Two vaccine toxicity-related genes Agp and Hpx could prove useful for pertussis vaccine safety control

Early postnatal injections of whole vaccines compared to placebo controls: Differential behavioural outcomes in mice

The present study was designed to evaluate the possible effects of the paediatric vaccination schedule in the United States on the central nervous system in a murine model. We compared the impact of treatment with the whole vaccines versus true placebo control. Seventy-six pups were divided into three groups: two vaccinated groups and unvaccinated control. The two vaccinated groups were treated between 7 and 21 post-natal days either with one or three times of the vaccine doses per body weight as used in children between newborn and eighteen months of age. The post-vaccination development, neuromotor behaviours and neurobehavioural abnormalities (NBAs) were evaluated in all mouse groups during the 67 post-natal weeks of mouse age. Mouse body weight was affected only in the vaccinated females compared to males and control. Some NBAs such as decreased sociability, increased anxiety-like behaviours, and alteration of visual-spatial learning and memory were observed in vaccinated male and female mice compared to controls. The present study also shows a slower acquisition of some neonatal reflexes in vaccinated female mice compared to vaccinated males and controls. The observed neurodevelopmental alterations did not show a linear relationship with vaccine dose, suggesting that the single dose gave a saturated response. The outcomes seemed to be sex-dependent and transient with age.

Gene expression profiling toward the next generation safety control of influenza vaccines and adjuvants in Japan

Influenza becomes epidemic worldwide every year, and many individuals receive vaccination annually. Quality control relating to safety and potency of influenza vaccines is important to maintain public confidence. The safety of influenza vaccines has been assessed by clinical trials, and animal safety tests are performed to monitor the consistent quality between vaccines used for clinical trials and marketing; the biological responses in vaccinated animals are evaluated, including changes in body weight and white blood cell count. Animal safety tests have been contributing to the quality relating to the safety of influenza vaccines for decades, but improvements are needed. Although precise mechanisms involving biological changes in animal safety tests have not been fully elucidated, the application of cDNA microarray technology make it possible to reliably identify genes related to biological responses in vaccinated animals. From analysis of the expression profile of >10,000 genes of lung in animals treated with an inactivated whole virion influenza vaccine, we identified 17 marker genes whose expression patterns correlated well to changes in body weight and leukocyte count in vaccinated animals. In influenza HA vaccine-treated animals exhibiting subtle changes in biological responses, a robust expression pattern of marker genes was found. Furthermore, these marker genes could also be used in the evaluation of adjuvanted influenza vaccines. The expression profile of marker genes is expected to be an alternative indicator for safety control of various influenza vaccines conferring high sensitivity and short turnaround time. Thus, gene expression profiling may be a powerful tool for safety control of vaccines in the future.

Modeling for influenza vaccines and adjuvants profile for safety prediction system using gene expression profiling and statistical tools

Historically, vaccine safety assessments have been conducted by animal testing (e.g., quality control tests and adjuvant development). However, classical evaluation methods do not provide sufficient information to make treatment decisions. We previously identified biomarker genes as novel safety markers. Here, we developed a practical safety assessment system used to evaluate the intramuscular, intraperitoneal, and nasal inoculation routes to provide robust and comprehensive safety data. Influenza vaccines were used as model vaccines. A toxicity reference vaccine (RE) and poly I:C-adjuvanted hemagglutinin split vaccine were used as toxicity controls, while a non-adjuvanted hemagglutinin split vaccine and AddaVax (squalene-based oil-in-water nano-emulsion with a formulation similar to MF59)-adjuvanted hemagglutinin split vaccine were used as safety controls. Body weight changes, number of white blood cells, and lung biomarker gene expression profiles were determined in mice. In addition, vaccines were inoculated into mice by three different administration routes. Logistic regression analyses were carried out to determine the expression changes of each biomarker. The results showed that the regression equations clearly classified each vaccine according to its toxic potential and inoculation amount by biomarker expression levels. Interestingly, lung biomarker expression was nearly equivalent for the various inoculation routes. The results of the present safety evaluation were confirmed by the approximation rate for the toxicity control. This method may contribute to toxicity evaluation such as quality control tests and adjuvant development.

A novel vaccinological evaluation of intranasal vaccine and adjuvant safety for preclinical tests

Vaccines are administered to healthy humans, including infants, so the safety and efficacy must be very high. Therefore, evaluating vaccine safety in preclinical and clinical studies, according to World Health Organization guidelines, is crucial for vaccine development and clinical use. A change in the route of administration is considered to alter a vaccine's immunogenicity. Several adjuvants have also been developed and approved for use in vaccines. However, the addition of adjuvants to vaccines may cause unwanted immune responses, including facial nerve paralysis and narcolepsy. Therefore, a more accurate and comprehensive strategy must be used to develope next-generation vaccines for ensuring vaccine safety. Previously, we have developed a system with which to evaluate vaccine safety in rats using a systematic vaccinological approach and 20 marker genes. In this study, we developed a safety evaluation system for nasally administered influenza vaccines and adjuvanted influenza vaccines using these marker genes. Expression of these genes increased dose-dependent manner when mice were intranasally administered the toxicity reference vaccine. When the adjuvant CpG K3 or a CpG-K3-combined influenza vaccine was administered intranasally, marker gene expression increased in a CpG-K3-dose-dependent way. A histopathological analysis indicated that marker gene expression correlated with vaccine- or adjuvant-induced phenotypic changes in the lung and nasal mucosa. We believe that the marker genes expression analyses will be useful in preclinical testing, adjuvant development, and selecting the appropriate dose of adjuvant in nasal administration vaccines.

Establishment of a new quality control and vaccine safety test for influenza vaccines and adjuvants using gene expression profiling

We have previously identified 17 biomarker genes which were upregulated by whole virion influenza vaccines, and reported that gene expression profiles of these biomarker genes had a good correlation with conventional animal safety tests checking body weight and leukocyte counts. In this study, we have shown that conventional animal tests showed varied and no dose-dependent results in serially diluted bulk materials of influenza HA vaccines. In contrast, dose dependency was clearly shown in the expression profiles of biomarker genes, demonstrating higher sensitivity of gene expression analysis than the current animal safety tests of influenza vaccines. The introduction of branched DNA based-concurrent expression analysis could simplify the complexity of multiple gene expression approach, and could shorten the test period from 7 days to 3 days. Furthermore, upregulation of 10 genes, Zbp1, Mx2, Irf7, Lgals9, Ifi47, Tapbp, Timp1, Trafd1, Psmb9, and Tap2, was seen upon virosomal-adjuvanted vaccine treatment, indicating that these biomarkers could be useful for the safety control of virosomal-adjuvanted vaccines. In summary, profiling biomarker gene expression could be a useful, rapid, and highly sensitive method of animal safety testing compared with conventional methods, and could be used to evaluate the safety of various types of influenza vaccines, including adjuvanted vaccine.

System vaccinology for the evaluation of influenza vaccine safety by multiplex gene detection of novel biomarkers in a preclinical study and batch release test

Vaccines are beneficial and universal tools to prevent infectious disease. Thus, safety of vaccines is strictly evaluated in the preclinical phase of trials and every vaccine batch must be tested by the National Control Laboratories according to the guidelines published by each country. Despite many vaccine production platforms and methods, animal testing for safety evaluation is unchanged thus far. We recently developed a systems biological approach to vaccine safety evaluation where identification of specific biomarkers in a rat pre-clinical study evaluated the safety of vaccines for pandemic H5N1 influenza including Irf7, Lgals9, Lgalsbp3, Cxcl11, Timp1, Tap2, Psmb9, Psme1, Tapbp, C2, Csf1, Mx2, Zbp1, Ifrd1, Trafd1, Cxcl9, β2m, Npc1, Ngfr and Ifi47. The current study evaluated whether these 20 biomarkers could evaluate the safety, batch-to-batch and manufacturer-to-manufacturer consistency of seasonal trivalent influenza vaccine using a multiplex gene detection system. When we evaluated the influenza HA vaccine (HAv) from four different manufactures, the biomarker analysis correlated to findings from conventional animal use tests, such as abnormal toxicity test. In addition, sensitivity of toxicity detection and differences in HAvs were higher and more accurate than with conventional methods. Despite a slight decrease in body weight caused by HAv from manufacturer B that was not statistically significant, our results suggest that HAv from manufacturer B is significantly different than the other HAvs tested with regard to Lgals3bp, Tapbp, Lgals9, Irf7 and C2 gene expression in rat lungs. Using the biomarkers confirmed in this study, we predicted batch-to-batch consistency and safety of influenza vaccines within 2 days compared with the conventional safety test, which takes longer. These biomarkers will facilitate the future development of new influenza vaccines and provide an opportunity to develop in vitro methods of evaluating batch-to-batch consistency and vaccine safety as an alternative to animal testing.

In vivo study of hepatitis B vaccine effects on inflammation and metabolism gene expression

Pharmaceutical companies usually perform safety testing of vaccines, but all requirements of the World Health Organization and drug pharmacopoeias depend on general toxicity testing, and the gene expression study of hepatitis B vaccine is not done routinely to test vaccine quality. In this study, we applied a new technique of gene expression analysis to detect the inflammation and metabolism genes that might be affected by hepatitis B vaccine in mouse liver. Mice were used and divided into three groups: the first and second groups were treated with one or two human doses of vaccine, respectively, and the third group was used as a control. A microarray test showed that expression of 144 genes in the liver was significantly changed after 1 day of vaccination. Seven of these genes, which were related to inflammation and metabolism, were chosen and confirmed by quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) at 1, 4 and 7 days. The expression level of these genes can be considered as a biomarker for the effects of the vaccine.

Emerging vaccine informatics

Vaccine informatics is an emerging research area that focuses on development and applications of bioinformatics methods that can be used to facilitate every aspect of the preclinical, clinical, and postlicensure vaccine enterprises. Many immunoinformatics algorithms and resources have been developed to predict T- and B-cell immune epitopes for epitope vaccine development and protective immunity analysis. Vaccine protein candidates are predictable in silico from genome sequences using reverse vaccinology. Systematic transcriptomics and proteomics gene expression analyses facilitate rational vaccine design and identification of gene responses that are correlates of protection in vivo. Mathematical simulations have been used to model host-pathogen interactions and improve vaccine production and vaccination protocols. Computational methods have also been used for development of immunization registries or immunization information systems, assessment of vaccine safety and efficacy, and immunization modeling. Computational literature mining and databases effectively process, mine, and store large amounts of vaccine literature and data. Vaccine Ontology (VO) has been initiated to integrate various vaccine data and support automated reasoning.

A new method for the evaluation of vaccine safety based on comprehensive gene expression analysis

For the past 50 years, quality control and safety tests have been used to evaluate vaccine safety. However, conventional animal safety tests need to be improved in several aspects. For example, the number of test animals used needs to be reduced and the test period shortened. It is, therefore, necessary to develop a new vaccine evaluation system. In this review, we show that gene expression patterns are well correlated to biological responses in vaccinated rats. Our findings and methods using experimental biology and genome science provide an important means of assessment for vaccine toxicity.

Identification of cancer stem cells in a Tax-transgenic (Tax-Tg) mouse model of adult T-cell leukemia/lymphoma

Adult T-cell leukemia/lymphoma (ATL) is a malignant lymphoproliferative disorder caused by HTLV-I infection. In ATL, chemotherapeutic responses are generally poor, which has suggested the existence of chemotherapy-resistant cancer stem cells (CSCs). To identify CSC candidates in ATL, we have focused on a Tax transgenic mouse (Tax-Tg) model, which reproduces ATL-like disease both in Tax-Tg animals and also after transfer of Tax-Tg splenic lymphomatous cells (SLCs) to nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice. Using a limiting dilution transplantation, it was estimated that one CSC existed per 10(4) SLCs (0.01%). In agreement with this, we have successfully identified candidate CSCs in a side population (0.06%), which overlapped with a minor population of CD38(-)/CD71(-)/CD117(+) cells (0.03%). Whereas lymphoma did not develop after transplantation of 10(2) SLCs, 10(2) CSCs could consistently regenerate the original lymphoma. In addition, lymphoma and CSCs could also be demonstrated in the bone marrow and CD117(+) CSCs were observed in both osteoblastic and vascular niches. In the CSCs, Tax, Notch1, and Bmi1 expression was down-regulated, suggesting that the CSCs were derived from Pro-T cells or early hematopoietic progenitor cells. Taken together, our data demonstrate that CSCs certainly exist and have the potential to regenerate lymphoma in our mouse model.

Application of DNA microarray technology to influenza A/Vietnam/1194/2004 (H5N1) vaccine safety evaluation

We propose that DNA microarray analysis can be used in the quality control of pandemic and endemic influenza vaccine. Based on the expression profiles of 76 genes in the rat lung one day after inoculation of influenza vaccine, we can distinguish whole-virion influenza vaccine (PDv: pandemic influenza vaccine and WPv: whole virion-particle vaccine) and sub-virion vaccine (HA vaccine) from saline. Among these 76 genes, we found genes up-regulated by influenza infection, as well as genes involved in the immune response, and interferon. Hierarchical clustering of each influenza vaccine by the expression profiles of these 76 genes matched data from current quality control tests in Japan, such as the abnormal toxicity test (ATT) and the leukopenic toxicity test (LTT). Thus, it can be concluded that DNA microarray technology is an informative, rapid and highly sensitive method with which to evaluate the quality of influenza vaccines. Using DNA microarray system, consistent with the results of the ATT and LTT, it was clarified that there was no difference in vaccine quality between PDv and WPv.