Antibody responses induced by the BNT162b2 mRNA COVID-19 vaccine in healthcare workers in a single community hospital in Japan.

INTRODUCTION: The effectiveness of several vaccines against coronavirus disease (COVID-19) has been reported in the real-world setting. However, it is still unknown how long antibodies persist following vaccination and whether or not the persistence of antibodies has a protective effect against COVID-19. METHODS: Healthcare workers who had received two doses of the BNT162b2 mRNA COVID-19 vaccine were enrolled, and a single-center study was conducted at the National Hospital Organization Hakodate National Hospital. Serum samples from all participants were collected 13-21 weeks (median: 20 weeks) after the second dose of vaccination. The antibody titers were measured using an electrochemiluminescence immunoassay (Elecsys® Anti-SARS-CoV-2 S). Data on characteristics of the participants were gathered from patient records and interview sheets. RESULTS: A total of 401 participants, among whom 70.1% were women and the median age was 42 years, were evaluated in this study. None of the participants had a definite COVID-19 history, and all participants who received complete vaccination showed positive antibody titers. The antibody titer was observed to be higher in participants with younger age (p < 0.001) and those who were females (p = 0.028). Despite the higher risk of infection than that of the general public, no vaccinated staff developed breakthrough infections. CONCLUSIONS: This study demonstrates the significant contribution of the BNT162b2 vaccine in the acquisition of anti-SARS-CoV-2S antibodies; therefore, the general population should benefit from these two vaccine doses, which are expected to be protective for at least five months.

Analysis of a plasmid encoding botulinum neurotoxin type G gene in Clostridium argentinense.

Clostridium argentinense produces botulinum neurotoxin type G (BoNT/G). We sequenced and analyzed the plasmid harboring the bont/G gene, designated pCAG, in C. argentinense strain 2740. The pCAG consisted of 140,070 bp containing the bont/G gene cluster. Although this gene cluster showed high similarities in its DNA sequence and ORF arrangement to those of other bont gene clusters, the other regions of the plasmid did not. A phylogenetic study suggested that pCAG had a unique evolutionary history compared with other clostridial bont-harboring plasmids. This suggests that pCAG is possibly a novel type of plasmid expressing the bont/G gene in C. argentinense.

Mutagenicity and clastogenicity of extracts of Helicobacter pylori detected by the Ames test and in the micronucleus test using human lymphoblastoid cells.

Epidemiological studies have demonstrated a close association between infection with Helicobacter pylori (H.pylori) and the development of gastric carcinoma. Chronic H.pylori infection increases the frequency of mutation in gastric epithelial cells. However, the mechanism by which infection of H.pylori leads to mutation in gastric epithelial cells is unclear. We suspected that components in H.pylori may be related to the mutagenic response associated with DNA alkylation, and could be detected with the Ames test using a more sensitive strain for alkylating agents. Our investigation revealed that an extract of H.pylori was mutagenic in the Ames test with Salmonella typhimurium YG7108, which is deficient in the DNA repair of O(6)-methylguanine. The extract of H.pylori may contain methylating or alkylating agents, which might induce O (6)-alkylguanine in DNA. Mutagenicity of the alkylating agents N-methyl-N-nitrosourea (MNU) and N-methyl-N'-nitro-N-nitrosoguanidine in the Ames test with S.typhimurium TA1535 was enhanced significantly in the presence of the extract of H.pylori. The tested extracts of H.pylori resulted in a significant induction of micronuclei in human-derived lymphoblastoid cells. Heat instability and dialysis resistance of the extracts of H.pylori suggest that the mutagenic component in the extracts of H.pylori is a heat-unstable large molecule or a heat-labile small molecule strongly attached or adsorbed to a large molecule. Proteins in the extracts of H.pylori were subsequently fractionated using ammonium sulphate precipitation. However, all fractions expressed enhancing effects toward MNU mutagenicity. These results suggest the mutagenic component is a small molecule that is absorbed into proteins in the extract of H.pylori, which resist dialysis. Continuous and chronic exposure of gastric epithelial cells to the alkylative mutagenic component from H.pylori chronically infected in the stomach might be a causal factor in the gastric carcinogenesis associated with H.pylori.

Phospholipase C produced by Clostridium botulinum types C and D: comparison of gene, enzymatic, and biological activities with those of Clostridium perfringens alpha-toxin.

Clostridium botulinum type C and D strains recently have been found to produce PLC on egg yolk agar plates. To characterize the gene, enzymatic and biological activities of C. botulinum PLCs (Cb-PLCs), the cb-plc genes from 8 strains were sequenced, and 1 representative gene was cloned and expressed as a recombinant protein. The enzymatic and hemolytic activities of the recombinant Cb-PLC were measured and compared with those of the Clostridium perfringens alpha-toxin. Each of the eight cb-plc genes encoded a 399 amino acid residue protein preceded by a 27 residue signal peptide. The protein consists of 2 domains, the N- and C-domains, and the overall amino acid sequence identity between Cb-PLC and alpha-toxin was greater than 50%, suggesting that Cb-PLC is homologous to the alpha-toxin. The key residues in the N-domain were conserved, whereas those in the C-domain which are important in membrane interaction were different than in the alpha-toxin. As expected, Cb-PLC could hydrolyze egg yolk phospholipid, p-nitrophenylphosphorylcholine, and sphingomyelin, and also exhibited hemolytic activity;however, its activities were about 4- to over 200-fold lower than those of alpha-toxin. Although Cb-PLC showed weak enzymatic and biological activities, it is speculated that Cb-PLC might play a role in the pathogenicity of botulism or for bacterial survival.

The genetic diversity of Helicobacter pylori virulence genes is not associated with gastric atrophy progression.

Atrophy of the gastric mucosa is a precursor of intestinal-type gastric cancer, and Helicobacter pylori infection causes atrophic gastritis. The aim of this study was to determine whether the genetic diversity of H. pylori virulence genes is associated with the development and progression of gastric atrophy in humans. We isolated and cultured H. pylori strains from patients with gastric ulcer and duodenal ulcer accompanied by atrophic gastritis in background mucosa. H. pylori strains were stored at －80℃ prior to the experiments being carried out. We analyzed iceA, babA, vacA, cagA, and cagE genes by PCR. The cagA gene was analyzed through sequencing of the C-terminal region containing the EPIYA motif, which is related to tyrosine phosphorylation. Severe atrophy was observed in patients with gastric ulcer. The major phenotype of the vacA gene was s1c/m1 (93%). The cagA gene was detected in all strains. The cagE gene was not detected in 2 and 5 strains from the mild cases and severe cases, respectively. The major cagA EPIYA motif, which is amino acids repeat in the C terminus, was the A-B-D type (44 of 58 strains). The virulence genes were not statistically associated with the severity of atrophy in the background gastric mucosa in humans. Not only identification of bacterial virulence factors but also studies of the host response will be necessary to investigate the progression of gastric atrophy and subsequent cancer development in humans.

[New Helicobacters other than H. pylori].

Since discovery of Helicobacter pylori, more than 30 species non-H. pylori Helicobacter spp. (NHPH) have been reported. Those NHPH were now classified into gastric Helicobacter spp. and enterohepatic Helicobacter spp.(EHS). Gastric NHPH show tight spiral and long shape in the gastric mucosa, and we can distinguish from H. pylori by light microscope. Some gastric NHPH may be zoonosis and cause gastritis in human. H. hepaticus and H. cinaedi belongs in EHS were detected in human diseases. H. hepaticus may be associated with hepatobiliary diseases in humans. Surprisingly, it was reported that H. cinaedi infection was associated with atrial arrhythmias and atherosclerosis. Many NHPH will be recognized as human pathogen in the future.

Intraprostatic botulinum neurotoxin type a injection for benign prostatic hyperplasia: preliminary results with a newly purified neurotoxin.

Several studies have demonstrated the efficacy of intraprostatic injection of botulinum neurotoxin type A (BoNT/A) against symptomatic benign prostatic hyperplasia (BPH). The most commonly used BoNT/A product, Botox(®), forms large complexes and composed of neurotoxin (NTX) as well as non-toxic components. We purified NTX lacking non-toxic components. We investigated the efficacy of this newly purified NTX for men with BPH. Ten male patients (mean age, 70.0 years) with BPH received 100 units (prostate volume [PV] ＜30 ml) or 200 units (PV >30 ml) of NTX injected into the prostate via a minimally invasive outpatient technique. Evaluation included uroflowmetry, postvoid residual urine volume (PVR), PV, and International Prostate Symptom Score (IPSS) measured at baseline and 1, 3, 6, and 12 months post-treatment. The status of 7 of the 10 patients examined was found to have improved within 1 month of treatment. The mean IPSS decreased from 23.8 ± 7.0 to 16.3 ± 10.3 (p＝0.0093) at 1 month, to 14.9 ± 8.2 (p＝0.0074) at 3 months, and to 16.9 ± 7.3 (p＝0.018) at 12 months. The mean PV decreased from 47.8 ± 21.2 to 39.2 ± 19.5 ml (p＝0.0076) at 3 months. The PVR improved at 3 and 6 months post-treatment. Intraprostatic NTX injection induces prostate shrinkage and is effective in men with BPH.

Clostridium botulinum type E toxins bind to Caco-2 cells by a different mechanism from that of type A toxins.

Cultured Clostridium botulinum strains produce progenitor toxins designated as 12S, 16S, and 19S toxins. The 12S toxin consists of a neurotoxin (NTX, 7S) and a non-toxic non-hemagglutinin (NTNH). The 16S and 19S toxins are formed by conjugation of the 12S toxin with hemagglutinin (HA), and the 19S toxin is a dimer of the 16S toxin. Type A cultures produce all 3 of these progenitor toxins, while type E produces only the 12S toxin. The 7S toxin is cleaved into heavy (H) and light (L) chains by a protease(s) in some strains, and the H chain has 2 domains, the N-terminus (Hn) and C-terminus (Hc). It has been reported that type A toxins bind to the intestinal cells or cultured cells via either HA or Hc. In this study, we investigated the binding of type A and E toxins to Caco-2 cells using Western blot analysis. Both the type E 7S and 12S toxins bound to the cells, with the 7S toxin binding more strongly, whereas, in the type A strain, only the 16S/19S toxins showed obvious binding. Pre-incubation of the type E 7S toxin with IgG against recombinant type E Hc significantly inhibited the 7S toxin binding, indicating that Hc might be a main binding domain of the type E toxin.

Botulinum toxin type A for the treatment of lower urinary tract disorders.

Many papers report the clinical success of botulinum toxin A as a method of management of various bladder dysfunctions. The rationale was that botulinum toxin A was able to block the presynaptic release of acetylcholine from the parasympathetic efferent nerve. The efficacy might result not only from an inhibitory effect on detrusor muscle, but also some effects might be mediated by altering the afferent nerve input. This systematic literature review discusses the efficacy and safety of botulinum toxin A therapy for idiopathic detrusor overactivity, neurogenic detrusor overactivity, interstitial cystitis/painful bladder syndrome and benign prostatic hyperplasia. The information was gathered from a PubMed literature research for abstracts from recent urological meetings. Injection of botulinum toxin A appears to have a positive therapeutic effect in multiple urological conditions, such as refractory idiopathic detrusor overactivity, neurogenic detrusor overactivity, interstitial cystitis/painful bladder syndrome and benign prostatic hyperplasia. Because the United States Food and Drug Administration has approved botulinum toxin A (Botox) for injection for the treatment of urinary incontinence as a result of neurogenic detrusor overactivity (e.g. spinal cord injury, multiple sclerosis) in adults who have an inadequate response to or are intolerant of an ant cholinergic medication, the use of botulinum toxin A will spread and be a more familiar therapy in the urological arena. However, further robust evidence should be awaited. We will discuss the current use of this agent within the urological field.

[Botulism: structure and function of botulinum toxin and its clinical application].

Clostridium botulinum produces seven immunological distinct poisonous neurotoxins, A to G, with molecular masses of approximately 150kDa. In acidic foods and culture fluid, the neurotoxins associate with non-toxic components, and form large complexes designated progenitor toxins. The progenitor toxins are found in three forms named LL, L, and M. These neurotoxins and progenitor toxins were purified, and whole nucleotide sequences of their structure genes were determined. In this manuscript, the structure and function of these toxins, and the application of these toxins to clinical usage have been described.

Molecular diversity of the two sugar-binding sites of the ß-trefoil lectin HA33/C (HA1) from Clostridium botulinum type C neurotoxin.

A critical role in internalizing the Clostridium botulinum neurotoxin into gastrointestinal cells is played by nontoxic components complexed with the toxin. One of the components, a ß-trefoil lectin has been known as HA33 or HA1. The HA33 from C. botulinum type A (HA33/A) has been predicted to have a single sugar-binding site, while type C HA33 (HA33/C) has two sites. Here we constructed HA33/C mutants and evaluated the binding capacities of the individual sites through mucin-assay and isothermal titration calorimetry. The mutant W176A (site I knockout) had a K(d) value of 31.5mM for galactose (Gal) and 61.3mM for N-acetylgalactosamine (GalNAc), while the K(d) value for N-acetylneuraminic acid (Neu5Ac) was too high to be determined. In contrast, the double mutant N278A/Q279A (site II knockout) had a K(d) value of 11.8mM for Neu5Ac. We also determined the crystal structures of wild-type and the F179I mutant in complex with GalNAc at site II. The results suggest that site I of HA33/C is quite unique in that it mainly recognizes Neu5Ac, and site II seems less important for the lectin specificity. The architectures and the properties of the sugar-binding sites of HA33/C and HA33/A were shown to be drastically different.

Behçet's disease (Adamantiades-Behçet's disease).

Adamantiades-Behçet's disease (ABD) is characterized by starting with oral aphthous ulceration and developing of the systemic involvements. The pathogenesis of ABD is closely correlated with the genetic factors and the triggering factors which acquire delayed-type hypersensitivity reaction against oral streptococci mediated by IL-12 cytokine family. HLA-B51 is associated in more than 60% of the patients and its restricted CD8+ T cell response is clearly correlated with the target tissues. Bes-1 gene encoded partial S. sanguinis genome which is highly homologous with retinal protein, and 65 kD heat shock protein (Hsp-65) released from streptococci is playing an important role with human Hsp-60 in the pathogenesis of ABD. Although Hsp-65/60 has homologies with the respective T cell epitope, it stimulates peripheral blood mononuclear cells (PBMCs) from ABD patients. On the other hand, some peptides of Hsp-65 were found to reduce IL-8 and IL-12 production from PBMCs of ABD patients in active stage.

In vivo oxidation, platelet activation and simultaneous occurrence of natural immunity in atherosclerosis-prone mice.

BACKGROUND: Several murine models are susceptible to atherosclerosis, such as low density-lipoprotein receptor-deficient (LDLR-/-) and apolipoprotein E-deficient (apoE-/-) mice, and are used for studying pathophysiological mechanisms. Atherosclerotic lesions in the aortic valve and thoracic/abdominal aorta are commonly associated with hyperlipidemia. We recently demonstrated the development of large atherosclerotic plaques in Helicobacter pylori-infected heterozygous LDLR+/- apoE+/- mice. OBJECTIVES: To measure novel biomarkers related to atherosclerosis, blood coagulation, and oxidative stress in order to investigate their possible pathogenic roles in atherosclerosis-prone mice. METHODS: Mice were fed with a normal chow diet or high-fat diet and sacrificed at different age intervals to measure aortic plaque size. Plasma cholesterol was enzymatically measured. Enzyme-linked immunosorbent assay was used to measure oxidized LDL (oxLDL)/beta-2-glycoprotein I (beta2GPI) complexes, immunoglobulin M (IgM) antibodies against native LDL, oxLDL, or oxLDL/beta2GPI, and urine 11-dehydro-thromboxane B2 (11-dhTxB2) or 8-hydroxy-deoxyguanosine. RESULTS: There was a parallel increase in plaque size, plasma cholesterol, and urinary 11-dhTxB2 in atherosclerosis-prone mice. In contrast to atherosclerosis-prone strains, an elevation of urinary 11-dhTxB2 with no significant plaque generation was observed in LDLR+/- 1 apoE+/- mice. The atherogenic autoantigen oxLDL/beta2GPI complex was detected only in LDLRI mice. These levels seem to depend on plaque size. IgM antibodies against oxLDL in apoE-/- mice were found, accompanied by atherosclerotic progression. CONCLUSIONS: Progression of atherosclerotic lesions was associated not only with hypercholesterolemia but also with platelet activation and natural autoimmune-mediated regulatory mechanism(s) in murine models.

Passive oral immunization by egg yolk immunoglobulin (IgY) to Vibrio cholerae effectively prevents cholera.

In an attempt to prepare egg yolk immunoglobulin (IgY) to treat and prevent cholera, hens were immunized by a mixture of heat- or formalin-killed Vibrio cholerae O1 and O139 organisms, or by the recombinant cholera toxin B subunit (CTB). The IgYs were partially purified from egg yolk and orally administered to suckling mice before or after challenge with live O1 or O139 cells. The anti-O1 and O139 IgYs and the mixture of either IgY with anti-CTB IgY significantly protected the occurrence of cholera caused by both O1 and O139 infection. Since large amounts of IgY can be prepared very easily and at low cost, this seems to be a useful procedure for preventing and treating cholera.

Molecular analysis of an extrachromosomal element containing the C2 toxin gene discovered in Clostridium botulinum type C.

Clostridium botulinum cultures are classified into seven types, types A to G, based on the antigenicity of the neurotoxins produced. Of these seven types, only types C and D produce C2 toxin in addition to the neurotoxin. The C2 toxin consists of two components designated C2I and C2II. The genes encoding the C2 toxin components have been cloned, and it has been stated that they might be on the cell chromosome. The present study confirmed by using pulsed-field gel electrophoresis and subsequent Southern hybridization that these genes are on a large plasmid. The complete nucleotide sequence of this plasmid was determined by using a combination of inverse PCR and primer walking. The sequence was 106,981 bp long and contained 123 potential open reading frames, including the c2I and c2II genes. The 57 products of these open reading frames had sequences similar to those of well-known proteins. It was speculated that 9 these 57 gene products were related to DNA replication, 2 were responsible for the two-component regulatory system, and 3 were sigma factors. In addition, a total of 20 genes encoding proteins related to diverse processes in purine catabolism were found in two regions. In these regions, there were 9 and 11 genes rarely found in plasmids, indicating that this plasmid plays an important role in purine catabolism, as well as in C2 toxin production.

Binding and internalization of Clostridium botulinum C2 toxin.

Clostridium botulinum C2 toxin is a binary toxin composed of an enzymatic component (C2I) and a binding component (C2II). The activated binding component (C2IIa) forms heptamers, and the oligomer with C2I is taken up by receptor-mediated endocytosis. We investigated the binding and internalization of C2IIa in cells. The C2IIa monomer formed oligomers on lipid rafts in membranes of MDCK cells. Methyl-beta-cyclodextrin inhibited the binding of C2IIa and the rounding of the cells induced by C2I plus C2IIa. C2I was localized to the rafts in the presence, but not the absence, of C2IIa. Surface plasmon resonance analysis revealed that C2I bound to the oligomer of C2IIa, but not the monomer of C2IIa. C2I and C2IIa were rapidly internalized in the cells. LY294002, a phosphatidylinositol 3-kinase (PI3K) inhibitor, inhibited the internalization of C2IIa in the cells and the rounding activity in the presence of C2I plus C2IIa. Incubation of the cells with C2I plus C2IIa resulted in the activation of PI3K and in phosphorylation of phosphoinositide-dependent kinase 1 and protein kinase B/Akt (Akt), but that with C2IIa alone did not. Akt inhibitor X, an Akt phosphorylation inhibitor, inhibited the rounding activity but not the internalization of C2IIa. The results suggest that the binding of C2I to the oligomer of C2IIa on rafts triggers the activation of the PI3K-Akt signaling pathway and, in turn, the initiation of endocytosis.

Autoimmunity, infectious immunity, and atherosclerosis.

INTRODUCTION: Vascular inflammation is common in certain systemic autoimmune diseases and contributes to the oxidation of low-density lipoprotein (oxLDL) and oxLDL/beta2-glycoprotein I (beta2GPI) complex formation. These complexes have been implicated as proatherogenic autoantigens that participate in the development of atherosclerotic disease. DISCUSSION: We have demonstrated that the in vitro macrophage uptake of oxLDL/beta2GPI complexes increases in the presence of IgG anti-beta2GPI antibodies and that IgG immune complexes containing oxLDL/beta2GPI upregulate the expression of both scavenger and Fcgamma receptors to activate beta2GPI specific T cells. Some persistent infections may cause immune responses that promote atherogenesis. Cellular immunity (Th1) against Helicobacter pylori (H. pylori) derived heat shock protein 60 (Hp-HSP60) cross-reacts with endogenous HSP60 to cause cardiovascular disease likely by molecular mimicry. CONCLUSION: Infectious cellular response may be proatherogenic,while the humoral response (antibody production) maybe protective. We review the recent progress in our understanding of autoimmunity and infectious immunity that promote atherosclerosis.

The HA proteins of botulinum toxin disrupt intestinal epithelial intercellular junctions to increase toxin absorption.

The type B botulinum neurotoxin (BoNT) elicits flaccid paralysis and death in humans by intoxicating peripheral nerves after oral absorption. Here, we examine the function of the haemagglutinin (HA), a non-toxic component of the large 16S BoNT complex. We find that the HA acts in the intestine to disrupt epithelial barrier function by opening intercellular tight and adherens junctions. This allows transport of BoNT and other large solutes into the systemic circulation and explains how the type B BoNT complexes are efficiently absorbed. In vitro, HA appears to act on the epithelial cell via the basolateral membrane only, suggesting the possibility of another step in the absorptive process. These studies show that the 16S BoNT complex is a multifunctional protein assembly equipped with the machinery to efficiently breach the intestinal barrier and act systemically on peripheral nerves.

Lincomycin-induced over-expression of mature recombinant cholera toxin B subunit and the holotoxin in Escherichia coli.

Cholera toxin (CT) B subunit (CTB) was overproduced using a novel expression system in Escherichia coli. An expression plasmid was constructed by inserting the gene encoding the full-length CTB and the Shine-Dalgarno (SD) sequence derived from CTB or from the heat-labile enterotoxin B subunit (LTB) of enterotoxigenic E. coli into the lacZalpha gene fragment in the pBluescript SK(+) vector. The E. coli strain MV1184 was transformed with each plasmid and then cultured in CAYE broth containing lincomycin. Recombinant CTB (rCTB) was purified from each cell extract. rCTB was overproduced in both transformants without obvious toxicity and was structurally and biologically identical to that of CT purified from Vibrio cholerae, indicating that the original SD and CTB signal sequences were also sufficient to express rCTB in E. coli. Lincomycin-induced rCTB expression was inhibited by mutating the lac promoter, suggesting that lincomycin affects the lactose operon. Based on these findings, we constructed a plasmid that contained the wild-type CT operon and successfully overproduced CT (rCT) using the same procedure for rCTB. Although rCT had an intact A subunit, the amino-terminal modifications and biological properties of the A and B subunits of rCT were identical to those of CT. These results suggest that this novel rCTB over-expression system would also be useful to generate both wild-type and mutant CT proteins that will facilitate further studies on the characteristics of CT, such as mucosal adjuvant activity.

Detection of Helicobacter hepaticus in human bile samples of patients with biliary disease.

BACKGROUND: Since the discovery of Helicobacter pylori, various enterohepatic Helicobacter spices have been detected in the guts of humans and animals. Some enterohepatic Helicobacters have been associated with inflammatory bowel disease or liver disease in mice. However the association of these bacteria with human diseases remains unknown. MATERIALS AND METHODS: We collected 126 bile samples from patients with cholelithiasis, cholecystitis, gallbladder polyp, and other nonbiliary diseases. Samples were screened for the presence of enterohepatic Helicobacter spp. using cultures, nested PCR, or in situ hybridization. We tested for antibodies to H. pylori and H. hepaticus by Western blot analysis. RESULTS: Attempts at cultivation were unsuccessful. However, H. hepaticus was detected in bile samples with nested PCR whereas H. bilis was not. Helicobacter hepaticus in the bile was confirmed by in situ hybridization, but H. hepaticus from bile samples was coccoid in appearance. We detected immunoglobulin G antibodies to H. hepaticus in bile samples by Western blotting. Helicobacter hepaticus was detected in 40 (32%) of total 126 samples as H. hepaticus positive if at least one of the three methods with nested PCR, in situ, or Western blotting. Patients with cholelithiasis (41%) and cholecystitis with gastric cancer (36%) had significantly higher (p = .029) prevalence of H. hepaticus infection than samples from patients with other diseases. CONCLUSION: Helicobacter hepaticus may closely associate with diseases of the liver and biliary tract in humans.