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Bcl-2 down modulation in WEHI-3B/CTRES cells resistant to cholera toxin(CT)-induced apoptosis

Cell Research 2006年第3期16卷 306-312页

作者： Augusto Pessina Cristina Croera Nicoletta Savalli Arianna Bonomi Loredana Cavicchini Elisa Turlizzi Fabiana Guizzardi Lucia Guido Laura Daprai Maria GraziaNeri Institute of Microbiology University of MilanVia Pascal 3620133 MilanItaly ECVAM Institute for Health and Consumer ProtectionEuropean Commission Joint Research CentreIspra 21020Italy UCLA Department of AnesthesiologyLos AngelesCA 90095USA

The very different effects of cholera toxin (CT) on cell growth and proliferation may depend on the type of ganglio-side receptors in cell membranes and different signal transduction mechanisms triggered,but other functions relatedto the drug resistance mechanisms can not be *** effect of CT treatment on the "in vitro" clonogenicity,thePopulation Doubling Time (PDT),apoptosis,PKA activation and Bax and Bcl-2 expression was evaluated in WEHI-3Bcell line and its CT-resistant subclone (WEHI-3B/CTRES).In WEHI-3B parental cells the dramatic accumulation ofcAMP induced by CT correlated well with PKA activation,increased PDT value,inhibition of clonogenicity and apop-tosis.H-89 treatment inhibited PKA activation by CT but did not protect the cells from apoptosis and growth *** WEHI-3B/CTRES no significant CT-dependent accumulation of cAMP occurred with any increase of PKA activityand *** CT resistant cells (WEHI-3B/CTRES),Bcl-2 expression was down regulated by both CT or drug treatment(eg.,ciprofloxacin,CPX) although these cells were protected from CT-dependent apoptosis but not from *** from other cell models described,down regulation of Bcl-2 is proved to be independent on cAMPaccumulation and PKA *** observations support the implication of cAMP dependent kinase (PKA) in theinhibition of WEHI-3B cells growth and suggest that,in WEHI-3B/CTRES,Bcl-2 expression could be modulated byCT in the absence of cAMP *** in consideration of many contradictory data reported in literature,ourcell models(of one sensitive parental cell strain and two clones with different uncrossed specific resistance to CT andCPX)provides a new and interesting tool for better investigating the relationship between the CT signal transductionmechanisms and Bcl-2 expression and function.

关键词： cholera toxin Bcl-2 PKA apoptosis ciprofloxacin resistance

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Intestinal lysozyme releases Nod2 ligand(s) to promote the intestinal mucosal adjuvant activity of cholera toxin

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Science China(Life Sciences) 2021年第10期64卷 1720-1731页

作者： Haifang Wang Xueying Shen Xiaojiao Zheng Ying Pan Qin Zhang Zhihua Liu Institute for Immunology and School of Medicine Tsinghua UniversityBeijing 100084China Key Laboratory of Infection and Immunity Institute of BiophysicsChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

Commensal bacteria boost serum IgG production in response to oral immunization with antigen and cholera toxin(CT)in a manner that depends on Nod2(nucleotide-binding oligomerization domain-containing protein 2).In this study,we examined the role of intestinal lysozyme(Lyz1)in adjuvant activity of *** found that Lyz1 released Nod2 ligand(s)from ***1 deficiency reduced the level of circulating Nod2 ligand in ***1 deficiency also reduced the production of IgG and T-cellspecific cytokines after oral immunization in *** Lyz1-deficient mice with MDP restored IgG ***,overexpression of Lyz1 in intestinal epithelium boosted the antigen-specific IgG response induced by ***,our results indicate that Lyz1 plays an important role in mediating the immune regulatory effect of commensal bacteria through the release of Nod2 ligand(s).

关键词： Paneth cell lysozyme 1 muramyl dipeptide cholera toxin Nod2

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cholera toxin Suppresses Interleukin (IL)-12 Production and IL-12 Receptor β1 and β2 Chain Expression

Cholera Toxin Suppresses Interleukin (IL)-12 Production and ...

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作者： Michae C．Braun Brian L．Kelsall Immune Cell Interaction Unit Mucosal Immunity Section

cholera toxin (CT) is a potent mucosal vaccine adjuvant, which has been shown to induce T helper cell type 2 (Th2) responses in systemic and mucosal tissues. We report that CT inhibits the production of interleukin (IL)-12,a major Th2 counterregulatory ***-12 p70 production by stimulated human monocytes was inhibited by CT in a dose-dependent manner. This suppression occurred at the level of gene transcription, was maximal at low concentrations of CT, and was dependent on the A subunit of the toxin, since purified CT B subunit had minimal effect. CT also inhibited the

关键词： interleukin 12 monocytes dendritic cells Th1 and Th2 cells cholera toxin

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Mutants of Escherichia coli heat-labile enterotoxin and cholera toxin as mucosal adjuvants

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Journal of Chongqing University 2003年第2期2卷 71-77页

作者：冯强 CollegeofBioengineering ChongqingUniversityChongqing400044P.R.China

Mucosal vaccination has been getting more and more recognition because of its compliance and low risk of spreading infectious disease by contaminated syringes used in subcutaneous immunization. However, most vaccines are unable to induce immune responses when given mucosally, and require the use of strong adjuvant for effective delivery systems. Heat-labile enterotoxin (LT) and cholera toxin(CT) are powerful mucosal adjuvants when co-administered with soluble antigens. But high toxicity hampers their use in humans. Thanks to the fine knowledge of the structure-function relationship of LT and CT, many nontoxic or low toxic mutants have been generated, part of them retain high adjuvanticity of mucosal immunization. Among these mutants, LTS63K, LTA72R, LTR192G and CTE29H, CTE112K have been widely investigated. LTS63K and CTE112K are fully non toxic, whereas LTA72R and CTE29H are low toxic, and LTR192G is nontoxic in vitro(it remains the same toxicity as wild type LT in vivo). These mutants are extremely active as mucosal adjuvants when co-administrated with a variety of antigens in different animal models. They will be investigated more widely and deeply in the future. Some of them will be tested soon in human bodies.

关键词： mutants mucosal adjuvant heat-labile enterotoxin cholera toxin

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Prolonged pretreatment of mice with cholera toxin,but not isoproterenol,alleviates acute lethal systemic inflammatory response

Prolonged pretreatment of mice with cholera toxin,but not is...

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第九届全国免疫学学术大会

作者：汪静洋郭祥瑞王庆阳孙德军张纪岩军事医学科学院吉林大学

Isoproterenol,a synthetic non-selectiveβ-adrenergic agonist,is often used during the immediate postoperative period after open heart surgery for its chronotropic and vasodilatory *** has been demonstrated that isoproterenol pretreatment followed by immediate LPS administration leads to reduced tumor necrosis factor-α(TNF-α)response in ***,sepsis never happens immediately after the surgery,but rather severe immune dysfunction occurs at least24 hours *** remains elusive what effects isoproterenol might exert to innate immunity during the *** this scenario,we investigated the effects of 24 hour-isoproterenol pretreatment on septic shock induced by experimental endotoxernia and bacterial peritonitis,with cholera toxin(CTX)as another cAMP ***,we found isoproterenol and CTX exhibited distinct effects in acute lethal systemic inflammatory *** worsened liver injury without enhancing NK/NKT ***,CTX but not isoproterenol showed dramatically reduced TNF-αresponse in LPS induced septic *** data provide a caution for the clinical use of isoproterenol and suggest that isoproterenol has cAMP-independent functions.

关键词： septic shock cAMP cholera toxin isoproterenol

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toxin-coregulated pilus-loaded microparticles as a vaccine against Vibrio cholerae O139

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Chinese Medical Journal 2004年第4期117卷 618-620页

作者：杜艳贾文祥刘莉 Department of Microbiology

The cholera epidemics is an important public health problem in many developing countries. Highly effective and preventive vaccines against cholera are under investigation as alternatives to the one available presently. Much of the vaccine research focuses on colonization factors. Colonization of a human by the Vibrio cholerae (V. cholerae Ol strain is mediated by toxin-coregulated pilus (TCP), 1 which was shown to play a role in the infant mouse cholera model and subsequently in human volunteers. 2 TCP-loaded vaccines could potentially provide cross-protection among experimental strains. Data have indicated that poly (D,L-lactide)-polyethylene glycol copolymer (PELA)microparticles loaded antigens were strongly immunogenic, 3 and that these microparticles served as an effective delivery system for a single dose of vaccine. 4Microparticle formulation could represent the next generation of vaccines, as they are highly effective at delivery of vaccines, thus requiring fewer doses. 5 We prepared PELA microparticles loaded with TCP for testing as a vaccine; their targeting distributions were identified and related immune responses were analyzed.

关键词： Animals Antibodies, Bacterial cholera toxin cholera Vaccines Fimbriae, Bacterial Mice Research Support, Non-U.S. Gov't Vibrio cholerae O139

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The diverse landscape of AB5-type toxins

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Engineering Microbiology 2023年第4期3卷 90-104页

作者： Paris I.Brown Adaobi Ojiakor Antonio J.Chemello Casey C.Fowler Department of Biological Sciences University of AlbertaEdmontonAB T6G2E9Canada

AB_(5)-type toxins are a group of secreted protein toxins that are central virulence factors for bacterial pathogens such as Shigella dysenteriae,Vibrio cholerae,Bordetella pertussis,and certain lineages of pathogenic Escherichia coli and Salmonella ***_(5) toxins are composed of an active(A)subunit that manipulates host cell biology in complex with a pentameric binding/delivery(B)subunit that mediates the toxin’s entry into host cells and its subsequent intracellular *** speaking,all known AB_(5)-type toxins adopt similar structural architectures and employ similar mechanisms of binding,entering and trafficking within host *** this,there is a remarkable amount of diversity amongst AB_(5)-type toxins;this includes different toxin families with unrelated activities,as well as variation within families that can have profound functional *** this review,we discuss the diversity that exists amongst characterized AB_(5)-type toxins,with an emphasis on the genetic and functional variability within AB_(5) toxin families,how this may have evolved,and its impact on human disease.

关键词： Bacterial pathogenesis Pathogen evolution Ab-type toxins Ab5-type toxins Shiga toxin cholera toxin Heat-labile toxin Pertussis toxin Typhoid toxin ArtAB toxin

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Growth hormone regulates intestinal ion transport through a modulation of the constitutive nitric oxide synthase-nitric oxide-cAMP pathway

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World Journal of Gastroenterology 2006年第29期12卷 4710-4715页

作者： Roberto Berni Canani Pia Cirillo Giuseppe Mallardo Vittoria Buccigrossi Annalisa Passariello Serena Ruotolo Giulio De Marco Francesco Porcaro Alfredo Guarino Department of Pediatrics University Federico Ⅱ Naples 80131 Italy

AIM： Growth hormone （GH） directly interacts with the enterocyte stimulating ion absorption and reducing ion secretion induced by agonists of cAMR Since nitric oxide （NO） is involved in the regulation of transepithelial ion transport and acts as a second messenger for GH hemodynamic effects, we tested the hypothesis that NO may be involved in the resulting effects of GH on intestinal ion transport. METHODS： Electrical parameters reflecting transepithelial ion transport were measured in Caco-2 cell monolayers mounted in Ussing chambers and exposed to GH and cholera toxin （CT） alone or in combination, in the presence or absence of the NO synthase （NOS） inhibitor, Nω-nitro-L-arginine methyl ester （L-NAME）. Similar experiments were conducted to determine cAMP and nitrite/nitrate concentrations. NOS expression was assayed by Western blot analysis. RESULTS： L-NAME causes total abrogation of absorptive and antisecretory effects by GH on intestinal ion transport, In addition, L-NAME was able to inhibit the GH-effects on intracellular cAMP concentration under basal conditions and in response to CT, GH induced a Ca^2＋ -dependent increase of nitrites/nitrates production, indicating the involvement of the constitutive rather than the inducible NOS isoform, which was directly confirmed by Western blot analysis. CONCLUSION： These results suggest that the GH effects on intestinal ion transport, either under basal conditions or in the presence of cAMP-stimulated ion secretion, are mediated at an intracellular level by the activity of cNOS.

关键词： Nitric oxide synthase cholera toxin Intestinal ion secretion cAMP Enterocyte

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Calcium-sensing receptor: A new target for therapy of diarrhea

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World Journal of Gastroenterology 2016年第9期22卷 2711-2724页

作者： Sam Xianjun Cheng Department of Pediatrics Gastroenterology Hepatology and Nutrition University of Florida

Management of acute diarrhea remains a global challenge, particularly in resource-limiting countries. Oral rehydration solution (ORS), a passive rehydrating therapy developed approximately 40 years ago, remains the mainstay treatment. Although ORS is effective for hydration, since it does not inhibit enterotoxin-mediated excessive secretion, reduced absorption and compromised barrier function - the primary mechanisms of diarrhea, ORS does not offer a rapid relief of diarrhea symptom. There are a few alternative therapies available, yet the use of these drugs is limited by their expense, lack of availability and/or safety concerns. Novel anti-diarrheal therapeutic approaches, particularly those simple affordable therapies, are needed. This article explores intestinal calcium-sensing receptor (CaSR), a newly uncovered target for therapy of diarrhea. Unlike others, targeting this host antidiarrheal receptor system appears “all-inclusive”: it is anti-secretory, pro-absorptive, anti-motility, and anti-inflammatory. Thus, activating CaSR reverses changes of both secretory and inflammatory diarrheas. Considering its unique property of using simple nutrients such as calcium, polyamines, and certain amino acids/oligopeptides as activators, it is possible that through targeting of CaSR with a combination of specific nutrients, novel oral rehydrating solutions that are inexpensive and practical to use in all countries may be developed.

关键词： Secretory diarrhea Inflammatory diarrhea Oral rehydration solution Anti-secretory Pro-absorptive Intestinal permeability Intestinal barrier function Enteric nervous system cholera toxin Escherichia coli heat stable toxin

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A safe and simple culture method for human melanocytes

A safe and simple culture method for human melanocytes

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International Forum 2003 Academic Conference of Dermatology of the Integration of TCM with Western Medicine

作者： Lu Tao,Gao Tianwen, Liu Yufeng, Li Chunying, Li Qiang,Gao Ge,Cao Yun-xin Dermatology Center of the Chinese PLA, Xijing Hospital, the Fourth Military Medical University, Xi''an Shaanxi 710032, China. Department of Immunology, the Fourth Military Medical University, Xi'an Shaanxi 710033, China

Objective: To establish a safe and simple method for humanmelanocytes culture in vitro. Methods:A pure culture of normal epidermal melanocytes in vitro wasprocessed in a medium which inculude basic fibroblast growth factor(bFGF) and cholera toxin(CT). Subpassaged and cultured in the mediumplus 10% heat-inactivated fetal calf serum, the morphology, function,

关键词： melanocyte culture basic fibroblast growth factor cholera toxin

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