空肠弯曲菌外膜蛋白亚单位疫苗的研制及免疫原性研究

目的 探索用脂质体包裹空肠弯曲菌(Campylobacter jejuni,CJ)Mr 28 000～31 000外膜蛋白制备安全、稳定、有效的CJ亚单位脂质体佐剂疫苗及其免疫原性、免疫剂量和途径.方法 采用薄膜-超声-冻融法制备阴离子脂质体(AL)、阳离子脂质体(CL)CJ疫苗后对其进行质量鉴定;用ELISA(间接法)检测经CJ疫苗免疫后的新西兰兔血清IgG抗体水平.结果 ①疫苗无菌试验及热原质试验均合格,均无明显不良反应;②阴、阳离子脂质体疫苗冻融前包裹率分别为32.1%、22.5%,冻融后分别是38.3%、28.4%;③CJ阴离子组比CJ阳离子组血清IgG的OD值显著增高(P<0.01),与CJ弗氏组无统计学差别(P0.1);CJ阴、阳离子组0.50 mg/kg的免疫剂量血清IgG的OD值最大;CJ阳离子皮下注射组与肌肉注射组IgG的OD值无统计学差别(P0.1);特异性IgG抗体经6个月动态观察,5个月后抗体效价下降.结论 ①采用薄膜-超声-冻融法制备CJ亚单位佐剂疫苗安全、稳定,冻融法可以提高脂质体疫苗包裹率;②同一剂量的阴离子脂质体疫苗血清抗体水平明显高于阳离子脂质体疫苗;③脂质体疫苗最佳接种剂量为0.50 mg/kg,肌肉注射与皮下注射免疫效果无显著差异;④较高水平的特异性抗体维持5个月,6个月后应加强免疫.     

EHF疫苗不同途径免疫后血清及黏膜抗体应答情况

目的探讨EHF疫苗经不同剂量和途径免疫后血清IgG及黏膜IgA产生情况,以探讨合适的免疫剂量和接种途径。方法以不同剂量EHF双价灭活疫苗分别经皮下和灌胃免疫小鼠,共3次（第0、5、10天）,末次接种后5d收集血清和小肠冲洗液,用间接免疫荧光法（IFA）检测血清EHF IgG抗体和小肠冲洗液IgA抗体。结果皮下注射能诱导血清特异性IgG和黏膜IgA的产生,灌胃免疫未见抗体产生,1．4 TCID50的EHF疫苗剂量在皮下注射组血清IgG和小肠冲洗液IgA有100％阳性率。结论EHF疫苗皮下注射能诱导血清特异性IgG和黏膜IgA的产生,1．4 TCID50的剂量为较佳剂量。     

合成纳米铝佐剂及其对乙型肝炎、狂犬病毒辅佐效应的研究

目的 通过自制纳米铝佐剂,研究其对乙型肝炎病毒和狂犬病毒的体液免疫应答。方法 在25℃条件下,采用微乳液法制备纳米铝佐剂。与常规铝佐剂比较,经皮下注射豚鼠和Balb／c小鼠后,于不同的时间测定血清中特异性酥;抗体的效价。结果 透射电镜（TEM）和差式量热扫描（DSC）,可知产物为平均粒径约为72．62nm,近球形的A1（OH）3结晶颗粒。纳米铝佐剂辅佐的HBsAg,在免疫Balb／c小鼠后第1周和第2周的血清抗体滴度明显高于常规铝佐剂组（P〈0．01;P〈0．05）;纳米铝佐剂辅佐的狂犬疫苗,其特异性IgG抗体效价高于常规铝佐剂组,并且在免疫后的第7天,抗体就呈现出阳性（P〈0．05）。结论 纳米铝佐剂在诱导HBsAg和Rabies疫苗体液免疫应答的早期优于目前的常规铝佐剂,能够快速地激活和提高Balb／c小鼠和豚鼠的免疫应答和应答水平。     

高致病性人禽流感H5N1疫苗滴鼻免疫应答效果的初步研究

目的 通过高致病性人禽流感H5N1全病毒-MF59佐剂疫苗滴鼻免疫Balb/c小鼠,评价该疫苗所诱导的系统免疫与黏膜免疫应答效果.方法 以不同剂量抗原按比例与MF59佐剂配伍制成粘膜疫苗,滴鼻免疫Balb/c小鼠,二免2周采血检测血清IgG、IgM效价及血清中HAI(HA inhibitor)的中和抗体效价,同时收集鼻、肺灌洗液,检测其lgG和slgA抗体效价.结果 H5NI+MF59组血清抗体效价较H5NI组有显著升高(P＜0.01);在各剂量组中,随着剂量的增加抗体效价呈上升趋势.12μg腭后抗体效价呈下降趋势,以HSNI+MF59(12μg)组效价最高;肺鼻灌洗液中,均可检测到特异性分泌型IrA、IsG,其中特异性分泌型IgA效价略高于IgG;抗体亚型的分布以IgG1、IgG2b为主.结论 灭活高致病性禽流感全病毒H5N1在佐剂MF59作用下可诱导机体产生体液免疫应答,同时还可以在黏膜局部产生特异性分泌型IgA、IsG,为高致病人禽流感病毒I-15N1黏膜疫苗的研制奠定了基础.     

沙鼠IgG兔抗血清的制备及其在IgG抗体检测中的应用

目的用纯化的蒙古沙鼠血清IgG制备相应兔抗血清,并用于幽门螺杆菌（Helicobacter pylori,Hp）疫苗免疫后沙鼠血清中抗原特异性IgG的检测。方法采用饱和硫酸铵沉淀法和Q sepharose high performance阴离子交换层析法纯化蒙古沙鼠血清IgG,免疫日本大白耳兔制备兔抗沙鼠IgG抗血清并进行rProtein A亲和纯化,建立间接ELISA方法用于检测Hp疫苗注射免疫蒙古沙鼠后血清抗原特异性IgG水平。结果以纯化的蒙古沙鼠血清IgG（纯度大于98％）免疫日本大白耳兔获得相应兔抗血清,经亲和层析后其纯度大于90％,回收率约为85％,双扩效价为1：16,ELISA效价为1：320000;ELISA检测结果显示Hp疫苗注射免疫蒙古沙鼠于第2次免疫后产生高水平IgG,第4次免疫后第7天IgG水平达到高峰,随后几周仍然保持高水平。结论所制备的兔抗沙鼠IgG抗体可以用于蒙古沙鼠血清中抗原特异性IgG的检测。     

脂质体流感疫苗制备及体液免疫应答的研究

目的：制备脂质体流感疫苗并对其体液免疫效果和保护效率进行研究.方法：采用薄膜法与冷冻干燥法相结合的方法制得多层脂质体;用制得的脂质体流感疫苗和普通疫苗分别免疫小鼠,用血凝抑制实验（HI）和酶联免疫吸附试验（ELISA）对免后2～13周的小鼠血清的抗体水平进行检测,HI检测其特异性抗体,ELISA检测IgG抗体水平并对小鼠的保护效率进行检测.结果：实验中,脂质体流感疫苗在2μg/mouse组和4μg/mouse两个剂量组中,不同免疫时间内其HI值可分别较非脂质体疫苗组高出2～3和4倍,产生抗体的水平经ELISA实验得出较非脂质体疫苗组高出1倍左右,故可激发更高的体液免疫;保护效力为4/6.结论：脂质体流感疫苗能够刺激机体产生更高的体液免疫和更高的保护效力.     

脑膜炎奈瑟菌外膜蛋白NMB0315作为B群流脑疫苗候选抗原的免疫效果

目的研究原核重组表达的B群脑膜炎奈瑟菌外膜蛋白0315(rNMB0315)在诱导小鼠产生特异性免疫应答中的作用、免疫血清抗体体外杀菌活性和重组蛋白的免疫保护效果,初步评价rNMB0315作为B群流脑疫苗候选抗原的潜力。方法将构建的原核表达载体p ET30a-NMB0315转化大肠杆菌BL21表达重组蛋白,纯化鉴定后的重组蛋白免疫雌性BALB/c小鼠,检测体液免疫和细胞免疫水平;测定血清抗体在补体介导下的体外杀菌活性,观察rNMB0315蛋白疫苗对实验小鼠的免疫保护效果。结果 rNMB0315具有良好的免疫原性,能诱导产生较高水平的体液免疫应答:包括血清特异性IgG、IgG1、IgG2a、IgG3、IgG2b和生殖道黏膜特异性分泌型IgA(s IgA),免疫后第6周抗体效价分别为1∶150 000、1∶85 000、1∶60 000、1∶35 000、1∶30 000和1∶30 000;也能激发较高水平的细胞免疫应答,免疫小鼠脾淋巴细胞增殖反应的刺激指数(SI)值明显高于PBS、Freund佐剂对照组。在免疫的2、4、6周,血清IgG2a/IgG1比值均小于1,提示rNMB0315疫苗以诱导Th2细胞性体液免疫应答为主。rNMB0315疫苗免疫血清在补体介导下的体外杀菌抗体效价为1∶128;72 h内,对实验小鼠的免疫保护率为90%。结论原核表达的rNMB0315具有良好的免疫活性和免疫保护效果,NMB0315外膜蛋白具有作为预防B群流脑蛋白疫苗候选抗原的潜力。     

鼠疫F1-V重组蛋白疫苗滴鼻免疫应答效果的研究

目的 以重组霍乱毒素B亚单位（rCT-B）为鼠疫F1-V重组蛋白的佐剂制备黏膜疫苗,观察小鼠诱导的黏膜免疫和系统免疫应答效果。方法以制备的鼠疫黏膜疫苗滴鼻免疫小鼠4次免疫后,采用间接ELISA检测血清特异性抗F1-V的IgG和IgA抗体及抗体亚型分类,检测鼻咽喉、肺、小肠及阴道灌洗液中特异性抗F1-V的黏膜分泌型IgA;采用流式细胞术检测鼻相关淋巴组织淋巴细胞、脾淋巴细胞、肠系膜淋巴结及小肠PP结T淋巴细胞表型的变化。结果以rCT-B为佐剂的鼠疫F1-V重组蛋白黏膜疫苗滴鼻免疫后,能够诱导血清中IgG、IgA抗体比正常对照组显著升高（P〈0．01）,同时诱导鼻咽、肺、小肠和阴道内特异性黏膜抗体升高,尤其是肺和生殖道冲冼液内抗体升高极为显著（P〈0．01）。与单纯的F1-V组相比,不同剂量比例疫苗组都能诱导较高、较快的血清IgG、IgA和黏膜sIgA,其中1：2疫苗组能诱导更强的系统免疫和黏膜免疫,但是相比之下,5：1疫苗组是最合适的免疫剂量。结论rCT-B佐剂不仅能提高鼠疫F1-V黏膜疫苗的系统全身免疫应答,还能促进诱导呼吸道、消化道和生殖道等局部黏膜sIgA抗体,增强局部免疫应答,提示rCT-B佐剂能显著提高鼠疫感染的免疫应答作用,这为下一步疫苗的免疫保护评价奠定了基础。     

SARS相关冠状病毒M蛋白基因重组核酸疫苗的实验研究

目的：构建针对SAILS相关冠状病毒M蛋白基因的重组核酸疫苗，观察其免疫小鼠后肌体的抗体产生情况，探讨其作为抗SAILS病毒疫苗的可能性。方法：通过分子生物学的方法构建SARS相关冠状病毒M蛋白基因真核表达质粒pcDNA3．1／M。经肌注免疫健康BALB／c小鼠，在免疫后的2．4、6周取小鼠血清，用ELISA法检测其中的抗体。结果：接种含M基因的真核表达质粒pcDNA3．1／M的低剂量组和高剂量组的小鼠血清在接种2周后就可检测出SARS-CoV特异性IgG，第4周时，这种特异性IgG水平有升高趋势，第6周时，血清中的抗体含量与4周时无大的差异。高剂量组产生抗体与低剂量组产生抗体无显著差异。pcDNA3．1空载体接种的对照组未检测出特异性抗体（其OD值低于0．18）。结论：构建的真核表达质粒pcDNA3．1／M能诱导小鼠产生了针对SARS的抗体。     

IL-12和IL-18基因免疫对HBcAg核酸疫苗诱导小鼠(H-2d)特异性免疫应答的影响

目的：观察IL-12和IL-18基因免疫对HBcAg核酸疫苗诱导小鼠（H-2d）特异性体液免疫和细胞免疫应答的影响.方法：用肌肉注射法将HBV核心区DNA疫苗、IL-12质粒和IL-18 质粒接种BALB/c小鼠;ELISA法检测小鼠血清抗-HBc（IgG）及IgG亚类（IgG1、IgG2a）;LDH释放法检测小鼠脾细胞HBcAg特异性CTL活性.结果：免疫6周后,HBcAg DNA疫苗联合IL-12质粒、IL-18质粒和IL-12＋IL-18质粒组小鼠的血清抗HBc终点滴度均明显高于单纯注射HBcAg DNA疫苗组小鼠（P＜0.05）,抗HBc IgG亚类以IgG2a占优.DNA疫苗免疫的各组小鼠,HBcAg特异性细胞毒性T淋巴细胞杀伤率均高于对照组（P组）,其中C＋IL-18组和C＋IL-12＋IL-18组中CTL值明显高于C组,尤以C＋IL-12＋IL-18组中的CTL杀伤率最高.结论：IL-12和IL-18基因与HBcAg DNA疫苗联合免疫,不仅能增强HBcAg特异性体液免疫应答,而且能增强HBcAg特异性CTL的杀伤活性.     

Mucosal immune responses to meningococcal group C conjugate and group A and C polysaccharide vaccines in adolescents

Previous studies in children have shown that Haemophilus influenzae type b (Hib) polysaccharide conjugate vaccines can reduce nasopharyngeal carriage of H. influenzae and provide herd immunity and suggest that this effect is mediated through mucosal antibodies. As this phenomenon may operate in other invasive bacterial infections which are propagated by nasopharyngeal carriage, mucosal antibody responses to meningococcal C conjugate and A/C polysaccharide vaccines were investigated. A total of 106 school children aged 11 to 17 years were randomized to receive a single dose of either conjugate or polysaccharide vaccine in an observer-blind study. Before and at 1, 6, and 12 months after immunization, samples of unstimulated saliva were collected and assayed by enzyme-linked immunosorbent assay for group C polysaccharide-specific immunoglobulin A (IgA), IgA1, IgA2 and secretory component, IgG antibodies, and total IgG and IgA. A subset of serum samples were also assayed for specific IgA and IgG antibodies. The concentrations of specific IgA and IgG in saliva were expressed both as nanograms per milliliter and as nanograms per microgram of total IgA or IgG. One month after immunization, significant increases in antibody titers (both IgA and IgG) were observed in saliva in both groups. There were significant subsequent falls in antibody titers by 6 months. Anti-meningococcal C-specific secretory component and IgA antibody titers were closely correlated (r = 0.85, P < 0.001), but there was no significant correlation between salivary and serum IgA titers, suggesting that IgA antibodies are locally produced. Significant correlation was found between salivary and serum IgG titers (r = 0.52, P < 0.01), suggesting that salivary IgG may be serum derived. Compared with polysaccharide vaccine, the conjugate vaccine induced significantly higher salivary IgG responses (P < 0.05), although there were no significant differences between salivary IgA responses to the two vaccines. The conjugate vaccine induced greater salivary IgG responses than a polysaccharide vaccine. Both vaccines induced significant salivary IgA antibodies. Further studies are needed to establish the functional significance of these mucosal responses.     

空肠弯曲菌pcDNA3.1(-)-peb1A壳聚糖佐剂疫苗对小鼠免疫原性和保护性研究

目的:研究空肠弯曲菌pcDNA3.1(-)-peb1A壳聚糖佐剂疫苗的免疫原性和保护性。方法:健康雄性昆明小鼠分为实验组和对照组。实验组设pcDNA3.1(-)-peb1A组3个剂量和壳聚糖-pcDNA3.1(-)-peb1A组3个剂量;对照组设空载体pcDNA3.1(-)(100μg/100μl)组和生理盐水(NS)组,各组均采用小鼠股四头肌注射法。在第0、10、20天免疫,于每次免疫后第10天采集各组小鼠血清,以间接ELISA法检测血清中特异性IgM、IgG的含量。分离各组小鼠脾淋巴细胞包被细胞培养板,以细胞ELISA法检测小鼠脾淋巴细胞CD20、CD21表达水平。设空肠弯曲菌液灌胃攻击免疫后小鼠,检测肠道分泌液细菌培养数量。结果:裸DNA组和壳聚糖-DNA组各组特异性IgG水平均高于两对照组(P<0.05)。裸DNA组和壳聚糖-DNA组小鼠脾淋巴细胞CD20、CD21表达水平均高于两对照组(P<0.05),壳聚糖-DNA组高于裸DNA组(P<0.05)。肠道分泌液细菌培养结果细菌指数裸DNA组的低于两对照组;佐剂DNA组低于裸DNA组。结论:重组质粒pcDNA3.1(-)-peb1A经肌肉注射免疫小鼠,具有较好的免疫原性和保护作用,壳聚糖能增强pcDNA3.1(-)-peblA的免疫原性,有望成为空肠弯曲菌基因疫苗的候选佐剂。     

Safety and immunogenicity of subcutaneous or intramuscular administration of a monovalent inactivated vaccine against Leptospira interrogans serogroup Icterohaemorrhagiae in healthy volunteers

The safety and immunogenicity of a monovalent inactivated vaccine against Leptospira interrogans serogroup Icterohaemorrhagiae was evaluated in 84 volunteers according to the route of administration, i.e., subcutaneous (SC) or intramuscular (IM), in a double-blind randomised trial. The volunteers were randomised into four groups: SC vaccine; IM vaccine; SC placebo; and IM placebo. Primary vaccination comprised two injections on day 0 and day 14, with a booster after 6 months. A second booster was given 30 months after primary vaccination. Local reactions within 1 h of injections were rare, with no difference between vaccine groups. Local reactions within 3 h were more frequent after the second, third and fourth SC injections than after IM injections. Systemic reactions never occurred within 1 h of vaccination and were rare within 3 days; the rates were comparable for the different vaccine groups. Evolution of the antibody responses, as assessed by microscopic agglutination tests and specific IgG and IgM ELISAs, were similar for both injection routes. IgG seroconversion rates after the first booster were 97% (95% CI 80-100%) for the SC vaccine group, and 96% (95% CI 80-100%) for the IM vaccine group, and both reached 100% for IgG after the second booster. The safety and immunogenicity of the anti-leptospiral vaccine were both good. Monitoring of antibody levels established that a booster dose triggered a strong antibody response in fully vaccinated subjects at 30 months after primary vaccination.     

Systemic and mucosal immunity in mice elicited by a single immunization with human adenovirus type 5 or 41 vector‐based vaccines carrying the spike protein of Middle East respiratory syndrome coronavirus

An ideal vaccine against mucosal pathogens such as Middle East respiratory syndrome coronavirus (MERS‐CoV) should confer sustained, protective immunity at both systemic and mucosal levels. Here, we evaluated the in vivo systemic and mucosal antigen‐specific immune responses induced by a single intramuscular or intragastric administration of recombinant adenoviral type 5 (Ad5) or type 41 (Ad41) ‐based vaccines expressing the MERS‐CoV spike (S) protein. Intragastric administration of either Ad5‐S or Ad41‐S induced antigen‐specific IgG and neutralizing antibody in serum; however, antigen‐specific T‐cell responses were not detected. In contrast, after a single intramuscular dose of Ad5‐S or Ad41‐S, functional antigen‐specific T‐cell responses were elicited in the spleen and pulmonary lymphocytes of the mice, which persisted for several months. Both rAd‐based vaccines administered intramuscularly induced systemic humoral immune responses (neutralizing IgG antibodies). Our results show that a single dose of Ad5‐S‐ or Ad41‐S‐based vaccines represents an appealing strategy for the control of MERS‐CoV infection and transmission.     

Cationic liposomal vaccine adjuvants in animal challenge models: overview and current clinical status

Cationic liposome formulations can function as efficient vaccine adjuvants. However, due to the highly diverse nature of lipids, cationic liposomes have different physical-chemical characteristics that influence their adjuvant mechanisms and their relevance for use in different vaccines. These characteristics can be further manipulated by incorporation of additional lipids or stabilizers, and inclusion of carefully selected immunostimulators is a feasible strategy when tailoring cationic liposomal adjuvants for specific disease targets. Thus, cationic liposomes present a plasticity, which makes them promising adjuvants for future vaccines. This versatility has also led to a vast amount of literature on different experimental liposomal formulations in combination with a wide range of immunostimulators. Here, we have compiled information about the animal challenge models and administration routes that have been used to study vaccine adjuvants based on cationic liposomes and provide an overview of the applicability, progress and clinical status of cationic liposomal vaccine adjuvants.     

Primary and booster mucosal immune responses to meningococcal group A and C conjugate and polysaccharide vaccines administered to university students in the United Kingdom

Meningococcal group A+C capsular polysaccharide (PS) conjugate vaccines may prime for serum immunoglobulin G (IgG) memory responses to meningococcal capsular PS. It is not known whether these vaccines induce immunological memory at the mucosal level, which may be important in reducing nasopharyngeal carriage. Mucosal immune responses to meningococcal conjugate and PS vaccines in young adults were investigated. Healthy university students were randomized to receive either a groups A+C meningococcal conjugate vaccine (MACconj, n = 100) or a group A+C meningococcal PS vaccine (MACPS, n = 95). One year after the primary immunization, both groups were randomized again to receive a MACconj or a MACPS booster vaccination. Saliva samples were collected before and 1 month after the primary and booster vaccinations. Anti-meningococcal A (MenA) and C (MenC) PS IgA and IgG antibody levels were measured by a standard enzyme-linked immunosorbent assay. After the primary vaccination, salivary MenA and MenC IgG and MenA IgA concentrations were significantly increased after immunization with both MACconj and MACPS vaccines, but the salivary Men C IgA level was increased only after MACPS vaccine (P < 0.01). IgA responses to both serogroups were greater for MACPS than MACconj vaccine (P < 0.05), whereas no significant differences were seen for IgG responses. MenA IgG titers were higher after the MACPS booster in MACconj-primed subjects than after the MACPS primary vaccination, suggesting the presence of IgG memory. Antibody responses to a dose of either MACPS or MACconj were not significantly reduced in those previously given MACPS compared to the primary responses to those vaccines. Meningococcal A+C conjugate and PS vaccines induce significant mucosal responses in young adults. MACconj priming may induce IgG memory at the mucosal level, which is likely to be a reflection of an anamnestic serum IgG response. No evidence of mucosal hyporesponsiveness was observed after MACPS priming in this study.     

Induction of protective serum meningococcal bactericidal and diphtheria-neutralizing antibodies and mucosal immunoglobulin A in volunteers by nasal insufflations of the Neisseria meningitidis serogroup C polysaccharide-CRM197 conjugate vaccine mixed with chitosan

Thirty-six healthy volunteers received either a single intramuscular injection of Neisseria meningitidis serogroup C polysaccharide (MCP)-CRM197 conjugate vaccine in alum or two nasal insufflations 28 days apart of the same vaccine powder, without alum, mixed with chitosan. Nasal immunization was well tolerated, with fewer symptoms reported than after intramuscular injection. The geometric mean concentrations of MCP-specific immunoglobulin G (IgG) after one nasal immunization were 3.25 microg/ml in na?ve subjects and 14.4 microg/ml in subjects previously immunized parenterally, compared with 4.30 microg/ml in na?ve subjects immunized intramuscularly. The geometric mean titer of serum bactericidal antibody (SBA) rose 24-fold after two nasal immunizations in na?ve subjects and was comparable to parenteral immunization (1,080 versus 1,625). All subjects achieved SBA titers associated with protection after two nasal immunizations: even those with titers of <8 at entry. A single nasal immunization boosted the SBA titer to > or =128 in 96% of previously immunized subjects, and two immunizations achieved this level in 92% of naive subjects. MCP-specific IgG levels were approximately 70% IgG2 and approximately 20% IgG1 after nasal or intramuscular immunization. Increases in CRM197-specific IgG and diphtheria toxin-neutralizing activity were observed after nasal or intramuscular immunization, with balanced IgG1/IgG2 and higher IgG4. Significant MCP-specific secretory IgA was detected in nasal wash only after nasal immunization and predominantly on the immunized side. Simple nasal insufflation of existing MCP-CRM197 conjugate vaccines in chitosan offers an inexpensive but effective needle-free prime and boost against serogroup C N. meningitidis and diphtheria.     

Needle-free jet injection of a mixture of Japanese encephalitis DNA and protein vaccines: a strategy to effectively enhance immunogenicity of the DNA vaccine in a murine model

Combined immunization with gene-based and protein-based vaccines can increase vaccine effectiveness. We previously demonstrated, using a murine model for Japanese encephalitis (JE), that simultaneous immunization with a DNA vaccine (pcJEME) by the intramuscular route and a protein vaccine consisting of subviral extracellular particles (EPs) by the subcutaneous route provided a synergistic increase in immunogenicities of these vaccines. Here, we investigated a novel immunization protocol consisting of a single inoculation with a mixture of DNA and protein vaccines using a needle-free jet injector. Immunization of ddY mice with 1 microg of pcJEME mixed with 1 microg of EPs or a 1/100 dose of commercial inactivated JE vaccine (JEVAX) induced neutralizing antibody titers of 1:40 to 1:80 (90% plaque reduction) 6 weeks after immunization, whereas immunization with DNA or protein alone only induced low titers (< or =1:10). Co-immunization with pcDNA3, a CpGcontaining vector of the vaccine plasmid, increased immunogenicity of JEVAX to some extent. IgG1/IgG2a isotype profiles supported increased production of EPs in pcJEME-inoculated mice by needle-free injection and an adjuvant effect of the vector on immunogenicity of JEVAX.     

Iscom佐剂增强含前S表位重组乙肝表面抗原的免疫原性

目的 探讨Iscom佐剂对含前S表位重组乙肝表面抗原(SS1S2)免疫原性的影响.方法 用纯化的SSIS2抗原与Al(OH)3和Iscom佐剂分别配制疫苗,在0 d和14 d时采用肌肉和皮下注射方式免疫BALB/c小鼠,免后14 d各取一半小鼠采血,测定乙肝病毒S、前S1和前S2抗体滴度以及总的IgG1和IgG2a抗体滴度,并计算IgG2a和IgG1抗体比例.同时分离脾淋巴细胞,进行IFN-γ酶联斑点(ELISPOT)测定.结果 单针免疫时,两组疫苗血清样品乙肝病毒S、前S1和前S2抗体阳转率、抗体滴度及IFN-γ分泌细胞数相当,但Iscom佐剂疫苗组IgG2a抗体比例较高;加强免疫后,两组疫苗抗体滴度均呈上升趋势,Iscom疫苗组抗体滴度上升幅度大于Al(OH)3疫苗组,两者S、前S1和前S2抗体滴度差异均有统计学意义.加强免疫后Iscom疫苗组IgG2a抗体比例保持平衡,而Al(OH)3疫苗组IgG2a抗体比例进一步降低.在细胞免疫方面,Iscom疫苗组在加强免疫后产生的特异性IFNγ分泌细胞数显著超过Al(OH)3疫苗组.结论 本研究初步显示,Iscom佐剂对含前S表位重组乙肝表面抗原具有比Al(OH)3佐剂更强地免疫增强作用.

Abstract：

Objective To investigate the effect of Iscom matrix on the immunogenicity of recombinant hepatitis B surface antigen containing PreS epitopes(SS1S2). Methods SS1S2+ Al(OH)3 and SS1S2+Iscom vaccines were made by combining purified SS1S2 antigen with Al( OH)3 adjuvant or Iscom matrix.Groups of BALB/c mice were injected i. m or s. c by either of the two vaccines at day 0 and day 14. Half of the mice were sacrificed and sera were taken and spleen cells separated from the mice 14 days after each injection. Anti-S, anti-PreS1, and anti-PreS2 antibody titers were measured, and total IgG1 and IgG2a titers were further detected for each serum sample. IFN-γ ELISPOT assay was performed to detect IFN-γsecreting cells from the pooled spleen cells for each vaccine group. Results The seroconversion rates and geometric mean titers(GMTs) and the numbers of IFN-γ secreting cells were approximately at the same level for the differently formulated vaccines after the first injection except that the ratio of IgG2a to IgG1 in the Iscom group was higher than the Al(OH)3 group. After boost injection, the GMTs of total IgG rise slightly in the Al(OH)3 group but significantly in the Iscom group. The IgG2a to IgG1 ratio in the Iscom group kept balanced while dropped further in the Al(OH)3 group. The number of specific IFN-γsecreting cells triggered by the Iscom vaccine exceeded significantly the number of Al( OH)3 vaccine, showinga stronger cellular response. Conclusion The results in this study shows that Iscom matrix is more potent in enhancing the immunogenicity of recombinant hepatitis B virus surface antigen containing PreS epitopes than Al( OH)3 adjuvant.     

疟疾DNA疫苗免疫接种方法对小鼠 体液免疫应答的影响

目的 探讨DNA疫苗免疫接种方法对抗体水平及辅助性T细胞极化的影响。方法 利用DNA重组技术构建恶性疟原虫红内期多表位DNA疫苗,通过基因枪、肌肉注射、皮内注射等接种方法免疫小鼠,经ELISA测定该疫苗诱导产生特异性抗体的总量、亚型及表位特异性,比较不同免疫接种方法对DNA疫苗诱导产生抗体及辅助性T细胞极化的影响。结果 接种DNA疫苗的小鼠经3次免疫后都产生了较高滴度的抗重组蛋白抗体。基因枪组单位DNA诱导抗体滴度是肌注组的120倍。基因枪组小鼠血清抗体以IgG1升高为主,而肌注和皮内注射组小鼠血清抗体均以IgG2a升高为主。各免疫接种组诱导产生的抗表位多肽抗体特异性相同。结论 不同免疫接种方法不但会影响血清总免疫球蛋白水平,还能使辅助性T细胞向不同方向极化。肌注和皮内注射诱导产生以IgG2a为主的TH1型免疫应答,基因枪接种诱导产生以IgG1为主的TH2型免疫应答。DN疫苗的摄取方式可明显影响辅助性T细胞的极化。