Immune responses elicited by a fourth dose of the HPV-16/18 AS04-adjuvanted vaccine in previously vaccinated adult women

Background

Vaccines are now available for the prevention of HPV-16/18-related cervical infections and pre-cancers, primarily targeting adolescent girls. Since the risk of HPV exposure potentially persists throughout a woman's sexual life, vaccine-derived immunity should be long-term. The current study, HPV-024 (NCT00546078, http://clinicaltrials.gov), assessed the immune memory in North American women who received three doses of HPV-16/18 AS04-adjuvanted vaccine 7 years earlier in HPV-001 (NCT00689741).

Methods

Women vaccinated in HPV-001 received a 4th-dose of the HPV-16/18 vaccine (024-4DV group, N = 65). Post 4th-dose immune responses were compared with post 1st-dose immune responses in cross-vaccination controls (024-3DV group, N = 50). Reactogenicity was compared between the 4th-dose and the 1st-dose administration.

Results

Pre 4th-dose, 100% of subjects in the 024-4DV group remained seropositive for anti-HPV-16/18 antibodies (ELISA). Compared to pre 4th-dose, GMTs for anti-HPV-16 and anti-HPV-18 antibodies were respectively 9.3-fold and 8.7-fold higher at day 7, and 22.7-fold and 17.2-fold higher at month 1. Compared to post 1st-dose, GMTs for anti-HPV-16 and anti-HPV-18 were respectively 80.5-fold and 205.4-fold higher at day 7, and 11.8-fold and 20.5-fold higher at month 1. Furthermore, 68.2% and 77.3% of women had HPV-16/18 specific memory B-cells, respectively, pre 4th-dose, rising to 100% one month post 4th-dose vaccination. The 4th-dose was generally well tolerated.

Conclusion

A 4th-dose of HPV-16/18 AS04-adjuvanted vaccine triggered a rapid and strong anamnestic response in previously vaccinated women, demonstrating vaccine-induced immune memory.     

Serological methods used for rabies post vaccination surveys: An analysis

The assessment of fox immunity following oral rabies vaccination (ORV) is commonly applied to assess the efficacy of an ORV campaign in the field. Several ELISA kits have been developed and validated for their use for rabies serology in wildlife as an alternative to neutralizing techniques (NT), such as the fluorescent antibody virus neutralization test (FAVN) and the rapid fluorescent foci inhibition test (RFFIT). At a European level, NT and ELISA tests are used interchangeably and on different types of samples collected for vaccination follow-up. This has resulted in a difficulty in comparing the results generated with different diagnostic tools. We have evaluated (a) the effect of two different matrices commonly used for serology in red foxes on the results of the FAVN and (b) the performance of two commercially available ELISAs in comparison with the FAVN, as a gold standard, using a panel of over 700 field fox samples. Moderate agreement was observed when comparing results from different matrices. We found a very low level of agreement and low values of relative sensitivity and specificity of the ELISAs tested in comparison with the FAVN. Our findings confirm, using a vast collection of field samples obtained during post-vaccination surveillance campaigns in Italy, the need for improved reliability of certain serological tests.     

A simple approach for enhanced immune response using engineered dendritic cell targeted nanoparticles

In this study, we demonstrate a simple strategy for enhanced immune response using a two-component dendritic cell (DC) targeted antigen delivery system. One component consists of a recombinant bifunctional fusion protein (bfFp) used for DC targeting, whereas, the other component is made of biotinylated PLGA nanoparticles that encapsulate the antigen. The fusion protein (bfFp) made of a truncated core-streptavidin fused to anti-DEC-205 single chain antibody (scFv) was mixed with ovalbumin-loaded biotinylated NPs that were formulated using biotin–PEG (2000)–PLGA, and the combination, bfFp functionalized NPs was used for DC targeted antigen delivery. In vitro DC uptake studies revealed a 2-fold higher receptor-mediated uptake of bfFp functionalized NPs when compared to non-targeted NPs. Immunization of the mice with the bfFp functionalized NPs in conjunction with DC maturation stimulus (anti-CD40 mAb) enhanced OVA-specific IgG and IgG subclass responses. Splenocytes of these mice secreted significantly higher levels of Th1 (IFN-γ and IL-2) cytokines upon ex vivo restimulation with OVA. The promising outcomes of the bfFp functionalized DC targeted system support its use as a versatile vaccine delivery system for the design of monovalent or polyvalent vaccines.     

Therapeutic vaccination with Salmonella-delivered codon-optimized outer inflammatory protein DNA vaccine enhances protection in Helicobacter pylori infected mice

Vaccination had demonstrated as an alternative way to combat Helicobacter pylori challenge. In the present study, codon-optimized outer inflammatory protein gene (oipA) for Mus species codon usage, the inclusion of optimal Kozak sequence, and modified of GC content was applied to construct a novel DNA construct. The Salmonella-delivered wild type oipA construct (SL7207/poipA) and the Salmonella-delivered codon-optimized oipA construct (SL7207/poipA-opt) were prepared and their therapeutic efficacy was evaluated in H. pylori-infected mice. The codon-optimized oipA construct (poipA-opt) expressed almost six-fold higher protein than that of wild type construct (poipA) as normalized to the β-actin expression in AGS cells. Oral therapeutic immunization with SL7207/poipA-opt significantly eliminated H. pylori colonization in the stomach; and protection was related to a robust Th1/Th2 immune response. Therefore, our results suggested that fine therapeutic efficacy was related to sufficient expression of the antigen. It is supposed that codon-optimized oipA gene improves protein expression and consequently enhances the immunogenicity of DNA vaccine, which resulted in a significant reduction of bacterial loads in H. pylori infected mice. The Salmonella-delivered codon-optimized DNA construct could be a candidate vaccine against H. pylori for the clinical application.     

Long-term persistence of neutralising antibodies against bluetongue virus serotype 8 in naturally infected cattle

Neutralising antibodies to bluetongue virus (BTV) in convalescent cattle have been described as persistent. Controlled laboratory studies, however, rarely last longer than a couple of weeks and long-term field data are lacking. This study followed twelve cattle that had been naturally infected with bluetongue virus serotype 8 (BTV-8) in Germany in 2006. Using ELISAs and a serum neutralisation test, we found a strong humoral immune response four to six years after the last exposure to BTV-8; based on data from long-term vaccine studies, it is highly likely that this coincides with immunity to reinfection with the same serotype.     

RNAi suppression of rice endogenous storage proteins enhances the production of rice-based Botulinum neutrotoxin type A vaccine

Mucosal vaccines based on rice (MucoRice) offer a highly practical and cost-effective strategy for vaccinating large populations against mucosal infections. However, the limitation of low expression and yield of vaccine antigens with high molecular weight remains to be overcome. Here, we introduced RNAi technology to advance the MucoRice system by co-introducing antisense sequences specific for genes encoding endogenous rice storage proteins to minimize storage protein production and allow more space for the accumulation of vaccine antigen in rice seed. When we used RNAi suppression of a combination of major rice endogenous storage proteins, 13 kDa prolamin and glutelin A in a T-DNA vector, we could highly express a vaccine comprising the 45 kDa C-terminal half of the heavy chain of botulinum type A neurotoxin (BoHc), at an average of 100 μg per seed (MucoRice-BoHc). The MucoRice-Hc was water soluble, and was expressed in the cytoplasm but not in protein body I or II of rice seeds. Thus, our adaptation of the RNAi system improved the yield of a vaccine antigen with a high molecular weight. When the mucosal immunogenicity of the purified MucoRice-BoHc was examined, the vaccine induced protective immunity against a challenge with botulinum type A neurotoxin in mice. These findings demonstrate the efficiency and utility of the advanced MucoRice system as an innovative vaccine production system for generating highly immunogenic mucosal vaccines of high-molecular-weight antigens.     

Supplementation with branched-chain amino acids attenuates hepatic apoptosis in rats with chronic liver disease

Branched-chain amino acids (BCAA) can function as pharmacologic nutrients for patients with decompensated cirrhosis. However, the effects of BCAA at the early stage of chronic liver disease are not clear. We hypothesized that early BCAA supplementation would attenuate the progression of chronic liver disease. The present study examined the effects of BCAA supplementation on the progression of chronic liver disease in rats caused by injected carbon tetrachloride (CCl₄). Sprague-Dawley rats were fed with a casein diet (control group) or the same diet supplemented with BCAA (BCAA group) for 11 weeks, and all rats were repeatedly injected with CCl₄. Food intake did not significantly differ between control and BCAA groups during the experimental period. Plasma alanine aminotransferase activities gradually increased during the experimental period in both groups but peaked later in the BCAA group. Liver fibrosis was more evident in the control group. Levels of connective tissue growth factor messenger RNA were significantly lower in the livers of rats in the BCAA group than in the control group. Terminal deoxynucleotidyl transferase–mediated deoxyuridine 5-triphosphate nick end labeling assays found considerably more hepatic apoptosis in the control group. Liver cytosolic cytochrome c levels and expression of the proapoptotic Bax protein in the mitochondrial fraction were significantly lower in the BCAA group than in the control group. These results suggest that supplementation with BCAA delays the progression of chronic liver disease caused by CCl₄ in rats by attenuating hepatic apoptosis.     

母亲外周血与脐带血麻疹抗体水平研究

目的研究母亲、新生儿麻疹抗体水平与麻疹发病的关系。方法采集60名妊娠母亲外周静脉血与脐带血分离血清,采用ELISA法检测麻疹IgG抗体水平。结果妊娠母亲外周静脉血、脐带血麻疹IgG抗体浓度分别为(4.883±4.687)ng/ml、(7.280±6.061)ng/ml;妊娠母亲麻疹IgG抗体浓度同正常育龄妇女(P﹥0.05);母亲平均血清麻疹IgG浓度低于新生儿(P﹤0.05);母血与脐血麻疹IgG抗体水平呈正的直线相关关系(r=0.946,P=0.000);曾有麻疹感染史的母亲静脉血麻疹IgG抗体浓度明显增加(β=0.259,t=2.058,P=0.044);自然感染麻疹母亲的脐血麻疹IgG浓度显著高于曾接种麻疹疫苗母亲的脐血麻疹IgG(P﹤0.05)。结论母亲麻疹IgG抗体水平是影响婴儿麻疹发病率的重要原因。     

2009—2011年恩施州HIV初筛阳性标本确证实验结果及带型分析

目的对2009—2011年恩施州186份人类免疫缺陷病毒(HIV)确证阳性样本进行免疫印迹(WB)条带分析,增强对WB试验结果的分析判断能力。方法采用酶联免疫吸附试验(ELISA)对2009—2011年恩施州辖区HIV抗体初筛阳性标本进行复核检测和使用WB试验进行确证检测。结果 269例初筛阳性者中ELISA复核HIV抗体阳性210份,阳性率为78.07%;复核HIV抗体阴性59份,阴性率为21.93%。WB试验阳性186份,占88.57%;15份为不确定,占7.14%;9份为阴性,占4.29%。WB带型分布:其中7条带以上共计181例,占97.31%;6条带的3例,占1.61%;5条带的1例;占0.54%。性别、不同年龄组间与各WB带型分布间的差异无统计学意义。结论在艾滋病HIV抗体初筛与确证实验中,复检试剂种类的选择对确证阳性率影响较大,WB带型的阳性判定应严格按照《全国艾滋病检测技术规范》,并结合试剂说明书,参考实际情况,谨慎判定。