The lipid composition of the exo-metabolome from Haemonchus contortus
Notice bibliographique
Résumé
Abstract Background Several livestock parasitic nematode species have developed anthelmintic resistance, limiting their control in grazing animals. Metabolomic studies of different parasite-derived biomolecules, such as lipids, are currently under investigation to expand novel strategies for controlling these pathogens and characterizing their metabolism. However, the extremely low concentrations and complexity of exocellular fluids produced by these organisms remain a challenge for untargeted approaches. Lipids are essential pleiotropic biomolecules in invertebrates, including helminths. Still, there is a gap in the knowledge about their functions in parasitic nematode biology and their impact on the interaction with the host. We aimed to describe the detailed lipid composition of the exo-metabolome secreted by Haemonchus contortus, the major parasitic nematode of small ruminants worldwide, using untargeted lipidomics. Methods H. contortus adult worms were recovered from infected sheep and cultured ex-vivo. Parasite medium was collected at three time points (2, 4 and 8h), and samples were subjected to an untargeted global lipidomic analysis. Firstly, lipids were isolated using a modified version of the classic Folch liquid-liquid extraction. The extracts were subjected to Liquid Chromatography-Mass Spectrometry (LC/MS) analysis. Chromatograms from samples and quality control injections were analyzed in positive and negative ionization. Lipid identification was run through a three-tier approach. For tiers 1 and 2, the experimental data was matched to databases through tandem-MS (MS/MS) spectral similarity scores. Lipids with MS/MS scores ≥ 500 were deemed Tier 1, while lower scores were considered Tier 2. Features not matched by MS/MS were subjected to mass-matching using the LIPID MAPS database (Tier 3). Lipids were subjected to a 9-tier filtering and scoring approach to select the best identification. The peak intensities were normalized by a set of internal standards to reduce experimental variability. The normalized peak intensities for identified lipids were subjected to statistical analysis comparing global lipid clusters' fold change (FC) and individual lipid features. Lipids were also analyzed by fatty acyl composition, segregating each lipid category by structural length and saturation bonding. Results Initially, 2562 lipid features were detected in all samples from our global untargeted lipidomic analysis, including background hits on the RPMI medium. A total of 1057 lipids were identified, including 171 lipids in Tiers 1 and 2 (high-confidence MS/MS identifications), whereas 886 putative lipids were identified in Tier 3 based on mass matches. The main lipid categories correspond to glycerophospholipids, followed by fatty acyls, sphingolipids, glycerolipids, and sterol lipids, structurally corresponding mainly to unsaturated lipids. We found variations in the parasite media lipid profile in a time-dependent manner. Many lipids have been described in multicellular organisms, but little is known about their role in parasitic nematodes. We predict their activity as signalling molecules in physiological functions such as adaptation to nutrient changes, life span and mating. Also, many lipids in the found profile have been documented as modulators on the host immune responses. Conclusions Our findings regarding the composition of the lipids secreted by H. contortus provide new information about how these biomolecules derived from this economically important veterinary nematode impact the host and how lipids play essential functions for the parasite’s homeostasis.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».