Vitally important – does early innate immunity predict recruitment and adult innate immunity?

Abstract

The immune system is one of the most important adaptations that has evolved to protect animals from a wide range of pathogens they encounter from early life onwards. During the early developmental period this is particularly true for the innate immunity, as other components of the immune system are, as yet, poorly developed. But innate immunity may not only be crucial for early life survival, but may also have long‐lasting effects, for example if early life immunity reflects the functioning of the immune system as a whole. For this reason, we investigated the importance of four constitutive innate immune parameters (natural antibodies, complement activity, concentrations of haptoglobin, and concentrations of nitric oxide) for recruitment in free‐living great tits. We compared nestling immunity of recruits with nestling immunity of their nonrecruited siblings. We also investigated within individual consistency of these innate immune parameters for those individuals that recruited, which may be taken as a measure of immune capacity. In accordance with previous studies, we found a clear effect of tarsus length and a trend for body mass on the likelihood to recruit. Nevertheless, we found no evidence that higher levels of constitutive innate immunity as a nestling facilitated local recruitment. Furthermore, individual innate immunity was not consistent across life stages, that is to say, nestling immune parameters did not determine, or respectively, reflect adult innate immune parameters. This plasticity in innate immune components may explain why we did not find long‐lasting survival benefits.

Immune function and blood parasite infections impact stopover ecology in passerine birds

“…Even though this relationship depended on one extreme point, we argue this reflects a true pattern, which may, however, be a more categorical relationship than a continuous relationship. First, in passerine birds, haptoglobin concentrations in the range of 1.0–2.0 mg/ml or even higher regularly occur (Hegemann et al 2012a; Vermeulen et al 2016; Ndithia et al 2017; Fowler and Williams 2017). Second, haptoglobin concentrations increase during inflammation (Thomas 2000; Buehler et al 2009; Matson et al 2012; Hegemann et al 2013a; but see Schultz et al 2017) and third, a recent study has shown that birds prolong their stopover duration during an experimentally induced inflammatory response (Hegemann et al 2018).…”

A Simulated Heat Wave Has Diverse Effects on Immune Function and Oxidative Physiology in the Corn Snake (Pantherophis guttatus)

“…These differences between hemolysis and hemagglutination may be due to hemolysis activation that is independent of NAbs (reviewed in Luoma et al 2016). Clearly, studies should continue to measure a suite of immune metrics (Demas et al 2011;Zylberberg 2015;Vermeulen et al 2016) and further strive to understand mechanistic links among these metrics. Though it was not possible for our study (e.g., because of limited sample size), incorporating the concept of integration (i.e., the degree to which within-individual biological variables are correlated and interdependent: Pavlicev et al 2009;Haber 2011;Costantini et al 2013) into experiments may yield new insight into the dynamics by which heat waves shift (or dysregulate) whole-organism physiology.…”

Sex-specific effects of inbreeding and early life conditions on the adult oxidative balance

“…We used the GSH/GSSG ratio, which is a conventional index of redox state with higher values indicating lower oxidative stress ( Jones, 2006 ). Finally, we measured in plasma the production of the free radical nitric oxide with a spectrophotometric assay (see for more details: Sild and Hõrak 2009 ; Vermeulen et al 2016 ).…”