RESUMO
BACKGROUND: Sudden temperature drops, resulting from extreme weather events, often occur during the boll-setting period of cotton in Xinjiang, China, causing decreased expression of Bacillus thuringiensis (Bt) insecticidal proteins in cotton bolls. The precise threshold temperatures and durations that lead to significant changes in Cry1Ac endotoxin levels under low temperatures remain unclear. To address this, we investigated the effects of different temperatures and stress durations on Cry1Ac endotoxin levels in cotton bolls. In 2020-2021, two Bt transgenic cotton varieties, conventional Sikang1 and hybrid Sikang3, were selected as experimental materials. Various low temperatures (ranging from 16 to 20 °C) with different durations (12 h, 24 h and 48 h) were applied during the peak boll-setting period. RESULTS: As the temperature decreased, the Cry1Ac endotoxin content in the boll shell, fiber, and seed exhibited a declining trend. Moreover, the threshold temperature which caused a significant reduction in Cry1Ac endotoxin content increased with the prolonged duration of low-temperature stress. Among the components of cotton bolls, seeds were most affected by low-temperature stress, with the threshold temperature for a significant reduction in Cry1Ac endotoxin content ranging from 17 °C to 19 °C. Correlation analysis indicated that low temperatures led to a decrease in protein synthesis capacity and an increase in degradation ability, resulting in reduced Cry1Ac endotoxin content. Pathway analysis revealed that both free amino acid and peptidase had significant negative effects on Cry1Ac endotoxin content. CONCLUSION: In summary, when the daily average temperature was ≤ 19 °C, implementing cultural practices to reduce free amino acid content and peptidase activity could serve as effective cold defense strategies for Bt cotton production.
Assuntos
Toxinas de Bacillus thuringiensis , Proteínas de Bactérias , Temperatura Baixa , Endotoxinas , Gossypium , Proteínas Hemolisinas , Nitrogênio , Sementes , Gossypium/genética , Gossypium/metabolismo , Proteínas Hemolisinas/metabolismo , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Sementes/metabolismo , Nitrogênio/metabolismo , Plantas Geneticamente Modificadas , Bacillus thuringiensisRESUMO
BACKGROUND: A cost-effective Escherichia coli expression system has gained popularity for producing virus-like particle (VLP) vaccines. However, the challenge lies in balancing the endotoxin residue and removal costs, as residual endotoxins can cause inflammatory reactions in the body. RESULTS: In this study, porcine parvovirus virus-like particles (PPV-VLPs) were successfully assembled from Decreased Endotoxic BL21 (BL21-DeE), and the effect of structural changes in the lipid A of BL21 on endotoxin activity, immunogenicity, and safety was investigated. The lipopolysaccharide purified from BL21-DeE produced lower IL-6 and TNF-α than that from wild-type BL21 (BL21-W) in both RAW264.7 cells and BALB/c mice. Additionally, mice immunized with PPV-VLP derived form BL21-DeE (BL21-DeE-VLP) showed significantly lower production of inflammatory factors and a smaller increase in body temperature within 3 h than those immunized with VLP from BL21-W (BL21-W-VLP) and endotoxin-removed VLP (ReE-VLP). Moreover, mice in the BL21-DeE-VLP immunized group had similar levels of serum antibodies as those in the BL21-W-VLP group but significantly higher levels than those in the ReE-VLP group. Furthermore, the liver, lungs, and kidneys showed no pathological damage compared with the BL21-W-VLP group. CONCLUSION: Overall, this study proposes a method for producing VLP with high immunogenicity and minimal endotoxin activity without chemical or physical endotoxin removal methods. This method could address the issue of endotoxin residues in the VLP and provide production benefits.
Assuntos
Endotoxinas , Escherichia coli , Lipídeo A , Camundongos Endogâmicos BALB C , Parvovirus Suíno , Vacinas de Partículas Semelhantes a Vírus , Animais , Camundongos , Escherichia coli/genética , Escherichia coli/metabolismo , Parvovirus Suíno/imunologia , Parvovirus Suíno/genética , Vacinas de Partículas Semelhantes a Vírus/imunologia , Endotoxinas/imunologia , Células RAW 264.7 , Lipídeo A/imunologia , Lipídeo A/análogos & derivados , Interleucina-6/imunologia , Fator de Necrose Tumoral alfa/metabolismo , Feminino , Suínos , Lipopolissacarídeos/imunologiaRESUMO
Exopolysaccharides (EPSs) are carbohydrate polymers that are synthesized and secreted into the extracellular during the growth of microorganisms. Bacillus thuringiensis (Bt) is a type of entomopathogenic bacterium, that produces various insecticidal proteins and EPSs. In our previous study, the EPSs produced by Bt strains were first found to enhance the toxicity of insecticidal crystal proteins against Plutella xylostella. However, the response of the intestinal bacterial communities of P. xylostella under the action of EPSs is still unelucidated. In this study, 16S rRNA amplicon sequencing was used to characterize the intestinal bacterial communities in P. xylostella treated with EPSs alone, Cry1Ac protoxin alone, and both the Cry1Ac protoxin and EPSs. Compared with the control group, alpha diversity indices, the Chao1 and ACE indices were significantly altered after treatment with EPSs alone, and no significant difference was observed between the groups treated with Cry1Ac protoxin alone and Cry1Ac protoxin + EPSs. However, compared with the gut bacterial community feeding on Cry1Ac protoxin alone, the relative abundance of 31 genera was significantly changed in the group treated with Cry1Ac protoxin and EPSs. The intestinal bacteria, through the oral of Cry1Ac protoxin and EPSs, significantly enhanced the toxicity of the Cry1Ac protoxin towards the axenic P. xylostella. In addition, the relative abundance of the 16S rRNA gene in the chloroplasts of Brassica campestris decreased after adding EPSs. Taken together, these results show the vital contribution of the gut microbiota to the Bt strain-killing activity, providing new insights into the mechanism of the synergistic insecticidal activity of Bt proteins and EPSs.
Assuntos
Toxinas de Bacillus thuringiensis , Proteínas de Bactérias , Endotoxinas , Microbioma Gastrointestinal , Proteínas Hemolisinas , Mariposas , Animais , Microbioma Gastrointestinal/efeitos dos fármacos , Endotoxinas/genética , Proteínas Hemolisinas/genética , Proteínas Hemolisinas/farmacologia , Mariposas/efeitos dos fármacos , Mariposas/crescimento & desenvolvimento , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , RNA Ribossômico 16S/genética , Bacillus thuringiensis/genética , Inseticidas/farmacologiaRESUMO
The LAL test has been the "gold standard" for endotoxin testing ever since it was first published as USP Chapter <85> in 1980. Since then, a number of innovative methods have been proposed to augment or replace the LAL test. However novel an alternate test method might be, we must be cognizant of our obligation to patient safety and heed compendial and compliance requirements to demonstrate results equivalence between any candidate (alternate) method and a predicate (compendial) test method. The following discussion explores the concepts of "equivalent", "different" and "not different", proposes the use of a two one sided test (TOST) for the demonstration of equivalence and provides examples of calculations using commercially available software to assess data on alternative endotoxins detection methods that have been published in the public domain1.
Assuntos
Endotoxinas , Endotoxinas/análise , Humanos , Teste do Limulus/métodos , Contaminação de Medicamentos/prevenção & controle , Software , Reprodutibilidade dos TestesRESUMO
Infection during the perinatal period can adversely affect brain development, predispose infants to ischemic stroke and have lifelong consequences. We previously demonstrated that diet enriched in n-3 polyunsaturated fatty acids (n-3 PUFA) transforms brain lipid composition in the offspring and protects the neonatal brain from stroke, in part by blunting injurious immune responses. Critical to the interface between the brain and systemic circulation is the vasculature, endothelial cells in particular, that support brain homeostasis and provide a barrier to systemic infection. Here, we examined whether maternal PUFA-enriched diets exert reprograming of endothelial cell signalling in postnatal day 9 mice after modeling aspects of infection using LPS. Transcriptome analysis was performed on microvessels isolated from brains of pups from dams maintained on 3 different maternal diets from gestation day 1: standard, n-3 enriched or n-6 enriched diets. Depending on the diet, in endothelial cells LPS produced distinct regulation of pathways related to immune response, cell cycle, extracellular matrix, and angiogenesis. N-3 PUFA diet enabled higher immune reactivity in brain vasculature, while preventing imbalance of cell cycle regulation and extracellular matrix cascades that accompanied inflammatory response in standard diet. Cytokine analysis revealed a blunted LPS response in blood and brain of offspring from dams on n-3 enriched diet. Analysis of cerebral vasculature in offspring in vivo revealed no differences in vessel density. However, vessel complexity was decreased in response to LPS at 72 h in standard and n-6 diets. Thus, LPS modulates specific transcriptomic changes in brain vessels of offspring rather than major structural vessel characteristics during early life. N-3 PUFA-enriched maternal diet in part prevents an imbalance in homeostatic processes, alters inflammation and ultimately mitigates changes to the complexity of surface vessel networks that result from infection. Importantly, maternal diet may presage offspring neurovascular outcomes later in life.
Assuntos
Animais Recém-Nascidos , Ácidos Graxos Ômega-3 , Transcriptoma , Animais , Camundongos , Ácidos Graxos Ômega-3/administração & dosagem , Feminino , Gravidez , Lipopolissacarídeos/toxicidade , Camundongos Endogâmicos C57BL , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Efeitos Tardios da Exposição Pré-Natal/patologia , Inflamação/metabolismo , Inflamação/patologia , Encéfalo/metabolismo , Encéfalo/patologia , Endotoxinas/toxicidadeRESUMO
The extensive use of Bacillus thuringiensis (Bt) in pest management has driven the evolution of pest resistance to Bt toxins, particularly Cry1Ac. Effective management of Bt resistance necessitates a good understanding of which pest proteins interact with Bt toxins. In this study, we screened a Helicoverpa armigera larval midgut cDNA library and captured 208 potential Cry1Ac-interacting proteins. Among these, we further examined the interaction between Cry1Ac and a previously unknown Cry1Ac-interacting protein, HaDALP (H. armigera death-associated LIM-only protein), as well as its role in toxicology. The results revealed that HaDALP specifically binds to both the Cry1Ac protoxin and activated toxin, significantly enhancing cell and larval tolerance to Cry1Ac. Additionally, HaDALP was overexpressed in a Cry1Ac-resistant H. armigera strain. These findings reveal a greater number of Cry1Ac-interacting proteins than previously known and demonstrate, for the first time, that HaDALP reduces Cry1Ac toxicity by sequestering both the protoxin and activated toxin.
Assuntos
Toxinas de Bacillus thuringiensis , Proteínas de Bactérias , Endotoxinas , Proteínas Hemolisinas , Proteínas de Insetos , Inseticidas , Larva , Mariposas , Animais , Toxinas de Bacillus thuringiensis/metabolismo , Toxinas de Bacillus thuringiensis/toxicidade , Toxinas de Bacillus thuringiensis/química , Endotoxinas/metabolismo , Endotoxinas/genética , Endotoxinas/toxicidade , Proteínas Hemolisinas/metabolismo , Proteínas Hemolisinas/farmacologia , Proteínas Hemolisinas/toxicidade , Proteínas Hemolisinas/genética , Mariposas/metabolismo , Mariposas/efeitos dos fármacos , Mariposas/genética , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/toxicidade , Proteínas de Insetos/metabolismo , Proteínas de Insetos/genética , Larva/metabolismo , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Larva/genética , Inseticidas/toxicidade , Inseticidas/farmacologia , Inseticidas/química , Bacillus thuringiensis/química , Bacillus thuringiensis/metabolismo , Bacillus thuringiensis/genética , Resistência a Inseticidas/genética , Controle Biológico de Vetores , Helicoverpa armigeraRESUMO
Sepsis, one of the leading causes of death, is still lacking specific treatment. OXIRIS (BAXTER, Deerfield, IL, USA) is the first device allowing combined removal of endotoxins, inflammatory mediators and uremic toxins, alongside fluid balance control. Available data is very limited. This retrospective propensity score-matched cohort study of adult patients with septic shock aimed to evaluate septic shock duration and mortality in patients treated with either standard of care renal replacement therapy (RRT) or RRT with combined hemoadsorption, who were admitted to the interdisciplinary surgical intensive care unit at Heidelberg University Hospital during the years 2018 through 2021. Main outcomes were duration of shock, thirty-day mortality and plasma interleukin-6 levels before and after initiation of hemoadsorption. Included were 117 patients (female, 33%; male 67%); median age: 67 (16) years. After matching: 42 patients (female, 33%; male, 67%); mean age: 59.1 ± 13.8 years. There was no statistically significant difference in septic shock duration (p = 0.94; hazard ratio (HR) 0.97 (95% CI, 0.48-1.97)). Thirty-day survival analysis showed a non-statistically significant survival difference. (p = 0.063; HR 0.43 (95% CI, 0.17-1.09)). A post-hoc 90-day survival analysis revealed statistically significant longer survival and lower death hazard ratio in patients treated with RRT + HA (p = 0.037; HR = 0.42 (95% CI, 0.18-0.99). In conclusion, RRT with combined hemoadsorption of endotoxins, inflammatory mediators and uremic toxins is a modality worth further investigation.
Assuntos
Endotoxinas , Mediadores da Inflamação , Unidades de Terapia Intensiva , Terapia de Substituição Renal , Choque Séptico , Toxinas Urêmicas , Humanos , Choque Séptico/mortalidade , Choque Séptico/sangue , Choque Séptico/terapia , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Estudos Retrospectivos , Endotoxinas/sangue , Mediadores da Inflamação/sangue , Toxinas Urêmicas/sangue , Terapia de Substituição Renal/métodos , Interleucina-6/sangueRESUMO
Bacillus thuringiensis is the most widely used biopesticide, targets a diversity of insect pests belonging to several orders. However, information regarding the B. thuringiensis strains and toxins targeting Zeugodacus cucurbitae is very limited. Therefore, in the present study, we isolated and identified five indigenous B. thuringiensisstrains toxic to larvae of Z. cucurbitae. However, of five strains NBAIR BtPl displayed the highest mortality (LC50 = 37.3 µg/mL) than reference strain B. thuringiensis var. israelensis (4Q1) (LC50 = 45.41 µg/mL). Therefore, the NBAIR BtPl was considered for whole genome sequencing to identify the cry genes present in it. Whole genome sequencing of our strain revealed genome size of 6.87 Mb with 34.95% GC content. Homology search through the BLAST algorithm revealed that NBAIR BtPl is 99.8% similar to B. thuringiensis serovar tolworthi, and gene prediction through Prokka revealed 7406 genes, 7168 proteins, 5 rRNAs, and 66 tRNAs. BtToxin_Digger analysis of NBAIR BtPl genome revealed four cry gene families: cry1, cry2, cry8Aa1, and cry70Aa1. When tested for the presence of these four cry genes in other indigenous strains, results showed that cry70Aa1 was absent. Thus, the study provided a basis for predicting cry70Aa1 be the possible reason for toxicity. In this study apart from novel genes, we also identified other virulent genes encoding zwittermicin, chitinase, fengycin, and bacillibactin. Thus, the current study aids in predicting potential toxin-encoding genes responsible for toxicity to Z. cucurbitae and thus paves the way for the development of B. thuringiensis-based formulations and transgenic crops for management of dipteran pests.
Assuntos
Bacillus thuringiensis , Proteínas de Bactérias , Genoma Bacteriano , Sequenciamento Completo do Genoma , Bacillus thuringiensis/genética , Animais , Proteínas de Bactérias/genética , Toxinas de Bacillus thuringiensis/genética , Endotoxinas/genética , Controle Biológico de Vetores , Tephritidae/genética , Tephritidae/microbiologia , Proteínas Hemolisinas/genética , Larva/genética , FilogeniaRESUMO
Bacillus thuringiensis (Bt) is widely used as a biopesticide worldwide. To date, at least eight pest species have been found to be resistant to Bt in the field. As the first pest that was reported having resistance to Bt in the field, considerable research has been done on the mechanisms of Bt resistance in Plutella xylostella. However, whether the acquisition of Bt resistance by P. xylostella comes at a fitness cost is also a valuable question. In this study, Aminopeptidase-N 2 (APN2), a Cry toxin receptor gene of P. xylostella, was knocked down by RNA interference, resulting in improved resistance to Cry1Ac. It was also found that larval mortality of APN2 knockdown P. xylostella was significantly higher than that of the control, while the pupation rate, pupal weight, eclosion rate, fecundity (egg/female), hatchability, and female adult longevity were significantly lower in APN2 knockdown P. xylostella than in the control. These results illustrate that if Cry1Ac resistance was obtained only through the reduction of APN2 expression, P. xylostella would need to incur some fitness costs for it.
Assuntos
Toxinas de Bacillus thuringiensis , Proteínas de Bactérias , Antígenos CD13 , Proteínas Hemolisinas , Proteínas de Insetos , Resistência a Inseticidas , Mariposas , Animais , Feminino , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Antígenos CD13/metabolismo , Antígenos CD13/genética , Endotoxinas/farmacologia , Proteínas Hemolisinas/farmacologia , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Resistência a Inseticidas/genética , Larva/crescimento & desenvolvimento , Larva/genética , Mariposas/genética , Mariposas/crescimento & desenvolvimento , Mariposas/enzimologia , Interferência de RNARESUMO
Genetically modified (GM) crops, expressing Bacillus thuringiensis (Bt) insecticidal toxins, have substantially transformed agriculture. Despite rapid adoption, their environmental and economic benefits face scrutiny due to unsustainable agricultural practices and the emergence of resistant pests like Spodoptera frugiperda, known as the fall armyworm (FAW). FAW's adaptation to Bt technology in corn and cotton compromises the long-term efficacy of Bt crops. To advance the understanding of the genetic foundations of resistance mechanisms, we conducted an exploratory comparative transcriptomic analysis of two divergent FAW populations. One population exhibited practical resistance to the Bt insecticidal proteins Cry1A.105 and Cry2Ab2, expressed in the genetically engineered MON-89Ø34 - 3 maize, while the other population remained susceptible to these proteins. Differential expression analysis supported that Cry1A.105 and Cry2Ab2 significantly affect the FAW physiology. A total of 247 and 254 differentially expressed genes were identified in the Cry-resistant and susceptible populations, respectively. By integrating our findings with established literature and databases, we underscored 53 gene targets potentially involved in FAW's resistance to Cry1A.105 and Cry2Ab2. In particular, we considered and discussed the potential roles of the differentially expressed genes encoding ABC transporters, G protein-coupled receptors, the P450 enzymatic system, and other Bt-related detoxification genes. Based on these findings, we emphasize the importance of exploratory transcriptomic analyses to uncover potential gene targets involved with Bt insecticidal proteins resistance, and to support the advantages of GM crops in the face of emerging challenges.
Assuntos
Toxinas de Bacillus thuringiensis , Proteínas de Bactérias , Endotoxinas , Proteínas Hemolisinas , Resistência a Inseticidas , Spodoptera , Transcriptoma , Spodoptera/efeitos dos fármacos , Spodoptera/genética , Animais , Endotoxinas/genética , Endotoxinas/farmacologia , Proteínas Hemolisinas/genética , Proteínas Hemolisinas/farmacologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Resistência a Inseticidas/genética , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/parasitologia , Zea mays/genética , Zea mays/parasitologia , Perfilação da Expressão GênicaRESUMO
Sepsis-associated encephalopathy (SAE) is associated with increased risk of long-term cognitive impairment. SAE is driven, at least in part, by brain endothelial dysfunction in response to systemic cytokine signaling. However, the mechanisms driving SAE and its consequences remain largely unknown. Here, we performed translating ribosome affinity purification and RNA-sequencing (TRAP-seq) from the brain endothelium to determine the transcriptional changes after an acute endotoxemic (LPS) challenge. LPS induced a strong acute transcriptional response in the brain endothelium that partially correlates with the whole brain transcriptional response and suggested an endothelial-specific hypoxia response. Consistent with a crucial role for IL-6, loss of the main regulator of this pathway, SOCS3, leads to a broadening of the population of genes responsive to LPS, suggesting that an overactivation of the IL-6/JAK/STAT3 pathway leads to an increased transcriptional response that could explain our prior findings of severe brain injury in these mice. To identify any potential sequelae of this acute response, we performed brain TRAP-seq following a battery of behavioral tests in mice after apparent recovery. We found that the transcriptional response returns to baseline within days post-challenge, but reductions in gene expression regulating protein translation and respiratory electron transport remained. We observed that mice that recovered from the endotoxemic shock showed mild, sex-dependent cognitive impairment, suggesting that the acute brain injury led to sustained effects. A better understanding of the transcriptional and non-transcriptional changes in response to shock is needed in order to prevent and/or revert the devastating consequences of septic shock.
Assuntos
Encéfalo , Disfunção Cognitiva , Lipopolissacarídeos , Camundongos Endogâmicos C57BL , Animais , Masculino , Encéfalo/metabolismo , Encéfalo/efeitos dos fármacos , Disfunção Cognitiva/metabolismo , Feminino , Lipopolissacarídeos/farmacologia , Camundongos , Encefalopatia Associada a Sepse/metabolismo , Endotélio/metabolismo , Endotélio/efeitos dos fármacos , Endotoxinas/farmacologia , Endotoxinas/toxicidadeRESUMO
Uveitis is a group of inflammatory ocular pathologies. Endotoxin-Induced Uveitis (EIU) model represent a well-known model induced by administration of Lipopolysaccharide (LPS). The aim is to characterize two models of EIU through two routes of administration with novel noninvasive imaging techniques. 29 rats underwent Intraocular Pressure (IOP) measurements, Optical Coherence Tomography (OCT), proteomic analysis, and Positron Emission Tomography and Computed Tomography (PET/CT). Groups included healthy controls (C), BSS administered controls (Ci), systemically induced EIU with LPS (LPSs), and intravitreally induced EIU with LPS (LPSi) for IOP, OCT, and proteomic studies. For 18F-FDG PET/CT study, animals were divided into FDG-C, FDG-LPSs and FDG-LPSi groups and scanned using a preclinical PET/CT system. LPSi animals exhibited higher IOP post-induction compared to C and LPSs groups. LPSi showed increased cellular infiltrate, fibrotic membranes, and iris inflammation. Proinflammatory proteins were more expressed in EIU models, especially LPSi. PET/CT indicated higher eye uptake in induced models compared to FDG-C. FDG-LPSi showed higher eye uptake than FDG-LPSs but systemic uptake was higher in FDG-LPSs due to generalized inflammation. OCT is valuable for anterior segment assessment in experimental models. 18F-FDG PET/CT shows promise as a noninvasive biomarker for ocular inflammatory diseases. Intravitreal induction leads to higher ocular inflammation. These findings offer insights for future inflammatory disease research and drug studies.
Assuntos
Modelos Animais de Doenças , Pressão Intraocular , Lipopolissacarídeos , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Proteômica , Tomografia de Coerência Óptica , Uveíte , Animais , Uveíte/induzido quimicamente , Uveíte/diagnóstico por imagem , Uveíte/metabolismo , Tomografia de Coerência Óptica/métodos , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Proteômica/métodos , Lipopolissacarídeos/toxicidade , Pressão Intraocular/efeitos dos fármacos , Ratos , Masculino , Fluordesoxiglucose F18/administração & dosagem , Endotoxinas/toxicidade , Ratos Sprague-DawleyRESUMO
Despite the re-emergence of the pioneering "Coley's toxin" concept in anti-cancer immune therapies highlighted by check-point inhibitors and CAR-T approaches, fundamental mechanisms responsible for the immune-enhancing efficacy of low-dose "Coley's toxin" remain poorly understood. This study examines the novel reprogramming of immune-enhancing neutrophils by super-low dose endotoxin conducive for anti-cancer therapies. Through integrated analyses including scRNAseq and functional characterizations, we examined the efficacy of reprogrammed neutrophils in treating experimental cancer. We observed that neutrophils trained by super-low dose endotoxin adopt a potent immune-enhancing phenotype characterized by CD177loCD11bloCD80hiCD40hiDectin2hi. Both murine and human neutrophils trained by super-low dose endotoxin exhibit relieved suppression of adaptive T cells as compared to un-trained neutrophils. Functionally, neutrophils trained by super-low dose endotoxin can potently reduce tumor burden when transfused into recipient tumor-bearing mice. Mechanistically, Super-low dose endotoxin enables the generation of immune-enhancing neutrophils through activating STAT5 and reducing innate suppressor IRAK-M. Together, our data clarify the long-held mystery of "Coley's toxin" in rejuvenating anti-tumor immune defense, and provide a proof-of-concept in developing innate neutrophil-based anti-tumor therapeutics.
Assuntos
Endotoxinas , Neutrófilos , Neutrófilos/imunologia , Animais , Camundongos , Humanos , Neoplasias/imunologia , Neoplasias/terapia , Neoplasias/tratamento farmacológico , Camundongos Endogâmicos C57BL , Fator de Transcrição STAT5/metabolismo , Linhagem Celular TumoralRESUMO
Exposure to particulate matter and endotoxin can lead to acute and chronic respiratory problems in workers. A study was conducted to quantify particulate matter with an aerodynamic diameter of ≤10 µm (PM10) and endotoxin levels in rice mills in northeast India. Sixty-four PM10 dust samples were collected from eight rice mills at two locations: the feeding and polishing sections for two varieties of paddy: Ranjit and Hali. Endotoxin exposures were analyzed using the Limulus Amoebocyte Lysate (LAL) gel clot test. The results showed that the geometric mean of the 8-h time-weighted average (TWA) PM10 dust concentration and endotoxin level in the rice mills were 10.69 mg/m³ and 2.2 EU/m³, respectively. Dust and endotoxin exposure were higher in the feeding section than in the polishing section. Endotoxin exposure in the feeding section during the milling of the Hali variety of paddy was 56.0 % higher than the milling of the Ranjit variety. Additionally, endotoxin exposure during the milling of the Hali variety was 24.2 % higher than that of the milling of the Ranjit variety in the polishing section. The dust exposure in the rice mills was 194.5 % higher than the standards set up by the United States Environmental Protection Agency. However, the exposure to endotoxin in rice mills was approximately 40.10 times below the recommended limit of 90 EU/m3.
Assuntos
Poeira , Endotoxinas , Exposição Ocupacional , Oryza , Endotoxinas/análise , Índia , Poeira/análise , Oryza/química , Exposição Ocupacional/análise , Humanos , Material Particulado/análise , Poluentes Ocupacionais do Ar/análise , Monitoramento AmbientalRESUMO
Cry toxins, produced by the bacterium Bacillus thuringiensis, are of significant agronomic value worldwide due to their potent and highly specific activity against various insect orders. However, some of these pore-forming toxins display specific activity against a range of human cancer cells whilst possessing no known insecticidal activity; Cry41Aa is one such toxin. Cry41Aa has similarities to its insecticidal counterparts in both its 3-domain toxic core structure and pore-forming abilities, but how it has evolved to target human cells is a mystery. This work shows that some insecticidal Cry toxins can enhance the toxicity of Cry41Aa against hepatocellular carcinoma cells, despite possessing no intrinsic toxicity themselves. This interesting crossover is not limited to human cancer cells, as Cry41Aa was found to inhibit some Aedes-active Cry toxins in mosquito larval assays. Here, we present findings that suggest that Cry41Aa shares a receptor with several insecticidal toxins, indicating a stronger evolutionary relationship than their divergent activities might suggest.
Assuntos
Toxinas de Bacillus thuringiensis , Bacillus thuringiensis , Proteínas de Bactérias , Endotoxinas , Proteínas Hemolisinas , Humanos , Endotoxinas/química , Endotoxinas/genética , Endotoxinas/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/química , Bacillus thuringiensis/genética , Bacillus thuringiensis/metabolismo , Toxinas de Bacillus thuringiensis/metabolismo , Proteínas Hemolisinas/química , Proteínas Hemolisinas/genética , Proteínas Hemolisinas/metabolismo , Proteínas Hemolisinas/farmacologia , Animais , Inseticidas/química , Inseticidas/farmacologia , Antineoplásicos/farmacologia , Antineoplásicos/química , Aedes/efeitos dos fármacos , Aedes/genética , Linhagem Celular TumoralRESUMO
Bacillus thuringiensis is a Gram-positive entomopathogenic bacterium that produces different pesticidal proteins: vegetative insecticidal proteins (Vpb1/Vpa2, Vip3, and Vpb4) during vegetative growth, which are secreted to the culture medium, and δ-endotoxins (Cry and Cyt) during sporulation, which accumulate into parasporal crystals. Cyt proteins are the smaller subset of δ-endotoxins targeting Diptera species. While Cry and Vip3 proteins undergo positive selection, our analysis suggests that Cyt proteins evolve following a conservative trend driven negative (purifying) selection.
Assuntos
Toxinas de Bacillus thuringiensis , Bacillus thuringiensis , Proteínas de Bactérias , Endotoxinas , Proteínas Hemolisinas , Seleção GenéticaRESUMO
Here, we present the whole genome sequence of Bt S2160-1, a potential alternative to the mosquitocidal model strain, Bti. One chromosome genome and four mega-plasmids were contained in Bt S2160-1, and 13 predicted genes encoding predicted insecticidal crystal proteins were identified clustered on one plasmid pS2160-1p2 containing two pathogenic islands (PAIs) designed as PAI-1 (Cry54Ba, Cry30Ea4, Cry69Aa-like, Cry50Ba2-like, Cry4Ca1-like, Cry30Ga2, Cry71Aa-like, Cry72Aa-like, Cry70Aa-like, Cyt1Da2-like and Vpb4C1-like) and PAI-2 (Cyt1Aa-like, and Tpp80Aa1-like). The clusters appear to represent mosquitocidal toxin islands similar to pathogenicity islands. Transcription/translation of 10 of the 13 predicted genes was confirmed by whole-proteome analysis using LTQ-Orbitrap LC-MS/MS. In summary, the present study identified the existence of a mosquitocidal toxin island in Bacillus thuringiensis, and provides important genomic information for understanding the insecticidal mechanism of B. thuringiensis.
Assuntos
Bacillus thuringiensis , Proteínas de Bactérias , Inseticidas , Proteômica , Bacillus thuringiensis/genética , Bacillus thuringiensis/metabolismo , Proteômica/métodos , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Inseticidas/farmacologia , Sequenciamento Completo do Genoma/métodos , Genoma Bacteriano , Endotoxinas/genética , Toxinas de Bacillus thuringiensis , Ilhas Genômicas , Proteoma , Plasmídeos/genética , Espectrometria de Massas em Tandem , Animais , Proteínas Hemolisinas/genéticaRESUMO
Metabolic endotoxemia is a severe health problem for residents in developed countries who follow a Western diet, disrupting intestinal microbiota and the whole organism's homeostasis. Although the effect of endotoxin on the human immune system is well known, its long-term impact on the human body, lasting many months or even years, is unknown. This is due to the difficulty of conducting in vitro and in vivo studies on the prolonged effect of endotoxin on the central nervous system. In this article, based on the available literature, we traced the path of endotoxin from the intestines to the blood through the intestinal epithelium and factors promoting the development of metabolic endotoxemia. The presence of endotoxin in the bloodstream and the inflammation it induces may contribute to lowering the blood-brain barrier, potentially allowing its penetration into the central nervous system; although, the theory is still controversial. Microglia, guarding the central nervous system, are the first line of defense and respond to endotoxin with activation, which may contribute to the development of neurodegenerative diseases. We traced the pro-inflammatory role of endotoxin in neurodegenerative diseases and its impact on the epigenetic regulation of microglial phenotypes.
Assuntos
Endotoxemia , Endotoxinas , Microbioma Gastrointestinal , Doenças Neurodegenerativas , Endotoxemia/metabolismo , Endotoxemia/etiologia , Humanos , Doenças Neurodegenerativas/metabolismo , Doenças Neurodegenerativas/etiologia , Animais , Endotoxinas/metabolismo , Microglia/metabolismo , Microglia/patologia , Barreira Hematoencefálica/metabolismo , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Mucosa Intestinal/microbiologia , Inflamação/metabolismoRESUMO
Bacillus thuringiensis (Bt) toxins are potential alternatives to synthetic insecticides for the control of lepidopteran pests. However, the evolution of resistance in some insect pest populations is a threat and can reduce the effectiveness of Bt toxins. In this review, we summarize the results of 161 studies from 20 countries reporting field and laboratory-evolved resistance, cross-resistance, and inheritance, mechanisms, and fitness costs of resistance to different Bt toxins. The studies refer mainly to insects from the United States of America (70), followed by China (31), Brazil (19), India (12), Malaysia (9), Spain (3), and Australia (3). The majority of the studies revealed that most of the pest populations showed susceptibility and a lack of cross-resistance to Bt toxins. Factors that delay resistance include recessive inheritance of resistance, the low initial frequency of resistant alleles, increased fitness costs, abundant refuges of non-Bt, and pyramided Bt crops. The results of field and laboratory resistance, cross-resistance, and inheritance, mechanisms, and fitness cost of resistance are advantageous for predicting the threat of future resistance and making effective strategies to sustain the effectiveness of Bt crops.
Assuntos
Toxinas de Bacillus thuringiensis , Bacillus thuringiensis , Resistência a Inseticidas , Controle Biológico de Vetores , Animais , Resistência a Inseticidas/genética , Bacillus thuringiensis/genética , Lepidópteros/efeitos dos fármacos , Aptidão Genética , Inseticidas/farmacologia , Endotoxinas/genéticaRESUMO
BACKGROUND: Transgenic insect-resistant rice offers an environmentally friendly approach to mitigate yield losses caused by lepidopteran pests, such as stem borers. Bt (Bacillus thuringiensis) genes encode insecticidal proteins and are widely used to confer insect resistance to genetically modified crops. This study investigated the integration, inheritance, and expression characteristics of codon-optimised synthetic Bt genes, cry1C* and cry2A*, in transgenic early japonica rice lines. METHODS: The early japonica rice cultivar, Songgeng 9 (Oryza sativa), was transformed with cry1C* or cry2A*, which are driven by the ubi promoter via Agrobacterium tumefaciens-mediated transformation. Molecular analyses, including quantitative PCR (qPCR), enzyme-linked immunosorbent assay (ELISA), and Southern blot analysis were performed to confirm transgene integration, inheritance, transcriptional levels, and protein expression patterns across different tissues and developmental stages. RESULTS: Stable transgenic early japonica lines exhibiting single-copy transgene integration were established. Transcriptional analysis revealed variations in Bt gene expression among lines, tissues, and growth stages, with higher expression levels observed in leaves than in other organs. Notably, cry2A* exhibited consistently higher mRNA and protein levels than cry1C* across all examined tissues and developmental time points. Bt protein accumulation followed the trend of leaves > stem sheaths > young panicles > brown rice, with peak expression during the filling stage in the vegetative tissues. CONCLUSIONS: Synthetic cry2A* displayed markedly elevated transcription and translation compared to cry1C* in the transgenic early japonica rice lines examined. Distinct spatiotemporal patterns of Bt gene expression were elucidated, providing insights into the potential insect resistance conferred by these genes in rice. These findings will contribute to the development of insect-resistant japonica rice varieties and facilitate the rational deployment of Bt crops.