A Chromosomally Encoded Virulence Factor Protects the Lyme Disease Pathogen against Host-Adaptive Immunity

Borrelia burgdorferi, the bacterial pathogen of Lyme borreliosis, differentially expresses select genes in vivo, likely contributing to microbial persistence and disease. Expression analysis of spirochete genes encoding potential membrane proteins showed that surface-located membrane protein 1 (lmp1) transcripts were expressed at high levels in the infected murine heart, especially during early stages of infection. Mice and humans with diagnosed Lyme borreliosis also developed antibodies against Lmp1. Deletion of lmp1 severely impaired the pathogen's ability to persist in diverse murine tissues including the heart, and to induce disease, which was restored upon chromosomal complementation of the mutant with the lmp1 gene. Lmp1 performs an immune-related rather than a metabolic function, as its deletion did not affect microbial persistence in immunodeficient mice, but significantly decreased spirochete resistance to the borreliacidal effects of anti-B. burgdorferi sera in a complement-independent manner. These data demonstrate the existence of a virulence factor that helps the pathogen evade host-acquired immune defense and establish persistent infection in mammals

Detailed Analysis of Sequence Changes Occurring during vlsE Antigenic Variation in the Mouse Model of Borrelia burgdorferi Infection

Lyme disease Borrelia can infect humans and animals for months to years, despite the presence of an active host immune response. The vls antigenic variation system, which expresses the surface-exposed lipoprotein VlsE, plays a major role in B. burgdorferi immune evasion. Gene conversion between vls silent cassettes and the vlsE expression site occurs at high frequency during mammalian infection, resulting in sequence variation in the VlsE product. In this study, we examined vlsE sequence variation in B. burgdorferi B31 during mouse infection by analyzing 1,399 clones isolated from bladder, heart, joint, ear, and skin tissues of mice infected for 4 to 365 days. The median number of codon changes increased progressively in C3H/HeN mice from 4 to 28 days post infection, and no clones retained the parental vlsE sequence at 28 days. In contrast, the decrease in the number of clones with the parental vlsE sequence and the increase in the number of sequence changes occurred more gradually in severe combined immunodeficiency (SCID) mice. Clones containing a stop codon were isolated, indicating that continuous expression of full-length VlsE is not required for survival in vivo; also, these clones continued to undergo vlsE recombination. Analysis of clones with apparent single recombination events indicated that recombinations into vlsE are nonselective with regard to the silent cassette utilized, as well as the length and location of the recombination event. Sequence changes as small as one base pair were common. Fifteen percent of recovered vlsE variants contained “template-independent” sequence changes, which clustered in the variable regions of vlsE. We hypothesize that the increased frequency and complexity of vlsE sequence changes observed in clones recovered from immunocompetent mice (as compared with SCID mice) is due to rapid clearance of relatively invariant clones by variable region-specific anti-VlsE antibody responses

Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches

Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its 'Minimal Information for Studies of Extracellular Vesicles', which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly

Targeted gene sanger sequencing should remain the first-tier genetic test for children suspected to have the five common X-linked inborn errors of immunity

DATA AVAILABILITY STATEMENT : The original contributions presented in the study are included in the article/Supplementary Material. Further inquiries can be directed to the corresponding author.To address inborn errors of immunity (IEI) which were underdiagnosed in resource-limited regions, our centre developed and offered free genetic testing for the most common IEI by Sanger sequencing (SS) since 2001. With the establishment of The Asian Primary Immunodeficiency (APID) Network in 2009, the awareness and definitive diagnosis of IEI were further improved with collaboration among centres caring for IEI patients from East and Southeast Asia. We also started to use whole exome sequencing (WES) for undiagnosed cases and further extended our collaboration with centres from South Asia and Africa. With the increased use of Next Generation Sequencing (NGS), we have shifted our diagnostic practice from SS to WES. However, SS was still one of the key diagnostic tools for IEI for the past two decades. Our centre has performed 2,024 IEI SS genetic tests, with in-house protocol designed specifically for 84 genes, in 1,376 patients with 744 identified to have disease-causing mutations (54.1%). The high diagnostic rate after just one round of targeted gene SS for each of the 5 common IEI (X-linked agammaglobulinemia (XLA) 77.4%, Wiskott–Aldrich syndrome (WAS) 69.2%, X-linked chronic granulomatous disease (XCGD) 59.5%, X-linked severe combined immunodeficiency (XSCID) 51.1%, and X-linked hyper-IgM syndrome (HIGM1) 58.1%) demonstrated targeted gene SS should remain the first-tier genetic test for the 5 common X-linked IEI.The Hong Kong Society for Relief of Disabled Children and Jeffrey Modell Foundation.http://www.frontiersin.org/Immunologyam2023Paediatrics and Child Healt

Educational interventions for health professionals managing chronic obstructive pulmonary disease in primary care

Background Chronic obstructive pulmonary disease (COPD) is a common, preventable and treatable health condition. COPD is associated with substantial burden on morbidity, mortality and healthcare resources. Objectives To review existing evidence for educational interventions delivered to health professionals managing COPD in the primary care setting. Search methods We searched the Cochrane Airways Trials Register from inception to May 2021. The Register includes records from the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Allied and Complementary Medicine Database (AMED) and PsycINFO. We also searched online trial registries and reference lists of included studies. Selection criteria We included randomised controlled trials (RCTs) and cluster‐RCTs. Eligible studies tested educational interventions aimed at any health professionals involved in the management of COPD in primary care. Educational interventions were defined as interventions aimed at upskilling, improving or refreshing existing knowledge of health professionals in the diagnosis and management of COPD. Data collection and analysis Two review authors independently reviewed abstracts and full texts of eligible studies, extracted data and assessed the risk of bias of included studies. We conducted meta‐analyses where possible and used random‐effects models to yield summary estimates of effect (mean differences (MDs) with 95% confidence intervals (CIs)). We performed narrative synthesis when meta‐analysis was not possible. We assessed the overall certainty of evidence for each outcome using Grades of Recommendation, Assessment, Development and Evaluation (GRADE). Primary outcomes were: 1) proportion of COPD diagnoses confirmed with spirometry; 2) proportion of patients with COPD referred to, participating in or completing pulmonary rehabilitation; and 3) proportion of patients with COPD prescribed respiratory medication consistent with guideline recommendations. Main results We identified 38 studies(22 cluster‐RCTs and 16 RCTs) involving 4936 health professionals (reported in 19/38 studies) and 71,085 patient participants (reported in 25/38 studies). Thirty‐six included studies evaluated interventions versus usual care; seven studies also reported a comparison between two or more interventions as part of a three‐ to five‐arm RCT design. A range of simple to complex interventions were used across the studies, with common intervention features including education provided to health professionals via training sessions, workshops or online modules (31 studies), provision of practice support tools, tool kits and/or algorithms (10 studies), provision of guidelines (nine studies) and training on spirometry (five studies). Health professionals targeted by the interventions were most commonly general practitioners alone (20 studies) or in combination with nurses or allied health professionals (eight studies), and the majority of studies were conducted in general practice clinics. We identified performance bias as high risk for 33 studies. We also noted risk of selection, detection, attrition and reporting biases, although to a varying extent across studies. The evidence of efficacy was equivocal for all the three primary endpoints evaluated: 1) proportion of COPD diagnoses confirmed with spirometry (of the four studies that reported this outcome, two supported the intervention); 2) proportion of patients with COPD who are referred to, participate in or complete pulmonary rehabilitation (of the four studies that reported this outcome, two supported the intervention); and 3) proportion of patients with COPD prescribed respiratory medications consistent with guideline recommendations (12 studies reported this outcome, the majority evaluated multiple drug classes and reported a mixed effect). Additionally, the low quality of evidence and potential risk of bias make the interpretation more difficult. Moderate‐quality evidence (downgraded due to risk of bias concerns) suggests that educational interventions for health professionals probably improve the proportion of patients with COPD vaccinated against influenza (three studies) and probably have little impact on the proportion of patients vaccinated against pneumococcal infection (two studies). Low‐quality evidence suggests that educational interventions for health professionals may have little or no impact on the frequency of COPD exacerbations (10 studies). There was a high degree of heterogeneity in the reporting of health‐related quality of life (HRQoL). Low‐quality evidence suggests that educational interventions for health professionals may have little or no impact on HRQoL overall, and when using the COPD‐specific HRQoL instrument, the St George's Respiratory Questionnaire (at six months MD 0.87, 95% CI ‐2.51 to 4.26; 2 studies, 406 participants, and at 12 months MD ‐0.43, 95% CI ‐1.52 to 0.67, 4 studies, 1646 participants; reduction in score indicates better health). Moderate‐quality evidence suggests that educational interventions for health professionals may improve patient satisfaction with care (one study). We identified no studies that reported adverse outcomes. Authors' conclusions The evidence of efficacy was equivocal for educational interventions for health professionals in primary care on the proportion of COPD diagnoses confirmed with spirometry, the proportion of patients with COPD who participate in pulmonary rehabilitation, and the proportion of patients prescribed guideline‐recommended COPD respiratory medications. Educational interventions for health professionals may improve influenza vaccination rates among patients with COPD and patient satisfaction with care. The quality of evidence for most outcomes was low or very low due to heterogeneity and methodological limitations of the studies included in the review, which means that there is uncertainty about the benefits of any currently published educational interventions for healthcare professionals to improve COPD management in primary care. Further well‐designed RCTs are needed to investigate the effects of educational interventions delivered to health professionals managing COPD in the primary care setting

Diagnosing COPD and supporting smoking cessation in general practice: Evidenceepractice gaps

Objectives: To review the accuracy of diagnoses of chronic obstructive pulmonary disease (COPD) in primary care in Australia, and to describe smokers\u27 experiences with and preferences for smoking cessation. Design, setting and participants: Patients were invited to participate if they were at least 40 years old and had visited participating general practice clinics in Melbourne at least twice during the previous 12 months, reported being current or ex-smokers with a smoking history of at least 10 pack-years, or were being managed for COPD. Interviews based on a structured questionnaire and case finding (FEV 1 /FEV 6 measurement) were followed, when appropriate, by spirometry testing and assessment of health-related quality of life, dyspnoea and symptoms. Results: 1050 patients attended baseline interviews (February 2015 - April 2017) at 41 practices. Of 245 participants managed for COPD, 130 (53.1%) met the spirometry-based definition (post-bronchodilator FEV 1 /FVC \u3c 0.7) or had a clinical correlation; in 37% of cases COPD was not confirmed, and no definitive result was obtained for 9.8% of patients. Case finding and subsequent spirometry testing identified 142 new COPD cases (17.6% of participants without prior diagnosis; 95% CI, 15.1-20.5%). 690 participants (65.7%) were current smokers, of whom 360 had attempted quitting during the previous 12 months; 286 (81.0%of those attempting to quit) reported difficulties during previous quit attempts. Nicotine replacement therapy (205, 57.4%) and varenicline (110, 30.8%) were the most frequently employed pharmacological treatments; side effects were common. Hypnotherapy was the most popular non-pharmacological option (62 smokers, 17%); e-cigarettes were tried by 38 (11%). 187 current smokers (27.6%) would consider using e-cigarettes in future attempts to quit. Conclusions: COPD was both misdiagnosed and missed. Case finding and effective use of spirometry testing could improve diagnosis. Side effects of smoking cessation medications and difficulties during attempts to quit smoking are common. Health professionals should emphasise evidence-based treatments, and closely monitor quitting difficulties and side effects of cessation aids. Trial registration: Australian New Zealand Clinical Trials Registry ACTRN12614001155684