Increasing FIM2/3 antigen-content improves efficacy of Bordetella pertussis vaccines in mice in vivo without altering vaccine-induced human reactogenicity biomarkers in vitro

Current acellular-pertussis (aP) vaccines appear inadequate for long-term pertussis control because of short-lived efficacy and the increasing prevalence of pertactin-negative isolates which may negatively impact vaccine efficacy. In this study, we added fimbriae (FIM)2 and FIM3 protein to licensed 2-, 3- or 5-component aP vaccines (Pentavac®, Boostrix®, Adacel®, respectively) to assess whether an aP vaccine with enhanced FIM content demonstrates enhanced efficacy. Vaccine-induced protection was assessed in an intranasal mouse challenge model. In addition, potential reactogenicity was measured by biomarkers in a human whole blood assay (WBA) in vitro and benchmarked the responses against licensed whole cell pertussis (wP) and aP vaccines including Easyfive®, Pentavac® and Pentacel®. The results show that commercial vaccines demonstrated reduced efficacy against pertactin-negative versus pertactin-positive strains. However, addition of higher amounts of FIM2/3 to aP vaccines reduced lung colonization and increased vaccine efficacy against a pertactin-negative strain in a dose-dependent manner. Improvements in efficacy were similar for FIM2 and FIM3-expressing strains. Increasing the amount of FIM2/3 proteins in aP formulations did not alter vaccine-induced biomarkers of potential reactogenicity including prostaglandin E₂, cytokines and chemokines in human newborn cord and adult peripheral blood tested in vitro. These results suggest that increasing the quantity of FIM proteins in current pertussis vaccine formulations may further enhance vaccine efficacy against B. pertussis infection without increasing the reactogenicity of the vaccine.     

破伤风毒素C端片段与心肌营养素-1融合蛋白表达、纯化与靶向神经元逆向运输及神经营养活性鉴定

目的 在BL21(DE3)大肠杆菌中表达破伤风毒素C端片段(TTC)与心肌营养素(CT)-1融合蛋白并纯化.探讨TTC转导结构域对CT-1的靶向神经元逆向运输活性与CT-1的神经营养活性.方法 异丙基-B-D硫代半乳糖苷(IPTG)诱导BL21(DE3)大肠杆菌表达CT-1/TTC融合蛋白,SDS-聚丙烯酰胺凝胶电泳(SDS-PAGE)与WB法鉴定融合蛋白表达.制备SD大鼠坐骨神经损伤模型,分别经神经再生室、肌肉注射给药,自由放养1周后处死,4%多聚甲醛灌注固定,取脊髓L4～L6腰膨大标本,冰冻切片,免疫组织化学检测.制备新生6～7 d龄sD大鼠坐骨神经损伤模型,肌肉注射CT-1/TTC融合蛋白,自由放养1周后处死,4%多聚甲醛灌注固定,取L4～L6腰膨大标本,冰冻切片,尼氏染色计数脊髓前角运动神经元.结果 原核表达目的 蛋白CT-1/TTC表达量占全菌蛋白总量的15%,以可溶性蛋白为主.通过谷胱甘肽S-转移酶(GST)标签亲和纯化获得2.7 g/L的CT-1/TTC重组融合蛋白.免疫组织化学于脊髓腰膨大检测到CT-1/TTC融合蛋白.坐骨神经损伤后,脊髓L4～L6腰膨大前角运动神经元计数较CT-1/TTC融合蛋白处理组减少,存活率下降.结论 基因重组CT-1/TTC蛋白在大肠杆菌中获得了表达和纯化,所获得的融合蛋白有靶向性脊髓神经元细胞的活性和对损伤后运动神经元的神经营养活性.     

TMC–MCC (N-trimethyl chitosan–mono-N-carboxymethyl chitosan) nanocomplexes for mucosal delivery of vaccines

In this study, for the first time, TMC/MCC complex nanoparticles as a delivery system and as an adjuvant were developed and evaluated to obtain systemic and mucosal immune responses against nasally administered tetanus toxoid (TT). Nanoparticles were developed by complexation between the oppositely charged chitosan derivatives, N-trimethyl chitosan (TMC, polycationic) and mono-N-carboxymethyl chitosan (MCC, polyampholytic) without using any crosslinker for mucosal vaccination. The cellular viability was found to be higher with TMC/MCC complex compared to that of MCC and TMC alone. Size, zeta potential and morphology of the nanoparticles were investigated as a function of preparation method. Nanoparticles with high loading efficacy (95%) and positively charged surface were obtained with an average particle size of 283 ± 2.5 nm. The structural integrity of the TT in the nanoparticles was confirmed by SDS–PAGE electrophoresis analysis. Cellular uptake studies indicated that FITC-BSA loaded nanoparticles were effectively taken up into the mouse Balb/c monocyte macrophages. Mice were nasally immunized with TT loaded TMC/MCC complex nanoparticles and compared to that of TMC and MCC nanoparticles. TMC/MCC complex nanoparticles were shown to induce both the mucosal and systemic immune response indicating that this newly developed system has potential for mucosal administration of vaccines.     

The mucosal adjuvanticity of the oligodeoxynucleotides containing a non-methylated CpG motif on BCG and diphtheria toxoid

CpG-DNA is currently attracting attention as an effective and safe vaccine adjuvant to prevent from microbial infections. In this report, we examined the effects of oligo B, which is a synthetic CpG-DNA, in mucosal administration of Bacillus Calmette-Guérin (BCG) and diphtheria toxoid (DT). Co-administration with oligo B enhanced BCG-induced delayed type hypersensitivity to purified protein derivative (PPD) in guinea pigs. The titers of anti-DT serum IgG, IgA and mucosal IgA antibodies induced by intranasal administration with DT plus oligo B were significantly higher than that with DT alone. In both C57BL/6 and BALB/c mice, intranasal administration of DT with oligo B induced enough level of antibodies to prevent onset of diphtheria. The analysis of antibody subclasses showed that intranasal administration of oligo B induced not only IgG1 but also IgG2a, IgG2c and IgA anti-DT antibodies. In contrast, there was no or little production of the anti-DT serum IgE. Taken together our data suggest that oligo B is a powerful adjuvant in mucosal immunization.     

Diphtheria: A zoonotic disease in France?

Thanks to vaccination, diphtheria has almost disappeared in France. The case definition, used for mandatory notification, was expanded in 2003 to include toxin-producing strains of Corynebacterium ulcerans. We describe the epidemiology of diphtheria in France from 1990 to 2008. No cases occurred between 1990 and 2001. Since 2002, 19 cases have been reported: 4 cases due to Corynebacterium diphtheriae related to exposure in endemic countries, and 15 cases due to other corynebacteria, including 4 cases of pseudomembranous pharyngitis, mainly related to contact with domestic animals. High vaccination coverage in the population and sensitive surveillance need to be maintained. Moreover, control measures need to be adapted to the non-C. diphtheriae toxigenic species.     

Booster vaccination of adults with reduced-antigen-content diphtheria,Tetanus and pertussis vaccine: Immunogenicity 5 years post-vaccination

At 60 months post-vaccination, adults (mean age 45.6 years) randomised to receive combined reduced-antigen-content diphtheria–tetanus and acellular pertussis vaccine (dTpa) versus tetanus–diphtheria (Td) + monovalent acellular pertussis (pa) were seroprotected against diphtheria (≥0.016 IU/mL Vero cell assay) and tetanus (≥0.1 IU/mL ELISA assay) in 94.4% and 96.2%, respectively (dTpa), compared with 93.7% and 90.6% (Td + pa). Anti-FHA, anti-PT and anti-PRN antibodies (≥5 EL.U/mL) were maintained in 100%, 89.5% and 95.0% of dTpa versus 100%, 85.5% and 90.6% of pa vaccine recipients. At 5 years post boosting, antibody levels to diphtheria and tetanus are similar amongst adults receiving a dTpa or dT, and pertussis antibodies remain above pre-booster levels in at least 85%.     

The evaluation of immune responses to hepatitis B vaccination in diabetic and non-diabetic haemodialysis patients and the use of tetanus toxoid

Aim: The aim of this study was to investigate whether haemodialysis (HD) patients suffering from diabetes mellitus could be considered at risk for the development of the protective antibodies to hepatitis B (HB) vaccination and, to evaluate the effectiveness of tetanus toxoid (TT) administrated 2 days before HB vaccination. Methods: Forty-nine HD patients were divided into two groups: group A (19 diabetic patients) and group B (30 non-diabetic patients). A dose of 40 μg recombinant HB vaccine was injected intramuscularly to the patients at 0, 1, 2 and 6 months. Results: After the completion of the course, the patients in group A were found to have a lower protective antibody rates than the patients in group B (57.8% vs 70%) (P > 0.05). After the administration of additional booster doses during 12 months, the protective antibody to hepatitis B surface antigen (HBsAb) levels were detected in 78.9% and 96.6% of the patients in group A and group B, respectively (P > 0.05). The patients not having protective HBsAb levels were administered TT and HB vaccines, and after course, all of them have produced protective HBsAb levels. Conclusion: The present study showed that diabetic patients on HD may carry a greater risk of not seroconverting than non-diabetic ones for antibody response to HB vaccination. The use of TT 2 days before HB vaccination may be a useful and effective method of enhancing the immune response to HB vaccination, especially in the patients with diabetes mellitus on HD.     

Autonomic impairment in tetanus: delayed baroreflex involvement

Autonomic nervous system impairment plays an important role in the clinical course of tetanus and is thought to be responsible for life-threatening complications. It is believed to be associated with predominance of sympathetic activity. Direct baroreflex involvement has not yet been reported. We hypothesized that impaired baroreflex may contribute to the autonomic cardiovascular dysregulation in tetanus. In a patient with tetanus baroreflex sensitivity was measured on the first 5 consecutive days non-invasively using a Finometer device. Baroreflex gain was calculated as sequential cross-correlation between heart rate and blood pressure. Short-time pulse interval standard deviations (SDNN) were derived. Additionally, heart rate and arterial blood pressure were monitored and recorded continuously. Baroreflex gain values and SDNN were compared to a sex- and age-matched control subject. Compared to the control subject the patient with tetanus initially did not show a significant difference in baroreflex gain values (mean 3.68 vs 3.15, p=0.1). However, in the course of the disease an almost complete baroreflex failure occurred (mean 1.0 vs 3.15 and 0.97 vs 3.15, both p<0.0001). No correlation was found between the dynamics of baroreflex gain values and blood pressure or heart rate variability expressed by standard deviation and variance. All 5 measurements in the tetanus patient showed decreased short-time SDNN when compared to the control subject and healthy standards. In our patient we found baroreflex impairment as a part of complex autonomic dysfunction in tetanus. Furthermore, baroreflex impairment occurred only delayed. Blood pressure instability could not be explained by baroreflex dynamics. We suggest that a shift towards sympathetic activity possibly overruled the effects of decreased baroreflex sensitivity on blood pressure regulation.     

破伤风抗毒素脱敏注射致敏1例报告

破伤风抗毒素系破伤风类毒素免疫马血浆经胃酶消化提纯制得的球蛋白制剂,主要用于预防和治疗破伤风.开放性外伤,特别是有感染破伤风危险的损伤后,临床常规用药.临床上注射治疗的病人很多,只有极少数过敏,与遗传,体质等因素有关.因此,在使用TAT时,①不但要在皮试前详细询问既往有无过敏史,而且在皮试注射后要严密观察患者病情变化,并向患者及家属交代注意事项,一旦发生过敏反应,要根据病情立即采取积极的抢救措施,防止过敏性休克的发生.②本例患者于皮试后50分钟出现过敏反应,故应延长对过敏体质患者的观察时间,③对条件简陋的门诊部,应加强完善抢救措施,以免贻误抢救时机.     

破伤风137例的发病原因分析及防治

目的:探讨破伤风的发病原因及防治对策。方法:回顾性分析137例破伤风病人的临床资料。结果:破伤风发病率最高的职业是农民(占64％);发病原因仍以外伤和感染占首位,而自行注射毒品引发破伤风者近来不断出现。绝大多数破伤风病人受伤后未及时做正确处理。结论:在广大农村加强破伤风防治和切断其感染途径是降低破伤风发病率的关键,一些新的感染途径如注射吸毒和医源性因素等应引起高度重视。