272.72 mlU/mL in the ENGERIX-B group. Two subjects in each group experienced pains at injection site after the first vaccination. A total of six subjects in both groups experienced a solicited adverse reaction, which included pains, swelling and redness at the injection site, three subjects in the group-B had a pain at the injection site after the third dose. No other serious adverse events occurred and no dose-related local or general symptoms were observed during the study. CONCLUSION: The vaccine is safe, efficacious and immunogenic in comparison with the well documented ENGERIX-B.

Therapeutic effect of autologous dendritic cell vaccine on patients with chronic hepatitis B: A clinical study

AIM: To investigate the therapeutic effect of autologous HBsAg-loaded dendritic cells (DCs) on patients with chronic hepatitis B. METHODS: Monocytes were isolated from fresh peripheral blood of 19 chronic HBV-infected patients by Ficoil-Hypaque density gradient centrifugation and cultured by plastic-adherence methods. DCs were induced and proliferated in the culture medium with recombinant human granulocyte-macrophage-colony- stimulating factor (rhGM-CSF) and human interleukin-4 (rhIL-4). DCs pulsed with HBsAg for twelve hours were injected into patients subcutaneously twice at intervals of two weeks. Two patients received 100 mg oral lamivudine daily for 12 mo at the same time. HBV-DNA and viral markers in sera of patients were tested every two months. RESULTS: By the end of 2003, 11 of 19 (57.9%) patients had a clinical response to DC-treatment. HBeAg of 10 (52.6%) patients became negative, and the copies of HBV-DNA decreased 101.77±2.39 averagely (t = 3.13, P<0.01). Two cases co-treated with DCs and lamivudine had a complete clinical response. There were no significant differences in the efficient rate between the cases with ALT level lower than 2xULN and those with ALT level higher than 2xULN before treatment (X2 = 0.0026). CONCLUSION: Autologous DC-vaccine induced in vitro can effectively suppress HBV replication, reduce the virus load in sera, eliminate HBeAg and promote HBeAg/anti-HBe transformation. Not only the patients with high serum ALT levels but also those with normal ALT levels can respond to DC vaccine treatment, and the treatment combining DCs with lamivudine can eliminate viruses more effectively.

Identification of the immunogenic domains in HBsAg preS1 region using overlapping preS1 fragment fusion proteins

AIM: The incorporation of hepatitis B virus (HBV) preS1 region into epitope-based vaccines against HBV has been accepted widely, but the incorporate site and size of preS1 sequence is controversial. Therefore our purpose was to further investigate its immunogenic domains for the epitopebased hepatitis B vaccine design.METHODS: Eight GST fusion proteins containing overlapping preS1 fragments in preS1 (21-119) region were expressed in E.coli. Using these purified fusion proteins, the immunogenic domains in preS1 region were identified in detail in mice and humans by Western blot analysis and ELISA.RESULTS: The results in mice showed that the immunogenic domains mainly existed in preS1 (21-59) and preS1 (95-109). Similarly, these fragments had strong immunogenicity in humans; whereas the other parts except for preS1 (60-70) also had some immunogenicity.More importantly, a major immunogenic domain, preS1 (34-59), which has much stronger immunogenicity, was identified. Additionally, the antibodies against some preS1 fragments, especially preS1 (34-59), were speculated to be virus-neutralizing.CONCLUSION: Eight GST fusion proteins containing overlapping preS1 fragments were prepared successfully. They were used for the study on the immunogenic domains in preS1 (21-119) region. The preS1 (34-59) fragments were the major immunogenic domains in the preS1 region, and the antibodies against these fragments were speculated to be virus-neutralizing. Therefore, the incorporation of preS1 (34-59) fragments into epitopebased HBV vaccines may be efficient for enhancement of immune response. Additionally, the results also imply that there are more complex immune responses to preS1 region and more abundant immunogenic domains in humans.

Study on Passive Immunity:time of Vaccination in Kids Born to Goats Vaccinated Against Peste des petits ruminants

In this study,the decay of maternal peste des petits ruminants virus(PPRV) antibodies in kids born to goats vaccinated with Asian lineage IV PPR vaccine and the efficacy of passive immunity against PPRV was assessed to determine the appropriate period for vaccination in kids.Serum samples collected from kids born to vaccinated,unvaccinated and infected goats at different time intervals were tested by PPR competitive ELISA and serum neutralization test(SNT).Maternal antibodies in kids were detectable up to 6 months with a decline trend from the third month onwards and receded below the protective level by the fourth month.The kid with an SN titre of 1:8 at the time of immunization showed significant PPRV specific antibody response(percentage inhibition of 76;SN titers >1:16),when tested on 21 day post-vaccination and was completely protected from infection upon virulent PPRV challenge.Similarly,the kid with 1:8 SN titers was completely protected from PPR infection on active challenge.Therefore,PPR vaccination is recommended in kids,aged 4 months and born to immunized or exposed goats.This could be a suitable period to avoid window of susceptibility in kids to PPRV and the effort to eliminate PPR infection from susceptible populations.

Improvement of the efficacy of influenza vaccination (H5N1) in chicken by using extract of Cochinchina momordica seed (ECMS)

Seeds of a Chinese traditional medicine plant, Cochinchina momordica were used in the present study for the improvement of influenza vaccine （HSN 1） in chicken. Crude extraction from Cochinchina momordica seed （ECMS） was obtained by ethanol extraction method. In experiment No. 1, two weeks old chickens were immunized with influenza vaccine （HSN1） alone or combined with ECMS （5, 10, 20, 40 and 80 μg/dose）. Serum IgG antibody levels （by ELISA） as well as effects on dally weight gain were measured on 0, 7, 14 and 28th day after immunization. Results revealed that all ECMS groups numerically increased the antibody levels while 10 and 20 μg/dose groups significantly （P〈0.05） enhanced total IgG antibody on day 28, when compared with control. Average daily weight gain was also significantly higher in 20 μg/dose ECMS group. Adjuvant effect was also confirmed in experiment No. 2 when chickens were immunized with 20 μg/dose ECMS and antibody titer was measured through hemagglutination inhibition （HI）. It is concluded that ECMS has potential to improve the immune responses and deserve further study as an adjuvant.

New therapeutic vaccination strategies for the treatment of chronic hepatitis B

Chronic hepatitis B virus(CHB) is currently treated with either interferon-based or nucleot(s)idebased antiviral therapies.However,treatment with pegylated interferon alpha results in a durable antiviral response in only about 30%patients and is associated with side effects.Most patients receiving nucleot(s)ide analogue treatment do not establish long-term,durable control of Infection and have rebounding viremia after cessation of therapy.Thus,novel therapy strategies are necessary to achieve the induction of potent and durable antiviral immune responses of the patients which can maintain long-term control of viral replication.Therapeutic vaccination of HBV carriers is a promising strategy for the control of hepatitis B.Here the authors review new therapeutic vaccination strategies to treat chronic hepatitis B which may be introduced for patient treatment in the future.

Oral vaccination of mice against rodent malaria with recombinant Lactococcus lactis expressing MSP-1_(19)

AIM： To construct the recombinant Lactococcus/actis as oral delivery vaccination against malaria. METHODS： The C-terminal 19-ku fragments of MSP1 （MSP-119） of Plasmodium yoelii265-BY was expressed in L. lactis and the recombinant L. lact/s was administered orally to BALB/c and C57BL/6 mice. After seven interval vaccinations within 4 wk, the mice were challenged with P. yoelii 265-BY parasites of erythroo/tic stage. The protective efficacy of recombinant L. lactiswas evaluated. RESULTS： The peak parasitemias in average for the experiment groups of BALB/c and C57BL/6 mice were 0.8± 0.4% and 20.8±26.5%, respectively, and those of their control groups were 12.0±0.8% and 60.8±9.6%, respectively. None of the BALB/c mice in both experimental group and control group died during the experiment. However, all the C57BL/6 mice in the control group died within 23 d and all the vaccinated mice survived well. CONCLUSION： The results imply the potential of recombinant L. lactis as oral delivery vaccination against malaria.

Vaccination in three different ways against vibriosis of Seriola dumerili caused by Vibrio hollisae

Bacterin was prepared by formalin-inactivating the virulent strain of Vibrio hollisae isolated from diseased Seriola dumerili （amberjack） suffering from vibriosis. Healthy S. dumeriIi were vaccinated by respective procedures of intramuscular injection, immersion, and orally administration. Results of the three different vaccinations were compared. Blood was drawn from the vaccinated fish every 7 days, and the antibody titers and lysozyme activities of the sera were determined. The antibody titer of injected fish was 1：40 at 7 d, and reached its peak of 1：320 at 28 d, while the fish vaccinated by immersion and orally administration exhibited weak antibody responses, the antibody titres of 〈1：10, 1：20, 1：160 were observed at 7 d, 14 d, 35 d respectively. Compared with the control, the vaccinated fish exhibited significantly higher lysozyme activities （P〈0.05）. Upon challenge with virulent strain, the relative percent survival （RPS） of injected, immersed and oral administrated fish were 75%, 45%, and 40% respectively, and the injected fish showed significantly higher RPS than immersed and oral administrated fish. The results suggested that vaccination of S. dumerili by the injection would be the best strategy to prevent the vibriosis in S. dumerili farm.

Oral attenuated Salmonella typhimurium vaccine against MG7-Ag mimotope of gastric cancer

AIM: To develop an oral attenuated Salmonella typhimurium vaccine against gastric cancer and to evaluate its efficacy in mice. METHODS: A complementary sequence of Nco Ⅰ site and a sequence coding for MG7-Ag mimotope were designed at the 5'terminus of forward primer. Using p1.2 Ⅱ-HBCAg plasmid as template, PCR was performed to get a fusion gene of the mimotope and a HBcAg gene. The fusion gene was then subcloned into the plasmid pYA3341 complementary to Salmonella typhimurium X4550, and the recombinant plasmid was then transformed into attenuated Salmonella typhimurium X4550. Balb/c mice were orally immunized with the recombinant Salmonella typhimurium X4550. The mice were immunized every 2 wk to reinforce the immunity. At the 6th wk, serum titer of antibody was detected by ELISA, and at the 8th wk, cellular immunity was detected by 51Cr release test. Ehrlich ascites carcinoma cells expressing MG7-Ag were used in tumor challenge assay as a model to evaluate the protective effect of the vaccine. RESULTS: Serum titer of antibody against MG7-Ag was significantly higher in mice immunized with the vaccine than in control groups (0.9538±0.043 vs 0.6531±0.018, P<0.01; 0.9538±0.043 vs 0.6915±0.012, P<0.01), while in vitro 51Cr release assay of the splenocytes showed no statistical difference in the three groups. Two weeks after tumor challenge, 1 in 5 immunized mice was tumor free, while all the mice in the control group presented tumor. CONCLUSION: Oral attenuated Salmonella typhimurium vaccine against the MG7-Ag mimotope of gastric cancer is immunogenic. It can induce significant humoral immunity against tumors in mice, and has some protective effects.

Genetic vaccination with Flt3-L and GM-CSF as adjuvants: Enhancement of cellular and humoral mmune responses that results in protective immunity in a murine model of hepatitis C virus infection

AIM： To investigate whether transfection of plasmid DNA encoding these cytokines enhances both humoral and cellular immune responses to hepatitis C virus （HCV） in a murine model. METHODS： We established a tumor model of HCV infection using syngenic mouse myeloma cells stably transfected with NS5. Co-vaccination of DNA encoding granulocyte macrophage colony-stimulating factor （GM- CSF） and Flt-3 ligand together with a plasmid encoding for the HCV NS5 protein was carried out. Mice were sacrificed 14 d after the last immunization event with collection of spleen cells and serum to determine humoral and cellular immune responses. RESULTS： Co-vaccination of DNA encoding GM-CSF and Fit-3 ligand together with a plasmid encoding for the HCV NS5 protein induced increased antibody responses and CD4＋ T cell proliferation to this protein, Vaccination with DNA encoding GM-CSF and FIt-3L promoted protection against tumor formation and/or reduction in mice co- immunized with cytokine-encoding DNA constructs, This suggests this strategy is capable of generating cytotoxic T lymphocyte activity in vivo, Following inoculation with plasmid DNA encoding Flt-3L, no increase in spleen size or in dendritic cell （DC） and natural killer cell numbers was observed. This was in contrast to a dramatic increase of both cell types after administration of recombinant Flt3-L in vivo. This suggests that vaccination with plasmid DNA encoding cytokines that regulate DC generation and mobilization may not promote unwanted side effects, such as autoimmunity, splenic fibrosis or hematopoietic malignancies that may occur with administration of recombinant forms of these proteins. CONCLUSION： Our data support the view that plasmid DNA vaccination is a promising approach for HCV immunization, and may provide a general adjuvant vaccination strategy against malignancies and other pathogens.

An Inactivated Vaccine from a Field Strain of Bovine Herpesvirus-1(BoHV-1) has High Antigenic Mass and Induces Strong Efficacy in a Rabbit Model

Bovine Herpesvirus-1 （BoHV-1） is a DNA virus belonging to the family Herpesviridae, subfamily Alfaherpesvirinae; it is a worldwide pathogen, causing serious economic losses in livestock. In Colombia there have been multiple isolates of BoHV-1 that have been subjected to molecular characterization, classifying most of the country isolates as BoHV-I.1. In the present study we developed and evaluated an ethyleneimine binary inactivated isolate from the native BoHV-1 strain （C6rdoba-2） in a rabbit model of vaccination and infection. The vaccine was evaluated in two phases, one of immunogenicity with vaccination and a booster after 21 days, and an evaluation phase of protection against challenge with a highly virulent reference strain. The results demonstrate optimum serum-conversion, with protective neutralizing antibody titers 28 days post vaccination and optimal protection against challenge with the reference strain with decreased clinical signs of infection, protection against the onset of fever and decrease of virus excretion post challenge. In conclusion, our results show the enormous potential that an immunogenic inactivated vaccine has produced from the native BoHV-I.1 strain, which produces a high antigen mass to the vaccine to induce optimal immunity and protection, and it is a strong candidate for evaluation and possible future use in different cattle populations.

Analysis of an Epidemic Model with Age of Vaccination

A simple SI epidemic model with age of vaccination is discussed in this paper.Both vexing birth rate, the mortality rate caused by disease and vaccine waning rate areconsidered in this model. We prove that the global dynamics is completely determined bythe basic reproductive number R（ψ）（ψ denotes per capita vaccination rate）. If R（0） 〈 1,the disease-free equilibrium is a global attractor; If R（ψ） 〈： 1, the disease-free equilibriumis locally asymptotically stable; If R（ψ） ：〉 1, an unique endemic equilibrium exists and islocally asymptotically stable under certain condition.

Vaccination with dendritic cells pulsed with hepatitis C pseudo particles induces specific immune responses in mice

AIM: To explore dendritic cells (DCs) multiple functions in immune modulation. METHODS: We used bone-marrow derived dendritic cells from BALB/c mice pulsed with pseudo particles from the hepatitis C virus to vaccinate naive BALB/c mice. Hepatitis C virus (HCV) pseudo particles consist of the genotype 1b derived envelope proteins E1 and E2, covering a non-HCV core structure. Thus, not a single epitope, but the whole "viral surface" induces immunogenicity. For vaccination, mature and activated DC were injected subcutaneously twice. RESULTS: Humoral and cellular immune responses measured by enzyme-linked immunosorbent assay and interferon-gamma enzyme-linked immunosorbent spot test showed antibody production as well as T-cellsdirected against HCV. Furthermore, T-cell responses confi rmed two highly immunogenic regions in E1 and E2 outside the hypervariable region 1. CONCLUSION: Our results indicate dendritic cells as a promising vaccination model for HCV infection that should be evaluated further.