Biology subjects

Lemonnier, G.

Publications and source records attributed to Lemonnier, G..

3 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

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↗

bioRxiv2018

Towards the quantitative characterization of piglets’ robustness to weaning: A modelling approach

Weaning is a critical transition phase in swine production in which piglets must cope with different stressors that may affect their health. During this period, the prophylactic use of antibiotics is still frequent to limit piglet morbidity, which raises both economic and public health concerns such as the appearance of antimicrobial-resistant microbes. With the interest of developing tools for assisting health and management decisions around weaning, it is key to provide robustness indexes that inform on the animals capacity to endure the challenges associated to weaning. This work aimed at developing a modelling approach for facilitating the quantification of piglet resilience to weaning. We monitored 325 Large White pigs weaned at 28 days of age and further housed and fed conventionally during the post-weaning period without antibiotic administration. Body weight and diarrhoea scores were recorded before and after weaning, and blood was sampled at weaning and one week later for collecting haematological data. We constructed a dynamic model based on the Gompertz-Makeham law to describe live weight trajectories during the first 75 days after weaning following the rationale that the animal response is partitioned in two time windows (a perturbation and a recovery window). Model calibration was performed for each animal. Our results show that the transition time between the two time windows, as well as the weight trajectories are characteristic for each individual. The model captured the weight dynamics of animals at different degrees of perturbation, with an average coefficient of determination of 0.99, and a concordance correlation coefficient of 0.99. The utility of the model is that it provides biological parameters that inform on the amplitude and length of perturbation, and the rate of animal recovery. Our rationale is that the dynamics of weight inform on the capability of the animal to cope with the weaning disturbance. Indeed, there were significant correlations between model parameters and individual diarrhoea scores and haematological traits. Overall, the parameters of our model can be useful for constructing weaning robustness indexes by using exclusively the growth curves. We foresee that this modelling approach will provide a step forward in the quantitative characterization of robustness.\n\nImplicationsThe quantitative characterization of animal robustness at weaning is a key step for management strategies to improve health and welfare. This characterization is also instrumental for the further design of selection strategies for productivity and robustness. Within a precision livestock farming optic, this study develops a mathematical modelling approach to describe the body weight of piglets from weaning with the rationale that weight trajectories provide central information to quantify the capability of the animal to cope with the weaning disturbance.

systems biology↗