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Candida albicans is an opportunistic pathogenic yeast that can survive in both normoxic and hypoxic environments. The involvement of C. albicans secretome on host biological processes has been demonstrated. However, the immunoregulatory function of C. albicans secretome released under hypoxic condition remains unclear. This study demonstrated the differences in cytokine responses and protein profiles between secretomes prepared under normoxic and hypoxic conditions. Furthermore, the immunoregulatory effects of heat shock protein SSA1(Ssa1), a protein candidate enriched in the hypoxic secretome, were investigated. Stimulation of mouse bone marrow-derived macrophages (BMMs) with Ssa1 resulted in the significant production of interleukin (IL)-10, IL-6, and tumor necrosis factor (TNF)-α as well as the significant expression of M2b macrophage markers (CD86, CD274 and tumor necrosis factor superfamily member 14), suggesting that C. albicans Ssa1 may promote macrophage polarization towards an M2b-like phenotype. Proteomic analysis of Ssa1-treated BMMs also revealed that Ssa1 reduced inflammation-related factors (IL-18-binding protein, IL-1 receptor antagonist protein, OX-2 membrane glycoprotein and cis-aconitate decarboxylase) and enhanced the proteins involved in anti-inflammatory response (CMRF35-like molecule 3 and macrophage colony-stimulating factor 1 receptor). Based on these results, we investigated the effect of Ssa1 on C. albicans infection and showed that Ssa1 inhibited the uptake of C. albicans by BMMs. Taken together, our results suggest that C. albicans alters its secretome, particularly by promoting the release of Ssa1, to modulate host immune response and survive under hypoxic conditions. [ABSTRACT FROM AUTHOR]

Vitamin A ensures intestinal homeostasis, impacting acquired immunity and epithelial barrier function; however, its role in innate immunity is mostly unknown. Here, we studied the impact of vitamin A in different dextran sulfate sodium (DSS)-induced colitis animal models. Interestingly, more severe DSS-induced colitis was observed in vitamin A-deficient (VAD) mice than in vitamin A-sufficient (VAS) mice; the same was observed in VAD severe combined immunodeficient mice lacking T/B cells. Remarkably, IL-1β production, LC3B-II expression, and inflammasome activity in the lamina propria were significantly elevated in VAD mice. Electron microscopy revealed numerous swollen mitochondria with severely disrupted cristae. In vitro, non-canonical inflammasome signaling-induced pyroptosis, LC3B-II and p62 expression, and mitochondrial superoxide levels were increased in murine macrophages (RAW 264.7) pretreated with retinoic acid receptor antagonist (Ro41-5253). These findings suggest that vitamin A plays a crucial role in the efficient fusion of autophagosomes with lysosomes in colitis. [ABSTRACT FROM AUTHOR]

Acinetobacter baumannii is a major causative agent of nosocomial infections and its outer membrane vesicles (AbOMVs) have been shown to be involved in pathogenicity by transporting virulence factors and transferring information for communication between pathogens and host cells. Despite the fact that the infected sites of A. baumannii such as lungs and skin soft tissues are hypoxic, most studies on AbOMV virulence have used AbOMVs prepared under aerobic conditions. The present study aims to elucidate the protein profile and pathogenic impact of AbOMVs released under hypoxic condition. AbOMVs were isolated from A. baumannii under normoxic and hypoxic conditions, and their protein profiles were compared. The different effects of both normoxic and hypoxic AbOMVs in cytokine response from mouse macrophages, cytotoxicity to the human lung epithelial cells, and bacterial invasion were then investigated. Our results showed that A. baumannii under hypoxia released larger amounts of OMVs with different protein profiles. Although the cytotoxic effect of AbOMVs from normoxia and hypoxia were comparable, AbOMVs from normoxia induced higher TNF-α production and invasion of Staphylococcus aureus and Pseudomonas aeruginosa than those from hypoxia. On the other hand, AbOMVs significantly enhanced A. baumannii invasion into lung epithelial cells in a dose-dependent manner. These results clearly demonstrate that AbOMVs released from normoxic and hypoxic have different impacts in pathogenesis. This finding provides new insight into the complex interactions between A. baumannii, coinfecting pathogens and host cells via OMVs, in particular the different pathogenic effects of AbOMVs under normoxic and hypoxic conditions. [ABSTRACT FROM AUTHOR]

It has been reported that 222-nm ultraviolet C (UVC) exerts a germicidal effect on bacteria and viruses as well as UV radiation emitted from a conventional germicidal lamp but is less toxic to the mammalian cells than that from a germicidal lamp. An excimer lamp filled with krypton chloride (KrCl) gas principally emits 222-nm UVC. However, the lamp also emits a wide band of wavelengths other than 222 nm, especially UVC at a longer wavelength than 222 nm and ultraviolet B, which cause DNA damage. There are some reports on the critical role of bandpass filters in reducing the harmful effect of UVC emitted from a KrCl excimer lamp in a human skin model and human subjects. However, the effectiveness of a bandpass filter has not been demonstrated in animal experiments. In the present study, mice were irradiated with UVC emitted from a KrCl excimer lamp with or without a bandpass filter. UVC emitted from an unfiltered KrCl lamp at doses of 50, 150 and 300 mJ/cm2 induced cyclobutyl pyrimidine dimer (CPD)-positive cells, whereas UVC emitted from a filtered lamp did not significantly increase CPD-positive cells in the epidermis. The present study suggested that the bandpass filter serves a critical role in reducing the harmful effect of emission outside of 222 nm to mouse keratinocytes. [ABSTRACT FROM AUTHOR]

This study investigated the effects of salmon nasal cartilage proteoglycan (PG), which shows anti‐inflammatory properties, on obesity induced by high‐fat diet (HFD) in a mouse model. Mice were fed either a HFD or normal diet (ND), with or without PG, for 8–12 weeks. After 12 weeks, the body weight of mice fed with PG‐free HFD was 54.08 ± 4.67 g, whereas that of mice fed with HFD containing PG was 41.83 ± 4.97 g. The results suggest that the increase in body weight was attenuated in mice fed with HFD containing PG. This effect was not observed in mice fed with ND. The PG administration suppressed the elevation of serum lipids (the level of serum lipids ranged between 54% and 69% compared to 100% in mice fed with PG‐free HFD) and the upregulated mRNA expression of sterol regulatory element‐binding protein‐1c (SREBP‐1c), which is a transcription factor that acts as a master regulator of lipogenic gene expression in the liver (the expression level was 77.5% compared to 100% in mice fed with PG‐free HFD). High leptin levels in mice fed with PG‐free HFD were observed during fasting (average at 14,376 ng/ml), and they did not increase after refeeding (average of 14,263 ng/ml), whereas serum leptin levels in mice fed with HFD containing PG were low during fasting (average of 6481 ng/ml) and increased after refeeding (average 13,382 ng/ml). These results suggest that PG feeding has an anti‐obesity effect and that the regulation of SREBP‐1c and leptin secretion play a role in this effect. [ABSTRACT FROM AUTHOR]

Background: UVC has been used to inactivate several pathogens. Unlike the conventional 254-nm UVC, 222-nm UVC is harmless to mammalian cells.Aim: To investigate the disinfection efficacy of 222-nm UVC against human pathogens which are commonly found in the environment and healthcare facilities.Methodology: Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Salmonella enterica subsp. serovar Typhimurium, Campylobacter jejuni, Bacillus cereus (vegetative cells and endospores), Clostridium sporogenes (vegetative cells and endospores), Clostoridioides difficile (endospores), Candida albicans (yeast), Aspergillus niger (hyphae and spores), Trichophyton rubrum (hyphae and spores), feline calicivirus and influenza A virus were irradiated with 222-nm UVC at various doses. The remaining live bacterial and fungal cells, and the viral infectivity were evaluated. The efficiency of 222-nm UVC germicidal effect was compared to that of the conventional 254-nm UVC.Results: The 222-nm UVC showed potent germicidal effect to vegetative bacterial cells, yeast and viruses as efficient as the 245-nm UVC. The 222-nm UVC exhibited more potent germicidal effect to bacterial endospores, compared with the 254-nm UVC. The fungicidal effect of 222-nm UVC against the fungal spores and hyphae was weaker than that of 254-nm UVC.Conclusions: The 222-nm UVC is able to inactivate a wide spectrum of microbial pathogens. In comparison with the conventional 254-nm UVC, the germicidal effect of 222-nm UVC to the fungal hyphae and spores is low, but the 222-nm UVC exhibits strong germicidal effect to the bacterial endospores. [ABSTRACT FROM AUTHOR]

Staphylococcal enterotoxins (SEs) produced by Staphylococcus aureus are known as causative agents of emetic food poisoning. We previously demonstrated that SEA binds with submucosal mast cells and evokes mast cell degranulation in a small emetic house musk shrew model. Notably, primates have been recognized as the standard model for emetic assays and analysis of SE emetic activity. However, the mechanism involved in SEA-induced vomiting in primates has not yet been elucidated. In the present study, we established common marmosets as an emetic animal model. Common marmosets were administered classical SEs, including SEA, SEB and SEC, and exhibited multiple vomiting responses. However, a non-emetic staphylococcal superantigen, toxic shock syndrome toxin-1, did not induce emesis in these monkeys. These results indicated that the common marmoset is a useful animal model for assessing the emesis-inducing activity of SEs. Furthermore, histological analysis uncovered that SEA bound with submucosal mast cells and induced mast cell degranulation. Additionally, ex vivo and in vivo pharmacological results showed that SEA-induced histamine release plays a critical role in the vomiting response in common marmosets. The present results suggested that 5-hydroxytryptamine also plays an important role in the transmission of emetic stimulation on the afferent vagus nerve or central nervous system. We conclude that SEA induces histamine release from submucosal mast cells in the gastrointestinal tract and that histamine contributes to the SEA-induced vomiting reflex via the serotonergic nerve and/or other vagus nerve. [ABSTRACT FROM AUTHOR]

Proteoglycan (PG) is a complex glycohydrate, which is widely distributed in the extracellular matrix. It has been reported that daily oral administration of PG (extracted from salmon nasal cartilage) modulates the severity of proinflammatory cytokine responses in mouse experimental colitis, autoimmune encephalomyelitis, collagen-induced arthritis and obesity-induced inflammation. The present study investigated the effect of salmon nasal cartilage PG on allergic responses using a mouse model of papain-induced respiratory inflammation. Low titers of immunoglobulin E were identified in the sera of the PG-administered mice. Oral administration of PG attenuated eosinophil infiltration in the lung. In the acute model of papain-induced allergic inflammation, PG-administered mice exhibited low titers of epithelium-derived and T helper 2-associated cytokines. The results of the present study demonstrated that salmon cartilage PG has an immunomodulatory effect on intranasally delivered papain. These results suggest a potential role for PG as a prophylactic agent which may attenuate allergic respiratory inflammation. [ABSTRACT FROM AUTHOR]

Surgical site infections (SSIs) represent an important clinical problem associated with increased levels of surgical morbidity and mortality. UVC irradiation during surgery has been considered to represent a possible strategy to prevent the development of SSI. 254-nm UVC induces marked levels of DNA damage by generating cyclobutyl pyrimidine dimers (CPD) in microorganisms. However, this effect is elicited not only in microorganisms, but also in human cells, and chronic exposure to 254-nm UVC has been established to represent a human health hazard. In contrast, despite short wavelength-UVC light, especially 222-nm UVC, having been demonstrated to elicit a bactericidal effect, single irradiation with a high dose of 222-nm UVC energy has been reported to not induce mutagenic or cytotoxic DNA lesions in mammalian cells. However, the effect of chronic irradiation with a high dose of 222-nm UVC to mammalian cells has not been determined. In this study, it was demonstrated that large numbers of CPD-expressing cells were induced in the epidermis of mice following treatment with a small amount of single exposure 254-nm UVC, and then less than half of these cells reduced within 24 h. Chronic 254-nm UVC irradiation was revealed to induce sunburn and desquamation in mouse skin. Histological analysis demonstrated that small numbers of CPD-expressing cells were detected only in hyperkeratotic stratum corneum after chronic irradiation with a high dose of 254-nm UVC, and that significant hyperplasia and intercellular edema were also induced in the epidermis of mice. In contrast, chronic irradiation with 222-nm UVC light was revealed not to induce mutagenic or cytotoxic effects in the epidermis of mice. These results indicated that 222-nm UVC light emitted from the lamp apparatus (or device), which was designed to attenuate harmful light present in wavelengths of more than 230 nm, represents a promising tool for the reduction of SSI incidence in patients and hospital staff. [ABSTRACT FROM AUTHOR]

Proteoglycan (PG) is a complex glycohydrate that is widely distributed in the extracellular matrix. Oral administration of PG extracted from salmon nasal cartilage has been reported to attenuate the severity and proinflammatory cytokine responses in mouse experimental colitis, autoimmune encephalomyelitis, collagen-induced arthritis and obesity-induced inflammation. In the present study, the effects of salmon nasal cartilage PG on skin allografts were investigated in a mouse model. Oral administration of PG prolonged the survival of skin grafts within 10 days of transplantation. Although PG failed to inhibit allograft rejection at the final stage of transplantation, PG attenuated the cell infiltration in the skin under the transplanted site. [ABSTRACT FROM AUTHOR]

Obesity is associated with chronic inflammation of adipose tissue and causes development of type 2 diabetes. M1 macrophage population was increased in adipose tissue of obese mouse. M1 macrophages induce insulin resistance through the secretion of proinflammatory cytokines. Our previous studies demonstrated that salmon cartilage proteoglycan (PG) suppresses excess inflammation in various mouse inflammatory diseases. In this study, we examined the effect of PG on type 2 diabetes using high-fat-diet (HFD) induced obese mouse model. Oral PG administration enhanced the population of small adipocytes (area less than 1000 μm 2 ) without body and tissue weight gain. In addition, PG administration suppressed mRNA expression of TNF-α, IL-6 and CXCL2 in adipose tissue. The proportion of M1 macrophages was decreased by PG administration. In addition, PG administration suppressed hyperglycemia after intraperitoneal glucose injection. Fasted serum insulin level was decreased in PG-administered mice. Moreover, insulin-stimulated phosphorylation of Akt was enhanced in the liver and gastrocnemius skeletal muscle of PG-administered mice. These data suggested that PG administration improves hyperglycemia and insulin sensitivity in obese mice by modulation of M1 macrophages which secrete proinflammatory cytokines in adipose tissue and activation of Akt in liver and skeletal muscle. [ABSTRACT FROM AUTHOR]

Toxic shock syndrome toxin-1 (TSST-1), a superantigen produced from Staphylococcus aureus, has been reported to bind directly to unknown receptor(s) and penetrate into non-immune cells but its function is unclear. In this study, we demonstrated that recombinant TSST-1 suppresses autophagosomal accumulation in the autophagic-induced HeLa 229 cells. This suppression is shared by a superantigenic-deficient mutant of TSST-1 but not by staphylococcal enterotoxins, suggesting that autophagic suppression of TSST-1 is superantigenic-independent. Furthermore, we showed that TSST-1-producing S. aureus suppresses autophagy in the response of infected cells. Our data provides a novel function of TSST-1 in autophagic suppression which may contribute in staphylococcal persistence in host cells. [ABSTRACT FROM AUTHOR]

Abstract: Aims: Proteoglycans (PGs) are complex glycohydrates, which are composed of core proteins and glycosaminoglycans and widely distributed in connective tissues. We investigated the effect of PG extracted from salmon cartilage in progression of mouse experimental autoimmune encephalomyelitis (EAE). Main methods: EAE was induced by immunization with myelin-oligodendrocyte glycoprotein (MOG). Mice were given orally once daily with salmon cartilage PG and severity of EAE was monitored. Expression of Th17- and regulatory T cell-related factors was determined by ELISA and/or quantitative real time PCR. Expression of Foxp3+ in CD4+CD25+ cells was analyzed by flow cytometry. Key findings: Daily oral administration of PG attenuated clinical and histological severity of EAE in a dose-dependent manner. It suppressed interferon- β (IFN- β ) production and CCL2 expression in spinal cord that is the inflamed site of EAE. Administration of PG suppressed IFN- γ and interleukin-17 (IL-17) production from lymphocytes from draining lymph nodes in response to MOG re-stimulation ex vivo. Moreover, administration of PG suppressed the expression of IL-6, IL-21, IL-23 receptor and retinoic acid-related orphan receptor γt and enhanced the expression of Foxp3 in both draining lymph nodes and spinal cords. Significance: Salmon cartilage PG attenuates the severity of EAE by suppressing the differentiation of Th17 linage and enhancement of Treg expansion. Our results indicated that PG has potential to be a novel prophylactic agent for autoimmune diseases. [Copyright &y& Elsevier]

Abstract: Adherence to the cell surface is a key event during infection of pathogenic microorganisms. We have previously reported that autolysin amidase (Ami) of Listeria monocytogenes promotes an efficient listerial adherence to mouse hepatocytes and requires for listerial pathogenicity. Cell wall anchoring (CWA) domain of Ami has been shown to bind lipoteichoic acid on listerial cell wall but the binding of Ami to host cell surface molecules remains to be determined. In this study, we present evidence here that Ami promotes efficient adherence of L. monocytogenes to mouse hepatocytes mediated by glycosaminoglycans (GAGs). The adhesion of L. monocytogenes wild type but not Ami-deficient mutant to the hepatocytes was dramatically attenuated by 4-nitrophenyl-β-d-xylopyranoside, a specific inhibitor of GAG association to cell surface. Full-length and truncated Ami were used to investigate the binding of Ami to GAGs and we found that four-repeated CWA of Ami is sufficient to bind GAGs on the host cell surface. Competitive assay and surface plasmon resonance demonstrated that Ami interacts with sulfated GAGs but not non-sulfated GAGs. The results suggest that Ami acts as an adhesin of L. monocytogenes to hepatocytes by interaction via its four-repeated CWA domain and sulfated GAGs. [Copyright &y& Elsevier]

Staphylococcal enterotoxins (SEs) are the cause of staphylococcal food poisoning (SFP) outbreaks. Recently, many new types of SEs and SE-like toxins have been reported, but it has not been proved whether these new toxins cause food poisoning. To develop an immunoassay for detection of SE-like J (SElJ), a non-characterized toxin in SFP, a mutant SElJ with C-terminus deletion (SElJ∆C) was expressed and purified in an E. coli expression system. Anti-SElJ antibody was produced in rabbits immunized with the SElJ∆C. Western blotting and sandwich enzyme-linked immunosorbent assay (ELISA) detection systems were established and showed that the antibody specifically recognizes SElJ without cross reaction to other SEs tested. The limit of detection for the sandwich ELISA was 0.078 ng/mL, showing high sensitivity. SElJ production in S. aureus was detected by using the sandwich ELISA and showed that selj-horboring isolates produced a large amount of SElJ in the culture supernatants, especially in that of the strain isolated from a food poisoning outbreak in Japan. These results demonstrate that the immunoassay for detection of SElJ is specific and sensitive and is useful for determining the native SElJ production in S. aureus isolated from food poisoning cases. [ABSTRACT FROM AUTHOR]

Listeria monocytogenes is an intracellular pathogen that causes listeriosis. Due to its intracellular niche, L. monocytogenes has evolved to limit immune recognition and response to infection. Antibodies that are slightly induced by listerial infection are completely unable to protect re-infection of L. monocytogenes. Thus, a role of antibody on the protective effect against L. monocytogenes infection has been neglected for a long time. In the present study, we reported that passive immunization with an excessive amount of antibodies against ActA and listeriolysin O (LLO) attenuates severity of L. monocytogenes infection. Combination of these antibodies improved survival of L. monocytogenes infected mice. Bacterial load in spleen and liver of listerial infected mice and infected RAW264.7 cells were significantly reduced by administration of anti-ActA and anti-LLO antibodies. In addition, anti-LLO antibody neutralized LLO activity and inhibited the bacterial escape from the lysosomal compartments. Moreover, anti-ActA antibody neutralized ActA activity and suppressed actin tail formation and cell-to-cell spread. Thus, our studies reveal that passive immunization with the excessive amount of anti-ActA and -LLO antibodies has potential to provide the protective effect against listerial infection. [ABSTRACT FROM AUTHOR]

Proteoglycan (PG) extracted from salmon nasal cartilage has potential to be a prophylactic agent. Daily oral administration of the PG attenuates systemic inflammatory response in the experimental mouse models. In this study, we applied the culture-independent approach to investigate an alteration of intestinal microbiota composition in PG-administered mice. The results indicated that the population level of bacilli increased in the small and large intestine upon PG administration. On the other hand, the population level of clostridia decreased in the large intestine. The proportion of bacteria that are able to ferment saccharides and produce short-chain fatty acids increased in the small intestine and decreased in the large intestine. Importantly, population level of probiotic lactobacilli and bacteria exhibiting the immunomodulatory effect increased in the PG-administered mice. In addition, several disease-associated bacteria decreased upon PG administration. These results provided an understanding of the specific role of PG involved in host immune modulation and supported our hypothesis that daily oral administration of PG improves the overall balance in composition of the intestinal microbial community. [ABSTRACT FROM AUTHOR]

Staphylococcal enterotoxins (SEs) produced by Staphylococcus aureus have superantigenic and emetic activities, which cause toxic shock syndrome and staphylococcal food poisoning, respectively. Our previous study demonstrated that the sequence of SET has a low level of similarity to the sequences of other SEs and exhibits atypical bioactivities. Hence, we further explored whether there is an additional SET-related gene in S. aureus strains. One SET-like gene was found in the genome of S. aureus isolates that originated from a case of food poisoning, a human nasal swab, and a case of bovine mastitis. The deduced amino acid sequence of the SET-like gene showed 32% identity with the amino acid sequence of SET. The SET-like gene product was designated SElY. In the food poisoning and nasal swab isolates, mRNA encoding SElY was highly expressed in the early log phase of cultivation, whereas a high level of expression of this mRNA was found in the bovine mastitis isolate at the early stationary phase. To estimate whether SElY has both superantigenic and emetic activities, recombinant SElY was prepared. Cell proliferation and cytokine production were examined to assess the superantigenic activity of SElY. SElY exhibited superantigenic activity in human peripheral blood mononuclear cells but not in mouse splenocytes. In addition, SElY exhibited emetic activity in house musk shrews after intraperitoneal and oral administration. However, the stability of SElY against heating and pepsin and trypsin digestion was different from that of SET and SEA. From these results, we identified SElY to be a novel staphylococcal emetic toxin. [ABSTRACT FROM AUTHOR]

Hair loss is a commonly encountered problem. In this study, hair growth was enhanced by daily oral ingestion of salmon nasal cartilage proteoglycan (PG) in mice. Proteoglycan stimulated vesicular endothelial growth factor production in human follicle dermal papilla cells through insulin growth factor-1 receptor signaling, suggesting the possibility of hair loss improvement by PG ingestion., (© The Author(s) 2023. Published by Oxford University Press on behalf of Japan Society for Bioscience, Biotechnology, and Agrochemistry.)

Objectives: This study aimed to clarify the disinfectant efficacy of the 222-nm far ultraviolet-C (UV-C) during esophagogastroduodenoscopy using bacterial cultures., Methods: The endoscopists performed esophagogastroduodenoscopy wearing a gown with a tryptic soy agar medium plate on their epigastric region and were divided into two groups: 222-nm far UV-C irradiation (UV group) and non-UV irradiation (non-UV group). As a control group, tryptic soy agar medium plates were placed about 110 cm above the floor. The incidence of bacterial contamination was determined by positive bacterial culture. The cultured bacteria were identified by 16S rRNA sequencing. Additionally, the actual UV exposure dose was measured using the UV-indicator card which changed colors upon exposure to 222 nm far UV-C., Results: The bacterial culture positivity in the UV group (5.03%) was significantly lower than that in the non-UV group (25.76%), p < 0.0001. Most of the bacteria identified in the UV and non-UV groups were normal constituents of the oral flora, including Streptococcus salivarius and Staphylococci . Conversely, pathogenic microbes were found in the control group. The actual exposure doses of 222-nm far UV-C at the endoscopists' face, neck, and epigastric region were 2.09 ± 0.29, 5.89 ± 0.49, and 7.36 ± 0.58 mJ/cm 2 , respectively., Conclusions: The 222-nm far UV-C irradiation reduced bacterial contamination for endoscopists. It can be used with conventional physical coverings to provide more effective infection control., Competing Interests: Kyosuke Yamane, Yoshimasa Ogawa, Masahiro Sasaki, Toru Koi, and Hiroyuki Ohashi are full‐time employees of Ushio Inc., (© 2023 The Authors. DEN Open published by John Wiley & Sons Australia, Ltd on behalf of Japan Gastroenterological Endoscopy Society.)

This study investigated the effects of salmon nasal cartilage proteoglycan (PG), which shows anti-inflammatory properties, on obesity induced by high-fat diet (HFD) in a mouse model. Mice were fed either a HFD or normal diet (ND), with or without PG, for 8-12 weeks. After 12 weeks, the body weight of mice fed with PG-free HFD was 54.08 ± 4.67 g, whereas that of mice fed with HFD containing PG was 41.83 ± 4.97 g. The results suggest that the increase in body weight was attenuated in mice fed with HFD containing PG. This effect was not observed in mice fed with ND. The PG administration suppressed the elevation of serum lipids (the level of serum lipids ranged between 54% and 69% compared to 100% in mice fed with PG-free HFD) and the upregulated mRNA expression of sterol regulatory element-binding protein-1c (SREBP-1c), which is a transcription factor that acts as a master regulator of lipogenic gene expression in the liver (the expression level was 77.5% compared to 100% in mice fed with PG-free HFD). High leptin levels in mice fed with PG-free HFD were observed during fasting (average at 14,376 ng/ml), and they did not increase after refeeding (average of 14,263 ng/ml), whereas serum leptin levels in mice fed with HFD containing PG were low during fasting (average of 6481 ng/ml) and increased after refeeding (average 13,382 ng/ml). These results suggest that PG feeding has an anti-obesity effect and that the regulation of SREBP-1c and leptin secretion play a role in this effect., Competing Interests: The authors have declared that no competing interest exists., (© 2021 The Authors. Food Science & Nutrition published by Wiley Periodicals LLC.)

Here, we report the complete genome sequence of Staphylococcus aureus strain 834, which was isolated from a septic patient in Japan and showed strong virulence and methicillin resistance. The complete genome consists of a 2,838,668-bp chromosome and a 24,653-bp plasmid. Genome annotation predicts 2,670 coding sequences, 16 rRNAs, and 61 tRNAs., (Copyright © 2021 Ono et al.)

Development of long-term memory is crucial for vaccine-induced adaptive immunity against infectious diseases such as Staphylococcus aureus infection. Toxic shock syndrome toxin 1 (TSST-1), one of the superantigens produced by S. aureus , is a possible vaccine candidate against infectious diseases caused by this pathogen. We previously reported that vaccination with less toxic mutant TSST-1 (mTSST-1) induced T helper 17 (Th17) cells and elicited interleukin-17A (IL-17A)-mediated protection against S. aureus infection 1 week after vaccination. In the present study, we investigated the host immune response induced by mTSST-1 vaccination in the memory phase, 12 weeks after the final vaccination. The protective effect and IL-17A production after vaccination with mTSST-1 were eliminated because of IL-10 production. In the presence of IL-10-neutralizing monoclonal antibody (mAb), IL-17A production was restored in culture supernatants of CD4 + T cells and macrophages sorted from the spleens of vaccinated mice. Vaccinated mice treated with anti-IL-10 mAb were protected against systemic S. aureus infection in the memory phase. From these results, it was suggested that IL-10 produced in the memory phase suppresses the IL-17A-dependent vaccine effect through downregulation of IL-17A production., (Copyright © 2019 American Society for Microbiology.)

Adipose tissue-derived stem cells (ASCs), which are mesenchymal stromal cells isolated from adipose tissues, exhibit immunomodulatory effects that are promising for several applications, including the therapeutics of inflammatory diseases. In the present study, the effect of ASCs on bacterial toxin-induced inflammation was investigated. Intraperitoneal administration of ASCs rescued mice from lethal shock induced by staphylococcal enterotoxin A (SEA) potentiated with lipopolysaccharide. In the sera and/or spleens of mice administered ASCs, the production of proinflammatory cytokines, including interferon gamma, tumor necrosis factor alpha, interleukin-6 (IL-6), and IL-2 was reduced. By quantitative real-time PCR, the expression of Foxp3 in the mice administered ASCs was not altered. On the other hand, the expression of IL-12 receptor and STAT4 was decreased with ASC administration. These results imply that the effect of ASCs is not involved in the lineage of regulatory T cells but that these cells may modulate TH1 differentiation. This information provides evidence that ASCs have properties that are effective to attenuate SEA-induced toxic shock and should prompt further exploration on other inflammatory diseases caused by bacterial toxins or bacterial infections., (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)

The role of mouse peptidoglycan recognition protein PGLYRP-1 in innate immunity against Listeria monocytogenes infection was studied. The recombinant mouse PGLYRP-1 and a polyclonal antibody specific to PGLYRP-1 were prepared. The mouse PGLYRP-1 showed antibacterial activities against L. monocytogenes and other Gram-positive bacteria. PGLYRP-1 mRNA expression was induced in the spleens and livers of mice infected with L. monocytogenes. The viable bacterial number increased, and the production of cytokines such as gamma interferon (IFN-γ) and tumor necrosis factor alpha (TNF-α) was reduced in mice when mice had been injected with anti-PGLYRP-1 antibody before infection. The levels of IFN-γ and TNF-α titers in the organs were higher and the viable bacterial number was reduced in mice injected with recombinant mouse PGLYRP-1 (rmPGLYRP-1) before infection. PGLYRP-1 could directly induce these cytokines in spleen cell cultures. The elimination of intracellular bacteria was upregulated in NMuLi hepatocyte cells overexpressing PGLYRP-1. The enhancement of the elimination of L. monocytogenes from the organs was observed in IFN-γ(-/-) mice by rmPGLYRP-1 administration but not in TNF-α(-/-) mice. These results suggest that PGLYRP-1 plays a role in innate immunity against L. monocytogenes infection by inducing TNF-α.

trans-translation is a rescue system for stalled ribosomes to terminate the translation for recycling of ribosome and lead the incomplete protein on the stalled ribosome to degradation. In trans-translation, several proteins and RNAs are involved. tmRNA and SmpB are only factors known to be essential for trans-translation. EF-Tu and EF-G functions in translation and also are seemed to function in trans-translation. Ribosomal protein S1 is known to bind tmRNA. In this study, we cloned the gene of tmRNA from Thermus thermophilus and analyzed the functions of factors involved in trans-translation in vitro.