Protection against malaria by immunization with plasmid DNA encoding cholera toxin B subunit andPlasmodium falciparum epitopes

Cholera toxin B subunit is a good carrier protein and an effective adjuvant which can boost both cellular and humoral immunity. DNA fragments encoding B cell, Th cell and CTL epitopes of P. falciparum CS, MSA-1, MSA-2 and RESA antigens were cloned down-stream of cholera toxin B subunit gene in the same reading frame. Another modification using IL2 as adjuvant was also made. High titer of anti-malaria epitopes antibodies and strong cellular immunogenicity were elicited after Balb/c mice were immunized three times with 100 μg recombinant plasmid DNA dissolved in 100 μL PBS. 200 vaccinees were challenged with mouse Plasmodium yoelli to investigate if cross protection existed. The protective efficacy was about 50%. And it is found that the protective efficacy is correlated with CTL activity which was considered to be the primary effects of anti-sporozoite protective immunity. Better results might be expected when the DNA vaccine candidates were applied to primates.     

绵羊溶血性曼氏杆菌灭活疫苗的制备

用实验室分离获得的溶血性曼氏杆菌菌株制备甲醛灭活疫苗,进行不同佐剂(AI(OH)3、蜂胶)菌苗的安全性及免疫保护试验研究.结果表明:所制备疫苗的各项指标均符合要求,安全可靠.     

乙肝病毒核酸疫苗诱导小鼠细胞免疫应答的研究

研究利用核酸疫苗诱生乙型肝炎病毒 (HBV)表面抗原 (S)细胞免疫应答的作用 .免疫前于BALB/C小鼠股四头肌注射 75 %盐酸布比卡因 ,三天后同样部位注射包含HBsAg基因片段的重组质粒pcDNAHBs .采用3H -TdR掺入法测定免疫小鼠脾细胞增殖能力 ;XTT法测定其脾细胞分泌IL 2活性 .结果表明注射乙肝核酸疫苗可以使小鼠脾细胞增殖 ,小鼠脾细胞分泌上清中可检测到IL - 2活性     

粤北地区鸡致病性大肠杆菌蜂胶佐剂疫苗的免疫试验

从粤北地区分离到的鸡致病性大肠杆菌中选择6株优势致病性大肠杆菌菌株做为制苗菌种，制备制苗菌液，按相同比例混合灭活，加蜂胶乙醇浸液为佐剂制备多价菌苗．安全试验结果证实，该灭活菌苗对20日龄肉仔鸡安全，试验鸡元不良反应；在5～10℃保存12个月，疫苗物理性状稳定．免疫效力试验结果：疫苗保护率为100％；接种20日龄雏鸡O．5ml／只，血凝试验检测结果为接种多价蜂胶灭活疫苗的试验鸡在免疫后第二周可检测出抗体，抗体滴度均数为3．10log2；免疫后第四周达到最高峰，抗体滴度均数为3．60log2；免疫后第五周抗体滴度开始下降，抗体滴度均数为2．10log2，但抗体滴度仍高于对照组（1．25log2）．在大肠杆菌感染鸡场进行的多批区域试验结果表明，该多价灭活疫苗安全，具有良好的保护作用．     

一种可作为抗金黄色葡萄球菌感染的新型广谱疫苗--PNSG

金黄色葡萄球菌是医院感染中最常见的病原菌，也是社会上大范围感染的主要病原菌．金黄色葡萄球菌感染可引起心内膜炎、骨髓炎、脓毒性关节炎、肺炎和脓肿等疾病．金黄色葡萄球菌也是重要经济动物的主要病原菌．金黄色葡萄球菌对青霉素这样的首选药物产生抗药性后引起的主要问题是，用甲氧西林治疗甲氧西林抗性的金黄色葡萄球菌（ｍｅｔｈｉｃｉｌｌｉｎ－ｒｅｓｉｓｔａｎｔ Ｓ．Ａｕｒｅｕｓ，ＭＲＳＡ）引起的感染无效，这就使金黄色葡萄球菌引起的疾病越来越流行，尤其是在住院的病人中．人们更为忧虑的是，最近在几个国家中，ＭＲＳＡ…     

中药方剂对家兔注射FMD疫苗部分生理指标影响试验

对家兔注射FMD疫苗前后,服用中草药制剂,观察其对部分生理指标影响。试验选取健康家兔16只,随机分为4组;A组:阴性对照组;B组:每只家兔肌注苗0.5mL,不口服中药制剂;C组:每兔注苗0.5mL,30min后口服中药剂量5mL;D组:每只家兔注苗0.5mL,注射前1h口服10mL中药制剂,观察不同时间段家兔血液部分生理指标的变化。实验结果表明:注射FMD疫苗能引起家兔的白细胞、红细胞、淋巴细胞、粒细胞数量显著增加;心率、血压下降。使用僵蚕、蚕蜕等中药,可抑制试验组家兔的白细胞、粒细胞、淋巴细胞数量;心率、血压有所上升。     

pH值对甲肝减毒活疫苗后处理得率的影响

在甲肝减毒疫苗生产工艺中不同pH对疫苗得率有一定的影响，为提高疫苗的产量，在传统的氯仿抽提条件下，使用不同pH值(pH1.0～12.0)的磷酸盐缓冲体系进行氯仿抽提，检测抽提后甲肝病毒(HepatitisAVirus，HAV)抗原滴度和感染性滴度，结果表明经氯仿抽提后，HAV抗原滴度和感染性滴度均在pH8.0～9.0时最高，相应得率也比常规处理的得率有显著的提高.说明改进pH抽提条件对甲型肝炎减毒活疫苗后处理工艺效率的提高，成品疫苗产量的增加具有实际应用价值.     

基因型乙肝疫苗的免疫效果的性别差异研究

探讨基因型乙型肝疫苗（YDV）接种成年男女后的抗－HBs滴度及抗－HBs阳转率变化的性别差异，从而进一步了解其免疫效果。     

疟疾疫苗的研究策略

从疟原虫的不同发育时期、不同的疫苗成份和宿主的遗传基因限制性等方面，深入研究抗疟疾疫苗。作用于红细胞前期的疟疾疫苗主要是抑制疟疾的临床发作，控制疟疾的传播；作用于红细胞期的疟疾疫苗诱导宿主体液免疫系统，产生特异性抗体，抑制疟原虫侵入和感染红细胞，达到减少疟原虫虫荷，降低疟疾的发病率和死亡率。作用于疟原虫有性生殖时期，控制疟疾传播的疟疾疫苗，其在于控制一个地区疟原虫的感染率和疟疾发病率，但对已感染疟原虫个体的免疫保护作用意义不大。在设计疟疾疫苗的过程中，必须克服不同个体的遗传基因限制性问题。由于疟原虫生活史的复杂性，同时也必须考虑到疟原虫不同发育阶段抗原成份的复杂性。     

Efficacy of tumor cell vaccine after incorporating monophosphoryl lipid A (MPL) in tumor cell membranes containing tumor-associated ganglioside

Murine B16 melanoma expresses the ganglioside. GM₃. GM₃ shed from tumor cells is immunosuppressive and promotes tumor growth¹. Reduction or elimination of the shed GM₃ could be therapeutic, and the anti-GM₃ antibodies may reduce and clear the shed ganglioside. To test this hypothesis, mice were challenged with tumor cells, with or without inducing anti-GM₃ antibody response. Since gangliosides are poor immunogens and T-cell independent antigens, an adjuvant (monophosphoryl lipid A (MPL), a non-toxic lipid A ofSalmonella), directed against B-cells, was employed. MPL was incorporated onto liposomes and into the surface membrane of B16 mouse melanoma cells; both are rich in GM₃. C57BL/6J mice immunized with MPL-liposomes or MPL-B16 cells responded with elevated levels of anti-GM₃ IgM. Non-immunized mice or mice immunized with B16 cells alone or ganglioside GM₃ alone (without MPL) elicited poor anti-GM₃ IgM response, confirming the GM₃'s immunologic crypticity and MPL's immunopotentiating effect. MPL's immunopotentiating effect was improved by coupling it to melanoma cell membranes C57BL/6J mice were immunized with irradiated B16 alone or MPL alone or MPL-conjugated irradiated B16. After three weekly immunizations, each mouse received a challenge dose of viable syngeneic B16. Neither MPL alone nor B16 alone had a significant effect on tumor growth or host survival; however, administration of MPL-conjugated B16 cells significantly prevented tumor growth and prolonged survival. Our results indicate that MPL-incorporated B16 cells augment the anti-GM₃ IgM response, which may reverse GM₃-induced immunosuppression by eliminating tumor-derived GM₃, and restore immunocompetence.