Immune‐Neuroendocrine Phenotypic Expression Changes Through Life in <i>Coturnix japonica</i> Quails

Immune-neuroendocrine characteristics can be used to classify individuals according to their physiological profiles or phenotypes (INPs). In avian models such as quail and domestic chickens, three subgroups based on INPs have been defined: Lewis-like (pro-inflammatory polarization), Fischer-like (anti-inflammatory polarization), and an intermediate INP. This study investigates the stability and alterations of INPs throughout ontogeny, from juvenile to adult stages in four time-points including an exposure to unpredictable and diverse chronic stress (CS) during early adulthood. We measured corticosterone levels, pro- (IFN-γ and IL-1β) and anti-inflammatory (IL-13, IL-4) cytokines, phytohemagglutinin (PHA-P) lymphoproliferative response, anti-sheep red blood cells antibody (Ab SRBC) response, and leukocyte distribution frequency. Cluster analyses were conducted to classify bird based on their similarities across all analyzed variables, to thereby establish their INP at each time point. The extreme Lewis- or Fischer-like profiles were less represented in juvenile and pre-stress adult birds showing a higher proportion of individuals with an intermediate profile. Following CS exposure, the prevalence of Lewis-like and Fischer-like profiles increased. This shift persisted 10 weeks later as birds matured to an advanced egg-laying stage, with females predominantly exhibiting the Fischer-like INP, and males the Lewis-like INP. The observed shift in INP distribution following CS towards more polarized Lewis- and Fisher-like profiles implies a more even representation of the three observed profiles and may reflect inter-individual differences in physiological response to CS associated to particular coping strategies. A more even INPs distribution could provide the population with a greater advantage when facing diverse environmental challenges.