Biology subjects

ESTELLE, J.

Publications and source records attributed to ESTELLE, J..

5 recordsLinked to original sources

bioRxiv2026

Identifying the immunocompetence markers at weaning to predict long-term vaccine response and persistence in pigs

Vaccination is a key strategy for controlling infectious disease in pigs, but the magnitude and persistence of vaccine-induced immunity vary among individuals. We investigated whether immune and physiological traits measured at weaning could predict long-term antibody (Ab) status and Ab persistence following vaccination against Mycoplasma hyopneumoniae (MH) and Influenza A virus (IAV), and whether predictive markers were shared between vaccines. Two vaccination trials were conducted in a cohort of 381 Large White pigs (MH, n=189; IAV, n=192). Animals were vaccinated at weaning (28 days of age) and received a booster 21 days later. Long-term Ab status was defined at 118 days post-vaccination (dpv) using assay-specific thresholds, while Ab persistence was defined as the decline from the individual peak response at 28 or 35 dpv to 118 dpv. A broad panel of immune and physiological traits measured at weaning was evaluated as candidate predictors. Sparse Partial Least Squares Discriminant Analysis (sPLS-DA) was used for variable selection, followed by PLS-DA classification models. Cross-validated accuracies ranged from 64.7% to 67.7%, indicating moderate predictive performance. Across vaccines, eight predictors were shared for long-term Ab status and twelve for Ab persistence. Hematocrit, IgG, platelet count, and plateletcrit (PCT) were associated with positive long-term Ab status for both vaccines, whereas mean corpuscular hemoglobin concentration (MCHC) and neutrophil percentage were associated with negative status. For persistence, higher vitamin D, -1 globulin concentration, platelet count, and PCT were consistently associated with persistent responses across vaccines, while MCHC and spectral absorbance traits were associated with non-persistence. These findings indicate that early-life immune and physiological traits measured at weaning are associated with immunocompetence traits that contribute to variation in subsequent long-term vaccine antibody outcomes and responsiveness. The identification of both shared and vaccine- or phenotype-specific predictors suggests that vaccine responsiveness reflects both general features of baseline immunocompetence and context-specific determinants.

immunology↗

bioRxiv2026

A comprehensive genetic study of the vaginal microbiota composition of Holstein cows

The vaginal microbiota is a potentially important component of the bovine reproductive tract and has been associated with fertility, health, and production-related traits in cattle. However, the impact of host genetics on the bovine vaginal microbiota and its genetic correlations with animal performance remain largely unexplored. To investigate this, we performed a comprehensive genetic study of the vaginal microbiota in Holstein cows. Vaginal swabs from 681 lactating cows across 18 herds in Northern France were collected, along with records of fertility, milk production, and health traits. The microbiota samples were sequenced for the 16S rRNA gene, generating count tables of amplicon sequence variants (ASV). We estimated genetic parameters for vaginal microbiota -diversity (Chao1, Shannon, and Simpson indices) and {beta}-diversity (Bray-Curtis dissimilarity matrix), as well as the centered log-ratio (CLR)-transformed abundances of taxa present in more than 50% of samples. Across the 173 analyzed taxa, heritability estimates ranged from low to moderate (h2 = 0.09 to 0.38) for five genera, three families, eight orders, three classes, and one phylum. Notably, the order Flavobacteriales exhibited the highest heritability estimate. The study also highlighted genetic correlations between heritable microbiota traits and host phenotypes related to fertility, production, and health. Sequence-based genome-wide association studies (GWAS) identified biologically relevant signals, including a quantitative trait locus (QTL) for the genus Alloprevotella on chromosome 6, with lead variants located within the NAF1 gene. Additionally, two signals on chromosome 17 for the Bacteroidales order and the Bacteroida class co-localized with IL15. Our findings show that host genetics contributes to variation in specific components of the bovine vaginal microbiota and suggest that microbiome-related traits may warrant further investigation as potential indicators in dairy cattle breeding and management research.

genetics↗

bioRxiv2026

Host genetics and pre-vaccination blood transcriptome as determinants of vaccine-induced immunity to Influenza A virus in swine

Influenza A virus (IAV) is a major respiratory pathogen in pigs, causing diseases that have significant economic and potential public health consequences. Vaccine effectiveness varies among animals, impacting long-term herd protection due to individual variabilities in antibody levels and persistence over time. Our aim was to identify the genetic factors and pre-vaccination blood transcriptomic profiles that influence immune response levels to the IAV vaccine. A total of 187 piglets were vaccinated at weaning (28 days of age, 0 days post-vaccination, dpv) and boosted three weeks later, and humoral responses were assessed until slaughter (21, 28, 35, and 118 dpv) by measuring serum IAV-specific IgG and hemagglutination inhibition (HAI) titers. The results revealed varying antibody responses and persistence. Genome-wide association studies identified two loci on chromosomes SSC5 and SSC8 associated with a persistence of HAI titers until slaughter. Pre-vaccination blood transcriptomic analyses showed that early and post-boost antibody responses (21, 28 and 35 dpv) and long-term persistence (118 dpv) were associated with distinct baseline immune programs, with extracellular matrix and myeloid-related signatures predicting strong early and peak responses, whereas interferon-related signatures were linked to reduced long-term antibody persistence. Our results highlight the importance of considering the role of immune competence and genetics in vaccine responses in pigs and suggest candidate biomarkers to improve vaccination strategies within breeding programs.

genomics↗

bioRxiv2024

Genetic selection for residual feed intake impacts the functional redundancy of the gut microbiota in pigs during the growing-finishing period

BackgroundImproving feed efficiency is an unvarying goal in livestock production. The role of gut microbial communities in feed efficiency was investigated in two divergent pig lines selected for their residual feed intake (RFI), which is the difference between the observed feed consumption of an animal and that predicted for its maintenance and production requirements. Hence, RFI is a measure of net feed efficiency. ResultsBy sequencing the 16S rRNA genes from fecal samples, we found that the microbiota of low RFI pigs (LRFI; n=12) was significantly depleted in four operational taxonomic units (OTUs) belonging to Prevotella, Feacalibacterium and Lactobacillus genera by comparison to high RFI pigs (HRFI; n=11). Inferring KEGG orthologs from the 16S rRNA gene sequencing data showed that LRFI pigs have 20% more functional redundancy than HRFI pigs. The inferred orthologs held more discriminative power than the OTU approach, which might be inherently flawed if functionally equivalent OTUs compete for the same niche. ConclusionsGut microbiota of LRFI pigs had different microbial operational taxonomic units and a higher functional redundancy, which were more shared suggesting a role of the gut microbiota in the global feed efficiency according to Tax4Fun but this inference based on 16S data has to be verified in future work.

microbiology↗

bioRxiv2022

Comparative analysis of the caecal tonsil transcriptome in two hen lines experimentally infected with Salmonella Enteritidis

Managing Salmonella enterica Enteritidis (SE) carriage in chicken is necessary to ensure human food safety and enhance chicken breeding viability. Salmonella can contaminate poultry products, causing human foodborne disease and economic losses for farmers. Both genetic selection for a decreased carriage and gut microbiota modulation strategies could reduce Salmonella propagation in farms. Two-hundred and twenty animals from the White Leghorn inbred lines N and 61 were raised together on floor, infected by SE at 7 days of age, transferred into isolators to prevent oro-fecal recontamination and euthanized at 19 days. Caecal content DNA was used to measure individual Salmonella counts (ISC) by droplet digital PCR. A RNA sequencing approach was used to measure gene expression levels in caecal tonsils after infection of 48 chicks with low or high ISC. The analysis between lines identified 7516 differentially expressed genes (DEGs) corresponding to 62 enriched Gene Ontology (GO) Biological Processes (BP) terms. A comparison between low and high carriers allowed us to identify 97 DEGs and 23 enriched GO BP terms within line 61, and 1034 DEGs and 288 enriched GO BP terms within line N. Among these genes, we identified several candidate genes based on their putative functions, including FUT2 or MUC4, which could be involved in the control of SE infection, maybe through interactions with commensal bacteria. Altogether, we were able to identify several genes and pathways associated with differences in SE carriage level. These results are discussed in relation to individual caecal microbiota compositions, obtained for the same animals in a previous study, which may interact with host gene expression levels for the control of the caecal SE load.

genetics↗