A nontoxic chimeric enterotoxin adjuvant induces protective immunity in both mucosal and systemic compartments with reduced IgE antibodies

A novel nontoxic form of chimeric mucosal adjuvant that combines the A subunit of mutant cholera toxin E112K with the pentameric B subunit of heat-labile enterotoxin from enterotoxigenic Escherichia coli was constructed by use of the Brevibacillus choshinensis expression system (mCTA/LTB). Nasal immunization of mice with tetanus toxoid (TT) plus mCTA/LTB elicited significant TT-specific immunoglobulin A responses in mucosal compartments and induced high serum immunoglobulin G and immunoglobulin A anti-TT antibody responses. Although TT plus native CT induced high total and TT-specific immunoglobulin E responses, use of the chimera molecule as mucosal adjuvant did not. Furthermore, all mice immunized with TT plus mCTA/LTB were protected from lethal systemic challenge with tetanus toxin. Importantly, the mice were completely protected from influenza virus infection after nasal immunization with inactivated influenza vaccine together with mCTA/LTB. These results show that B. choshinensis-derived mCTA/LTB is an effective and safe mucosal adjuvant for the induction of protective immunity against potent bacterial exotoxin and influenza virus infection.     

日本脑炎病毒DNA疫苗和基因工程亚单位颗粒疫苗的动物保护实验研究

目的　评价 3种日本脑炎病毒 (JEV)新型疫苗 ,即E蛋白病毒样颗粒 (VLPs)、DNA疫苗 (pV/JE)以及E蛋白颗粒 (Eps)的动物免疫效果。方法　BALB/c小鼠经 2次接种疫苗后 ,测定其病毒特异性的CTL活性、结合抗体、中和抗体 ,并以10LD5 0JEV攻击免疫小鼠 ,观察其保护效果。结果　各新型疫苗组的CTL活性为 33%～ 5 6 % ,灭活疫苗组为 2 2 % ,而载体和PBS对照组的CTL活性分别为 17%和 18%。一次免疫后 ,实验组小鼠血清结合抗体阳转率为 90 %。除DNA疫苗组外 ,各组小鼠的二次免疫血清抗体效价高于一次免疫的抗体效价 (P <0 0 5 ) ,且以VLPs加佐剂组小鼠血清抗体效价最高 ,Eps加佐剂组次之 ,均高于 pV/JE组和灭活疫苗组 (P <0 0 5 )。三种疫苗可诱发小鼠产生中和抗体。各实验组小鼠能够抵抗JEV的攻击 ,而对照组小鼠的死亡率为 37 5 %。结论　三种新型疫苗可以正确表达JEV的E蛋白表位 ,可诱发免疫小鼠产生抗JEV的中和抗体并有保护性作用 ,免疫效果优于灭活疫苗 ,有可能成为候选的JEV新型疫苗。     

Toll-like receptor 2 dependent immunogenicity of glycoconjugate vaccines containing chemically derived zwitterionic polysaccharides

Group B Streptococcus (GBS) causes serious infection in neonates and is an important target of vaccine development. Zwitterionic polysaccharides (ZPS), obtained through chemical introduction of positive charges into anionic polysaccharides (PS) from GBS, have the ability to activate human and mouse antigen presenting cells (APCs) through toll-like receptor 2 (TLR2). To generate a polysaccharide vaccine with antigen (Ag) and adjuvant properties in one molecule, we have conjugated ZPS with a carrier protein. ZPS-glycoconjugates induce higher T-cell and Ab responses to carrier and PS, respectively, compared to control PS-glycoconjugates made with the native polysaccharide form. The increased immunogenicity of ZPS-conjugates correlates with their ability to activate dendritic cells (DCs). Moreover, protection of mothers or neonate offspring from lethal GBS challenge is better when mothers are immunized with ZPS-conjugates compared to immunization with PS-conjugates. In TLR2 knockout mice, ZPS-conjugates lose both their increased immunogenicity and protective effect after vaccination. When ZPS are coadministered as adjuvants with unconjugated tetanus toxoid (TT), they have the ability to increase the TT-specific antibody titer. In conclusion, glycoconjugates containing ZPS are potent vaccines. They target Ag to TLR2-expressing APCs and activate these APCs, leading to better T-cell priming and ultimately to higher protective Ab titers. Thus, rational chemical design can generate potent PS-adjuvants with wide application, including glycoconjugates and coadministration with unrelated protein Ags.     

Intranasal interleukin-12 is a powerful adjuvant for protective mucosal immunity.

The use of interleukin (IL)-12 as a new vaccine adjuvant for stimulating protective antiviral mucosal immunity has been examined. Mice were immunized intranasally (in) with an influenza vaccine consisting of soluble hemagglutinin (H1) and neuraminidase (N1) plus IL-12. This treatment resulted in elevated levels of lung and splenic interferon-gamma and IL-10 mRNA. Total and IgG2a anti-H1N1 antibody levels in serum were significantly elevated, as were total, IgG1, IgG2a, and secretory IgA antibody levels in bronchoalveolar lavage (BAL) fluids compared with animals receiving vaccine alone. Mice immunized in with vaccine and IL-12 also exhibited decreased weight loss and dramatically enhanced survival after lethal challenge with infectious influenza virus. Protection was dependent upon the presence of B cells and could be transferred to naive mice by inoculation of either serum or BAL fluid from IL-12-treated mice. These findings show for the first time that soluble IL-12 delivered in serves as a powerful respiratory adjuvant for protective antiviral immunity.     

Protective effects of murine monoclonal antibodies in experimental septicemia: E. coli antibodies protect against different serotypes of E. coli

Murine monoclonal antibodies that bind outer membrane antigens of the J5 mutant of Escherichia coli O111:B4 were derived from spleen cells of BALB/c mice immunized with killed whole cells and boosted with lipopolysaccharide (LPS) and LPS-associated proteins. Seven hybridomas were selected for their reactivity against the J5 LPS; they cross-reacted with O111, O55, O127, and O128 E. coli LPS. One (B7B3) also reacted with the Serratia marcescens LPS and Klebsiella pneumoniae lipid A. A protective effect was obtained with D6B4 antibody in a lethal endotoxemia model induced by LPS from O111, O127, and O128 E. coli serotypes in D-galactosamine-sensitized mice. D6B4 and D6B3 antibodies protected mice infected with E. coli O111:B4, when administered before infection. The D6B4 antibody was also protective when administered after infection. The antibodies D6B3 and D4B5 were protective in heterologous infection induced by E. coli O2:K1.     

Th1 immune response to Plasmodium falciparum recombinant thrombospondin‐related adhesive protein (TRAP) antigen is enhanced by TLR3‐specific adjuvant,poly(I:C) in BALB/c mice

Sporozoite‐based malaria vaccines have provided a gold standard for malaria vaccine development, and thrombospondin‐related adhesive protein (TRAP) serves as the main vaccine candidate antigen on sporozoites. As recombinant malaria vaccine candidate antigens are poorly immunogenic, additional appropriate immunostimulants, such as an efficient adjuvant, are highly essential to modulate Th1‐cell predominance and also to induce a protective and long‐lived immune response. In this study, polyinosinic:polycytidylic acid [poly(I:C)], the ligand of TLR3, was considered as the potential adjuvant for vaccines targeting stronger Th1‐based immune responses. For this purpose, BALB/c mice were immunized with rPfTRAP delivered in putative poly(I:C) adjuvant, and humoural and cellular immune responses were determined in different immunized mouse groups. Delivery of rPfTRAP with poly(I:C) induced high levels and titres of persisted and also high‐avidity anti‐rPfTRAP IgG antibodies comparable to complete Freund's adjuvant (CFA)/incomplete Freund’s adjuvant (IFA) adjuvant after the second boost. In addition, rPfTRAP formulated with poly(I:C) elicited a higher ratio of IFN‐γ/IL‐5, IgG2a/IgG1, and IgG2b/IgG1 than with CFA/IFA, indicating that poly(I:C) supports the induction of a stronger Th1‐based immune response. This is a first time study which reveals the potential of rPfTRAP delivery in poly(I:C) to increase the level, avidity and durability of both anti‐PfTRAP cytophilic antibodies and Th1 cytokines.     

Active immunization with a detoxified endotoxin vaccine protects against lethal polymicrobial sepsis: its use with CpG adjuvant and potential mechanisms

BACKGROUND: An experimental vaccine for sepsis, composed of detoxified Escherichia coli J5 lipopolysaccharide (LPS) complexed with the outer membrane protein (OMP) of Neisseria meningitidis group B, induces anti-core glycolipid antibody and has been tested in pilot studies in human volunteers. METHODS: Mice were immunized with the LPS-J5/OMP vaccine with or without synthetic oligodeoxynucleotides (ODNs) containing unmethylated CpG motifs as a vaccine adjuvant (CpG ODN). The efficacy of the vaccine-induced antibody response was tested in a cecal ligation and puncture model. RESULTS: Immunization resulted in a >20-fold increase in anti-core glycolipid antibody levels, which were further increased 5-fold by the addition of CpG ODN, compared with the levels in mice in the control group. The vaccine provided a survival advantage after a cecal ligation and puncture was performed (P < .01) and significantly decreased the levels of bacteria in organs. Immunoglobulin G (IgG) anti-core glycolipid antibodies were decreased in mice to a significantly greater extent than were levels of total circulating IgG or IgG to the OMP part of the vaccine complex, suggesting specific epitope binding and clearance. CONCLUSIONS: These results indicate that the detoxified LPS-J5/OMP vaccine induces high levels of antibody against the core glycolipid of LPS and functions in vivo to promote clearance of gram-negative bacteria and improve the outcome of experimental polymicrobial intra-abdominal sepsis.     

Adjuvant immunization induces high levels of pathogenic antiphospholipid antibodies in genetically prone mice: another facet of the ASIA syndrome

Adjuvants may induce autoimmune diseases in susceptible individuals, a phenomenon recently defined as autoimmune/inflammatory syndrome induced by adjuvants (ASIA). Patients with both antiphospholipid antibodies (aPL) and the genetic coagulopathy factor V Leiden (FVL) are frequently found. We therefore evaluated whether adjuvant can induce aPL in heterozygous FVL mice. aPL were measured in na?ve mice and at 1 and 5 months after immunization with either complete or incomplete Freund's adjuvant (CFA, IFA) in FVL and control C57/B6 background mice. We defined antibody levels 3 SD above the mean of C57/B6 mice immunized with adjuvant as positive (specificity of 99%). For β(2)GPI-dependent aPL, 28.6% (6/21) of FVL mice 5 months after immunization with adjuvant (both IFA and CFA) were positive compared with 4.8% (1/22) of FVL mice 1 month after adjuvant and 0% of na?ve FVL and C57/B6 mice (0/16, p < 0.001). aPL levels correlated with behavioral hyperactivity in the staircase test. FVL mice immunized with adjuvant did not develop β(2)GPI-independent aPL. We hypothesize that the FVL aPL association is not a coincidence, but that chronic coagulation defects combined with external inflammatory stimuli analogous to adjuvant may induce aPL and also antiphospholipid syndrome, thus supporting the notion of ASIA.     

日本血吸虫核糖体制剂的佐剂作用的探讨

目的 :探讨日本血吸虫核糖体制剂用作血吸虫抗原佐剂的可能性 ,以及日本血吸虫核糖体制剂的保护作用。方法 :小鼠用日本血吸虫核糖体制剂 ( SRP)、日本血吸虫成虫抗原( SWA)和日本血吸虫核糖体制剂加日本血吸虫成虫抗原 ( SRP SWA)免疫后 ,用 ELISA检测体液免疫水平 ,用减虫率表示保护性免疫力。结果 :用 SRP或 SRP SWA免疫小鼠均产生较高滴度的特异性抗体 ,然而均未能诱导比 SWA组小鼠高的减虫率。结论 :SRP可以增强小鼠的体液免疫应答反应 ,但未能使小鼠产生保护性免疫力。     

Serological response of cattle following Brucella abortus strain 19 vaccination and simultaneous administration of levamisole

The serological response of heifers to injection with Brucella abortus strain 19 vaccine and simultaneous administration of levamisole hydrochloride were compared with those of heifers inoculated with Brucella abortus strain 19 vaccine alone. The Rose Bengal, serum agglutination, complement fixation and Coombs' antibovine globulin tests were used to measure the humoral responses for a period of sixteen weeks after vaccination. The results indicated that antibody titres in the heifers injected with levamisole and the vaccine were moderately elevated. It was suggested that the heightened antibody titres were possibly mediated through helper T-cells and macrophages. The significance of using levamisole as an adjuvant with Brucella abortus strain 19 vaccine in cattle is briefly discussed.     

Administration of naloxone in combination with recombinant Plasmodium vivax AMA‐1 in BALB/c mice induces mixed Th1/Th2 immune responses

Naloxone (NLX) has the ability to shift the immune response to a Th1 profile. Therefore, the adjuvant efficacy of NLX with recombinant P. vivax apical membrane antigen‐1(rPvAMA‐1) in BALB/c mice was evaluated. Mice were immunized subcutaneously with purified rPvAMA‐1 formulated with NLX (doses of 5 mg/kg body weight) alone or in combination with IFA. A significant increase in anti‐PvAMA‐1 IgG antibody after the second boost (mean OD₄₉₀ = 2·08 and 2·17, in groups received, rPvAMA‐1/NLX and rPvAMA‐1/NLX/IFA, respectively) was detected. IgG1 and IgG2b were the predominant isotypes in all immunized mouse groups. In immunized mice with rPvAMA‐1/NLX (mean: 1036 pg/mL) and with rPvAMA‐1/NLX/IFA (mean: 1024 pg/mL), IFN‐γ was elicited in response to rPvAMA‐1 after the second boost. No detectable IL‐4 secretion was determined in all tested groups. In conclusion, the administration of NLX alone or NLX/IFA with rPvAMA‐1 in BALB/c mice, which induced mixed Th1/Th2 immune responses, was comparable with that of the same recombinant antigen with CFA/IFA adjuvant. The results indicate that NLX alone may possibly not be considered as a potent Th1 adjuvant in PvAMA‐1‐based vaccine. However, in order to modulate immune responses from mixed Th1/Th2 to strong and protective Th1 response, further study is warranted on combination of NLX with other adjuvants such as CpG motifs or MPL in proper vaccine formulation. Additionally, dose–response study is necessary to determine the effect of different doses of antigen combined with NLX (at various doses) in Balb/c mice.     

弓形虫主要表面抗原1核酸疫苗与蛋白疫苗联合免疫保护作用的研究

目的 研究刚地弓形虫RH株主要表面抗原1(P30)DNA疫苗诱导BALB/c小鼠的保护性免疫作用。方法 根据弓形虫P30基因的DNA序列设计一对引物,,将PCR扩增到的P30基因克隆到真核表达载体pcDNA.3.1中。大量制备pcDNA3. 1-P30和pcDNA3.1质粒DNA。将48只 BALB/c小鼠随机分成4组,每组1 2只,空质粒对照组(A组)第O、2、4周经小鼠股四头肌注射100 μg pcDNA3.1质粒DNA;重组P30抗原免疫组(B组)第0、2、4周每鼠经背部皮下多点注射50 μg rP30+福氏完全佐剂;P30 DNA疫苗免疫组(C组)第O、2、4周经小鼠股四头肌注射100 μg pcD- NA3. 1-P30质粒DNA;P30 DNA疫苗和重组P30抗原联合免疫组(D组)第O、2周经小鼠股四头肌洼射100 μg pcDNA3. 1-P30质粒DNA,第4周每鼠经背部皮下多点注射50 μg rP30+福氏完全佐剂。末次免疫4周后每鼠用100个弓形虫速殖子经腹腔感染,观察小鼠存活时间。结果 成功构建刚地弓形虫RH株P30DNA疫苗,动物保护性实验表明,虽然与对照组相比实验组小鼠的存活时间有一定的延长,但差异无显著性。结论 pcDNA3.1-P30 DNA疫苗具有弓形虫病候选DNA疫苗分子的潜力。     

钙纳米颗粒作为血吸虫病抗独特型抗体疫苗佐剂的研究

目的 探索钙（Ca）纳米颗粒作为日本血吸虫病抗独特型抗体NP30疫苗佐剂的可行性。方法 将钙纳米颗粒与NP30制备成Ca-NP30结合物（Ca-NP30)，主动免疫BALB/c小鼠，观察其对小鼠的保护性作用并探讨其免疫保护机制。结果 Ca纳米颗粒可增强NP30对宿主的保护性作用，减虫率明显提高，从单用NP30的30.4%提高到57.8%；血清特异性抗体IgG水平较对照组显著升高；足垫试验可引发迟发型变态反应。结论 Ca纳米颗粒可作为血吸虫病抗独特型抗体NP30疫苗的佐剂，其作用机制与同时引起宿主体液免疫和细胞免疫应答增强有关。     

牛布鲁氏菌抗独特型抗体菌苗对大动物（牛）的抗菌保护研究

用氢氧化铝佐剂配制的牛抗独特型抗体菌苗（简称二抗佐剂苗）免疫大动物牛，通过免疫程序的测定，确定用２种程序，２个剂量进行免疫。免疫后观察其不同时期的血学清免疫反应和保护力。初步结果表明：二抗佐剂苗免疫后与Ｓ１９号苗具有同等的抗原刺激作用，在引发同源抗体的能力上Ｓ１９号苗诱发的血清滴度高于二抗佐剂苗，所做的抗菌保护试验表明，保护力可达６个月以上。     

日本血吸虫31kDa组织蛋白酶B DNA疫苗保护性免疫效果观察

目的观察日本血吸虫31kDa组织蛋白酶BDNA疫苗(Sj31B1N)在小鼠体内的保护性免疫效果.方法用Sj31B1N和Sj31B1N+pUCDNA疫苗肌注免疫BALB/C小鼠,用空白质粒载体VR1012做对照,在0、4、8周共免疫3次,每次免疫前及末次免疫后4周从尾静脉采血收集血清,经ELISA法检测小鼠血清抗体升高时,用日本血吸虫尾蚴攻击感染小鼠.结果Sj31B1N和Sj31B1N+pUC减虫率分别为24.2%和22.0%;肝卵减少率分别为34.9%和39.5%,每雌肝卵减少率分别为30.4%和35.3%.结论小鼠接种Sj31B1N后对日本血吸虫感染有减虫、减卵作用及抗雌虫生殖的作用.加质粒佐剂pUC未见有增强免疫效果的作用.     

布鲁杆菌基因工程疫苗免疫保护效率的初步观察

目的比较布鲁杆菌6种抗原表位所获得的基因工程疫苗的免疫保护效率。方法布鲁杆菌核糖体蛋白L7/L12、胞质蛋白P39、细胞表面蛋白BCSP31、二氧四氢喋啶合成酶BLS、16.5×103的外膜蛋白PAL和翻译起始因子IF3的基因片段与真核表达载体pcDNA3.1( )构建的核酸疫苗及上述6条片段转入pET32a( )后诱导表达的的重组蛋白免疫小鼠,3次免疫后进行攻毒实验,对其免疫保护效率进行初步观察。结果L7/L12和BLS的重组蛋白疫苗和核酸疫苗都产生了非常显著的保护作用,P39的核酸疫苗、IF3和BCSP31的重组蛋白疫苗也产生了非常显著的保护作用,其中L7/L12核酸疫苗的保护效率最高。结论初步认为布鲁杆菌的优势抗原表位所获得的基因工程疫苗可产生一定的抗布鲁杆菌作用,可作为未来布鲁杆菌新型疫苗的候选者,有进一步研究的价值。     

Vaccine model of antiphospholipid syndrome induced by tetanus vaccine

Successful induction of antiphospholipid syndrome (APS) in two different non-autoimmune prone mouse strains, BALB/c and C57BL/6, was achieved by tetanus toxoid (TTd) hyperimmunization using different adjuvants (glycerol or aluminium hydroxide), and different adjuvant pretreatments (glycerol or Complete Freund's Adjuvant (CFA)). APS had different manifestations of reproductive pathology in BALB/c and C57BL/6 mice: fetal resorption (as a consequence of extreme T-cell activation obtained in the course of pretreatment), and lowering of fecundity (as a consequence of polyclonal B-cell stimulation), respectively. In BALB/c mice fetal resorption coincided with glycerol and CFA pretreatments, while in C57BL/6 mice lowering of fecundity was most obvious in CFA-pretreated mice immunized with TTd in aluminium hydroxide. Both molecular mimicry and polyclonal B-cell activation occur in APS induction, with molecular mimicry effects being dominant in BALB/c mice, and polyclonal cell activation being dominant in C57BL/6 mice. Confirmation of molecular mimicry effects, which in the condition of T-cell stimulation generated fetal resorptions in the BALB/c strain, was achieved by passive infusion of monoclonal antibody (MoAb) T-26 specific for TTd and anti-β(2)-glycoprotein I obtained after TTd hyperimunization. High polyclonal B-cell activation in C57BL/6 mice prevented fetal resorption but induced fecundity lowering, as was the case in passive administration of MoAb T-26 in this mouse strain. Passive infusion of anti-idiotypic MoAb Y7 into C57BL/6 mice induced fetal resorptions and confirmed the above suggestion on the protective role of polyclonal B-cell stimulation in fetal resorptions.     

卡介菌CpG DNA复合佐剂-02系统(BC-C02)有效性与安全性评价

目的 对卡介菌（BCG）CpG DNA复合佐剂-02系统（BC-C02）的有效性及安全性进行评价，为其应用提供研究基础。方法 以流式细胞法检测经CpG DNA与细胞体外共培养后B细胞内TLR-9,巨噬细胞内IL-12、TLR-9表达，以酶联免疫斑点法检测人外周血单个核细胞（PBMC）经CpG DNA刺激后IL-12的分泌。单纯H1N1抗原低、中、高三个剂量组及三个剂量抗原添加CpG DNA后免疫小鼠, 每组 20只动物，免疫后测定其抗体效价及H1N1病毒感染后死亡率。经Mtb感染后豚鼠，以Ag85B+ BC-C02疫苗低、中、高组与BC-C02及生理盐水（NS）进行免疫治疗，每组10只豚鼠，观察动物脏器结核病变指数。同时分别检测CpG DNA注射小鼠后IgE产生和复合佐剂BC-C02注射豚鼠后全身过敏毒性。结果 BC-C02中的生物佐剂可刺激B细胞增殖［佐剂组CD19⁺%为41%,培养基对照组(NCS)组为27%；t=-4.40，P＜0.05］；促进B细胞内TLR-9表达（佐剂组CD19⁺TLR-9⁺%为2.8%,NCS组为1.1%；t=-5.92，P＜0.05）；上调巨噬细胞表面MHC Ⅱ类分子表达（佐剂组F4/80⁺I-A/I-E⁺%为82%,NCS组为31%；t=-4.32，P＜0.05）；可促进巨噬细胞内TLR-9和IL-12的分泌（佐剂组F4/80⁺I-A/I-E⁺TLR-9⁺IL-12⁺%为2.1%,NCS组为0.1%；t=4.80 ，P<0.05)。BC-C02中的生物佐剂作为H1N1疫苗佐剂，在检测时间内（5、7、14、28 d），PBS组4个时间点血凝抑制(HI)抗体滴度均<10； H1N1低剂量组滴度<中剂量组滴度<高剂量组滴度，抗原复合CpG 组均高于单纯抗原组，且佐剂可促进抗原特异性IgG2a的提高。H1N1保护力实验中，PBS组、H1N1低剂量组、H1N1低剂量+CpG DNA组、H1N1高剂量组、H1N1高剂量+CpG DNA组存活率分别为30%、50%、90%、100%、100%，显示佐剂可提高40%动物存活率。Mtb潜伏感染动物经疫苗治疗后，对照组动物100%病变，疫苗组完全转阴的动物达到30%，而且病变指数＜30的动物达到60%～70%。佐剂注射小鼠后IgE抗体与NS无区别，豚鼠过敏毒性试验显示佐剂不会引起动物全身过敏反应。结论 BC-C02既能诱导细胞免疫反应，也能诱导体液免疫反应，并能提高疫苗保护效力，可作为一种新型疫苗用佐剂的候选佐剂。     

鼠疫菌荚膜抗原和重组rV270抗原免疫小鼠后保护效果观察

目的 对小鼠血清抗体滴度检测和对小鼠的保护力观察,评价鼠疫菌荚膜抗原(F1抗原)和重组rV270抗原对鼠疫的免疫保护效果.方法 40只6～8周雌性Balb/c小鼠,按体质量随机分成4个实验组(F1-10 μg+铝佐剂、F1-20μg+铝佐剂、rV-10 μg+铝佐剂、rV-20 μg+铝佐剂)和1个对照组,每组8只.将天然F1抗原和重组rV270抗原分别吸附到25％铝佐剂中免疫实验组小鼠,对照组小鼠以免疫等量的铝佐剂.每只动物每次后腿肌肉免疫100 μ1,初次免疫后,第21天加强免疫1次.所有动物分别于第1次免疫后第8周采血,酶联免疫吸附试验(ELISA)测定抗体滴度.同时用2000倍半数致死量(LD50)的鼠疫菌141强毒株皮下攻毒,观察14d,以观察免疫后保护效果.结果 对照组未产生抗体,F1-10 μg+铝佐剂组、F1-20 μg+铝佐剂组的抗体几何平均滴度(GMT)分别为1∶30443.9、1∶21527.8,组间比较差异无统计学意义(t=1.1282,P＞0.05);rV-10 μg+铝佐剂组和rV-20μg+铝佐剂组的GMT分别为1∶13957.3、1∶18100.9,组间比较差异无统计学意义(t=0.9408,P＞0.05).用141强毒株皮下攻毒后,实验组小鼠全部存活,对照组8只小鼠全部死亡.结论 实验用天然F1抗原及重组rV270抗原具有较高的免疫活性,可作为鼠疫亚单位疫苗的主要组分用于鼠疫亚单位疫苗的研究.     

Immunologic response to a single dose of tetanus toxoid in older people

OBJECTIVES: Several studies have demonstrated that a large percentage of older people are inadequately immunized against tetanus. The aim of this study was to assess the immunity against tetanus in a group of individuals aged 69 and older and to examine the immune response to a single dose of tetanus toxoid. DESIGN: A convenience sample of 115 residents of a large retirement home, aged 69 and older, was studied. After a blood sample for anti-tetanus antibody titer, a single dose of tetanus toxoid vaccine was administered. Repeat titers were obtained 6 weeks after the vaccination and analyzed by ELISA assay. Antibody levels equal to or greater than 0.1 IU/mL were considered protective. RESULTS: Sixty-seven of 115 (58.3%) individuals had adequate antibody titers. Those individuals who reported having been vaccinated with tetanus toxoid in the past were more likely to be immunized adequately compared with those who reported having never been vaccinated (66.7% vs 39.3%, P = .02). After vaccination, 34 of 46 (73.9%) individuals with inadequate antibody titers became seropositive. Those who remained seronegative had mean prevaccination antibody titers significantly lower than those who seroconverted. Sixteen of 17 (94.1%) persons who reported having been vaccinated in the past and were found to be seronegative developed adequate antibody titers following vaccination, compared with only nine of 16 (56.2%) who reported never having been vaccinated (P = .04). There was no association between seroconversion rate and age, sex, underlying diseases, and army service. CONCLUSIONS: Most individuals will develop an adequate anti-tetanus antibody titer following administration of a single dose of tetanus vaccine. A history of past immunization is a good predictor of becoming adequately immunized. It is important that physicians follow the current recommendations for adult immunization and initiate campaigns to ensure that the older population is protected against tetanus.