Allogeneic transplantation in advanced cutaneous T-cell lymphomas (CUTALLO): a propensity score matched controlled prospective study.

BACKGROUND: Advanced-stage cutaneous T-cell lymphomas (CTCLs) are rare, usually refractory, and fatal diseases. Case series have suggested that allogeneic haematopoietic stem cell transplantation (HSCT) might improve the prognosis of advanced-stage CTCLs. The objective of this study was to investigate the effect of allogeneic HSCT compared with non-HSCT therapy on the outcome of individuals with advanced-stage CTCLs. METHODS: In this prospective, multicentre, matched controlled trial, conducted at 30 hospitals, participants with advanced CTCLs were allocated treatment: if they had an available compatible related donor they were assigned to allogeneic HSCT, or if not they were allocated to non-allogeneic HSCT therapy. Key inclusion criteria were participants aged 18-70 years, with advanced stage mycosis fungoides or Sézary syndrome, and at least one poor prognostic criteria. Participants were excluded if they were not in complete or partial remission of the disease. Propensity score 1:1 matching with replacement (ie, that each participant treated with HSCT was matched to the participant with the closest propensity score treated with non-HSCT therapy, even if they had already been matched) was used to handle confounding factors, with the balance of covariate distribution between HSCT and non-HSCT groups assessed using standardised mean differences. The primary endpoint was progression-free survival in the matched intention-to-treat population. This trial is registered with ClinicalTrials.gov (NCT02520908), and is currently active but not recruiting. FINDINGS: From June 1, 2016, to March 3, 2022, total of 99 participants were enrolled at 17 centres in France. Participants with a sibling or matched unrelated donor were assigned to allogeneic HSCT (HSCT group, n=55 [56%]) and participants without a donor were assigned to non-allogeneic HSCT treatment (non-HSCT group, n=44 [44%]). The median follow-up among survivors was 12·6 months (IQR 11·0-35·2). In the HSCT group, 51 participants (93%) were 1:1 matched to participants from the non-HSCT group. In the intention-to-treat analysis, median progression-free survival was significantly longer in the HSCT group (9·0 months [95% CI 6·6-30·5]) than in the non-HSCT group (3·0 months [2·0-6·3]), with a hazard ratio of 0·38 (95% CI 0·21-0·69; p<0·0001). In the per-protocol population, 40 participants (78%) in the HSCT group had 101 serious events and 29 participants (67%) in the non-HSCT group had 70 serious adverse events. The most common serious adverse event other than graft-versus-host disease in both groups was infections, occurring in 30 participants (59%) in the HSCT group and in 19 participants (44%) in the non-HSCT group. INTERPRETATION: Allogeneic HSCT was associated with significantly longer progression-free survival in participants with advanced-stage CTCLs. These results indicate that allogeneic HSCT treatment should be made available to individuals with high-risk, advanced-stage mycosis fungoides or Sézary syndrome who achieve pre-transplant disease remission. FUNDING: French Ministry of Health, National Cancer Institute, Programme Hospitalier de Recherche Clinique en Cancérologie.

PD-1 blockade and allogeneic hematopoietic stem cell transplantation in Hodgkin lymphoma, a matter of time: a national study on behalf of the Société Francophone de Greffe de Moelle et de Thérapie Cellulaire.

Not available.

Staged Ventricular Septation of the Double-Inlet Ventricle: How-I-Do-It.

Ventricular septation of the double-inlet ventricle is a largely abandoned operation due to poor historical outcomes. However, there has been renewed interest in septation as an alternative to Fontan palliation given its long-term sequelae. As one of the few centers to revisit septation in the early 1990s, our institution has long-term data on a series of patients with a double-inlet ventricle who underwent biventricular repair. This manuscript is a summary of our approach to staged septation of the double-inlet ventricle, with a focus on patient selection criteria, surgical techniques, perioperative considerations on timing of interventions, and long-term results. We believe that septation of the double-inlet ventricle should be reconsidered in patients with suitable anatomy in light of the known complications of Fontan palliation.

Strategies for the Surgical Management of Highly Aggressive Williams Syndrome Aortopathy: A Three Case Report.

Severe aortopathy in Williams syndrome can sometimes present with an initial ascending aortic pathology, followed in short order by more distal multilevel obstruction and recurrence requiring reintervention. In this series, an early, comprehensive surgical approach using a combination of various access and perfusion strategies yielded excellent long-term results.

Ventricular Septation of the Double-Inlet Ventricle: Over Three Decades of Follow-Up.

There is renewed interest in septation of the double-inlet ventricle as an alternative to Fontan palliation. We examined our septation experience with over 30 years of follow-up. We retrospectively reviewed patients with double-inlet ventricle from 1990 to 2011. Patients with two adequate atrioventricular valves, a volume-overloaded ventricle, and no significant subaortic obstruction were septation candidates. Of 98 double-inlet ventricle patients, 9 (9.2%) underwent attempted septation via a one-stage (n = 2, 22.2%) or two-stage (n = 7, 77.8%) approach. Ages at primary septation were 7.5 and 20.2 months. In the staged group, median age at the first and second stage was 8.3 months [range 4.1-14.7] and 22.4 months [range 11.4-195.7], respectively. There were no operative mortalities. Median follow-up was 18.8 years [range 0.4-32.9] and 30-year transplant-free survival was 77.8% ± 13.9%. Both single stage patients are alive and in sinus rhythm; 1 underwent bilateral outflow tract obstruction repair 27 years later. Of 7 patients planned for two-stage septation, there was 1 interval mortality and 1 deferred the second stage. Five patients underwent the second stage; 1 required early reintervention for a residual neo-septal defect and 1 underwent right atrioventricular valve replacement 28 years later. Three patients required a pacemaker preoperatively (n = 1) or after partial septation (n = 2). At latest follow-up, 7 patients have normal biventricular function and no significant valvulopathy. All remain NYHA functional class I. Select double-inlet ventricles may be septated with excellent long-term outcomes. Reconsideration of this strategy is warranted to avoid the sequelae of Fontan circulation.

Liberal use of veno-arterial extracorporeal membrane oxygenation in combined sequential heart-liver transplantation.

Combined heart-liver transplantation (CHLT) is a rarely though increasingly performed procedure with evolving indications. Despite CHLT being performed at only a handful of centers, the use of intraoperative mechanical circulatory support to optimize hemodynamics and facilitate dual-organ transplantation varies widely. At our center, we liberally utilize veno-arterial extracorporeal membrane oxygenation (V-A ECMO) when a veno-venous shunt is anticipated to be insufficient in mitigating the hemodynamic perturbations associated with liver reperfusion. In this series, we describe our experience with V-A ECMO in sequential (heart-first) CHLT and demonstrate highly favorable outcomes with this strategy.

A 16-month-long experience of COVID-19 in allogeneic haematopoietic stem cell transplantation recipients: An SFGM-TC multicentre cohort study.

This 16-month-long multicentre retrospective study of 225 allogeneic haematopoietic stem cell transplantation (alloHSCT) recipients with COVID-19 examines risk factors for severity and mortality, describing the successive waves of infections (from March to June 2020 and from August 2020 to June 2021). We confirm the negative role of low respiratory tract disease and immunosuppressive treatment. We highlight significantly lower percentages of severe forms and COVID-19-related mortality during the second wave. Monthly comparative evolution of cases in alloHSCT recipients and in the French population shows a higher number of cases in alloHSCT recipients during the first wave and a decrease from February 2021.

A personalized approach to guide allogeneic stem cell transplantation in younger adults with acute myeloid leukemia.

A multistage model instructed by a large dataset (knowledge bank [KB] algorithm) has recently been developed to improve outcome predictions and tailor therapeutic decisions, including hematopoietic stem cell transplantation (HSCT) in acute myeloid leukemia (AML). We assessed the performance of the KB in guiding HSCT decisions in first complete remission (CR1) in 656 AML patients younger than 60 years from the ALFA-0702 trial (NCT00932412). KB predictions of overall survival (OS) were superior to those of European LeukemiaNet (ELN) 2017 risk stratification (C-index, 68.9 vs 63.0). Among patients reaching CR1, HSCT in CR1, as a time-dependent covariate, was detrimental in those with favorable ELN 2017 risk and those with negative NPM1 minimal residual disease (MRD; interaction tests, P = .01 and P = .02, respectively). Using KB simulations of survival at 5 years in a scenario without HSCT in CR1 (KB score), we identified, in a similar time-dependent analysis, a significant interaction between KB score and HSCT, with HSCT in CR1 being detrimental only in patients with a good prognosis based on KB simulations (KB score ≥40; interaction test, P = .01). We could finally integrate ELN 2017, NPM1 MRD, and KB scores to sort 545 CR1 patients into 278 (51.0%) HSCT candidates and 267 (49.0%) chemotherapy-only candidates. In both time-dependent and 6-month landmark analyses, HSCT significantly improved OS in HSCT candidates, whereas it significantly shortened OS in chemotherapy-only candidates. Integrating KB predictions with ELN 2017 and MRD may thus represent a promising approach to optimize HSCT timing in younger AML patients.

Salvage haploidentical or cord-blood allogeneic stem cell transplantation after a prior alternative allograft in hematologic malignancies: A retrospective study from the SFGM-TC.

BACKGROUND: Haploidentical (haplo-) donors and cord-blood (CB) stem cells provide alternative transplant options in patients lacking an HLA-matched donor. In case of relapse or graft failure after a first alternative allogeneic hematopoietic stem cell transplant (HSCT), a second alternative HSCT (HSCT2) is rarely considered due to a high risk of toxicity. METHODS: A retrospective French multicentre study was performed, including patients with hematologic malignancies who underwent two consecutive HSCT from alternative donors. All data were exported from the national ProMISE database between 2000 and 2016. RESULTS: Forty-three patients (61.4%) received a CB-HSCT2 and 27 (38.6%) a haplo-HSCT2. Indications for HSCT were graft failure (51.4%) or disease progression (48.6%). Two-years probabilities of overall survival, progression-free survival and toxicity-related mortality were 18.5%, 17.8% and 55.8%, respectively. In multivariate analysis, complete remission status at HSCT2 and year of HSCT2 ≥ 2012 were significantly associated with a better outcome (with respectively hazard ratio [HR] = 0.42, p = .002 and HR = 0.5, p = .051). CONCLUSIONS: Neither the indication of HSCT2 nor the source of stem cell was more advantageous towards overall patient survival. A salvage haploidentical or cord-blood stem cell transplantation is a high-risk procedure, that may be considered for patients achieving a complete remission before receiving the second HSCT.

Techniques improving electrical cardioversion success for patients with atrial fibrillation: a systematic review and meta-analysis.

AIMS: Electrical cardioversion is commonly used to restore sinus rhythm in patients with atrial fibrillation (AF), but procedural technique and clinical success vary. We sought to identify techniques associated with electrical cardioversion success for AF patients. METHODS AND RESULTS: We searched MEDLINE, EMBASE, CENTRAL, and the grey literature from inception to October 2022. We abstracted data on initial and cumulative cardioversion success. We pooled data using random-effects models. From 15 207 citations, we identified 45 randomized trials and 16 observational studies. In randomized trials, biphasic when compared with monophasic waveforms resulted in higher rates of initial [16 trials, risk ratio (RR) 1.71, 95% CI 1.29-2.28] and cumulative success (18 trials, RR 1.10, 95% CI 1.04-1.16). Fixed, high-energy (≥200 J) shocks when compared with escalating energy resulted in a higher rate of initial success (four trials, RR 1.62, 95% CI 1.33-1.98). Manual pressure when compared with no pressure resulted in higher rates of initial (two trials, RR 2.19, 95% CI 1.21-3.95) and cumulative success (two trials, RR 1.19, 95% CI 1.06-1.34). Cardioversion success did not differ significantly for other interventions, including: antero-apical/lateral vs. antero-posterior positioned pads (initial: 11 trials, RR 1.16, 95% CI 0.97-1.39; cumulative: 14 trials, RR 1.01, 95% CI 0.96-1.06); rectilinear/pulsed biphasic vs. biphasic truncated exponential waveform (initial: four trials, RR 1.11, 95% CI 0.91-1.34; cumulative: four trials, RR 0.98, 95% CI 0.89-1.08) and cathodal vs. anodal configuration (cumulative: two trials, RR 0.99, 95% CI 0.92-1.07). CONCLUSIONS: Biphasic waveforms, high-energy shocks, and manual pressure increase the success of electrical cardioversion for AF. Other interventions, especially pad positioning, require further study.

The use of antibiotics in acute oral health patients presenting at public dental clinics in the Western Sydney region.

BACKGROUND: There is a limited need for antibiotics when treating oral health problems, yet they are often prescribed, increasing risk of antimicrobial resistance (AMR). With AMR a threat to public health, the objectives of this study were to assess the frequency, suitability, and factors associated with antibiotic prescriptions for acute dental problems across Greater Western Sydney public dental clinics. METHODS: Patients' reason for attending, details of any antibiotics use, and the treating dental practitioner's clinical examination and diagnosis were compared to current prescribing guidelines, and logistic regression was used to identify predictors of antibiotic prescription. RESULTS: In all, 1,071 patients participated in the study, and 15.9% reported to using antibiotics for their dental problem. Over three-quarters obtained the antibiotics from their general medical practitioner (GMP). A high prevalence of antibiotics were not indicated for the patient's complaint (71.8%) including for those with a history of extraction, pain, or intraoral swelling, who had significantly higher odds of antibiotic prescription (OR > 9). The antibiotic type prescribed was generally suitable. CONCLUSIONS: In summary, the data suggest that the majority of antibiotics were inappropriately prescribed for the patient's dental complaints and there is a need for interventions to improve compliance with antibiotic prescribing guidelines.

Effects of Exercise Preconditioning on Doxorubicin-Induced Liver and Kidney Toxicity in Male and Female Rats.

Doxorubicin (DOX) is a highly effective chemotherapy agent prescribed for cancer treatment. However, the clinical use of DOX is limited due to off-target toxicity in healthy tissues. In this regard, hepatic and renal metabolic clearance results in DOX accumulation within these organ systems. Within the liver and kidneys, DOX causes inflammation and oxidative stress, which promotes cytotoxic cellular signaling. While there is currently no standard of care to treat DOX hepatic- and nephrotoxicity, endurance exercise preconditioning may be an effective intervention to prevent elevations in liver alanine transaminase (ALT) and aspartate aminotransferase (AST) and to improve kidney creatinine clearance. To determine whether exercise preconditioning is sufficient to reduce liver and kidney toxicity resulting from acute exposure to DOX chemotherapy treatment, male and female Sprague-Dawley rats remained sedentary or were exercise trained prior to saline or DOX exposure. Our findings demonstrate that DOX treatment elevated AST and AST/ALT in male rats, with no effects of exercise preconditioning to prevent these increases. We also showed increased plasma markers of renin-angiotensin-aldosterone system (RAAS) activation and urine markers of proteinuria and proximal tubule damage, with male rats revealing greater differences compared to females. Exercise preconditioning showed improved urine creatinine clearance and reduced cystatin c in males, while females had reduced plasma angiotensin II (AngII) levels. Our results demonstrate both tissue- and sex-specific responses related to the effects of exercise preconditioning and DOX treatment on markers of liver and kidney toxicity.

A structural model of the human plasminogen and Aspergillus fumigatus enolase complex.

The metabolic enzyme, enolase, plays a crucial role in the cytoplasm where it maintains cellular energy production within the process of glycolysis. The main role of enolase in glycolysis is to convert 2-phosphoglycerate to phosphoenolpyruvate; however, enolase can fulfill roles that deviate from this function. In pathogenic bacteria and fungi, enolase is also located on the cell surface where it functions as a virulence factor. Surface-expressed enolase is a receptor for human plasma proteins, including plasminogen, and this interaction facilitates nutrient acquisition and tissue invasion. A novel approach to developing antifungal drugs is to inhibit the formation of this complex. To better understand the structure of enolase and the interactions that may govern complex formation, we have solved the first X-ray crystal structure of enolase from Aspergillus fumigatus (2.0 Å) and have shown that it preferentially adopts a dimeric quaternary structure using native mass spectrometry. Two additional X-ray crystal structures of A. fumigatus enolase bound to the endogenous substrate 2-phosphoglycerate and product phosphoenolpyruvate were determined and kinetic characterization was carried out to better understand the details of its canonical function. From these data, we have produced a model of the A. fumigatus enolase and human plasminogen complex to provide structural insights into the mechanisms of virulence and aid future development of small molecules or peptidomimetics for antifungal drug design.

High tumor burden before blinatumomab has a negative impact on the outcome of adult patients with B-cell precursor acute lymphoblastic leukemia. A real-world study by the GRAALL.

Blinatumomab is a bispecific T-cell engager approved for B-cell precursor acute lymphoblastic leukemia (B-ALL) with persistent minimal residual disease (MRD) or in relapse. The prognostic impact of tumor load has been suggested before other immunotherapies but remains poorly explored before blinatumomab. We retrospectively analyzed the outcome of 73 patients who received blinatumomab either in first complete remission (CR) with MRD (n=35) or at relapse (n=38). Among MRD patients, 91% had MRD >0.01% before blinatumomab, and 89% achieved complete MRD response after blinatumomab. High pre-blinatumomab MRD levels were associated with shorter relapse-free survival (P=0.049) and overall survival (OS) (P=0.011). At 3 years, OS was 33%, 58% and 86% for pre-blinatumomab MRD >1%, between MRD 0.1- 1% and <0.1% respectively. Among relapsed patients, 23 received blinatumomab with overt relapse and 15 were in complete response (CR) after bridging chemotherapy. At 3 years, overall CR rate was 68% and complete MRD response rate was 84%. Patients who directly received blinatumomab had shorter relapse-free survival (P=0.033) and OS (P=0.003) than patients bridged to blinatumomab. Three-year OS was 66% in the latter group compared to 16% in the former group. Our observations suggest that pre-blinatumomab tumor burden should help to design more tailored strategies including tumor load reduction in relapsed patients.

Pre-treatment with antiarrhythmic drugs for elective electrical cardioversion of atrial fibrillation: a systematic review and network meta-analysis.

AIMS: Our objective was to compare the efficacy of pre-treatment with different classes of anti-arrhythmic drugs (AADs) in patients with atrial fibrillation (AF) undergoing electrical cardioversion. METHODS AND RESULTS: We performed a systematic review and network meta-analysis (NMA) of randomized controlled trials (RCTs) comparing different AADs in patients with AF undergoing electrical cardioversion. We grouped AADs into five network nodes: no treatment or rate control, Class Ia, Class Ic, Class III, and amiodarone. Outcomes were (i) acute restoration and (ii) maintenance of sinus rhythm. We searched MEDLINE and EMBASE from inception until June 2020. We used Python 3.8.3 and R 3.6.2 for data analysis. We evaluated the overall certainty of evidence with the GRADE framework. We included 28 RCTs. Compared with no treatment or rate control, Class III AADs [odds ratio (OR): 2.41; 95% credible interval (CrI): 1.37 to 4.62, high certainty] and amiodarone (OR: 2.58; 95% CrI: 1.54 to 4.37, high certainty) improved restoration of sinus rhythm. Amiodarone improved long-term maintenance of sinus rhythm when compared with no treatment or rate control (OR: 5.37; 95% CrI: 4.00-7.39, high certainty), Class Ic (OR: 1.89; 95% CrI: 1.05-3.45, moderate certainty) and Class III AADs (OR: 2.19; 95% CrI: 1.39-3.26, high certainty). CONCLUSION: Before electrical cardioversion of AF, treatment with Class III AADs or amiodarone improves the acute restoration of sinus rhythm. Amiodarone is most likely to improve the maintenance of sinus rhythm after electrical cardioversion, but Class Ic and Class III AADs are also effective.

Hepatocellular Carcinoma in Evolution: Correlation with CEUS LI-RADS.

Hepatocellular carcinoma (HCC) is the most common primary malignancy of the liver with a high incidence worldwide and a high associated mortality. Well-recognized risk factors that cause a predisposition to the development of HCC include chronic infection with the hepatitis B or C virus, alcohol-related and non-alcohol-related fatty liver disease, and cirrhosis. In these chronically diseased livers, benign regenerative nodules can increase in size and develop cellular atypia that progress into dysplastic nodules and ultimately HCC. This sequence of hepatocarcinogenesis is coupled with changes in nodule vascularity, including progressive decreased density of portal triads and induced neoangiogenesis, resulting in increased hepatic arterial recruitment. Changes in vascularity result in an array of patterns of nodule enhancement and washout, which can be sensitively depicted with dynamic real-time contrast-enhanced US. Regenerative nodules are isoenhancing relative to the liver with all phases, while HCC classically shows avid arterial phase hyperenhancement with late mild washout. In between, there is great variation as nodules evolve through progressive grades of dysplasia toward HCC. Observed patterns of enhancement and washout can be used to diagnose or stratify the risk of malignancy in liver nodules by using the diagnostic algorithm described by the American College of Radiology Liver Imaging Reporting and Data System (LI-RADS). This facilitates the detection and close monitoring of potential early-stage disease. LI-RADS categorizes nodules according to a probabilistic likelihood for HCC with criteria for LR-5 nodules that are highly specific for the diagnosis of HCC, allowing treatment without exposing the patient to invasive biopsy. An invited commentary by Fetzer is available online. Online supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article. ©RSNA, 2022.

Comparing Public Sentiment Toward COVID-19 Vaccines Across Canadian Cities: Analysis of Comments on Reddit.

BACKGROUND: Social media enables the rapid consumption of news related to COVID-19 and serves as a platform for discussions. Its richness in text-based data in the form of posts and comments allows researchers to identify popular topics and assess public sentiment. Nonetheless, the vast majority of topic extraction and sentiment analysis based on social media is performed on the platform or country level and does not account for local culture and policies. OBJECTIVE: The aim of this study is to use location-based subreddits on Reddit to study city-level variations in sentiments toward vaccine-related topics. METHODS: Comments on posts providing regular updates on COVID-19 statistics in the Vancouver (r/vancouver, n=49,291), Toronto (r/toronto, n=20,764), and Calgary (r/calgary, n=21,277) subreddits between July 13, 2020, and June 14, 2021, were extracted. Latent Dirichlet allocation was used to identify frequently discussed topics. Sentiment (joy, sadness, fear, and anger) scores were assigned to comments through random forest regression. RESULTS: The number of comments on the 250 posts from the Vancouver subreddit positively correlated with the number of new daily COVID-19 cases in British Columbia (R=0.51, 95% CI for slope 0.18-0.29; P<.001). From the comments, 13 topics were identified. Two were related to vaccines, 1 regarding vaccine uptake and the other about vaccine supply. The levels of discussion for both topics were linked to the total number of vaccines administered (Granger test for causality, P<.001). Comments pertaining to either topic displayed higher scores for joy than for other topics (P<.001). Calgary and Toronto also discussed vaccine uptake. Sentiment scores for this topic differed across the 3 cities (P<.001). CONCLUSIONS: Our work demonstrates that data from city-specific subreddits can be used to better understand concerns and sentiments around COVID-19 vaccines at the local level. This can potentially lead to more targeted and publicly acceptable policies based on content on social media.

Hybrid repair of ascending aortic pseudoaneurysm.

For ascending aortic pseudoaneurysms with a large aortic entry site and thrombus burden, temporary stent-graft placement at induction of circulatory arrest can prevent thrombotic complication.

Family dynamics moderate the impact of discrimination on wellbeing for Latino young adults.

OBJECTIVES: This study examined family dynamics as a moderator of the association between discrimination and both depression and life satisfaction for Latino youth. Specifically, we hypothesized that discrimination would have a negative impact on depression and life satisfaction. We also hypothesized that negative family dynamics would compound the negative impact of discrimination, whereas positive family dynamics would buffer against the impact of discrimination on depression and life satisfaction. METHOD: Participants were 229 Latino youth (Mage = 22.40, SD = 2.46, % female = 81.7) from a diverse region who completed measures of perceived discrimination, depressive symptoms, life satisfaction, and family relationship dynamics. Regression models were used to test both direct associations and moderation (i.e., interaction effects) between these variables. RESULTS: Findings indicated that negative aspects of family dynamics marginally exacerbated the link between discrimination and depression and life satisfaction, and were also directly associated with these outcomes. Family positivity significantly moderated the association between discrimination and both depression and life satisfaction. However, positive aspects of family dynamics were only associated with more positive outcomes when discrimination was minimal to absent. CONCLUSIONS: Family dynamics moderated the association between discrimination and both depression and life satisfaction in Latino youth. However, family dynamics did not appear sufficient to buffer against the negative impact of discrimination, suggesting that even positive and cohesive families cannot buffer youth from discrimination. Marginal findings suggest that negative family dynamics compound the negative impact of discrimination. Implications for improving the mental health of Latino youth through targeting both discrimination and family dynamics are discussed. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Biochemical characterisation of class III biotin protein ligases from Botrytis cinerea and Zymoseptoria tritici.

Biotin protein ligase (BPL) is an essential enzyme in all kingdoms of life, making it a potential target for novel anti-infective agents. Whilst bacteria and archaea have simple BPL structures (class I and II), the homologues from certain eukaryotes such as mammals, insects and yeast (class III) have evolved a more complex structure with a large extension on the N-terminus of the protein in addition to the conserved catalytic domain. The absence of atomic resolution structures of any class III BPL hinders structural and functional analysis of these enzymes. Here, two new class III BPLs from agriculturally important moulds Botrytis cinerea and Zymoseptoria tritici were characterised alongside the homologue from the prototypical yeast Saccharomyces cerevisiae. Circular dichroism and ion mobility-mass spectrometry analysis revealed conservation of the overall tertiary and secondary structures of all three BPLs, corresponding with the high sequence similarity. Subtle structural differences were implied by the different thermal stabilities of the enzymes and their varied Michaelis constants for their interactions with ligands biotin, MgATP, and biotin-accepting substrates from different species. The three BPLs displayed different preferences for fungal versus bacterial protein substrates, providing further evidence that class III BPLs have a 'substrate validation' activity for selecting only appropriate proteins for biotinylation. Selective, potent inhibition of these three BPLs was demonstrated despite sequence and structural homology. This highlights the potential for targeting BPL for novel, selective antifungal therapies against B. cinerea, Z. tritici and other fungal species.