Hepatitis B virus vaccination and revaccination response in children diagnosed with coeliac disease : a multicentre prospective study.

AIM: This study evaluates hepatitis B virus (HBV) vaccination response in children with celiac disease (CD). Response in initial non-responders after a single booster vaccination as well as factors influencing HBV vaccination response were evaluated. METHODOLOGY: Anti-hepatitis B surface antibodies (a-HBsAB) were checked in all children with CD and a documented complete HBV vaccination. An a-HBsAB <10 U/L was considered as non-response. A single intramuscular HBV-vaccine booster was advised to all non-responders. Response was checked at the next appointment. RESULTS: 133 children with CD were included, median age of 7.3 years (range 1.7-17.3) and 46 (35%) were male. The age at CD diagnosis was 6.0 years (range 1.1-15.7). HBV non-response was documented in 55% (n=73/133). No other factors were influencing the response. A booster was documented in 34/73 (47 %) initial non-responders (3 refused (4%), 36 (49%) had no follow up). Response after booster vaccination resulted in immunity in 22/34 (65%) and persisting non-response in 12/34 (35%). A single booster is able to reduce non-response from 55% (73/133) to 23% (22/94). CONCLUSION: A significantly lower immune response following HBV vaccination in children with CD was confirmed. A single intramuscular booster vaccination is able to induce a serologic response in two thirds of the initial non-responders. Control of HBV vaccination response has to become part of the follow-up in CD patients.

Hepatitis B core VLP-based mis-disordered tau vaccine elicits strong immune response and alleviates cognitive deficits and neuropathology progression in Tau.P301S mouse model of Alzheimer's disease and frontotemporal dementia.

BACKGROUND: Truncated mis-disordered tau protein plays an important role in the pathogenesis of Alzheimer's disease (AD) and frontotemporal dementia (FTD). Tau294-305, an epitope in the truncated tau, is essential for pathological tau-tau interaction and aggregation. A tau294-305-targeted approach may have beneficial effects in the treatment of AD and FTD. METHODS: In this study, we genetically fused tau294-305 epitope to the hepatitis B virus core protein (HBc) major immunodominant region (MIR) (with the resultant protein termed T294-HBc), and we subcutaneously immunized a Tau.P301S transgenic mouse model of FTD and AD with T294-HBc four times. The levels and characteristics of antibodies induced by T294-HBc were determined by enzyme-linked immunosorbent assay. The effect of T294-HBc on the cognitive deficits of Tau.P301S mice was tested using the Morris water maze test, novel object recognition, and a Y-maze test. Western blot analysis and IHC were applied to measure the effect of T294-HBc on tau pathologies and neuroinflammation in the mouse brains. RESULTS: The results showed that T294-HBc self-assembled into HBc chimeric virus-like particles (VLPs) with tau294-305 displayed on the surface and that it induced high antibody titers specifically against the mis-disordered truncated tau. Further investigation showed that these antibodies simultaneously bound to microtubule-binding regions 1-4 (MTBR1-4) [tau263-274, tau294-305, tau325-336, tau357-368 and tau294-305(P301S)]. Moreover, T294-HBc VLP vaccination significantly ameliorated memory and cognitive decline; reduced the levels of AT8-positive tau, truncated tau monomer, and oligomer; attenuated microgliosis and astrogliosis; and rescued synaptic deficits in Tau.P301S transgenic mice. CONCLUSIONS: T294-HBc VLP vaccine elicited strong immune response and alleviated cognitive deficits and neuropathology progression in Tau.P301S mice, indicating that the T294-HBc VLP vaccine has promising therapeutic potential for the treatment of AD and FTD.

Characterization of the disassembly and reassembly of the HBV glycoprotein surface antigen, a pliable nanoparticle vaccine platform.

While nanoparticle vaccine technology is gaining interest due to the success of vaccines like those for the human papillomavirus that is based on viral capsid nanoparticles, little information is available on the disassembly and reassembly of viral surface glycoprotein-based nanoparticles. One such particle is the hepatitis B virus surface antigen (sAg) that exists as nanoparticles. Here we show, using biochemical analysis coupled with electron microscopy, that sAg nanoparticle disassembly requires both reducing agent to disrupt intermolecular disulfide bonds, and detergent to disrupt hydrophobic interactions that stabilize the nanoparticle. Particles were otherwise resistant to salt and urea, suggesting the driving mechanism of particle formation involves hydrophobic interactions. We reassembled isolated sAg protein into nanoparticles by detergent removal and reassembly resulted in a wider distribution of particle diameters. Knowledge of these driving forces of nanoparticle assembly and stability should facilitate construction of epitope-displaying nanoparticles that can be used as immunogens in vaccines.

Donor- and recipient-derived immunity in ABO incompatible living-related liver transplantation.

This report describes how donor- and recipient-derived immunity was influenced by immunosuppressive treatment of ABO incompatibility (rituximab and immunoadsorption/plasmaphereses) in the long-term. We present an 8-year course of Hepatitis B virus (HBV) immunity, isohemagglutinins and B cell numbers. Whereas cellular HBV immunity was transferred from the HBV vaccinated donor (blood group A1) to the HBV naïve recipient (blood group 0), humoral HBV specific immune transfer was lacking. Starting at month 17 after transplantation, the recipient was vaccinated six times against HBV. Anti-HBs did not appear until the sixth vaccination at month 44. Immunoadsorption prior to transplantation reduced anti-A1 IgG titers from 256 to 2. Titers after transplantation remained low (⩽64). B cell numbers were below standard values up to month 26, then normalized and exceeded normal values from year 7 to 8 post transplantation. In conclusion, donor-derived B cell immunity was lost but recipient-derived immunity persisted after ABO incompatible transplantation.

Hepatitis B Virus Revaccination With Standard Versus Pre-S Vaccine in Previously Immunized Patients With Celiac Disease.

OBJECTIVE: Previous studies have suggested that hepatitis B virus (HBV) vaccines may be less immunogenic in individuals with celiac disease (CD). A pre-S vaccine (Sci-B-Vac) has demonstrated superior immunogenicity compared with standard HBV vaccines in several diseases. We compared the short-term immunogenicity of a pre-S vaccine with a HBV vaccine (Engerix B) for repeat vaccination of seronegative, previously immunized patients with CD. METHODS: Participants were 1 to 18-year-old children with CD who despite standard HBV vaccines in infancy had nonprotective hepatitis B surface antibody (HBs-Ab) concentrations (≤10 mIU/mL). Patients were randomized to receive either Engerix B or pre-S vaccine. HBs-Ab concentrations were measured 1 month after the first dose. For those who had not responded after 1 dose, measurement was repeated after the third dose. RESULTS: Children (n = 82) were analyzed (42 pre-S vaccine and 40 Engerix B). Baseline characteristics were similar for both groups, including gluten-free diet status. Both arms showed high response rates following the first injection: 41 (98%) versus 35 (87%) for pre-S vaccine and Engerix B recipients, respectively (P = 0.08). All other patients responded when measured after dose 3. HBs-Ab concentrations (mIU/mL) were higher in the pre-S vaccine group (median 925, interquartile range [IQR] 424-1000) than the Engerix B group (median 363, IQR 106-996, P = 0.005). Twenty (48%) of the pre-S vaccine recipients were "high responders" (>1000 mIU/mL) versus 10 (25%) in Engerix B recipients (P = 0.008). CONCLUSIONS: Both vaccines elicited adequate booster responses in most previously vaccinated patients with CD with nonprotective HBs-Ab concentrations. Pre-S vaccine administration resulted in higher Hbs-Ab concentrations. Our data suggest that a single dose of either vaccine is sufficient to raise titers to protective levels in most patients with CD.

Chronic Schistosoma japonicum infection reduces immune response to vaccine against hepatitis B in mice.

BACKGROUND: Hepatitis B and schistosomiasis are most prevalent in Africa and Asia, and co-infections of both are frequent in these areas. The immunomodulation reported to be induced by schistosome infections might restrict immune control of hepatitis B virus (HBV) leading to more severe viral infection. Vaccination is the most effective measure to control and prevent HBV infection, but there is evidence for a reduced immune response to the vaccine in patients with chronic schistosomiasis japonica. METHODOLOGY/PRINCIPAL FINDINGS: In this paper, we demonstrate in a mouse model that a chronic Schistosoma japonicum infection can inhibit the immune response to hepatitis B vaccine (HBV vaccine) and lead to lower production of anti-HBs antibodies, interferon-γ (IFN-γ) and interleukin-2 (IL-2). After deworming with Praziquantel (PZQ), the level of anti-HBs antibodies gradually increased and the Th2-biased profile slowly tapered. At 16 weeks after deworming, the levels of anti-HBs antibodies and Th1/Th2 cytokines returned to the normal levels. CONCLUSIONS/SIGNIFICANCE: The results suggest that the preexisting Th2-dominated immune profile in the host infected with the parasite may down-regulate levels of anti-HBs antibodies and Th1 cytokines. To improve the efficacy of HBV vaccination in schistosome infected humans it may be valuable to treat them with praziquantel (PZQ) some time prior to HBV vaccination.

The orchestration of cellular and humoral responses is facilitated by divergent intracellular antigen trafficking in nanoparticle-based therapeutic vaccine.

Therapeutic vaccination for the treatment of chronic hepatitis B is promising but has so far shown limited clinical efficacy. Herein, we employ polylactide nanoparticles (NPs) as the vaccine adjuvant and systematically explore their effect on activation of specific immunity and the underlying theoretical mechanisms. In vitro studies show that hepatitis B surface antigen (HBsAg) accumulates in antigen-presenting cells (APCs) to a larger content (270%) with the assistant of NP in comparison with the pure-antigen group. Besides the elevated costimulators (CD80/86) and increased major histocompatibility complex (MHC) II molecules, the MHC I molecules are also found upregulated. This result is mostly owing to the divergent antigen trafficking ways of NP-antigen in APCs, especially for the escape of exogenous HBsAg from the lysosomes to the cytosol. Interestingly, the MHC I level is downregulated in alum-antigen group, indicating a possible reason for its inefficiency in priming cellular response. Further in vivo experiments establish that NP-antigen group indeed enhances the CD8(+) CTL cytotoxicity and IFN-γ cytokine secretion. Meanwhile, specific antibody titer is also upregulated, and even surpasses that of the commercialized alum-antigen. All these results strongly support that NP-based antigen promotes an orchestration of cellular and humoral immune response, exhibiting favorable intrinsic properties to be applied in therapeutic vaccines.

Meta-analysis: the impact of nutritional status on the immune response to hepatitis B virus vaccine in chronic kidney disease.

BACKGROUND: Patients with chronic kidney disease (CKD) typically show a diminished immune response to hepatitis B virus (HBV) vaccine compared with individuals with intact kidney function. A number of inherited or acquired factors have been implicated in this suboptimal response. Patients with chronic kidney disease frequently have a compromised nutritional status; however, the impact of malnutrition on the immune response to hepatitis B virus vaccine in chronic kidney disease patients remains unclear. AIM: To evaluate the influence of nutrition status on the immune response to HBV vaccine in CKD population by performing a systematic review of the literature with a meta-analysis of clinical studies. METHODS: Study-specific relative risks were weighted by the inverse of their variance to obtain fixed- and random-effects pooled estimates of impaired vaccine response across the published studies. The risk of poor serological response to HBV vaccine in chronic kidney disease population according to nutritional parameters was regarded as the most reliable outcome end-point. Only studies performing multivariate analysis in order to make adjustments for potential confounders were included. RESULTS: We identified seven studies (15,172 unique patients with CKD). The serum protection rate after a full course of recombinant or plasma-derived vaccine towards HBV ranged between 40 and 86%. Aggregation of study results showed an independent and adverse effect of poor nutrition status, as mostly detected by serum albumin levels, on the protection rate after HBV vaccine course; the summary estimate for adjusted RR was 1.50 with a 95% confidence interval (CI) of 1.02, 2.21; R( i ) = 0.01 (random-effects model). The P value for study heterogeneity was significant (Q = 0.0001). In the subgroup of patients who received HBV recombinant vaccine, the relative risk of impaired serological response after HBV vaccination was 1.63 (95% CI, 1.08, 2.45), R( i ) = 0.90, Q = 0.00001, with poor nutritional parameters at baseline. CONCLUSIONS: An increased risk exists of impaired serologic response to HBV vaccine response among chronic kidney disease patients having poor nutrition status. Additional studies are needed to understand better the mechanisms underlying the relationship between nutritional status and serological response to HBV vaccine among patients with CKD.

An anti-viral peptide derived from the preS1 surface protein of hepatitis B virus.

The preS1 surface protein of the hepatitis B virus (HBV) is a key factor involved in initial viral entry into hepatocytes. It has been long postulated that an anti-HBV effect should be achievable using peptide fragments of the preS1. Recent reports demonstrated that several preS1-derived lipo-peptides in genotype D HBV exhibit nano to picomolar inhibitory activity against HBV infection. In this study, an acylated analog of a preS1 fragment, a 21-residue lipo-peptide (named 7524 BVS7) with a sequence of palmitoyl-GMGTNLSVPNPLGFFPDHQLDC-NH2, from genotype C HBV was produced base upon a previous structural study and was shown potently inhibits HBV infection with an IC(50) of approximately 20 nM.

[Construction and expression of non-fusional expression vector of the multi-epitope gene of hepatitis B virus].

AIM: To study the cloning, expression and antigen of therapeutic multi-epitope gene of hepatitis B virus. METHODS: The multi-epitope gene of hepatitis B virus(BPT) was designed, synthesized and cloned into the prokaryotic expression vector pBAD/gIIIA. Then it was transformed into E.coli Top10 and multi-epitope protein of hepatitis B virus(B-BPT) was expressed under the induction of Arabinose. The immunogenicity of the protein was analyzed by Western blot detection. RESULTS: The recombinant plasmid pBAD/BPT was constructed successfully and the protein of multi-epitope gene of hepatitis B virus was expressed in E.coli. Western blot detection showed the protein had ideal antigenicity. CONCLUSION: The design of therapeutic multi-epitope gene of hepatitis B virus is proved to be correct. The expressed protein may be a good therapeutic vaccine.

The ability of Hepatitis B surface antigen DNA vaccine to elicit cell-mediated immune responses, but not antibody responses, was affected by the deglysosylation of S antigen.

Hepatitis B Virus (HBV) infection remains a major worldwide infectious disease with serious long-term morbidity and mortality. The limited selections of drug treatment are not able to control the progress of disease in people with active and persistent HBV infection. Immunotherapy to control the degree of viral infection is one possible alternative solution to this challenge. HBV DNA vaccines, with their strong ability to induce cell-mediated immune responses, offer an attractive option. HBV surface protein is important in viral immunity. Re-establishing anti-S immunity in chronic HBV infected patients will bring significant benefit to the patients. Previous studies have shown that HBV S DNA vaccines are immunogenic in a number of animal studies. In the current study, we further investigated the effect of glycosylation to the expression and immunogenicity of S DNA vaccines. Our results demonstrate that deglycosylation at the two potential N-linked glycosylation sites in S protein resulted in a significant decrease of S-specific cell-mediated immune responses, but did not affect anti-S antibody responses. This finding provides important direction to the development of S DNA vaccines to elicit the optimal and balanced antibody and cell-mediated immune responses to treat people with HBV chronic infections.

Cationic transfersomes based topical genetic vaccine against hepatitis B.

DNA vaccines have been shown to elicit both cellular and humoral immune responses and to be effective in a variety of preclinical bacterial, viral, and parasitic animal models. We have recently described a needle-free method of vaccination, transcutaneous immunization, based on topical application of vaccine antigens on intact skin using a novel carrier system, namely transfersomes. In the present study, a novel modified version of transfersomes, i.e., cationic transfersomes for topical DNA vaccine delivery has been developed. Cationic transfersomes composed of cationic lipid DOTMA and sodium deoxycholate as constitutive lipids were prepared and optimized for their size, shape, zeta potentials, deformability and loading efficiency. Plasmid DNA encoding hepatitis B surface antigen (HBsAg) was loaded in the cationic transfersomes using charge neutralization method. The immune stimulating activity was studied by measuring serum anti-HBsAg titer and cytokines level (IL-2 and IFN-gamma) following topical applications of plasmid DNA loaded cationic transfersomes in Balb/c mice and results were compared with naked DNA applied topically as well as naked DNA and pure recombinant HBsAg administered intramuscularly. Results revealed that DNA loaded cationic transfersomes elicited significantly (*P<0.05) higher anti-HBsAg antibody titer and cytokines level as compared to naked DNA. It was also observed that topical application of DNA loaded cationic transfersomes elicited a comparable serum antibody titer and endogenous cytokines levels as produced after intramuscular recombinant HBsAg administration. The study signifies the potential of cationic transfersomes as DNA vaccine carriers for effective topical immunization.

Immunogenicity of a novel, bivalent, plant-based oral vaccine against hepatitis B and human immunodeficiency viruses.

A synthetic chimeric gene, TBI-HBS, encoding the immunogenic ENV and GAG epitopes of human immunodeficiency virus (HIV-1) and the surface protein antigen (HBsAg) of hepatitis B virus (HBV), was expressed in tomato plants. Tomato fruits containing the TBI-HBS antigen were fed to experimental mice and, on days 14 and 28 post-feeding, high levels of HIV- and HBV-specific antibodies were present in the serum and feces of the test animals. Intraperitoneal injection of a DNA vaccine directing synthesis of the same TBI-HBsAg antigen boosted the antibody response to HIV in the blood serum; however, it had no effect on the high level of antibodies produced to HBV.

Elastic liposomes mediated transcutaneous immunization against Hepatitis B.

Transcutaneous immunization presents a major challenge due to poor permeability of antigens through the skin barrier. To overcome this limitation ultradeformable lipid vesicles, the elastic liposomes, could be a better module for transcutaneous delivery of these proteinaceous antigens. In the present investigation Hepatitis B surface antigen (HBsAg)-loaded elastic liposomes were utilized as a mode for enhanced immunity against the antigen. Elastic liposomes were prepared by conventional rotary evaporation method and characterized for various parameters such as vesicles shape and surface morphology, size and size distribution, entrapment efficiency, elasticity, turbidity, stability and in vitro release pattern. Ex vivo cellular uptake and fluorescence studies were also conducted. In vivo studies were performed by measuring the immune response elicited by topically applied HBsAg-loaded elastic liposomes and compared to the intramuscularly administered alum-adsorbed HBsAg solution, topically applied plain HBsAg solution and physical mixture of HBsAg and elastic liposomes. Results indicate that transcutaneous immunization via elastic liposomes induces robust systemic and mucosal antibody response against HBsAg as compared to other formulations. The fluorescence microscopy results suggest prominent skin permeation and biodistribution, demonstrating efficient delivery of antigens to the immunocompetent Langerhans cells (LC) and lymphatics. The elastic liposomal formulation provides higher entrapment efficiency, enhanced penetration and effective immunoadjuvant property justifying its potential for improved vaccine delivery.

[Effect of hepatitis B vaccine immunization on HBV associated nephritis in children].

OBJECTIVE: Hepatitis B has been extensively prevalent in China and hepatitis B virus associated nephritis (HBV-GN) has been one of the common renal damages secondary to HBV infection in Chinese children. Regular vaccination against hepatitis B has been carried out nation-wide in China since January 1st, 1992. The present study was conducted to evaluate the effect of regular vaccination against hepatitis B virus on the incidence of childhood HBV-GN and membranous nephropathy (MN). METHODS: Retrospective analysis on the results of renal biopsy in 727 patients (from Nov. 1979 to March 2002) was carried out. The patients were first divided into two groups according to the date when the patients were seen. Group A patients were seen from Nov. 1979 through Dec. 1991; Group B patients were seen from Jan. 1992 through March 2002. Group B patients were further divided into 5 subgroups (Group B(1) to B(5)), with a 2-year interval after 1992. Secondly, each of these groups and subgroups were again divided into two groups, vaccinated and unvaccinated groups. RESULTS: In 727 renal biopsies, 64 cases (8.80%) met HBV-GN diagnostic criteria. Twenty-eight cases were diagnosed as HBV-GN in Group A (211 cases), accounting for 13.27%, while there were 36 cases with HBV-GN in 516 renal biopsies of Group B, accounting for 6.98% (chi(2) = 7.397 and P < 0.01). The frequency in Group B was significantly lower. Prevalence rate (from Group A to Group B(5)) was 13.3% (28/211), 13.0% (9/69), 7.3% (6/82), 6.3% (4/64), 4.9% (4/82), 5.9% (13/219), respectively, which showed a tendency of decline. Only 8 cases of HBV-GN occurred in vaccinated group (231 cases), accounting for 3.5%, while 48 cases of HBV-GN were seen in unvaccinated group (381 cases), accounting for 12.6% (chi(2) = 14.44 and P < 0.001), vaccination history was unknown in 115 of the 727 cases. In 727 renal biopsies, pathological type of 46 cases (6.3%) was membranous nephropathy and all of them had HBV-GN. Six cases of MN occurred in vaccinated group, accounting for 2.60%, while 40 cases with membranous nephropathy were found in unvaccinated group, accounting for 10.5% (chi(2) = 12.92 and P < 0.001). On the other hand, in vaccinated group there still were 8 cases of HBV-GN whose serum markers of HBV were positive. Two of their mothers had apparent evidence of hepatitis B virus infection. CONCLUSION: The frequency of HBV-GN has decreased significantly after vaccination against hepatitis B virus was routinely carried out since 1992; at the same time, childhood membranous nephropathy might be decreasing gradually, too. The cause of individual cases of HBV-GN who has be vaccinated was probably due to maternal-infant transmission and immunization failure. Attention should be paid to interruption of maternal-infant transmission and serological follow-up should be performed in high-risk newborns after vaccination to further lower the incidence of hepatitis B virus associated nephritis.

Anamnestic response to administration of purified non-adsorbed hepatitis B surface antigen in healthy responders to hepatitis B vaccine with long-term non-protective antibody titres.

A clinical trial with four groups receiving either 0.6, 3.5, 10 or 20 micro g of purified non-adsorbed hepatitis B surface antigen (HBsAg) was performed to study the kinetics as well as the capacity of the immune memory to respond following exposure to HBsAg in responders to a complete course of hepatitis B vaccine, in whom anti-HBs titres had declined below the seroprotective level. The study population included 64 healthy individuals. All response parameters seropositivity, seroprotection rates, booster response rates and geometric mean titres (GMTs), consistently showed that the immune response was highly satisfactory and dose-dependent. A remarkable immune response was obtained even with a trace amount of HBsAg. This study further supports recent indication that booster hepatitis B vaccine doses may be unnecessary in healthy adult responders to a full course of hepatitis B vaccination.

In vitro versus in vivo concordance: a case study of the replacement of an animal potency test with an immunochemical assay.

Early in its development, the potency of Merck's recombinant hepatitis B vaccine, RECOMBIVAX HB, was monitored using an assay performed in mice. A specification was determined to be the lowest potency which induced acceptable response in clinical trials. As a post-licensing commitment, Merck was asked to replace its mouse potency assay with an in vitro procedure for product release in the US market. Early studies with a commercial enzyme immunoassay (EIA) yielded highly variable results. That assay, combined with a sample pretreatment step, proved more dependable and predictive of potency in the mouse assay. Based on measurements made on manufactured materials, combined with experiments contrived to yield a wide range of reactivity in the two assays, concordance was established between the EIA and the mouse potency assay. This concordance was used to calibrate a specification for the in vitro assay that is predictive of a satisfactory response in vivo. Data from clinical trials established a correspondence between human immunogenicity and these potency markers.

Technology evaluation: naked DNA.

Vical and Merck are investigating vaccines against hepatitis B which use Vical's patented naked DNA technology. Both therapeutic and prophylactic vaccines are under development [177132], [268397]. The technology, and subsequent collaboration, stems from the observation by Vical that by directly injecting exogenous cDNA into muscle tissue, protein is expressed which gives rise to a strong immune response and protective immunity [163222].