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Biomedical subjects

Fang Yan

Publications and source records attributed to Fang Yan.

3 recordsLinked to original sources

Comparative evaluation of probe-capture and conventional metagenomic sequencing across multiple clinical sample types, with analysis of paired bronchoalveolar lavage fluid and blood samples.

Conventional metagenomic next-generation sequencing (mNGS) suffers from host nucleic acid interference and poor performance in low-biomass samples. Probe-capture metagenomic sequencing (PC-mNGS), which enriches microbial targets via hybridization probes, shows superior sensitivity but lacks systematic multi-sample evaluations. This study compared PC-mNGS and mNGS across diverse clinical specimens (bronchoalveolar lavage fluid [BALF], blood, cerebrospinal fluid [CSF]) and assessed the clinical utility of pathogen co-detection in paired BALF-blood samples from sepsis patients. A total of 282 samples (81 BALF, 141 blood, 25 CSF, 35 others) sequenced by both PC-mNGS and mNGS were analyzed. Additionally, 621 paired BALF-blood samples from sepsis patients with pulmonary infections were evaluated. PC-mNGS achieved higher pathogen detection rates (66.67% vs 57.10%, P = 0.000198) than mNGS, particularly in blood (66.67% vs 47.52%, P = 2.5 × 10⁻⁵). PC-mNGS detected more bacteria (19 species exclusive) and fungi (11 species exclusive) than mNGS. Viruses showed comparable detection. BALF and CSF exhibited high overall agreement (OPA: 96.30% and 88%, respectively), while blood had lower concordance (NPA: 54.05%, OPA: 70.92%). A total of 60.55% of BALF-positive samples (PC-mNGS) had co-detected pathogens in blood. Gram-negative bacteria (e.g., Klebsiella pneumoniae) and fungi (e.g., Candida albicans) showed higher blood co-detection rates than viruses. In this study, PC-mNGS detected more pathogens and showed a higher positivity rate than mNGS in blood samples. BALF sequencing data, particularly bacterial reads per million (RPM), may predict bloodstream co-detection, aiding in sepsis management. However, clinical validation and integration with traditional diagnostics are needed to confirm utility. This study highlights PC-mNGS as a promising tool for complex infections but underscores the need for rigorous multi-context validation.IMPORTANCEAccurate and rapid identification of pathogens is critical for effective treatment of severe infectious diseases, such as sepsis. This study demonstrates that probe-capture metagenomic sequencing (PC-mNGS) detected more pathogens in blood samples compared to conventional metagenomic sequencing, especially for bacterial and fungal infections. By analyzing paired lung and blood samples, we show that high pathogen levels in lung fluid may predict bloodstream infection, offering a potential early warning for clinicians. These findings support the use of PC-mNGS as a more sensitive diagnostic tool, which could lead to faster, more targeted therapies and better outcomes for patients with complex infections.

Humans

Genetic diversity of Collaborative Cross mice implicates FFAR3 as a target for ILC2 anti-inflammatory reprogramming.

Pulmonary group 2 innate lymphoid cells (ILC2s) are key drivers of Type 2 inflammation in diseases like asthma, yet the molecular mechanisms regulating their function are incompletely understood. Using the genetically diverse Collaborative Cross (CC) mouse panel, we mapped a quantitative trait locus (QTL) that governs ILC2 prevalence in the lung after aeroallergen exposure. This QTL induces a large population of ILC2s in the lung that are resistant to activation and have diminished Type 2 effector function. We identified free-fatty acid receptor 3 (Ffar3) as a gene responsible for this effect and demonstrated that FFAR3 signaling reprograms ILC2s to an anti-inflammatory state by promoting their survival, reducing Type 2 cytokine production, and enhancing IL-10 expression. This anti-inflammatory state is dependent on IL-2 signaling, is characterized by decreased ST2 expression, and is distinct from previously described IL-10-producing ILC2 phenotypes. FFAR3-dependent reprogramming is mediated by epidermal growth factor receptor (EGFR) upregulation, and FFAR3's anti-inflammatory effect is partially conserved in human ILC2s.

Animals

Efficient genome editing in Pseudomonas syringae pv. actinidiae using the CRISPR/FnCas12a system.

CRISPR-based gene editing has rarely been studied in plant pathogens. In this report, the CRISPR/FnCas12a system was successfully established for gene editing in Pseudomonas syringae pv. actinidiae (Psa), which causes bacterial canker (BC) of kiwifruit. The system was constructed in a Psa-suitable vector pBBR1-MCS2 to edit hopH1 or/and hopZ5, which encode effectors only present in Psa biovar 3 (Psa3) responsible for BC pandemic in kiwifruit worldwide. Two different CRISPR RNAs (crRNA) were designed to edit either hopH1 or/and hopZ5, and two different sets of PCR primers were used to screen deletions of the target genes and the presence of the vector in Psa. The deletion in Psa was impacted by the position of the DNAs targeted by the crRNAs. The vector-eliminated mutant could receive the editing system iteratively. Interestingly, the double mutant ΔhopZ5ΔhopH1 showed significantly stronger virulence than the wild-type Psa on Actinidia eriantha cv. White (resistant to BC), but weak virulence on A. chinensis cv. Hongyang (highly susceptible to BC), respectively, suggesting that hopH1 or/and hopZ5 potentially matches an unknown resistance gene in White. In summary, we have established the CRISPR/FnCas12a genome-editing system to probe gene function in the pathogen and to explore effector-target interactions in kiwifruit-Psa-pathosyetem.

Bacterial canker