Expression of a viral ecdysteroid UDP-glucosyltransferase enhanced the insecticidal activity of the insect pathogenic fungus Beauveria bassiana.

BACKGROUND: Entomopathogenic fungi, such as Beauveria bassiana, hold promise as biological control agents against insect pests. However, the efficacy of these fungi can be hindered by insect immune responses. One strategy to enhance fungal virulence is to manipulate host immune by targeting key regulatory molecules like 20-hydroxyecdysone (20E). RESULTS: In this study, we engineered B. bassiana strains to constitutively express the enzyme ecdysteroid UDP-glucosyltransferase (EGT), which inactivates 20E, a crucial insect molting hormone. The engineered strain Bb::EGT-1 exhibited robust expression of EGT, leading to a significant reduction in insect 20E levels upon infection. Moreover, infection with Bb::EGT-1 resulted in accelerated larval mortality. Immune responses analysis revealed repression of insect immune response genes and decreased phenoloxidase (PO) activity in larvae infected with Bb::EGT-1. Microbiome analysis indicated alterations in bacterial composition within infected insects, with increased abundance observed during infection with Bb::EGT-1. Additionally, the presence of bacteria hindered hyphal emergence from insect cadavers, suggesting a role for microbial competition in fungal dissemination. CONCLUSIONS: Constitutive expression of EGT in B. bassiana enhances fungal virulence by reducing insect 20E levels, suppressing immune responses, and altering the insect microbiome. These findings highlighted the potential of engineered fungi as effective biocontrol agents against insect pests and provide insights into the complex interactions between entomopathogenic fungi, their hosts, and associated microbes. © 2024 Society of Chemical Industry.

Manipulation of host ecdysteroid hormone levels facilitates infection by the fungal insect pathogen, Metarhizium rileyi.

Entomopathogenic fungi such as Metarhizium rileyi and Beauveria bassiana are widely used insect biological control agents. Little, however, is known concerning genetic or enzymatic factors that differentiate the mechanisms employed by these two fungal pathogens to infect target hosts. Infection by either of these organisms is known to increase levels of the growth and molting hormone, ecdysone, which also regulates the expression of a number of innate immune pathways. M. rileyi, but not B. bassiana, has apparently evolved an ecdysteroid-22-oxidase (MrE22O) that inactivate ecdysone. We show that deletion of MrE22O impaired virulence compared with the wild-type strain, with an increase in ecdysone titer seen in hosts that was coupled to an increase in the expression of antimicrobial genes. An M. rileyi strain engineered to overexpress MrE22O (MrE22OOE ), as well as trans-expression in B. bassiana (Bb::MrE220OE ) resulted, in strains displaying enhanced virulence and dampening of host immune responses compared with their respective wild-type parental strains. These results indicate that ecdysone plays an important role in mediating responses to fungal infection and that some insect pathogenic fungi have evolved mechanisms for targeting this hormone as a means for facilitating infection.

Prevalence, Predictors, and Clinical Presentation of Acute Pericardial Effusion Following Percutaneous Coronary Intervention.

Background: Iatrogenic pericardial effusion (PE) has been demonstrated to lead to cardiac injury as a sign of systemic inflammatory response. Objectives: This study sought to determine the anatomical characteristics and clinical presentation associated with PE after percutaneous coronary intervention (PCI) by using echocardiography. Methods: The clinical outcomes of all patients with coronary artery disease who underwent PCI from July 2014 to December 2018 were evaluated. The quantitative and qualitative analyses of PE were performed. The associations between the presence of PE and procedural factors were also evaluated. Results: A total of 882 patients were enrolled. PE was found in 144 patients (16.3%) and was mostly located in the anterior pericardium at low amounts. The serum levels of high-sensitive C-reaction protein before PCI and troponin T in the group with PE after PCI were significantly higher than those in the group without PE (p < 0.0001). The presence of PE was associated with the procedural time (OR = 1.02, p = 0.035) and the degree of interventional complexity (multiple vessels OR = 1.89, p = 0.014; chronic total occlusion OR = 2.04, p = 0.005; and PCI with rotational atherectomy OR = 1.15, p = 0.011) independent of the number of culprit vessels and stents. During 1-year follow-up, a significantly higher number of cardiac deaths (3) and myocardial infarctions (8) occurred in patients with PE than in patients without PE (P < 0.05). Conclusion: Post-PCI acute PE was frequent, generally mild, mainly asymptomatic, and independently associated with procedural time and complexity. This effusion, which is considered as a cardiac damage marker, could be a predominant clinical sign for long-term prognosis.

Chemokine CX3CL1 and its receptor CX3CR1 are associated with human atherosclerotic lesion volnerability.

BACKGROUND: CX3CL1 and its receptor CX3CR1 have been emphasized in atherosclerosis recently. In this study we investigated the role of the chemokines CX3CL1 and their receptor CX3CR1 in atherogenesis and identified whether the genetic variations in CX3CL1 and CX3CR1 impacted the atherosclerosis process in coronary artery disease (CAD) or not. METHODS: CX3CL1/CX3CR1 expression in coronary and carotid artery specimens were analysed by immunohistochemistry. CX3CR1 expression on CD4(+) CD28(-) T cells was analysed by flow cytometry. We also screened for CX3CL1/CX3CR1 sequence variations selected from the hapmap database and examined the association between CX3CL1/CX3CR1 and CAD in the Chinese Han population. RESULTS: Immunohistochemical staining of tissue from CAD patients showed increased CX3CL1/CX3CR1 expression in atherosclerotic coronary and carotid artery plaques compared with normal arteries. CX3CL1/CX3CR1 expression was correlated with the severity of the atherosclerosis lesion. Patients with CAD also showed an increased number of CX3CR1(+) CD4(+) CD28(-) T cells. Compared with their corresponding wild-type genotypes, CX3CL1 rs170364 and CX3CR1 rs17793056 were associated with increased susceptibility to CAD. CONCLUSIONS: CX3CL1 and CX3CR1 may contribute to the formation of coronary atherosclerotic plaque in CAD.CX3CL1 rs170364 and CX3CR1 rs17793056 polymorphisms may be independent genetic risk factors for CAD.

Contribution of homeostatic chemokines CCL19 and CCL21 and their receptor CCR7 to coronary artery disease.

OBJECTIVE: Our aim was to identify the role of the homeostatic chemokines CCL19 and CCL21 and their common receptor CCR7 in atherogenesis and to study the relationships between CCL19, CCL21, and CCR7 gene variants and coronary artery disease in a Chinese Han population. APPROACH AND RESULTS: Immunohistochemical analysis of samples with atherosclerosis of various stages showed increased CCL19, CCL21, and CCR7 expression in atherosclerotic coronary plaques compared with nonatherosclerotic controls. Expression levels increased in positive correlation with coronary lesion stage. Cell adhesion assays confirmed that CCL19 promoted monocyte adhesion, which was induced by CCR7, to human umbilical vein endothelial cells, an effect partially antagonized by atorvastatin. After the human umbilical vein endothelial cells were treated with CCR7-neutralizing antibody, both CCL19- and CCL21-induced monocyte to human umbilical vein endothelial cell migration and CCL19-induced monocyte to human umbilical vein endothelial cell adhesion were abolished. The associations between genetic variants of CCL19, CCL21, CCR7, and coronary artery disease in a Chinese Han population were determined by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The following single nucleotide polymorphisms were associated with coronary artery disease: CCL19 rs2227302, CCL21 rs2812377, and CCR7 rs588019. Individuals with the CCL19 rs2227302 T allele or CCL21 rs2812377 G allele had higher plasma CCL19 levels than those with C/C genotype and higher CCL21 levels than those with T/T genotype in both case and control subjects. CONCLUSION: CCL19/CCL21-CCR7 is a novel homeostatic chemokine system that modulates human monocyte adhesion and migration, promoting atherogenesis. It is associated with coronary artery disease risk in Chinese Han individuals. These data suggest that the CCL19/CCL21-CCR7 axis plays an important role in atherosclerosis progression.

Association of ALOX5AP haplotypes with susceptibility to coronary artery disease in a Chinese Han population.

BACKGROUND: The 5-lipoxygenase activating protein (FLAP), encoded by the activating 5-lipoxygenase (ALOX5AP) gene, is a crucial mediator of the biosynthesis of leukotrienes, which have been implicated in atherosclerosis. This study investigates whether ALOX5AP polymorphisms are associated with coronary artery disease (CAD) in a Chinese Han population. METHODS: The promoter, exons, splice site region and 3'-untranslated region of the ALOX5AP gene were sequenced in 48 subjects. Three polymorphic sites (-1340T/G, +8733T/C, +20616G/C) found through sequencing were evaluated in 656 patients with angiographically proven CAD and 678 controls with normal coronary angiograms using a polymerase chain reaction and restriction fragment length polymorphism assay. Allelic, genotypic linkage disequilibrium and haplotypic association testing were performed using SHEsis and LDA software. Binary logistic regression was used to control for the presence of vascular risk factors. RESULTS: Seven single nucleotide polymorphisms (SNPs) were found through screening. No significant differences in allele carriers and genotype frequencies of the ALOX5AP polymorphisms were observed between the two groups. However, when the results of the three SNPs were combined, there was a significant association between two of the haplotypes and the risk of CAD. The haplotype GCG had a significantly greater frequency in patients than in controls (P<0.001, OR=1.728, 95%CI=1.375-2.171), and the frequency of haplotype TCG was higher in controls (P<0.001, OR=0.623, 95%CI=0.519-0.748). CONCLUSION: The data indicate that ALOX5AP gene variation is a genetic factor associated with interindividual differences in CAD risk.