Advanced maternal age induces fetal growth restriction through decreased placental inflammatory cytokine expression and immune cell accumulation in mice.

Advanced maternal age is a risk factor for female infertility, and placental dysfunction is considered one of the causes of pregnancy complications. We investigated the effects of advanced maternal aging on pregnancy outcomes and placental senescence. Female pregnant mice were separated into three groups: young (3 months old), middle (8-9 months old), and aged (11-13 months old). Although the body weights of young and middle dams gradually increased during pregnancy, the body weight of aged dams only increased slightly. The placental weight and resorption rate were significantly higher, and live fetal weights were reduced in a maternal age-dependent manner. Although mRNA expression of senescence regulatory factors (p16 and p21) increased in the spleen of aged dams, mRNA expression of p16 did not change and that of p21 was reduced in the placenta of aged dams. Using a cytokine array of proteins extracted from placental tissues, the expression of various types of senescence-associated secretory phenotype (SASP) factors was decreased in aged dams compared with young and middle dams. The aged maternal placenta showed reduced immune cell accumulation compared with the young placenta. Our present results suggest that models using pregnant mice older than 8 months are more suitable for verifying older human pregnancies. These findings suggest that general cellular senescence programs may not be included in the placenta and that placental functions, including SASP production and immune cell accumulation, gradually decrease in a maternal age-dependent manner, resulting in a higher rate of pregnancy complications.

Translocation domain of botulinum neurotoxin A subtype 2 potently induces entry into neuronal cells.

Botulinum neurotoxin (BoNT) is the causative agent of botulism in humans and animals. Only BoNT serotype A subtype 1 (BoNT/A1) is used clinically because of its high potency and long duration of action. BoNT/A1 and BoNT/A subtype 2 (BoNT/A2) have a high degree of amino acid sequence similarity in the light chain (LC) (96%), whereas their N-and C-terminal heavy chain (HN and HC ) differ by 13%. The LC acts as a zinc-dependent endopeptidase, HN as the translocation domain, and HC as the receptor-binding domain. BoNT/A2 and BoNT/A1 had similar potency in the mouse bioassay, but BoNT/A2 entered faster and more efficiently into neuronal cells. To identify the domains responsible for these characteristics, HN of BoNT/A1 and BoNT/A2 was exchanged to construct chimeric BoNT/A121 and BoNT/A212. After expression in Escherichia coli, chimeric and wild-type BoNT/As were purified as single-chain proteins and activated by conversion to disulfide-linked dichains. The toxicities of recombinant wild-type and chimeric BoNT/As were similar, but dropped to 60% compared with the values of native BoNT/As. The relative orders of SNAP-25 cleavage activity in neuronal cells and toxicity differed. BoNT/A121 and recombinant BoNT/A2 have similar SNAP-25 cleavage activity. BoNT/A2 HN is possibly responsible for the higher potency of BoNT/A2 than BoNT/A1.

Palmitic acid activates NLRP3 inflammasome and induces placental inflammation during pregnancy in mice.

Maternal obesity is one of the major risk factors for pregnancy complications and is associated with low-grade chronic systemic inflammation due to higher levels of pro-inflammatory cytokines such as interleukin (IL)-1ß. Pregnant women with obesity have abnormal lipid profiles, characterized by higher levels of free fatty acids, especially palmitic acid (PA). Previously, we reported that PA stimulated IL-1ß secretion via activation of NLRP3 inflammasome in human placental cells. These observations led us to hypothesize that higher levels of PA induce NLRP3 inflammasome activation and placental inflammation, resulting in pregnancy complications. However, the effects of PA on NLRP3 inflammasome during pregnancy in vivo remain unclear. Therefore, PA solutions were administered intravenously into pregnant mice on day 12 of gestation. Maternal body weight was significantly decreased and absorption rates were significantly higher in PA-injected mice. The administration of PA significantly increased IL-1ß protein and the mRNA expression of NLRP3 inflammasome components (NLRP3, ASC, and caspase-1) within the placenta. In murine placental cell culture, PA significantly stimulated IL-1ß secretion, and this secretion was suppressed by a specific NLRP3 inhibitor (MCC950). Simultaneously, the number of macrophages/monocytes and neutrophils, together with the mRNA expression of these chemokines increased significantly in the placentas of PA-treated mice. Treatment with PA induced ASC assembling and IL-1ß secretion in macrophages, and this PA-induced IL-1ß secretion was significantly suppressed in NLRP3-knockdown macrophages. These results indicate that transient higher levels of PA exposure in pregnant mice activates NLRP3 inflammasome and induces placental inflammation, resulting in the incidence of absorption.

Isolation of Salmonella enterica serovar Agona strains and their similarities to strains derived from a clone caused a serovar shift in broilers.

Salmonella enterica serovar Agona strains isolated from human cases were compared to strains that were derived from a clone caused a serovar shift in broilers. Pulsed field gel electrophoresis (PFGE) analysis with XbaI or BlnI digestion showed that three of seven strains from human case strains and most of the 81 strains from broilers were clustered in single complex in a minimum spanning tree (MST) reconstructed from the PFGE data. All the strains from human cases and 22 randomly selected strains from broilers were also analyzed by whole genome sequencing (WGS). Analysis of single nucleotide polymorphism (SNP) in the S. Agona core genes showed that four strains from human cases and all the strains from broilers were clustered in a maximum likelihood phylogenetic tree (ML tree) and an MST. These results indicated that the strains derived from the clone caused the serovar shift had already spread to humans. PFGE analysis with XbaI showed that four strains from broilers did not cluster with the other strains in an MST, though all those strains clustered in an ML tree and an MST reconstructed from SNP data. Moreover, three strains from broilers did not cluster in an MST reconstructed from PFGE with BlnI digestion, though those strains clustered in an ML tree and an MST reconstructed from SNP data. Therefore, it was suggested that S. Agona strains derived from a particular clone could not be traced by PFGE analysis but can be investigated by WGS analysis.

Characterization of the functional activity of botulinum neurotoxin subtype B6.

Clostridium botulinum produces the highly potent neurotoxin, botulinum neurotoxin (BoNT), which is classified into seven serotypes (A-G); the subtype classification is confirmed by the diversity of amino acid sequences among the serotypes. BoNT from the Osaka05 strain is associated with type B infant botulism and has been classified as BoNT/B subtype B6 (BoNT/B6) by phylogenetic analysis and the antigenicity of its C-terminal heavy chain (HC ) domain. However, the molecular bases for its properties, including its potency, are poorly understood. In this study, BoNT/B6 holotoxin was purified and the biological activity and receptor binding activity of BoNT/B6 compared with those of the previously-characterized BoNT/B1 and BoNT/B2 subtypes. The derivative BoNT/B6 was found to be already nicked and in an activated form, indicating that endogenous protease production may be higher in this strain than in the other two strains. BoNT/B1 exhibited the greatest lethal activity in mice, followed by BoNT/B6, which is consistent with the sensitivity of PC12 cells. No significant differences were seen in the enzymatic activities of the BoNT/Bs against their substrate. HC /B1 and HC /B6 exhibited similar binding affinities to synaptotagmin II (SytII), which is a specific protein receptor for BoNT/B. Binding to the SytII/ganglioside complex is functionally related to the toxic action; however, the receptor recognition sites are conserved. These results suggest that the distinct characteristics and differences in biological sensitivity of BoNT/B6 may be attributable to the function of its Hc .domain.

Transsynaptic inhibition of spinal transmission by A2 botulinum toxin.

Type A botulinum toxin blocks not only ACh release from motor nerve terminals but also central synaptic transmission, including glutamate, noradrenaline, dopamine, ATP, GABA and glycine. Neurotoxins (NTXs) are transported by both antero- and retrogradely along either motor or sensory axons for bidirectional delivery between peripheral tissues or the CNS. A newly developed type A2 NTX (A2NTX) injected into one rat foreleg muscle was transported to the contralateral muscle. This finding was consistent with the NTX traveling retrogradely via spinal neurons and then transsynaptically through motor neurons to the contralateral motor neurons within the spinal cord and on to the soleus muscle. In the present study we found that toxin injection into the rat left soleus muscle clearly induced bilateral muscle relaxation in a dose-dependent fashion, although the contralateral muscle relaxation followed the complete inhibition of toxin-injected ipsilateral muscles. The toxin-injected ipsilateral muscle relaxation was faster and stronger in A2NTX-treated rats than A1LL (BOTOX). A1LL was transported almost equally to the contralateral muscle via neural pathways and the bloodstream. In contrast, A2NTX was mainly transported to contralateral muscles via the blood. A1LL was more successfully transported to contralateral spinal neurons than A2NTX. We also demonstrated that A1LL and A2NTX were carried from peripheral to CNS and vice versa by dual antero- and retrograde axonal transport through either motor or sensory neurons.

Inhibition of Membrane Na+ Channels by A Type Botulinum Toxin at Femtomolar Concentrations in Central and Peripheral Neurons.

Recent studies have demonstrated that the botulinum neurotoxins inhibit the release of acetylcholine, glutamate, GABA, and glycine in central nerve system (CNS) neurons. The Na+ current (INa) is of major interest because it acts as the trigger for many cellular functions such as transmission, secretion, contraction, and sensation. Thus, these observations raise the possibility that A type neurotoxin might also alter the INa of neuronal excitable membrane. To test our idea, we examined the effects of A type neurotoxins on INa of central and peripheral neurons. The neurotoxins in femtomolar to picomolar concentrations produced substantial decreases of the neuronal INa, but interestingly the current inhibition was saturated at about maximum 50% level of control INa. The inhibitory pattern in the concentration-response curve for the neurotoxins differed from tetrodotoxin (TTX), local anesthetic, and antiepileptic drugs that completely inhibited INa in a concentration-dependent manner. We concluded that A type neurotoxins inhibited membrane Na+-channel activity in CNS neurons and that INa of both TTX-sensitive and-insensitive peripheral dorsal ganglion cells were also inhibited similarly to a maximum 40% of the control by the neurotoxins. The results suggest evidently that A2NTX could be also used as a powerful drug in treating epilepsy and several types of pain.

Inhibition of membrane Na+ channels by A type botulinum toxin at femtomolar concentrations in central and peripheral neurons.

Recent studies have demonstrated that the botulinum neurotoxins inhibit the release of acetylcholine, glutamate, GABA, and glycine in central nerve system (CNS) neurons. The Na(+) current (I(Na)) is of major interest because it acts as the trigger for many cellular functions such as transmission, secretion, contraction, and sensation. Thus, these observations raise the possibility that A type neurotoxin might also alter the I(Na) of neuronal excitable membrane. To test our idea, we examined the effects of A type neurotoxins on I(Na) of central and peripheral neurons. The neurotoxins in femtomolar to picomolar concentrations produced substantial decreases of the neuronal I(Na), but interestingly the current inhibition was saturated at about maximum 50% level of control I(Na). The inhibitory pattern in the concentration-response curve for the neurotoxins differed from tetrodotoxin (TTX), local anesthetic, and antiepileptic drugs that completely inhibited I(Na) in a concentration-dependent manner. We concluded that A type neurotoxins inhibited membrane Na(+)-channel activity in CNS neurons and that I(Na) of both TTX-sensitive and -insensitive peripheral dorsal ganglion cells were also inhibited similarly to a maximum 40% of the control by the neurotoxins. The results suggest evidently that A2NTX could be also used as a powerful drug in treating epilepsy and several types of pain.

Molecular analysis of bovine leukemia virus in early epidemic phase in Japan using archived formalin fixed paraffin embedded histopathological specimens.

Bovine leukemia virus (BLV) is an important pathogen associated with enzootic bovine leukosis. In this study, we performed PCR and sequencing analysis to characterize BLVgp51 sequences from formalin-fixed paraffin-embedded (FFPE) specimens made from 1974 to 2000 and successfully obtained BLV proviral genome sequences from 94% of the analyzed samples. Furthermore, from these samples, we reconstructed eight full-length and nearly full-length BLVgp51 sequences. These sequences were classified as BLV genotype 1, implying that genotype1 has already been circulating in Japan since the 1970s. In our results, the proviral DNA was detected in the 1970s, 1980s, and 1990s in the same manner, indicating that the detection of BLV proviral genome depends on storage conditions rather than storage period. The sequences obtained in this study provide direct insights into BLV sequences before 2000, which serves as a good calibrator for inferring ancient BLV diversity.

NLRP3 inflammasome is involved in testicular inflammation induced by lipopolysaccharide in mice.

PROBLEM: Systemic inflammation induced by infection, which is associated with testicular inflammation, predisposes males to subfertility. Recently, the nucleotide-binding oligomerization domain, leucine-rich repeat-, and pyrin domain-containing 3 (NLRP3) inflammasome was identified as a key mediator of inflammation, and excessive activation of the NLRP3 inflammasome was shown to contribute to the pathogenesis of a wide variety of diseases. However, the mechanisms underlying infectious inflammation in the testis remain unclear. We investigated the effect of lipopolysaccharide (LPS)-induced systemic inflammation on the role of the NLRP3 inflammasome in murine testes. METHOD OF STUDY: We performed in vivo and in vitro studies using an LPS-induced model of NLRP3 inflammasome activation and testicular inflammation. RESULTS: Intraperitoneal administration of LPS significantly impaired sperm motility in the epididymis of wild type (WT) and NLRP3-knockout (KO) mice. LPS administration stimulated interleukin (IL)-1ß production and secretion in the testes of WT mice, and these adverse effects were improved in the testes of NLRP3-KO mice. LPS administration also stimulated neutrophil infiltration as well as its chemoattractant C-C motif chemokine ligand 2 (CCL2) in WT testes, which were suppressed in NLRP3-KO testes. In in vitro cell culture, treatment with LPS and NLRP3 inflammasome activation significantly induced IL-1ß and CCL2 secretion from WT but not NLRP3-KO testicular cells. CONCLUSIONS: Taken together, our results suggest that testicular cells have the potential to secrete IL-1ß and CCL2 in an NLRP3 inflammasome-dependent manner and that these cytokines from the testis may further exacerbate testicular function, resulting in subfertility during infectious diseases.

Phylogenomics and Spatiotemporal Dynamics of Bovine Leukemia Virus Focusing on Asian Native Cattle: Insights Into the Early Origin and Global Dissemination.

Bovine leukemia virus (BLV), the causative agent of enzootic bovine leukosis, is currently one of the most important pathogens affecting the cattle industry worldwide. Determining where and in which host it originated, and how it dispersed across continents will provide valuable insights into its historical emergence as the cattle pathogen. Various species in the Bos genus were domesticated in Asia, where they also diversified. As native cattle (taurine cattle, zebu cattle, yak, and water buffalo) are indigenous and adapted to local environments, we hypothesized that Asian native cattle could have harbored BLV and, therefore, that they were important for virus emergence, maintenance, and spread. In this study, phylogeographic and ancestral trait analyses-including sequences obtained from Asian native cattle-were used to reconstruct the evolutionary history of BLV. It was shown that, since its probable emergence in Asia, the virus spread to South America and Europe via international trade of live cattle. It was inferred that zebu cattle were the hosts for the early origin of BLV, while taurine cattle played the significant role in the transmission worldwide. In addition, the results of positive selection analysis indicate that yak had a substantially minor role in the transmission of this virus. In this study, endogenous deltaretrovirus sequences in bats, collected in Asian countries, were also analyzed on whether these sequences were present in the bat genome. Endogenous deltaretrovirus sequences were detected from bat species endemic to specific regions and geographically isolated for a long time. Endogenous deltaretrovirus sequences from these geographically isolated species represent ancient exogenous deltaretroviruses distributions. The phylogenetic analysis revealed that these newly obtained endogenous deltaretrovirus sequences were closely related to those of BLV from Asian native cattle, indicating that BLV-related ancient deltaretroviruses circulated in Asia long before the emergence of BLV. Together, our analyses provide evidence for origin and spatiotemporal dynamics of BLV.

Type A1 but not type A2 botulinum toxin decreases the grip strength of the contralateral foreleg through axonal transport from the toxin-treated foreleg of rats.

The adverse effects of botulinum LL toxin and neurotoxin produced by subtype A1 (A1LL and A1NTX) are becoming issues, as the toxins could diffuse from the toxin-treated (ipsilateral) to contralateral muscles. We have attempted to produce neurotoxin from subtype A2 (A2NTX) with an amino acid sequence different from that of neurotoxin subtype A1. We measured the grip strength on the contralateral foreleg as an indicator of toxin spread from the ipsilateral to contralateral muscles. Doses of 0.30 log U or above of A1LL and A1NTX reduced the contralateral grip strength, whereas a dose of 0.78 log U of A2NTX was required to do so. We investigated the route of toxin spread using denervated, colchicine-treated, and antitoxin-treated rats. A1LL was transported via axons at doses higher than 0.30 log U and via both axons and body fluid at about 0.80 log U or a higher dose. Interestingly, A2NTX was transported via body fluid at about 0.80 log U or a higher dose, but not via axons to the contralateral side. It was concluded that A1LL and A1NTX decreased the grip strength of the toxin-untreated foreleg via both axonal transport and body fluids, while A2NTX was only transported via the body fluid.

Long-Term Grow-Out Affects Campylobacter jejuni Colonization Fitness in Coincidence With Altered Microbiota and Lipid Composition in the Cecum of Laying Hens.

Campylobacter jejuni is one of the leading causes of gastrointestinal illness worldwide and is mainly transmitted from chicken through the food chain. Previous studies have provided increasing evidence that this pathogen can colonize and replicate in broiler chicken during its breeding; however, its temporal kinetics in laying hen are poorly understood. Considering the possible interaction between C. jejuni and gut microbiota, the current study was conducted to address the temporal dynamics of C. jejuni in the cecum of laying hen over 40 weeks, with possible alteration of the gut microbiota and fatty acid (FA) components. Following oral infection with C. jejuni 81-176, inocula were stably recovered from ceca for up to 8 weeks post-infection (p.i.). From 16 weeks p.i., most birds became negative for C. jejuni and remained negative up to 40 weeks p.i. 16S rRNA gene sequencing analyses revealed that most of the altered relative rRNA gene abundances occurred in the order Clostridiales, in which increased relative rRNA gene abundances were observed at >16 weeks p.i. in the families Clostridiaceae, Ruminococcaceae, Lachnospiraceae, and Peptococcaceae. Lipidome analyses revealed increased levels of sterols associated with bile acid metabolisms in the cecum at 16 and/or 24 weeks p.i. compared with those detected at 8 weeks p.i., suggesting that altered microbiota and bile acid metabolism might underlie the decreased colonization fitness of C. jejuni in the gut of laying hens.

Uncaria tomentosa extract (AC-11) improves pregnancy hypertension together with suppression of sFlt-1 and sEng.

Disruption of well-controlled reproductive functions leads to pregnancy complications such as hypertensive disorders of pregnancy (HDP). Uncaria tomentosa (Wild), known as cat's claw, is widely used for the treatment of a various types of health problems; AC-11 (AC-11®, hot-water extract of U. tomentosa) is unique phytochemical compound and has potential roles as anti-inflammatory or anti-oxidant processes. We investigated whether AC-11 has a protective effect on pathogenesis of HDP in vivo and production of anti-angiogenic factors (sFlt-1 and sEng, major factors for the onset of HDP) in in vitro. Non-pregnant or pregnant mice were administered AC-11 (4 mg/mL), then, angiotensin II (Ang II) was subcutaneously infused to increase blood pressure. Human placental tissues or human umbilical vein endothelial cells (HUVECs) were incubated with or without AC-11. Treatment with AC-11 significantly reduced blood pressure induced by Ang II infusion. The population of CD8+T cells, the ratio of CD8/CD4, and plasma interleukin-6 levels were increased by Ang II infusion, and were decreased by AC-11 both in pregnant and non-pregnant mice. In pregnant mice, plasma levels of sFlt-1 and sEng were decreased by AC-11. In in vitro cell culture of HUVECs or placental tissue culture, treatment with AC-11 significantly inhibited secretion of sFlt-1 and sEng. We suggest a novel role of AC-11 in regulating blood pressure by controlling the balance of T cell population and inflammatory cytokine production both in non-pregnant and pregnant conditions. In addition, AC-11 inhibits HDP-related factors, including sFlt-1 and sEng, suggesting that AC-11 may useful for relieving HDP.

A target enrichment high throughput sequencing system for characterization of BLV whole genome sequence, integration sites, clonality and host SNP.

Bovine leukemia virus (BLV) is an oncogenic retrovirus which induces malignant lymphoma termed enzootic bovine leukosis (EBL) after a long incubation period. Insertion sites of the BLV proviral genome as well as the associations between disease progression and polymorphisms of the virus and host genome are not fully understood. To characterize the biological coherence between virus and host, we developed a DNA-capture-seq approach, in which DNA probes were used to efficiently enrich target sequence reads from the next-generation sequencing (NGS) library. In addition, enriched reads can also be analyzed for detection of proviral integration sites and clonal expansion of infected cells since the reads include chimeric reads of the host and proviral genomes. To validate this DNA-capture-seq approach, a persistently BLV-infected fetal lamb kidney cell line (FLK-BLV), four EBL tumor samples and four non-EBL blood samples were analyzed to identify BLV integration sites. The results showed efficient enrichment of target sequence reads and oligoclonal integrations of the BLV proviral genome in the FLK-BLV cell line. Moreover, three out of four EBL tumor samples displayed multiple integration sites of the BLV proviral genome, while one sample displayed a single integration site. In this study, we found the evidence for the first time that the integrated provirus defective at the 5' end was present in the persistent lymphocytosis cattle. The efficient and sensitive identification of BLV variability, integration sites and clonal expansion described in this study provide support for use of this innovative tool for understanding the detailed mechanisms of BLV infection during the course of disease progression.

Genetic characteristics of emerging Salmonella enterica serovar Agona strains isolated from humans in the prior period to occurrence of the serovar shift in broilers.

Our previous studies found that a dominant serovar of Salmonella enterica isolates from three farms raising broilers in 2014 and 2015 was serovar Agona and the number of Infantis isolates decreased (the serovar shift). In this study, 52 S. Agona strains which isolated between 1993 and 2008, were compared to the serovar shift clone by molecular epidemiology and phylogenetic analyses, using pulsed field gel electrophoresis and whole genome sequence analyses. Of the 52 strains, one strain isolated from a human case in 1995 was genetically identical to the serovar shift clone, even though it was isolated prior to the serovar shift. These results suggested that the S. Agona serovar shift clone had existed in a source other than chicken penetrated chicken population.

Comparison of efficacy and toxicity between botulinum toxin subtypes A1 and A2 in cynomolgus macaques.

Botulinum toxin type A (subtype A1) is used as therapeutic agent for some neurological disorders causing spasticity. The toxin products have an upper dosage limit, and their adverse events, such as side effects of diffusion following high-dose administration, have become serious issues. Therefore, a preparation with greater therapeutic efficacy at lower dosages and less diffusion in the body is desired. We have attempted to produce neurotoxin derived from subtype A2 (A2NTX), which has a different amino acid sequence from that of neurotoxin derived from subtype A1. In this study, to investigate whether A2NTX is applicable for treatment, we compared the muscle relaxation effects and the toxicity between A1LL and A2NTX in adult cynomolgus macaques. In the isometric muscle contraction test elicited by 30 Hz tetanus stimulation, the contractions observed in the 0.4 U/site A1LL-treated group were similar in value to those in the 0.13 U/site A2NTX-treated group. In the toxicity test, the 12 and 24 U/kg A1LL- and A2NTX-treated groups all exhibited similar signs of toxicity regarding symptoms, rate of weight loss, and decrease in the length of the right lower leg perimeter. Thus, A2NTX demonstrated approximately 3.0-times higher muscle relaxation activity than A1LL, and their toxicity was equivalent. This study suggested that A2NTX products are more suitable for the treatment of neurological disorders.

Actinomyces denticolens as a causative agent of actinomycosis in animals.

The name "Actinomyces suis" was applied to each actinomycete isolate from swine actinomycosis by Grässer in 1962 and Franke in 1973. Nevertheless, this specific species was not included in the "Approved List of Bacterial Name" due to absence of the type cultures. Therefore, "Actinomyces suis" based on the description of Franke 1973 has been considered as "species incertae sedis". We isolated a number of Actinomyces strains from swine. The representative strains of them was designated as Chiba 101 that was closely similar to the description in "Actinomyces suis" reported by Franke in 1973. Interestingly, it was found that the biological characteristics of these strains were also very similar to those of Actinomyces denticolens. Furthermore, the average nucleotide identity (ANI) value between strain Chiba 101 and the type-strain of Actinomyces denticolens (=DSM 20671T) was found to be 99.95%. Sequences of the housekeeping genes and 16S rRNA gene showed 100% homology. These results strongly suggested that "Actinomyces suis" Franke 1973 is the same species as Actinomyces denticolens. Since actinomycosis caused by Actinomyces denticolens have been demonstrated in horses recently, it is necessary to recognize that Actinomyces denticolens is the pathogenic actinomycetes in broader range of animals.

Clinical Study of New Tetravalent (Type A, B, E, and F) Botulinum Toxoid Vaccine Derived from M Toxin in Japan.

Botulinum toxin is the most poisonous substance known, and is believed to be a highly lethal as a biological weapon; researchers of the toxin are exposed to this hazard. Botulinum toxoid vaccines have been produced and used in Japan. However, since clinical studies involving these vaccines were conducted before establishment of the Ethical Guidelines for Clinical Research in Japan, their immunogenicity and safety were not systematically assessed. In this study, we produced a new tetravalent (type A, B, E, and F) botulinum toxoid vaccine, the first ever to be derived from M toxin, and conducted quality control tests with reference to the Minimum Requirements in Japan for adsorbed tetanus toxoid vaccine. Subsequently, a clinical study using the new vaccine in 48 healthy adult volunteers was conducted according to the guidelines in Japan. No clinically serious adverse event was noted. Neutralizing antibody titers for each type of toxin in the participants' sera, 1 month after the 4th injection were more than 0.25 IU/mL, indicating sufficient protection. This study demonstrated that the vaccine has marked immunogenicity and is safe for use in humans.