LCO Receptors Involved in Arbuscular Mycorrhiza Are Functional for Rhizobia Perception in Legumes.

Bacterial lipo-chitooligosaccharides (LCOs) are key mediators of the nitrogen-fixing root nodule symbiosis (RNS) in legumes. The isolation of LCOs from arbuscular mycorrhizal fungi suggested that LCOs are also signaling molecules in arbuscular mycorrhiza (AM). However, the corresponding plant receptors have remained uncharacterized. Here we show that petunia and tomato mutants in the LysM receptor-like kinases LYK10 are impaired in AM formation. Petunia and tomato LYK10 proteins have a high affinity for LCOs (Kd in the nM range) comparable to that previously reported for a legume LCO receptor essential for the RNS. Interestingly, the tomato and petunia LYK10 promoters, when introduced into a legume, were active in nodules similarly to the promoter of the legume orthologous gene. Moreover, tomato and petunia LYK10 coding sequences restored nodulation in legumes mutated in their orthologs. This combination of genetic and biochemical data clearly pinpoints Solanaceous LYK10 as part of an ancestral LCO perception system involved in AM establishment, which has been directly recruited during evolution of the RNS in legumes.

Brachypodium distachyon tar2lhypo mutant shows reduced root developmental response to symbiotic signal but increased arbuscular mycorrhiza.

Auxin is a major phytohormone that controls root development. A role for auxin is also emerging in the control of plant-microbe interactions, including for the establishment of root endosymbiosis between plants and arbuscular mycorrhizal fungi (AMF). Auxin perception is important both for root colonization by AMF and for arbuscule formation. AMF produce symbiotic signals called lipo-chitooligosaccharides (LCOs) that can modify auxin homeostasis and promote lateral root formation (LRF). Since Brachypodium distachyon (Brachypodium) has a different auxin sensitivity compared to other plant species, we wondered whether this would interfere with the effect of auxin in arbuscular mycorrhizal (AM) symbiosis. Here we tested whether tar2lhypo a Brachypodium mutant with an increase in endogenous auxin content is affected in LRF stimulation by LCOs and in AM symbiosis. We found that, in contrast to control plants, LCO treatment inhibited LRF of the tar2lhypo mutant. However, the level of AMF colonization and the abundance of arbuscules were increased in tar2lhypo compared to control plants, suggesting that auxin also plays a positive role in both AMF colonization and arbuscule formation in Brachypodium.

Use of the Ion PGM and the GeneReader NGS Systems in Daily Routine Practice for Advanced Lung Adenocarcinoma Patients: A Practical Point of View Reporting a Comparative Study and Assessment of 90 Patients.

Background: With the integration of various targeted therapies into the clinical management of patients with advanced lung adenocarcinoma, next-generation sequencing (NGS) has become the technology of choice and has led to an increase in simultaneously interrogated genes. However, the broader adoption of NGS for routine clinical practice is still hampered by sophisticated workflows, complex bioinformatics analysis and medical interpretation. Therefore, the performance of the novel QIAGEN GeneReader NGS system was compared to an in-house ISO-15189 certified Ion PGM NGS platform. Methods: Clinical samples from 90 patients (60 Retrospectively and 30 Prospectively) with lung adenocarcinoma were sequenced with both systems. Mutations were analyzed and EGFR, KRAS, BRAF, NRAS, ALK, PIK3CA and ERBB2 genes were compared and sampling time and suitability for clinical testing were assessed. Results: Both sequencing systems showed perfect concordance for the overlapping genes. Correlation of allele frequency was r² = 0.93 for the retrospective patients and r² = 0.81 for the prospective patients. Hands-on time and total run time were shorter using the PGM system, while the GeneReader platform provided good traceability and up-to-date interpretation of the results. Conclusion: We demonstrated the suitability of the GeneReader NGS system in routine practice in a clinical pathology laboratory setting.

HLA-G Haplotypes Are Differentially Associated with Asthmatic Features.

Human leukocyte antigen (HLA)-G, a HLA class Ib molecule, interacts with receptors on lymphocytes such as T cells, B cells, and natural killer cells to influence immune responses. Unlike classical HLA molecules, HLA-G expression is not found on all somatic cells, but restricted to tissue sites, including human bronchial epithelium cells (HBEC). Individual variation in HLA-G expression is linked to its genetic polymorphism and has been associated with many pathological situations such as asthma, which is characterized by epithelium abnormalities and inflammatory cell activation. Studies reported both higher and equivalent soluble HLA-G (sHLA-G) expression in different cohorts of asthmatic patients. In particular, we recently described impaired local expression of HLA-G and abnormal profiles for alternatively spliced isoforms in HBEC from asthmatic patients. sHLA-G dosage is challenging because of its many levels of polymorphism (dimerization, association with ß2-microglobulin, and alternative splicing), thus many clinical studies focused on HLA-G single-nucleotide polymorphisms as predictive biomarkers, but few analyzed HLA-G haplotypes. Here, we aimed to characterize HLA-G haplotypes and describe their association with asthmatic clinical features and sHLA-G peripheral expression and to describe variations in transcription factor (TF) binding sites and alternative splicing sites. HLA-G haplotypes were differentially distributed in 330 healthy and 580 asthmatic individuals. Furthermore, HLA-G haplotypes were associated with asthmatic clinical features showed. However, we did not confirm an association between sHLA-G and genetic, biological, or clinical parameters. HLA-G haplotypes were phylogenetically split into distinct groups, with each group displaying particular variations in TF binding or RNA splicing sites that could reflect differential HLA-G qualitative or quantitative expression, with tissue-dependent specificities. Our results, based on a multicenter cohort, thus support the pertinence of HLA-G haplotypes as predictive genetic markers for asthma.

NGS analysis on tumor tissue and cfDNA for genotype-directed therapy in metastatic NSCLC patients. Between hope and hype?

INTRODUCTION: The advent of genomic based precision medicine led to the implementation of biomarker testing in metastatic non-small cell lung cancer (NSCLC) patients. Next generation sequencing (NGS) has been recently implemented to routine diagnostic requirements in lung oncology. Areas covered: Two cases of patients with metastatic NSCLC for whom NGS analysis performed on both tumor and liquid biopsy has not improved the clinical course of their disease are reported. These cases illustrate the difficulty of the so-called 'personalized or precision' medicine in clinical routine practice for metastatic NSCLC. Expert commentary: Discovery and detection of critical cancer-gene alterations better indicates targeted therapies that must be administered to improve the care of NSCLC patients in the personalized medicine era. There has been much interest in the literature and the scientific community for NGS tailored therapies approach for patients. However, there may be a gap between this theoretical stratified medicine and clinical practice. The advantages and drawbacks of NGS on tumor tissue and cell-free DNA for metastatic NSCLC are discussed.