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Streptococcus pneumoniae (S. pneumoniae) causes severe pulmonary diseases, leading to high morbidity and mortality. It has been reported that inflammasomes such as NLR family pyrin domain containing 3 (NLRP3) and absent in melanoma 2 (AIM2) play an important role in the host defense against S. pneumoniae infection. However, the role of NLRP6 in vivo and in vitro against S. pneumoniae remains unclear. Therefore, we investigated the role of NLRP6 in regulating the S. pneumoniae-induced inflammatory signaling pathway in vitro and the role of NLRP6 in the host defense against S. pneumoniae in vivo by using NLRP6−/− mice. The results showed that the NLRP6 inflammasome regulated the maturation and secretion of IL-1β, but it did not affect the induction of IL-1β transcription in S. pneumoniae-infected macrophages. Furthermore, the activation of caspase-1, caspase-11, and gasdermin D (GSDMD) as well as the oligomerization of apoptosis-associated speck-like protein (ASC) were also mediated by NLRP6 in S. pneumoniae-infected macrophages. However, the activation of NLRP6 reduced the expression of NF-κB and ERK signaling pathways in S. pneumoniae-infected macrophages. In vivo study showed that NLRP6−/− mice had a higher survival rate, lower number of bacteria, and milder inflammatory response in the lung compared with wild-type (WT) mice during S. pneumoniae infection, indicating that NLRP6 plays a negative role in the host defense against S. pneumoniae. Furthermore, increased bacterial clearance in NLRP6 deficient mice was modulated by the recruitment of macrophages and neutrophils. Our study provides a new insight on S. pneumoniae-induced activation of NLRP6 and suggests that blocking NLRP6 could be considered as a potential therapeutic strategy to treat S. pneumoniae infection.
Dongyi Xu; Xingping Wu; Lianci Peng; Tingting Chen; Qingyuan Huang; Yu Wang; Chao Ye; Yuanyi Peng; Dongliang Hu; Rendong Fang. The Critical Role of NLRP6 Inflammasome in Streptococcus pneumoniae Infection In Vitro and In Vivo. International Journal of Molecular Sciences 2021, 22, 3876 .
AMA StyleDongyi Xu, Xingping Wu, Lianci Peng, Tingting Chen, Qingyuan Huang, Yu Wang, Chao Ye, Yuanyi Peng, Dongliang Hu, Rendong Fang. The Critical Role of NLRP6 Inflammasome in Streptococcus pneumoniae Infection In Vitro and In Vivo. International Journal of Molecular Sciences. 2021; 22 (8):3876.
Chicago/Turabian StyleDongyi Xu; Xingping Wu; Lianci Peng; Tingting Chen; Qingyuan Huang; Yu Wang; Chao Ye; Yuanyi Peng; Dongliang Hu; Rendong Fang. 2021. "The Critical Role of NLRP6 Inflammasome in Streptococcus pneumoniae Infection In Vitro and In Vivo." International Journal of Molecular Sciences 22, no. 8: 3876.
Staphylococcus aureus is a Gram-positive opportunistic pathogen which causes infections in a variety of vertebrates. Virulence factors are the main pathogenesis of S. aureus as a pathogen, which induce the host’s innate and adaptive immune responses. Toxic shock syndrome toxin 1 (TSST-1) is one of the most important virulence factors of S. aureus. However, the role of nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) in TSST-1-induced innate immune response is still unclear. Here, purified recombinant TSST-1 (rTSST-1) was prepared and used to stimulate mouse peritoneal macrophages. The results showed that under the action of adenosine-triphosphate (ATP), rTSST-1 significantly induced interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) production in mouse macrophages and the production was dose-dependent. In addition, rTSST-1+ATP-stimulated cytokine production in macrophage depends on the activation of toll like receptor 4 (TLR4), but not TLR2 on the cells. Furthermore, the macrophages of NLRP3−/− mice stimulated with rTSST-1+ATP showed significantly low levels of IL-1β production compared to that of wild-type mice. These results demonstrated that TSST-1 can induce the expression of inflammatory cytokines in macrophages via the activation of the TLR4 and NLRP3 signaling pathways. Our study provides new information about the mechanism of the TSST-1-inducing host’s innate immune responses.
Lianci Peng; Jiali Jiang; Tingting Chen; Dongyi Xu; Fengqing Hou; Qingyuan Huang; Yuanyi Peng; Chao Ye; Dong-Liang Hu; Rendong Fang. Toxic Shock Syndrome Toxin 1 Induces Immune Response via the Activation of NLRP3 Inflammasome. Toxins 2021, 13, 68 .
AMA StyleLianci Peng, Jiali Jiang, Tingting Chen, Dongyi Xu, Fengqing Hou, Qingyuan Huang, Yuanyi Peng, Chao Ye, Dong-Liang Hu, Rendong Fang. Toxic Shock Syndrome Toxin 1 Induces Immune Response via the Activation of NLRP3 Inflammasome. Toxins. 2021; 13 (1):68.
Chicago/Turabian StyleLianci Peng; Jiali Jiang; Tingting Chen; Dongyi Xu; Fengqing Hou; Qingyuan Huang; Yuanyi Peng; Chao Ye; Dong-Liang Hu; Rendong Fang. 2021. "Toxic Shock Syndrome Toxin 1 Induces Immune Response via the Activation of NLRP3 Inflammasome." Toxins 13, no. 1: 68.
Background Salmonella is one of the most important foodborne pathogens, causing outbreaks of human salmonellosis worldwide. Owing to large scales of consumption markets, pork and poultry that contaminated by Salmonella could pose a tremendous threat to public health. The aim of this study was to investigate the contamination of Salmonella from chicken, pork and the environment in slaughtering and retail processes in Chongqing, China. Results A total of 115 Salmonella isolates were recovered from 1112 samples collected from pork, chicken and the environment. Compared with the isolation rate of samples from chicken (9.50%) and the environment (6.23%), samples from pork had a significant higher isolation rate (44.00%). The isolation rates in slaughterhouses (10.76%) and in supermarkets (10.07%) showed no statistical difference. Thirty different serotypes were identified among all the isolates. S. Derby (n = 26), S. London (n = 16) and S. Rissen (n = 12) were the dominant serotypes. Antimicrobial susceptibility testing revealed that 73.04% isolates were resistant to tetracycline, followed by 66.96% to ampicillin and 59.13% to doxycycline. More than half (50.43%) of the isolates were multidrug resistant (MDR), and most of the MDR isolates were from supermarkets. Multilocus sequence typing results showed 24 out of 115 isolates were ST40, which was the most prevalent. Furthermore, isolates from supermarkets had 20 different sequence types while isolates from slaughterhouses only had 8 different sequence types. Conclusion Our study highlighted that Salmonella was more frequently isolated in pork production chain than that in chicken. Compared with isolates from slaughterhouses, isolates from supermarkets had more MDR profiles and represented a wider range of serotypes and sequence types, indicating that the retail process had more diverse sources of Salmonella contamination than that of slaughtering process.
Tingting Chen; Jiali Jiang; Chao Ye; Jianhua Xie; Xia Chen; Dongyi Xu; Zheng Zeng; Yuanyi Peng; Dong-Liang Hu; Rendong Fang. Genotypic characterization and antimicrobial resistance profile of Salmonella isolated from chicken, pork and the environment at abattoirs and supermarkets in Chongqing, China. BMC Veterinary Research 2019, 15, 1 -8.
AMA StyleTingting Chen, Jiali Jiang, Chao Ye, Jianhua Xie, Xia Chen, Dongyi Xu, Zheng Zeng, Yuanyi Peng, Dong-Liang Hu, Rendong Fang. Genotypic characterization and antimicrobial resistance profile of Salmonella isolated from chicken, pork and the environment at abattoirs and supermarkets in Chongqing, China. BMC Veterinary Research. 2019; 15 (1):1-8.
Chicago/Turabian StyleTingting Chen; Jiali Jiang; Chao Ye; Jianhua Xie; Xia Chen; Dongyi Xu; Zheng Zeng; Yuanyi Peng; Dong-Liang Hu; Rendong Fang. 2019. "Genotypic characterization and antimicrobial resistance profile of Salmonella isolated from chicken, pork and the environment at abattoirs and supermarkets in Chongqing, China." BMC Veterinary Research 15, no. 1: 1-8.
Staphylococcus aureus is an important bacterial pathogen causing bovine mastitis, but little is known about the virulence factor and the inflammatory responses in the mammary infection. Staphylococcal enterotoxin C (SEC) is the most frequent toxin produced by S. aureus, isolated from bovine mastitis. To investigate the pathogenic activity of SEC in the inflammation of the mammary gland and the immune responses in an animal model, mouse mammary glands were injected with SEC, and the clinical signs, inflammatory cell infiltration, and proinflammatory cytokine production in the mammary glands were assessed. SEC induced significant inflammatory reactions in the mammary gland, in a dose-dependent manner. SEC-injected mammary glands showed a severe inflammation with inflammatory cell infiltration and tissue damage. In addition, interleukin (IL)-1β and IL-6 production in the SEC-injected mammary glands were significantly higher than those in the PBS control glands. Furthermore, the SEC-induced inflammation and tissue damage in the mammary gland were specifically inhibited by anti-SEC antibody. These results indicated, for the first time, that SEC can directly cause inflammation, proinflammatory cytokine production, and tissue damage in mammary glands, suggesting that SEC might play an important role in the development of mastitis associated with S. aureus infection. This finding offers an opportunity to develop novel treatment strategies for reduction of mammary tissue damage in mastitis.
Rendong Fang; Jingchun Cui; Tengteng Cui; Haiyong Guo; Hisaya K. Ono; Chun-Ho Park; Masashi Okamura; Akio Nakane; Dong-Liang Hu. Staphylococcal Enterotoxin C Is an Important Virulence Factor for Mastitis. Toxins 2019, 11, 141 .
AMA StyleRendong Fang, Jingchun Cui, Tengteng Cui, Haiyong Guo, Hisaya K. Ono, Chun-Ho Park, Masashi Okamura, Akio Nakane, Dong-Liang Hu. Staphylococcal Enterotoxin C Is an Important Virulence Factor for Mastitis. Toxins. 2019; 11 (3):141.
Chicago/Turabian StyleRendong Fang; Jingchun Cui; Tengteng Cui; Haiyong Guo; Hisaya K. Ono; Chun-Ho Park; Masashi Okamura; Akio Nakane; Dong-Liang Hu. 2019. "Staphylococcal Enterotoxin C Is an Important Virulence Factor for Mastitis." Toxins 11, no. 3: 141.
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.
Hisaya K. Ono; Nobuaki Hachiya; Yasunori Suzuki; Ikunori Naito; Shouhei Hirose; Krisana Asano; Katsuhiko Omoe; Akio Nakane; Dong-Liang Hu. Development of an Immunoassay for Detection of Staphylococcal Enterotoxin-Like J, A Non-Characterized Toxin. Toxins 2018, 10, 458 .
AMA StyleHisaya K. Ono, Nobuaki Hachiya, Yasunori Suzuki, Ikunori Naito, Shouhei Hirose, Krisana Asano, Katsuhiko Omoe, Akio Nakane, Dong-Liang Hu. Development of an Immunoassay for Detection of Staphylococcal Enterotoxin-Like J, A Non-Characterized Toxin. Toxins. 2018; 10 (11):458.
Chicago/Turabian StyleHisaya K. Ono; Nobuaki Hachiya; Yasunori Suzuki; Ikunori Naito; Shouhei Hirose; Krisana Asano; Katsuhiko Omoe; Akio Nakane; Dong-Liang Hu. 2018. "Development of an Immunoassay for Detection of Staphylococcal Enterotoxin-Like J, A Non-Characterized Toxin." Toxins 10, no. 11: 458.
Pathogenic bacteria use various strategies to interact with the host organisms. Among them, toxin production constitutes an efficient way to alter specific functions of target cells. Various enterotoxins interact with the enteric nervous system, by stimulating afferent neurons or inducing neurotransmitter release from enterochromaffin cells which result either in vomiting, diarrhea, or in the intestinal inflammation process. Staphylococcus aureus produces a wide variety of toxins including staphylococcal enterotoxins (SEs) with demonstrated emetic activity; and staphylococcal enterotoxin-like (SEl) proteins, which are not emetic in a primate model or have yet to be tested. SEs and SEls have been traditionally subdivided into classical (SEA to SEE) and new (SEG to SElX) types. These toxins possess superantigenic activity and are highly resistant to denaturation which allows them to remain intact in contaminated foods and trigger food poisoning outbreaks. Symptoms are of rapid onset, and include nausea and violent vomiting. SEA is the most recognizable toxin causing food poisoning in humans throughout the world. However, it remains unclear how SEs induce emesis and via which signal pathway. This review is divided into four parts, and will focus on the following: (1) how bacterial toxins interact with the nervous system, (2) biological characteristics of SEs and SEls, (3) mechanisms of SE-induced emesis, and (4) use of a vaccine for the prevention of SE-induced emesis.
Dong-Liang Hu; Akio Nakane. Mechanisms of staphylococcal enterotoxin-induced emesis. European Journal of Pharmacology 2014, 722, 95 -107.
AMA StyleDong-Liang Hu, Akio Nakane. Mechanisms of staphylococcal enterotoxin-induced emesis. European Journal of Pharmacology. 2014; 722 ():95-107.
Chicago/Turabian StyleDong-Liang Hu; Akio Nakane. 2014. "Mechanisms of staphylococcal enterotoxin-induced emesis." European Journal of Pharmacology 722, no. : 95-107.